| Entries |
| Document | Title | Date |
|---|
| 20080205559 | TEMPLATE PULSE GENERATING CIRCUIT, COMMUNICATION DEVICE, AND COMMUNICATION METHOD - A template pulse generating circuit that generates a template pulse used for detection of a received pulse in pulse communication includes an output mode switching circuit for switching an output mode in accordance with a supplied control signal between a continuous output mode that continuously outputs the template pulses and an intermittent output mode that intermittently outputs the template pulses so that the template pulse is generated in either one of the continuous output mode and the intermittent output mode. | 08-28-2008 |
| 20080219386 | QUADRATURE IMBALANCE ESTIMATION USING UNBIASED TRAINING SEQUENCES - A system and method are provided for removing quadrature imbalance errors in received data. The method accepts an unbiased training sequence in a quadrature demodulation receiver. An unbiased training sequence has a uniform accumulated power evenly distributed in a complex plane, and includes predetermined reference signals (p) at frequency +f and predetermined mirror signals (p | 09-11-2008 |
| 20080232514 | GPS signal acquisition circuit - A GPS signal acquisition circuit includes a correlation engine, a decimator, a coherent integrator and an incoherent integrator. An over sampled GPS signal is fed into and processed by the correlation engine. The processed signal is sent to the decimator. The decimator generates an output for every M input from the correlation engine. When the decimated correlation engine output is processed in subsequent coherent and incoherent accumulations, the size of the memory required for high-sensitivity signal processing is greatly reduced. Therefore, the production cost can be lowered significantly. | 09-25-2008 |
| 20080232515 | METHOD AND APPARATUS FOR GENERATING TRAINING SEQUENCE CODES IN A COMMUNICATION SYSTEM - A method and apparatus for generating training sequence codes in a communication system. In the method, a pair of sequences A and B having cross-correlation properties as well as autocorrelation properties are generated, and protection sequences A′ and B′ are generated by copying last L symbols of the sequences A and B, respectively. The training sequence codes are generated by locating the protection sequences A′ and B′ in the most significant positions (MSPs) of the sequences A and B. The training sequence codes can be extended and applied to 16-QAM and 32-QAM used in a GERAN system, and the use of such training sequence codes enables data to be efficiently transmitted/received without performance deterioration in a GERAN system. | 09-25-2008 |
| 20080240306 | CORRELATION DEVICE FOR PERFORMING CORRELATION ON A RECEIVED GLOBAL NAVIGATION SATELLITE SYSTEM SIGNAL AND METHOD FOR SAME - The invention provides a correlation device performing correlation on a received Global Navigation Satellite System (GNSS) signal. The correlation device comprises a first decimation module, a second decimation module, and a correlation module. The first decimation module decimates a plurality of samples of the received GNSS signal to obtain a plurality of decimated samples. The second decimation module decimates a plurality of code bits of a locally generated replica code to obtain a plurality of decimated code bits. The correlation module correlates the decimated samples with the decimated code bits to obtain a plurality of correlation results, thus achieving a coarse correlation between the received GNSS signal and the locally generated replica code. | 10-02-2008 |
| 20080240307 | SINGLE CARRIER HIGH RATE WIRELESS SYSTEM - The present invention relates to a signal generator and signal processor for single carrier wireless communication systems with frequency domain equalizer, which are operable to use pseudorandom-noise sequences for cyclic prefix. The different arrangements and examples of said pseudorandom-noise sequences could be used for coarse timing synchronization, channel estimation, carrier synchronization, signal-noise-ration estimation and channel equalization. | 10-02-2008 |
| 20080240308 | APPARATUS AND METHOD FOR ESTIMATING CHANNEL USING SLIDING WINDOWS IN A BROADBAND WIRELESS COMMUNICATION SYSTEM - An apparatus and a method for estimating a channel using sliding windows in a broadband wireless communication system are provided. The apparatus includes an estimator, a first calculator, a second calculator, and a third calculator. The estimator estimates a speed of travel. The first calculator calculates a time correlation values using the estimated speed. The second calculator calculates weight factors using the time correlation values. The third calculator calculates a channel estimation value by multiplying corresponding pilot symbols by the weight factors and equalizing the pilot symbols. | 10-02-2008 |
| 20080247494 | Wireless Receiver For Sorting Packets - A wireless receiver that sorts packets including a packet detector, multiple correlators, and multiple packet processors. Each correlator correlates a received signal according to packet type. Each packet processor processes the received signal according to packet type. A signal power detector may be provided to initially qualify the received signal as containing a packet, and the correlators determine whether a packet is present. The correlators may be configured for sequential or simultaneous correlation. For the simultaneous correlator configuration, a correlation monitor is provided to monitor correlation results to determine if the received signal contains a packet, and if so, to determine packet type. A low SNR packet detector may be provided which correlates the received signal to detect weak packet signals. The signal power detector may be omitted, where the correlators simultaneously monitor the received signal while a correlation monitor continuously monitors correlation results for packet detection. | 10-09-2008 |
| 20080253484 | METHOD AND APPARATUS FOR REFERENCE SIGNAL GENERATION IN WIRELESS COMMUNICATION SYSTEM - To provide a reference signal generation method and apparatus capable of obtaining many reference signal sequences having excellent properties. CAZAC sequences that satisfy the condition that the absolute value (|N−L|) of a difference between a sub-carrier number N in a resource block and a CAZAC sequence length L is not larger than a threshold value K are selected, and a sequence having a largest among greatest prime factors among the prime factors constituting the sequence length(s) is further selected from the initially selected sequences. Then, a reference signal sequence(s) is generated from a selected CAZAC sequence. | 10-16-2008 |
| 20080267324 | Impulse Radio Communication Device - An impulse radio communication device includes a wave detector for generating a detected signal, a switching section for selecting either a received signal or the detected signal in accordance with an external control signal and outputting it as a demodulation target signal, a reference waveform generating section synchronized with the demodulation target signal and generating a reference waveform signal having a different waveform in accordance with the external control signal, a demodulator for generating a demodulated signal from the demodulation target signal in accordance with the reference waveform signal, and a decoding section for decoding received data from the demodulated signal. This impulse radio communication device switches the demodulation target signal and the reference waveform signal simultaneously in accordance with a receiving and synchronizing state. This makes it difficult that synchronization is pulled in a correlation position having low electric power, and can reduce a acquisition time. | 10-30-2008 |
| 20080273633 | METHOD AND DEVICE FOR ENHANCING SIGNAL DETECTION IN A FREQUENCY SELECTIVE FADING CHANNEL - A method and system are provided for enhanced signal detection in a frequency selective fading channel. Improved signal detection is realized by replacing single matched filters with multiple matched filters. The single matched filter spectrum is partitioned by frequency into M matched filter groups, where M is a positive integer greater than one. The filter bandwidth of each of the M matched filters is less than the bandwidth of the single matched filter from which they are derived. The M matched filters are provided to filter in parallel fashion the input signal into M sub-spectrums of the signal. The input signal is filtered through the M matched filters and also sent to the energy detector. The matched filter outputs are combined and the received signal is detected using the combined output and the energy in the received signal. | 11-06-2008 |
| 20080273634 | Parallel preamble search architectures and methods - The present invention provides architectures and methods which enables faster and more power efficient detection of channel parameters used by a communication system. Various parallel preamble correlator structures are able to perform searches for multiple preambles in parallel. The received samples are correlated with different delays between the samples corresponding to the different possible channel parameters that may be used by the communication system. Processing elements used in the preamble search may be shared among the parallel preamble search sections of a given architecture to reduce costs and power consumption. Decimation and filtering may also be used to reduce the interference from adjacent channels. | 11-06-2008 |
| 20080298515 | Method and Apparatus for Implementing a Digital Signal Quality Metric - A method for detecting a digital radio signal includes the steps of receiving the digital radio signal including a series of symbols, developing a correlation waveform having a peak that corresponds to a symbol boundary, normalizing the correlation waveform, and calculating a peak value of the normalized correlation waveform, wherein the peak value represents the quality of the received digital radio signal. A receiver that performs the method is also provided. | 12-04-2008 |
| 20080304602 | DIGITAL BROADCASTING SYSTEM AND METHOD OF PROCESSING DATA - A digital broadcast system including a broadcast receiving system and data processing method are disclosed. In the broadcast receiving system receiving broadcast signals, the broadcast receiving system includes a transmission parameter decoding unit, a known sequence detector, and a burst controller. The transmission parameter decoding unit detects information on a burst of a received signal from broadcast data having main service data and mobile service data multiplexed therein within a field of the received signal and outputs the detected information on the burst. The known sequence detector receives burst information from the transmission parameter decoding unit and uses the received burst information and known data position information included in the received data, so as to output burst control information. The burst controller uses the burst control information to control power supply of the broadcast receiving system. | 12-11-2008 |
| 20080310561 | SIMPLIFIED RACH PREAMBLE DETECTION RECEIVER - A low complexity RACH preamble detector is described herein. The RACH preamble detection algorithm uses the peak detection of the time domain correlation function through frequency domain processing. The frequency domain processing considers the reference signals generated directly from frequency domain CAZAC sequence or time domain CAZAC sequence with DFT conversion. A low-complexity poly-phase LPF along with down sampling is implemented before the FFT to reduce the required length of the long FFT operation N-folded. | 12-18-2008 |
| 20080317174 | RECEIVER AND RECEIVING METHOD - When a correlation judging circuit judges that the correlation degree between r pulses in a reception signal and a generated substantially the same template as the r pulses is small, a pulse number adjusting circuit outputs a pulse number signal representing s pulses in place of the r pulses, and a template generating circuit generates the substantially the same template as the s pulses, whereby the correlation judging circuit judges the correlation degree between the r pulses in the reception signal and the generated substantially the same template as the s pulses. Accordingly, even when a confronted transmitter changes the number of pulses contained in a reception signal, synchronization capture of the reception signal can be established. | 12-25-2008 |
| 20090028275 | FRAME-BASED CARRIER FREQUENCY AND PHASE RECOVERY SYSTEM AND METHOD - Header information is used to facilitate coarse frequency and frame recovery. The coarse frequency and frame recovery is thereafter utilized to perform adaptive phase and frequency synchronization on a frame-by-frame basis. | 01-29-2009 |
| 20090041167 | Demodulator, Receiver, and Demodulation Method - In an OFDM receiver with a diversity configuration having a plurality of demodulation modules, to perform FFT window position recovery and clock recovery, the gain values calculated by the AGC units ( | 02-12-2009 |
| 20090052596 | DECODER AND DECODING METHOD - Provided are a decoding apparatus and method for a system supporting an Orthogonal Frequency Division Multiplexing (OFDM)/Orthogonal Frequency Division Multiple Access (OFDMA) scheme, the apparatus and method capable of simply performing decoding by a non-coherent method. The decoding method includes the steps or receiving quadrature phase shift keying (QPSK) modulated signal; performing subcarrier demodulation whereby correlation metrics are generated on the basis of the received signal; and performing decoding using a decoding metric derived from the correlation metrics. The correlation metrics are obtained by multiplying tile, bin or zone of received signal by sets of basis vectors. The decoding apparatus includes: a receiving buffer for buffering received QPSK modulated signal; a correlation metric generator for generating correlation metrics on the basis of the received signal buffered in the receiving buffer; and a decoding processor for performing decoding using a decoding metric derived from the correlation metrics. | 02-26-2009 |
| 20090060099 | DEVICES FOR CARRIER RECOVERY AND RELATED METHODS - Devices for carrier recovery and related methods are provided. A receiving signal is provided to perform an interpolation filtering process and a frequency multiplication sampling process. The receiving signal is then processed with a dealing signal. The dealing signal is generated by shifting a PN code with a frequency offset. | 03-05-2009 |
| 20090074117 | Pulse Radio Receiver - A pulse radio receiver not needing re-setting of the threshold for reception synchronization, judging the direction and amount of adjustment of the synchronization even if the signal strength varies, and having a shortened pull-in time of the synchronization position. The receiver comprises a detect ( | 03-19-2009 |
| 20090092206 | WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD USING PLURAL COMMUNICATION CHANNELS HAVING DIFFERENT BANDWIDTHS - A wireless communication apparatus includes a measuring unit, a matched filter, and a control unit. The measuring unit measures an electric power of a received signal. The matched filter is capable of operating as a first filter and a second filter for the received signal. The first and second filters detect a frame in a first and second communication channel, respectively. The second communication channel uses a frequency band including a frequency bands used in the first and third communication channel. The control unit determines whether or not the frame exists in the third communication channel according to a detection result of the measuring unit and the matched filter. The control unit operates the matched filter as the first filter when the frame exists in the third communication channel and operates the matched filter as the second filter when the frame does not exist in the third communication channel. | 04-09-2009 |
| 20090103667 | Methods for Modified Signal Acquisition for OFDM Schemes - This invention relates to methods for determining coarse symbol timing and mode detection by using CP correlation-based techniques. In particular, this invention relates to methods for determining symbol timing, frame timing, and system mode for signal acquisition, comprising the steps of: detecting symbol timing and system mode based on cyclic prefix correlation; and determining a null symbol as a function of a pre-defined number of consecutive symbols and using said null symbol to determine frame timing. | 04-23-2009 |
| 20090116591 | SPECTRAL DECOMPOSITION OF LARGE SIGNALS IN A NARROW-RANGE SAMPLING SYSTEM - A sampling method that determines the deterministic and random components of a signal when the magnitude of the signal exceeds the range of the sampler. | 05-07-2009 |
| 20090122926 | DATA THROUGHPUT IN AN INTERFERENCE-RICH WIRELESS ENVIRONMENT - Systems and methods for improving data throughput in an interference-rich wireless environment are described herein. Some illustrative embodiments include a method including receiving a modulated radio frequency (RF) signal including a message packet, identifying a preamble of the message packet generating a correlated preamble by combining the message packet preamble with a correlation sequence corresponding to an expected preamble, determining a characteristic of a correlated signal representing the correlated preamble, comparing the determined characteristic of the correlated signal to a first threshold value, and discarding the message packet if the determined characteristic of the correlated signal is below the first threshold value. | 05-14-2009 |
| 20090122927 | RECEIVER FOR WIRELESS COMMUNICATION NETWORK WITH EXTENDED RANGE - Techniques for detecting and demodulating a signal/transmission are described. Signal detection is performed in multiple stages using different types of signal processing, e.g., using time-domain correlation for a first stage, frequency-domain processing for a second stage, and time-domain processing for a third stage. For the first stage, products of symbols are generated for at least two different delays, correlation between the products for each delay and known values is performed, and correlation results for all delays are combined and used to declare the presence of a signal. For demodulation, the timing of input samples is adjusted to obtain timing-adjusted samples. A frequency offset is estimated and removed from the timing-adjusted samples to obtain frequency-corrected samples, which are processed with a channel estimate to obtain detected symbols. The phases of the detected symbols are corrected to obtain phase-corrected symbols, which are demodulated, deinterleaved, and decoded. | 05-14-2009 |
| 20090129520 | DIGITAL SIGNAL RECEIVING APPARATUS - A digital signal receiving apparatus includes: detection-judging portion judging a possible presence of a desired signal when a signal level of a smoothed signal is greater than a reference level; wherein said first smoothed signal and said second smoothed signal are compared in order to generate a detection signal representing a judgment of a possible presence of a desired signal, said second smoothed signal having a convergence speed slower than that of the first smoothing filter, a filter controlling portion switching an adaptive filter from an adaptive mode to a non-adaptive mode when the detection-judging portion judges the possible presence of the desired signal and switching from the non-adaptive mode to the adaptive mode when the detection-judging portion judges the absence of the desired signal; a limiting portion limiting a signal level of an auto-correlation signal to the signal level of the smoothed signal; and a demodulating portion demodulating the auto-correlation signal having the signal level limited by the limiting means so as to generate a demodulated signal, wherein the input to the demodulator is limited to the level of a smoothed signal, said smoothed signal being generated from the input of the detection judging portion. | 05-21-2009 |
| 20090141836 | RECEPTION DEVICE - A reception device according to the present invention receives a transmission frame including a synchronization symbol string, having a synchronization symbol repeated multiple times, inserted before a data symbol string. The synchronization symbol is obtained by synthesizing a plurality of sub band symbols which are mutually orthogonal and having different carrier frequencies. The carrier frequencies of the sub band symbols are located at an equal predetermined frequency interval. The synchronization symbol includes a repeated synchronization pattern. The reception device detects a rough carrier frequency error from a phase difference of a synchronization pattern correlation value to correct the frequency, and then detects a residual frequency error from an inter-symbol phase difference of each sub band to correct the frequency. The reception device detects a sampling clock frequency error from an inter-sub band phase difference to correct the frequency. Thus, the demodulation error of the data symbol is reduced. | 06-04-2009 |
| 20090154609 | APPARATUS AND METHOD FOR SELECTING CORRELATION SCHEME BASED ON CARRIER FREQUENCY ERROR - Provided is a correlation scheme selecting apparatus and method that can acquire initial synchronization efficiently by calculating frequency error criterion threshold between correlation schemes and selecting a correlation scheme for each region when a correlation value is calculated for initial sync in a communication system with carrier frequency errors. The method for selecting a correlation scheme based on a carrier frequency error includes: calculating mis-detection probability values based on a normalized frequency offset for each correlation scheme; determining as a frequency-error criterion threshold a crossing point of graphs of the calculated mis-detection probability values for each correlation scheme; and selecting a correlation scheme based on the determined frequency-error criterion threshold. | 06-18-2009 |
| 20090154610 | GUARD INTERVAL ANALYSIS METHOD AND APPARATUS - A receiver circuit processes a received signal to determine information regarding a guard interval therein. The receiver circuit typically forms digital samples from the received signal; generates a correlation function with peaks at positions that are determined by the size of the guard interval and a position of the guard interval within the received signal. The receiver circuit includes one or more comb filters, each corresponding to a possible guard interval size, each receiving a series of locations at which the correlation function exceeds a predetermined threshold, and each producing an output that provides information about the guard interval size and/or position. This advantageously allows the receiver circuit to determine the guard interval size quickly, for example, even in the case of received signals with relatively low signal-noise ratio. | 06-18-2009 |
| 20090154611 | METHODS AND APPARATUS FOR LOW OVERHEAD MSK DECODING - Methods and apparatus for receiving a signal having a intermediate frequency (IF), sampling the IF signal at a selected sampling frequency, correlating the sampled IF signal with a preamble signal, determining a correlation peak for the correlated signals, identifying chips of the preamble signal based upon the correlation peak, and decoding the IF signal to obtain and store information encoded in the IF signal. | 06-18-2009 |
| 20090161800 | METHOD AND APPARATUS FOR PACKET DETECTION - A present invention provides a method and an apparatus for packet detection. The packet detection method with adaptive strategy includes several stages, and each stage has different parameter setting for packet detection. The method provides the packet detection apparatus with adaptive advantage to adapt various channel environments. The method and an apparatus for packet detection can effectively promote the success probability to detect packets. | 06-25-2009 |
| 20090168928 | Data Slicer Reference Generator For Multiple Burst Data Signals - A slice level reference generator and method for performing improved data slicing operations when gaps are present in a data stream is disclosed that involves applying a nominal reference signal to the comparator the during signal gaps. In one embodiment, a receiver circuit includes a slice level detector and a comparator that operate in a conventional manner, and control circuitry that utilizes a signal detector and a switch to store a slice level reference signal generated by the slice level detector during a first signal burst, and to apply the stored reference signal to the comparator during signal gaps. In one embodiment a timer circuit is used to detect signal gaps. In another embodiment a predetermined fixed reference signal is applied to the comparator during signal gaps. | 07-02-2009 |
| 20090175391 | MATCHED FILTER AND RECEIVER - A matched filter and receiver is provided to delete the tap coefficients of a matched filter used in an OFDM receiver. In the matched filter and receiver, a transmitting signal is generated by using a symmetric series (Y) obtained from C[k]=exp [j*π*M/N*(k+0.5)̂2], where X=[0, C[N/2], C[N/2+1], . . . , C[N−1], 0, 0, . . . , 0, C[0], C[1], . . . , C[N/2−1]], and Y=inverse FFT (X) as a base symbol. The matched filter, which detects the signal, reduces the number of multipliers by using the coefficient symmetric property. | 07-09-2009 |
| 20090185645 | Receiver Device, Error Detection Circuit, and Receiving Method - A receiver device which is small in scale of circuit configuration yet capable of detecting an error between symbol timing of a received signal and that generated therein and also restraining an error signal from varying due to variation in input level of the received signal. A delayer delays the received signal for one effective symbol period, a correlator calculates a correlation signal from the product of the received signal and the delayed signal, and an integrator calculates an integral value of the correlation signal. First and second accumulative adders accumulatively add up the integral values over respective predetermined periods before and after symbol start timing generated within the receiver device. An error signal generator generates an error signal by normalizing the difference between first and second sums obtained from the first and second accumulative adders, respectively, by means of the sum total of the first and second sums. | 07-23-2009 |
| 20090185646 | ESTIMATING FREQUENCY SHIFT - Techniques, systems and apparatus are described for estimating a frequency shift. An apparatus for estimating a frequency shift includes a fast Fourier transform unit to transform a signal of a time domain into a frequency domain and output fast Fourier transform symbols. A complex conjugate multiplier is in communication with the fast Fourier transform unit and output a continual pilot correlation between every two of the fast Fourier transform symbols output from the fast Fourier transform unit. A correlation memory unit is in communication with the complex conjugate multiplier to store the continual pilot correlation output from the complex conjugate multiplier. An adder is in communication with the correlation memory unit to add the continual pilot correlations stored in the correlation memory unit and generate an output signal comprising estimated values of the frequency shift. | 07-23-2009 |
| 20090196383 | CORRELATION APPARATUS AND METHOD FOR FREQUENCY SYNCHRONIZATION IN BROADBAND WIRELESS ACCESS COMMUNICATION SYSTEM - A correlation apparatus and method for frequency synchronization are provided. A frequency synchronization method of a receiver in a broadband wireless access communication system includes acquiring a highest correlation value by conducting a differential correlation of a variable interval between a received signal and a reference signal and performing a frequency synchronization according to the highest correlation value. | 08-06-2009 |
| 20090207949 | TRANSMITTER IDENTIFICATION INFORMATION SIGNAL DETECTION APPARATUS AND METHOD - A transmitter identification information (TII) signal detection circuit is suitable for an orthogonal frequency division modulation system. A TII signal detection circuit receives a TII signal and conducts a cross-correlation calculation on the TII signal and a phase reference symbol (PRS) so as to obtain a present cross-correlation result, and then, sums the cross-correlation results obtained by conducting cross-correlations on AVE_TF_NUM- | 08-20-2009 |
| 20090207950 | MODULATION SCHEME ESTIMATION APPARATUS AND METHOD - A modulation scheme estimation apparatus includes a receiving unit receiving a first signal, a generation unit generating a plurality of first phase amounts, an acquisition unit acquiring a plurality of multiplication signals by multiplying the first signal by each of the first phase amounts, an extraction unit extracting a plurality of second signals corresponding to respective direct-current components of third signals obtained by subjecting the multiplication signals to Fourier transform, a first computation unit computing a plurality of sums, each of which is a sum of each of the multiplication signals and a corresponding one of the second signals, a second computation unit computing a plurality of absolute values of the sums, and a first identifying unit identifying a modulation scheme corresponding to one of the absolute values which has a highest similarity with respect to reference values associated with modulation schemes. | 08-20-2009 |
| 20090207951 | Apparatus and Method for Processing Signal Using Single Correlator - An apparatus and method for processing a signal using a single correlator are provided. The apparatus may include a first storage unit storing satellite signal samples, a correlator receiving the satellite signal samples stored in the first storage unit in units of at least two satellite signal samples and performing correlation, and a controller storing the satellite signal samples received from an RF terminal in the first storage unit and controlling the correlator based on a predetermined control value. Accordingly, it is possible to ensure speed and performance even when tracking a plurality of satellite signals using a single correlator. | 08-20-2009 |
| 20090213968 | Method and apparatus to detect random access channel preamble - A method (and operation of a computer program) includes receiving a signal over a wireless channel; correlating the received signal with a reference sequence and providing a correlation output; processing the correlation output to detect a presence of a first predetermined preamble sequence using a main correlation peak and two first order frequency shift peaks and nulling second and higher order frequency shift peaks from the correlation output prior to further processing the correlation output to detect a presence of a second predetermined preamble sequence. Apparatus that embody the method are also disclosed. | 08-27-2009 |
| 20090213969 | Wireless Communication Device, Equalizer, Computer-Readable Medium Storing Program for Obtaining Weight Coefficients in the Equalizer, and Process for Obtaining Weight Coefficients in the Equalizer - In an equalizer arranged in a wireless communication device: information on correlation in one or more first wireless signals is generated; a channel vector is generated on the basis of the one or more first wireless signals; an extended correlation matrix which contains a correlation matrix indicating the information on correlation and is extended so as to become a circulant matrix is generated; an extended channel vector is generated by extending the channel vector so that the extended channel vector contains elements of the channel vector and has rows the number of which is identical to the number of rows of the extended correlation matrix; and weight coefficients are calculated as a solution, in the frequency domain, of an equation expressed by the extended correlation matrix and the extended channel vector, where the solution is obtained by solving the equation. | 08-27-2009 |
| 20090220035 | APPARATUS FOR EQUALIZING CHANNEL IN FREQUENCY DOMAIN AND METHOD THEREFOR - Provided is an apparatus for channel equalization in frequency domain, including: a channel estimation unit for estimating a channel on received signal from outside, a channel matched filter for changing channel characteristic of the channel estimated by the channel estimation unit and the received signal to channel characteristic to meet condition required for noncausal filtering, a noncausal filter for changing the channel characteristic changed by the channel matched filter from nonminimum phase channel to minimum phase channel, a reverse channel calculation unit for calculating a reverse of the channel changed by the non-causal filter in frequency domain, and a frequency domain equalization unit for performing channel equalization with respect to the channel changed by the noncausal filter in the frequency domain by using the reverse obtained by the reverse channel calculation unit as coefficients of the frequency domain equalization apparatus. | 09-03-2009 |
| 20090232258 | DEVICE AND METHOD FOR DEMODULATING CONTROL SIGNALS - A device performs demodulation of control signals from multiple radio terminals, based on the correlations in the frequency domain between a predetermined code and the orthogonalized control signals and reference signals of the multiple radio terminals obtained by cyclic shifts of the predetermined code. The device includes: a demultiplexer which demultiplexes a reference signal component and a control signal component based on a correlation profile; a path detector which detects a path location or path locations for each radio terminal based on the power values of the reference signal components; extractor which extracts the correlation values of the reference signal components and the correlation values of the control signal components, respectively; and RAKE combiner which combines the extracted values. | 09-17-2009 |
| 20090245436 | Systems and Methods For Sending An Acknowledgement Message In A Wireless Communication System - A method for sending an acknowledgment message in a wireless communication system is disclosed. A first signal is received before receiving a second signal from a transmitter. Decoded first data is extracted from the first signal. A third signal is produced by encoding and modulating the decoded first data. The second signal is demodulated to produce second symbols. The third signal and the second symbols are correlated. | 10-01-2009 |
| 20090252260 | METHOD FOR GENERATING A REFERENCE SIGNAL SEQUENCE USING GROUPING - Method for generating reference signal sequence using grouping is explained. In this method, base sequences are grouped such that each group contains at least one base sequence of each length, so UE(s) can use various length sequences as a reference signal. And in this method, inter cell interference caused by using various length sequence as a reference signal sequence can be minimized by grouping sequences having the high cross correlation relation. | 10-08-2009 |
| 20090252261 | System, Apparatus, and Method for Processing a Received Orthogonal Frequency Division Multiplexing Signal - A wireless communication system, an apparatus and a method for processing a received OFDM signal is provided. The wireless communication system comprises an interface and a processing apparatus. The interface is configured to receive a received OFDM signal. The processing apparatus comprises an estimation module and a calculation module. The estimation module is configured to estimate an auto-correlation matrix relating to the received OFDM signal, with the auto-correlation matrix comprising a plurality of elements. Then, the calculation module is configured to calculate an amplitude and a phase for each of the elements to determine the carrier frequency offset (CFO) and timing offset (TO) of the received OFDM signal according to the amplitudes and phases. By exploiting the auto-correlation matrix of the received OFDM signal, the CFO and TO can be derived efficiently. | 10-08-2009 |
| 20090257532 | Determining Burst Transmission Signals - Described are computer-based methods and apparatuses, including computer program products, for determining burst transmission signals. A receiver receives radio frequency data from a data source through a network. The receiver converts the radio frequency data to digital data. The receiver converts the digital data to baseband data. The receiver generates a correlation magnitude from the baseband data based on one or more correlation templates. The receiver determines one or more statistics based on the correlation magnitude and stored statistics. The receiver determines the presence of a burst transmission signal based on a comparison of a threshold value computed as a function of the statistics and the correlation magnitude. If the correlation magnitude exceeds the computed threshold, the receiver demodulates the burst transmission signal to packet data and transmits the packet data to a server. | 10-15-2009 |
| 20090268855 | SIGNAL RECEIVING APPARATUS, SIGNAL RECEIVING METHOD AND SIGNAL RECEIVING PROGRAM - A signal receiving apparatus for receiving signals is provided. The signal receiving apparatus includes a correlation-value computation section configured to sequentially compute a correlation value representing a correlation between the received signal and a series of known symbols while sliding the series of known symbols for every symbol included in the received signal, a maximum-value detection section configured to detect a largest correlation value among the correlation values computed by the correlation-value computation section for one frame of the received signal, and a correlation-value storage section configured to store each of the correlation values at one of a predetermined number of storage locations, before and after the largest correlation value is detected by the maximum-value detection section. | 10-29-2009 |
| 20090268856 | DEMODULATION DEVICE, DEMODULATION DEVICE CONTROL METHOD, DEMODULATION DEVICE CONTROL PROGRAM, AND RECORDING MEDIUM WITH RECORDED DEMODULATION DEVICE CONTROL PROGRAM - This demodulation device receives and demodulates a digital broadcast wave. This demodulation device includes an RF search control unit ( | 10-29-2009 |
| 20090279646 | Wireless communication device - A wireless communication device is provided to carry out correlation peak detection processing properly and efficiently in intermittent receiving unit. If a correlation peak is not detected in a first period in which a correlation peak detecting unit detects the correlation peak at a default frequency and a first frequency in a detecting period of a coarse frequency deviation detecting unit in the first period, a control unit makes the correlation peak detecting unit carry out the peak detection at the first frequency in a second period. If the correlation peak is detected in the correlation peak detecting unit and a second frequency is detected in a detecting period of a fine frequency deviation detecting unit in the first period, the control unit makes the correlation peak detecting unit carry out the peak detection at the first and second frequencies in a third period. | 11-12-2009 |
| 20090285337 | FREQUENCY DOMAIN ROOT CAZAC SEQUENCE GENERATOR - The present invention provides a method for implementation in a random access channel receiver. One embodiment of the method includes generating at least one frequency domain reference sequence by multiplying a generator function and a first frequency domain root CAZAC sequence. The frequency domain reference sequence(s) is generated in response to receiving a signal at the random access channel receiver. This embodiment of the method also includes correlating the received signal and the frequency domain reference sequence(s). | 11-19-2009 |
| 20090285338 | BANK OF CORRELATORS FOR SETS OF GCL SEQUENCES - A method for correlation of an input signal in a receiver is disclosed as well as a receiver and a communication system for implementing the method. The input signal is correlated with Generalized Chirp-Like (GCL) sequences being derived from a single Zadoff-Chu sequence modulated with at least two modulation sequences. The method includes at least the steps of processing samples of the input signal in a first delay line, in a Discrete Fourier Transform (DFT) circuit and in a second delay line. According to the invention, a multiplication of samples of the input signal with elements of modulation sequences corresponding to the at least two modulation sequences being used for deriving the GCL sequences is performed in a step after the processing in the first delay line. Then a DFT processing is performed using a DFT circuit. | 11-19-2009 |
| 20090285339 | Apparatus for Generating Spreading Sequences and Determining Correlation - An apparatus includes a signal generator to output one of a first sequence or a second sequence and to augment sequences with cover codes, such that a sum of out-of-phase aperiodic autocorrelation coefficients of the first sequence and the second sequence of is zero, a physical layer preamble controller to control the signal generator to generate a preamble of a data unit, including a short training field (STF) formatter to cause the signal generator to generate an STF for use in at least frame synchronization, and a long training field (LTF) formatter to cause the signal generator to generate an LTF for use in at least channel estimation, such that the STF formatter controls the signal generator to include the first sequence in a last portion of the STF, and the LTF formatter controls the signal generator to include the second sequence in a beginning portion of the LTF. | 11-19-2009 |
| 20090290661 | DETECTION OF TIME-DOMAIN SEQUENCES SENT ON A SHARED CONTROL CHANNEL - Techniques for sending and receiving signaling messages in a control segment are described. The control segment may be sent with CDM in multiple OFDM symbols. At a receiver, a received sequence is obtained for the control segment. A time-domain signaling sequence is generated based on a signaling message hypothesized to have been sent in the control segment. A correlating sequence is generated based on the signaling sequence. In one design, the signaling sequence is partitioned into multiple sub-sequences, one sub-sequence for each symbol period in which the control segment was sent. Each sub-sequence is cyclically shifted by an amount determined by a channel tap delay. The correlating sequence is then formed by concatenating all of the cyclically shifted sub-sequences. The correlating sequence may also be generated in other manners. The received sequence is correlated with the correlating sequence to determine whether the signaling message was sent in the control segment. | 11-26-2009 |
| 20090290662 | METHOD FOR GENERATING A REFERENCE SIGNAL SEQUENCE USING GROUPING - Method for generating reference signal sequence using grouping is explained. In this method, base sequences are grouped such that each group contains at least one base sequence of each length, so UE(s) can use various length sequences as a reference signal. And in this method, inter cell interference caused by using various length sequence as a reference signal sequence can be minimized by grouping sequences having the high cross correlation relation. | 11-26-2009 |
| 20090296862 | RECEIVING APPARATUS AND RECEIVING METHOD - A receiving apparatus that can properly determine the position of an effective symbol included in a received signal is provided. A receiver acquires a signal from a sending apparatus that transmits a signal into which a guard interval which is a replica of at least part of an effective symbol is inserted between the effective symbol and another effective symbol. A timing detector finds a correlation between the received signal and a signal obtained by shifting the received signal in a time direction, detects timing at which a maximum correlation value is obtained, and determines that timing which is predetermined time (> | 12-03-2009 |
| 20090304126 | OFDM Communication Device and Guard Interval Length Decision Method - Even if background noise is present, it is possible to control a guard interval length so that a minimum required SINR can be obtained. An OFDM communication device ( | 12-10-2009 |
| 20090304127 | NARROW BAND RECEIVER - An RF receiver comprises a signal processor arranged to perform a method of decoding data contained within a signal that comprises a set of slots, at least one said slot comprising a preamble portion and a payload portion and being transmitted at a predetermined transmission frequency. The signal processor is arranged to perform a first process to derive timing data from the preamble portion and perform a second process to extract information from the payload portion, the second process being triggered from said timing data derived from the first process. The preamble portion comprises at least a first sequence of data and a second sequence of data, and the second sequence is the inverse of the first sequence. In preferred embodiments the first process comprises identifying a transition between said first and second sequences of data and deriving said timing data from the identified transition. | 12-10-2009 |
| 20090304128 | Packet Detection Apparatus and Method, Wireless Communication Apparatus and Method, and Computer Program - A packet detection apparatus detects a packet from a received signal by using a preamble containing an established, repeating training sequence. A first autocorrelation calculator computes a first autocorrelation of the received signal over a first interval. A first determining unit determines packet discovery by comparing the first autocorrelation to a first autocorrelation threshold value. A second autocorrelation calculator computes a second autocorrelation of the received signal over a second interval equivalent to the interval length for packet discovery announcement. A second determining unit determines packet discovery announcement by comparing the second autocorrelation to a second autocorrelation threshold value lower than the first autocorrelation threshold value. | 12-10-2009 |
| 20090323867 | Adaptive synchronization enhancement technique for serial modulated waveforms - Methods and apparatus for synchronization (SYNC) detection of a received serial offset quadrature pulse shaped waveform modulated by a symbol SYNC sequence are provided. The waveform is serially demodulated into a serial baseband signal and correlated in parallel with segments of the symbol SYNC sequence. Correlation strength estimates of each of the correlated output signals are computed and used to adjust a SYNC threshold level. The correlation strength estimates or the correlated output signals are combined and a peak is determined in the resulting signal. The peak in the resulting signal is compared to the SYNC threshold level to detect synchronization. | 12-31-2009 |
| 20090323868 | Selection of a Received Sequence By Means of Metrics - A method of received data sequence assessment, the method comprising producing a correlation metric describing the fit to a received sequence of the most likely of a set of candidates for the received sequence and calculating an error metric indicative of discrepancies between the received sequence and its most likely candidate. | 12-31-2009 |
| 20090323869 | METHOD AND APPARATUS FOR SPACE DIVISION MULTIPLE ACCESS RECEIVER - Methods and systems consistent with this invention receive a plurality of transmitted signals in a receiver having a plurality of receive elements, wherein each transmitted signal has a different spatial location. Such methods and systems receive the plurality of transmitted signals at the plurality of receive elements to form a plurality of receive element signals, form a combined signal derived from the plurality of receive element signals, and detect each of the plurality of transmitted signals from the combined signal by its different spatial location. To achieve this, methods and systems consistent with this invention generate a plurality of arbitrary phase modulation signals, and phase modulate each of the plurality of receive element signals with a different one of the phase modulation signals to form a plurality of phase modulated signals. Such methods and systems then combine the plurality of phase modulated signals into a combined signal, generate expected signals, and cross-correlate the combined signal with the expected signals to form correlation signals. Such methods and systems then store the correlation signals in a correlation signal memory and analyze the correlation signals to extract information from the transmitted signals. | 12-31-2009 |
| 20100002812 | MULTI-ANTENNA WIRELESS RECEIVER CHAINS WITH VECTOR DECODING - A receiver chain is provided for use in wireless data communication including a plurality of receive antennas and a vector Barker decoder or a CCK decoder. The vector Barker decoder operates on the plurality of received signals, preferably processed through a plurality of channel matched filters. The weightings of the plurality of channels can be done using a slicer variance, a PLL variance or another method. | 01-07-2010 |
| 20100008451 | Symbol Detection in a MIMO Communication System - Circuits are provided for detecting symbols transmitted from multiple transmitting antennas to multiple receiving antennas. A circuit includes distance blocks, selectors, and an identifier block. Each distance-block includes at least one sub-block, and each sub-block inputs a candidate for a corresponding transmitting antenna. The sub-block determines partial distances for pairings of the candidate and each symbol in a constellation from a partial distance of the candidate and signals received at the receiving antennas. At least one selector assigns each pairing for each candidate for a corresponding transmitting antenna to a bin having a range that includes the partial distance of the pairing. The selector selects candidates for a successive transmitting antenna from the bins having the smaller ranges. The identifier block selects a final candidate that is one of the pairings for a last transmitting antenna having a smaller partial distance. | 01-14-2010 |
| 20100008452 | METHOD AND APPARATUS FOR ESTIMATING DOPPLER FREQUENCY IN A MOBILE TERMINAL - A method and apparatus for estimating a Doppler frequency in a mobile terminal are provided. The method includes calculating two autocorrelation values for intervals of at least one sample from a channel estimation tap with a maximum power, and estimating a maximum Doppler frequency using the two autocorrelation values. The two autocorrelation values are autocorrelation values for intervals of different numbers of samples. | 01-14-2010 |
| 20100008453 | ANTENNA ARRAY PATTERN DISTORTION MITIGATION - At least one feature provides a way to perform point-to-multipoint transmissions using adaptive or directional antennas while reducing antenna pattern distortion. Generally, rather than transmitting the same waveform to two or more receivers, an information-bearing signal is transformed into different decorrelated waveforms and each decorrelated waveform is transmitted to a different receiver. In one implementation, an information-bearing signal is transformed into two decorrelated signals such that their crosscorrelation, or autocorrelation of the information-bearing signal, is zero or very small. Such decorrelation may be achieved by sending a first signal to a first receiver while sending a second signal, having a radio frequency spectrum that is the spectrally inverted version of the first signal, to a second receiver. In another implementation, a first signal is transmitted to a first receiver and is also transmitted to a second receiver with a time delay. | 01-14-2010 |
| 20100014617 | METHOD AND APPARATUS FOR SINGULAR VALUE DECOMPOSITION OF A CHANNEL MATRIX - A method and apparatus for decomposing a channel matrix in a wireless communication system are disclosed. A channel matrix H is generated for channels between transmit antennas and receive antennas. A Hermitian matrix A=H | 01-21-2010 |
| 20100020905 | APPARATUS AND METHODS FOR COMPUTING CONSTANT AMPLITUDE ZERO AUTO-CORRELATION SEQUENCES - Apparatus and methods for calculating constant amplitude zero auto-correlation sequences are disclosed. One method includes calculating an argument of trigonometric functions used for calculating a constant amplitude zero auto-correlation sequence based at least on additive recursion of an input sequence root constant and without multiplication by a variable. A constant amplitude zero auto-correlation sequence is then computed using a CORDIC algorithm configured to calculate trigonometric functions used in determining the sequence without performing multiplication operations and based on the calculated argument. The disclosed methods and apparatus may be applied, in particular, to efficiently computing Zadoff-Chu sequences in preamble detection in particular physical random access channels in Long Term Evolution LTE communication systems. By allowing computation of such sequences, memory requirements can be reduced. | 01-28-2010 |
| 20100027723 | TIME SYNCHRONIZATION METHOD AND FREQUENCY OFFSET ESTIMATION METHOD USING THE SAME IN OFDM NETWORK - Provided are a time synchronization method and a frequency offset estimation method using the same in an OFDM system. The time synchronization method using a preamble transmitted from a transmitter to a receiver in the OFDM communication network includes the steps of: a) calculating a moving sum of a first sequence and a second sequence obtained by a product of neighboring elements in a received signal when the received signal containing a preamble is received from the transmitter; b) estimating a location of the received signal corresponding to the moving sum having a maximum value; and c) acquiring a time synchronization with respect to the received signal, based on the estimated location, wherein the first sequence is obtained from a product of neighboring elements in the preamble and a correlation value obtained by correlating another sequence with the first sequence is smaller than a predetermined value. | 02-04-2010 |
| 20100027724 | RECEIVER AND RECEIVING METHOD - Quick resumption of reproduction of received data is achieved with low cost. A receiver for receiving an OFDM signal has a demodulation unit and a transmission mode control unit. The demodulation unit performs, on a received signal, demodulation and detection of establishment of synchronization in accordance with a transmission mode that is a combination of an FFT mode and a guard interval, and outputs a synchronization establishment signal indicating an obtained result of the detection of establishment of synchronization. The transmission mode control unit holds an FFT mode and a guard interval adopted when the synchronization establishment signal indicates establishment of synchronization, and outputs a combination of the held FFT mode and the held guard interval as the transmission mode to be used in the demodulation unit. | 02-04-2010 |
| 20100034326 | Receiver for receiving data symbols having a symbol period - A receiver and method for receiving symbols having a symbol period with duration SP comprising. N antenna signals are selected equally in time over a symbol period to obtain a combined antenna signal. An autocorrelation is performed on the combined antenna signal to obtain a combined signal. The combined signal is split into the corresponding antenna signal parts and subjected to an integration function. The output of the integration function is used the select the antenna signal with the best signal quality. The invention enables to perform an efficient antenna diversity circuit, which can partially be used for simultaneously preamble detection and frequency offset estimation. | 02-11-2010 |
| 20100061492 | Reduced Frequency Data Processing Using a Matched Filter Set Front End - Various embodiments of the present invention provide systems and methods for reduced clock rate data processing. As an example, a circuit is disclosed that includes a matched filter bank that receives a series of symbols at a rate corresponding to a sample clock. The matched filter bank includes a first matched filter tuned to detect a first bit sequence in the series of symbols and to assert a first symbol proxy upon detection of the first bit sequence, and a second matched filter tuned to detect a second bit sequence in the series of symbols and to assert a second symbol proxy upon detection of the second bit sequence. The circuit further includes a detector circuit that processes a series of symbol proxies including the first symbol proxy and the second symbol proxy at a rate corresponding to a reduced rate clock. The reduced rate clock is the sample clock divided by a factor. | 03-11-2010 |
| 20100061493 | SYNCHRONIZATION CIRCUIT AND SYNCHRONIZATION METHOD, WIRELESS COMMUNICATION DEVICE AND WIRELESS COMMUNICATION METHOD, AND COMPUTER PROGRAM - A synchronizing circuit comprising: a coarse synchronizing circuit which determines temporary reception timing using a preamble consisting of a repetition of known training signals added to a reception packet; a synchronization candidate timing control section which sets up multiple synchronization candidates based on the temporary reception timing and controls synchronization of received signal s in each of the multiple synchronization candidates; a signal quality monitoring section which monitors signal quality of the received signal s synchronized in each of the multiple synchronization candidates; and a synchronization candidate selecting section which selects one of the synchronization candidates as a final reception timing based on a monitoring result of the signal quality in the signal quality monitoring section. | 03-11-2010 |
| 20100074379 | Tuning replica generation methods and apparatus for their most optimum performance in processing transient signals - The embodiments of the present invention are most optimum methods and apparatus for processing transient (pulsed, non-cooperative, non-reproducible, complex, or simultaneous) signals; in particular, for their unbeatable vigor in passive source identifications; for their ultra precision transient spatial range and Doppler measurements; for their supreme powers in rejection noise and interference contamination; for their utmost abilities in deciphering random, chaotic, turbulent, explosive, thermo nuclear, and other countless transient phenomena. In particular, an embodiment of the present invention is an apparatus for processing transient signals that uses replica generations and which comprises: (a) a signal receiving apparatus which receives one or more signals having transient in nature, at least one of them cannot be repeatedly produced or is a signal of opportunity, and the signals have pulse lengths ranging from less than tenth of a picosecond to higher than several microseconds, and frequency widths from less than 0.10 MHz to higher than 40 GHz; (b) a tuning apparatus which accepts signals from the receiving apparatus as inputs, tunes one or more of these signals in response to a requirement of interest, where the requirement of interest includes, but not limited to, shortening or elongating the one or more of signals; (c) a replica generation apparatus, which accepts signals from the tuning apparatus as inputs, and outputs a train of replica pairs, where relative separations between two members in the replica pairs are same or different; (d) an integration apparatus which performs correlation integrations that is to correlate between two members in the replica pairs and to convert the train of replica pairs into a baseband signal. | 03-25-2010 |
| 20100086085 | Method and system for estimating the speed of a mobile device in a network - A method for estimating the speed of a mobile device in a network is provided that includes selecting a correlation length from a plurality of possible correlation lengths. A correlation result is generated based on the selected correlation length. A speed estimate is generated for the mobile device based on the correlation result. | 04-08-2010 |
| 20100091915 | METHODS AND SYSTEMS FOR MIMO PREAMBLE DETECTION - Certain embodiments of the present disclosure allow for detection of a transmitted preamble sequence by processing a correlation of a received signal and a preamble hypothesis in a way that exploits the good correlation properties of the known set of preamble sequences. For certain embodiments, the highest peaks of the correlation output may be compared across all preamble hypotheses to decide which preamble sequence is transmitted. | 04-15-2010 |
| 20100091916 | ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYNCHRONIZATION - Embodiments are directed to first and second OFDM pilot symbols. The first and second pilot symbols may have first and second sets, respectively, of allowed, forbidden, and active carrier frequencies. The second sets of carrier frequencies may be formed by frequency shifting the respective first sets by a predetermined frequency, such as the frequency difference between adjacent carriers. An embodiment is directed to frequency translating part of a first received pilot symbol by one carrier interval in a first direction, frequency translating part of a second received pilot symbol by one carrier interval in a second direction that is opposite from the first direction, and forming a correlation by multiplying the frequency translated parts of the first and second pilot symbols by complex conjugates of parts of the pilot symbols upon which frequency translation has not been performed, and summing the multiplication results. | 04-15-2010 |
| 20100111235 | METHOD OF DETERMINING AS TO WHETHER A RECEIVED SIGNAL INCLUDES AN INFORMATION SIGNAL - A method of determining as to whether a received signal includes an information signal is provided. The method provided includes determining a covariance matrix from a received signal and transforming the covariance matrix into a transformed covariance matrix, wherein the transformation is configured such that the transformed covariance matrix is a non-diagonal matrix in case the received signal includes the information signal, wherein the non-diagonal matrix includes non-zero non-diagonal matrix elements. The method provided further includes determining a first function using at least one of the non-zero non-diagonal matrix elements of the transformed covariance matrix, determining a second function using at least one matrix element of the transformed covariance matrix, wherein the second function is different from the first function, and determining as to whether a received signal includes an information signal based on a comparison of a value of the first function and a value of the second function. | 05-06-2010 |
| 20100111236 | COURSE TIMING SYNCHRONIZATION - A system for determining the burst start timing of a signal includes logic configured to receive the signal, generate correlation moduli and generate a first timing output based on the correlation moduli. The logic may also be configured to receive operating mode information and timing information and generate search controls. The logic may further be configured to identify a maximum of the correlation moduli using the search controls and determine a second timing output associated with the maximum correlation modulus. The second timing output represents a more accurate approximation of a burst start time than the first timing output. | 05-06-2010 |
| 20100119018 | Method And Apparatus For Frequency Tracking In A Space Time Transmit Diversity Receiver - A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed herein. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function. | 05-13-2010 |
| 20100128822 | OFDM RECEIVING APPARATUS, OFDM RECEIVING METHOD, OFDM RECEIVING CIRCUIT, INTEGRATED CIRCUIT, AND PROGRAM - A synchronization section | 05-27-2010 |
| 20100128823 | DOPPLER FREQUENCY ESTIMATING DEVICE, RECEIVING DEVICE, RECORDING MEDIUM AND DOPPLER FREQUENCY ESTIMATING METHOD - A device of an example of the invention comprises a first section which performs IFFT for a channel estimation value obtained by channel estimation to obtain a channel impulse response, a second section which selects paths that belong to a group having a large element based on elements of paths for the channel impulse response, a third section which calculates autocorrelation values by time averaging for each of the paths selected by the second section, a fourth section which obtains an ensemble average value of the autocorrelation values by time averaging obtained by the third section, and a fifth section which obtains a Doppler frequency associated with the ensemble average value based on a characteristic of a relationship between an autocorrelation value and an Doppler frequency and the ensemble average value. | 05-27-2010 |
| 20100142657 | SELECTION SCHEME FOR SELECTING A PEAK IN A CORRELATION SIGNAL - A method and associated module for selection of a maximum peak in a correlation signal corresponding to the correlation between a code periodically transmitted by a transmitter, and an input signal received by a receiver on a radio channel, includes a selection criteria which is the time recurrence of the same position of peaks of correlation, taking into account a margin around the peak position compensating for a drift due to a frequency offset between the receiver and the transmitter. | 06-10-2010 |
| 20100142658 | APPARATUS AND METHOD FOR REMOVING COMMON PHASE ERROR IN A DVB-T/H RECEIVER - A receiver is a Digital Video Broadcasting-Terrestrial/Handheld (DVB-T/H) receiver. The DVB-T/H receiver comprises a phase error corrector and a channel estimation and equalization element. The phase error corrector rotates a signal in accordance with an estimate of a phase error, e.g., CPE, which is determined as a function of channel state information (CSI) provided by the channel estimation and equalization element. | 06-10-2010 |
| 20100142659 | SYSTEM AND METHOD FOR FFT WINDOW TIMING SYNCHRONIZATION FOR AN ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXED DATA STREAM - A system and method for determining an FFT window location for reception of an OFDM signal received over a transmission channel. The OFDM signal includes a plurality of symbols each having a guard interval. The system includes a correlation module that determines a location of maximum correlation in a first symbol, an FFT module to perform an FFT on the OFDM signal based upon an initial FFT window location, and an adjustment module. The adjustment module determines a plurality of permissible echo location options based upon the initial FFT window location, selects a permissible echo location option that corresponds most closely to the location of maximum correlation, and adjusts the initial FFT window location based upon the selected permissible echo location option so that the adjusted FFT window location includes substantially all of a useful symbol length of the first symbol while a maximum number of echoes are included within the guard interval of the first symbol. | 06-10-2010 |
| 20100150283 | METHOD AND APPARATUS FOR DIGITAL SIGNAL RECEPTION - The present invention relates to a digital signal reception method and apparatus. Said digital signal receiver comprises a Common Phase Error removal unit for eliminating CPE contained in the received signal by using CSI corrected pilot sub-carriers; a channel estimation unit for estimating channel state information of the received signal after removing the CPE and feed the CSI to the CPE removal unit, and a means for generating the CSI corrected pilot sub-carriers by multiplying the CSI with 1 or −1 according to positive or negative sign of the local pilot sub-carriers only in response to continual pilots of the received signal. Said method comprises estimating the CSI of the received digital signal after removing CPE; and eliminating the CPE of the received signal by using the CSI corrected pilot sub-carriers, whereby a low complexity and high accuracy are achieved. | 06-17-2010 |
| 20100158163 | Velocity Estimation Algorithm for a Wireless System - A method for estimating the velocity of the Mobile Station (MS) in Orthogonal Frequency Divisional Multiplexing (OFDM)/Orthogonal Frequency Divisional Multiplexing Access (OFDMA) system is disclosed. First, the pilots in the preamble are received by MS and the pilots in a specified symbol of the specific zone are received by MS. An auto-correlation between the received pilots in preamble and the received pilots in the specified symbol of the specific zone is calculated. The auto-correlation is the calculated with frame by frame basis, and the average auto-correlation is calculated from number of frames. Once the average auto-correlation is obtained, the velocity of MS is estimated from predetermined function according to the obtained average auto-correction. | 06-24-2010 |
| 20100158164 | APPARATUS AND METHOD FOR TIME SYNCHRONIZATION AND RECEPTION APPARATUS OF OFDM SYSTEM - An apparatus for time synchronization of an orthogonal frequency division multiplexing (OFDM) system oversamples a received signal using a master clock having a frequency at least four times higher than a minimum sampling frequency in a transmission apparatus, sets one of a plurality of oversampled signals to an on-time signal, and shifts each of the remaining oversampled signals by a predetermined time on the basis of the on-time signal. The apparatus for time synchronization calculates a correlation value by correlating each of the shifted signals and the on-time signal with a previously known signal, detects a maximum energy value among the calculated correlation values, and detects a start point of a frame by comparing the maximum energy value with a predetermined threshold value. | 06-24-2010 |
| 20100166120 | Method and Apparatus for Correlating Two Data Sections - Watermarking of audio signals intends to manipulate the audio signal in a way that the changes in the audio content cannot be recognised by the human auditory system. The watermark data are decoded from the received watermarked audio signal by correlation with corresponding candidate reference sequences. One or more of the sync symbols are embedded twice in the watermark data frame in the encoder. Thereafter a circular correlation is calculated instead of a standard correlation. | 07-01-2010 |
| 20100166121 | METHODS AND APPARATUS FOR RECEIVER HAVING FAST WALSH TRANSFORM - Methods and apparatus for correlating a receiving signal using a Fast Walsh Transform for efficient processing. In one embodiment, a Walsh encoded signal is received and then processing using a Fast Walsh Transform to generate outputs from which a largest one of the orthogonal sequences is selected. | 07-01-2010 |
| 20100172448 | METHOD AND RECEIVER APPARATUS FOR DETERMINING A CORRELATION VALUE CONSIDERING FREQUENCY CORRECTION - A receiver apparatus for determining a correlation value of a predetermined repetitive chip sequence in a receive signal, the chip sequence having a chip sequence duration and a chip sequence duration cycle. The receiver apparatus has a receive unit for receiving the receive signal and a segmenter for providing receive signal segments from the receive signal, two receive signals representing the same chip sequence in different repetition cycles and having at least one repetition cycle time spacing. | 07-08-2010 |
| 20100183103 | Method and apparatus for signal detection - In order to reduce the complexity of complex signal correlator and realize algorithm optimization, the present invention provides a method and an apparatus for implement complex signal correlation by means of shifter and adder instead of complex multiplier. In the method, the amplitude and radial angle of a corresponding received symbol is firstly adjusted based on a pre-stored local reference symbol. Then, the radial angle of the adjusted received signal is rotated based on a corresponding interchange indicator. Finally, all the processed received signals are combined to obtain a final complex correlation signal. With this method, the chip size and computing load can be greatly reduced. | 07-22-2010 |
| 20100195774 | LEAST SQUARES CHANNEL IDENTIFICATION FOR OFDM SYSTEMS - An OFDM system generates a channel estimate in the time domain for use in either a frequency domain equalizer or in a time domain equalizer. Preferably channel estimation is accomplished in the time domain using a locally generated reference signal. The channel estimator generates an initial estimate from a cross correlation between the time domain reference signal and an input signal input to the receiver and generates at least one successive channel estimate. Preferably the successive channel estimate is determined by vector addition (or subtraction) to the initial channel estimate. The at least one successive channel estimate reduces the minimum mean square error of the estimate with respect to a received signal. | 08-05-2010 |
| 20100202574 | SPECTRUM SENSING FOR OFDM SIGNALS BY UTILIZING PILOT TONES - An apparatus comprises a downconverter for providing a signal that may be a received orthogonal frequency division multiplexed (OFDM) symbols from a selected channel, each OFDM symbol comprising N subcarriers at least some of which are pilot subcarriers; and a processor that (a) correlates the received OFDM symbols for providing at least one correlated value, (b) generates a metric value as a function of the at least one correlated value and (b) compares the metric value to a threshold value for detecting if an incumbent signal is present. | 08-12-2010 |
| 20100208852 | Cascaded 4G, 3G, 2G and other systems - A Global Positioning System (GPS), a touch screen generated signal, a first Orthogonal Frequency Division Multiplexed (OFDM) signal, a first Code Division Multiple Access (CDMA) signal and a first Time Division Multiple Access (TDMA) signal is received by two or more antennas and is processed into processed GPS, touch screen, OFDM, CDMA and TDMA signal and is provided to a subscriber unit-interface circuitry. The processed CDMA signal is a cross-correlated in-phase and quadrature-phase baseband signal. One or more of the processed GPS, touch screen, first OFDM, first CDMA or first TDMA baseband signal is provided for cascade processing, modulation and transmission into a second OFDM, second CDMA or second TDMA signal, wherein the second signal is distinct from the first signal. The transmitter has two or more antennas for transmission and linearly and a non-linearly amplified amplifier for linear and for non-linear amplification of modulated signals. | 08-19-2010 |
| 20100226462 | RECEIVING APPARATUS AND METHOD WITH NO OVERSAMPLING ANALOG TO DIGITAL CONVERSION - The present invention relates to a receiving apparatus for receiving signals in a wireless communication system, in which the signals comprise a dedicated channel estimation sequence, comprising an analog to digital converter adapted to convert received signals into digital samples with a sampling rate identical to a symbol rate of the received signals, a channel estimation means adapted to perform a channel estimation on the basis of the dedicated channel estimation sequence comprised in a digital samples of the received signals, an evaluation means adapted to evaluate the channel estimation result from the channel estimation means, and a control means adapted to control a phase of the sampling rate of the analog to digital converter on the basis of an evaluation of the channel estimation result. | 09-09-2010 |
| 20100226463 | SYNCHRONIZATION STRUCTURE AND METHOD FOR A RECEIVING APPARATUS OF A COMMUNICATION SYSTEM - The present invention relates to a synchronization structure for a receiving apparatus for receiving signals in a communication system, in which the signals are transmitted in frames, each frame comprising a synchronization part with synchronization sequences, wherein at least one of the synchronization sequences as a different phase than the other synchronization sequences, comprising correlation means adapted to perform a correlation on the synchronization part, peak detection means adapted to detect candidate correlation peaks and the correlation result, and correlation peak detection means adapted to detect a correlation peak among said candidate correlation peaks on the basis of a confidence value and phase information. | 09-09-2010 |
| 20100260294 | SYSTEM AND METHOD FOR TIME SYNCHRONIZATION OF OFDM-BASED COMMUNICATIONS - Systems and methods for time synchronization of orthogonal frequency-division multiplexing (OFDM)-based communications are disclosed. A cyclic prefix (CP) correlation-based timing synchronization method is disclosed for early path (e.g. first-received path) detection for OFDM-based communication. Systems and methods are disclosed for performing double peak value detection in an OFDM-based system for reliably detecting an early (e.g., first-received) path in a received OFDM symbol for use in timing synchronization. In the double peak value detection method, a first peak value detection is performed to detect the path with the largest power, and a second peak value detection is then performed to detect a desired early (e.g., first-received) path. A compensation linear curve is used to facilitate the second peak value detection. | 10-14-2010 |
| 20100266075 | INFRARED SIGNAL DECODE CIRCUIT AND INFRARED SIGNAL DECODE METHOD - According to one embodiment, an infrared signal decode circuit includes: a comparator; a correlation signal generator generating a sum of a first detection signal and a second detection signal as a correlation signal, the first detection signal being obtained by performing an absolute value calculation on a first correlation signal, the second detection signal being obtained by performing an absolute value calculation on a second correlation signal, the first correlation signal corresponding to a correlation between a binary signal and a first reference signal with a frequency substantially identical to a base frequency of a subcarrier of an infrared signal, the second correlation signal corresponding to a correlation between the binary signal and a second reference signal with a phase that differ from a phase of the first reference signal by 90 degrees; and a decoder binarizing the correlation signal generated by the correlation signal generator. | 10-21-2010 |
| 20100278288 | CHANNEL ESTIMATION METHOD AND SYSTEM FOR INTER-CARRIER INTERFERENCE-LIMITED WIRELESS COMMUNICATION NETWORK - A method and system for wireless communication channel estimation. A frequency offset hypothesis is determined. An interchannel interference (“ICI”) matrix based on the frequency offset hypothesis is generated. Pilot channel estimates based on the ICI matrix are obtained. A correlation error of the pilot channel estimates to the frequency offset hypothesis is calculated. The correlation error is compared with a predetermined correlation error value. The frequency offset hypothesis is updated and the aforementioned steps are iteratively repeated if the correlation error is greater than the predetermined correlation error value. The pilot channel estimates are used to estimate the wireless communication channel. | 11-04-2010 |
| 20100284498 | Circuit for Detecting a Predetermined Symbol in a Digital Data Stream and Associated Method - A circuit for detecting a predetermined symbol of a digital data stream includes a frequency shifter, a correlator, a filter and a decision unit. The frequency shifter performs inverse-frequency shifting upon a first data to generate a first frequency-shifted data. The correlator calculates correlation upon the first frequency-shifted data and a second data to generate a correlated data. The filter, coupled to the correlator, filters and the correlated data to generate a filtered correlated data according to a time-domain windowing length. The decision unit, coupled to the filter, determines the predetermined symbol from the digital data stream according to the filtered correlated data. | 11-11-2010 |
| 20100290569 | POST DFT/FFT TIME TRACKING ALGORITHM FOR OFDM RECEIVERS - A method for time synchronization tracking in an orthogonal frequency division multiplexing (OFDM) receiver is described, the method comprising the steps: obtaining a DFT output vector; determining a sample timing offset indication using reference symbols that are extracted from the DFT output vector; and adapting the OFDM symbol timing using said determined indication. In order to provide an improved post-DFT algorithm for estimating a time tracking error in OFDM receivers such as to allow an effective time tracking even in single frequency networks, and more particular to devise a time tracking algorithm for OFDM receivers that supports longer channel impulse responses without causing inter-symbol interference, said determining step comprises the steps of: (a) estimating ( | 11-18-2010 |
| 20100296611 | DOWNLINK PREAMBLE PROCESSING TECHNIQUES FOR INITIAL ACQUISITION - An apparatus, system, method, and article for downlink (DL) preamble processing for initial acquisition are described. The apparatus may include an autocorrelator node to determine an autocorrelation response of samples and to detect a downlink preamble based on the autocorrelation response. The samples may include a periodic sequence having two or more periods. The apparatus may include a frequency domain matched filter processing node to perform downlink preamble recognition based on a maximum peak of a frequency domain matched filter response and on an index of the downlink preamble. Other embodiments are described and claimed. | 11-25-2010 |
| 20100303178 | Method and System for Down-Converting an Electromagnetic Signal, and Transforms for Same - Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal. | 12-02-2010 |
| 20100303179 | SYNCHRONIZATION TIMING DETECTING APPARATUS, RECEIVING APPARATUS, AND SYNCHRONIZATION TIMING DETECTING METHOD - A synchronization timing detecting apparatus includes a correlation calculator configured to generate a first correlation value by calculating a cross-correlation between an input signal being sampled and a reference signal or an auto-correlation of the sampled input signal, an interpolation processor configured to generate a second correlation value interpolating a plurality of the first correlation values having a different combination of sampling points of the input signal, and a detector to detect a synchronization timing based on the first and the second correlation values. | 12-02-2010 |
| 20100310021 | METHOD FOR COMPUTING CORRELATION OF PN SEQUENCE AND CIRCUIT THEREOF - The present invention relates to a method for computing correlation of a PN sequence and a circuit thereof. A plurality of input values of an input sequence is summed up to give a first sum. A PN sequence comprising a plurality of first values and a plurality of second values, which correspond to the plurality of input values, are received. Summing up the plurality of input values corresponding to the plurality of first input values in the PN sequence gives a second sum. According to the first sum and the second sum, a correlation value is given. The present invention uses a simple method for computing correlation of a PN sequence. Hence, the operation efficiency is enhanced and the time to give the correlation of the PN sequence is shortened. | 12-09-2010 |
| 20100310022 | DATA PROCESSING APPARATUS AND METHOD - A receiver detects and recovers data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including a plurality of sub-carrier symbols formed in the frequency domain and transformed into the time domain for transmission, the time domain OFDM symbols including a guard interval. The guard interval of the OFDM symbols is one of a plurality of predetermined temporal lengths and the guard interval is formed by repeating time domain samples of the OFDM symbol from useful samples of the OFDM symbols for a period corresponding to the guard interval from the OFDM symbols. The receiver includes a correlator operable to correlate the time domain samples at a separation determined in accordance with the useful samples of the OFDM symbols and for each of a plurality of possible guard intervals combining the correlated samples for a period equal to the guard interval, for a plurality of consecutively received OFDM symbols, to form for each of the possible guard intervals a correlation output value, and a guard interval identifier arranged to receive the output from the correlator and to identify one of the guard intervals used for the received OFDM symbols from the correlation output value for each of the plurality of possible guard intervals. Accordingly in a system such as DVB-T2, where the guard interval is provided in signalling data communicated with the OFDM symbols, the guard interval can be detected without or before the signalling data is detected, thereby reducing a time for detecting the data conveyed by the OFDM symbols or the guard interval and/or improving an integrity with which the guard interval and therefore the data can be detected. | 12-09-2010 |
| 20100316171 | DATA PROCESSING APPARATUS AND METHOD, RECEIVING APPARATUS AND METHOD, SYNCHRONOUS DETECTION APPARATUS AND METHOD, AND COMPUTER PROGRAM - A data processing apparatus includes a first correlation operation unit which performs a mutual correlation operation of a first input series and a second input series, a threshold value operation unit which calculates a threshold value based on the first input series, a first comparison unit which compares a first mutual correlation value with the threshold value, a search window setting unit which sets a search window for detecting the second input series to the first input series on the basis of the comparison result, a hard decision unit which performs binarization of the first input series, a second correlation operation unit which performs a mutual correlation operation of a first input hard decision value, and a detection position determining unit which searches for a maximum value of the mutual correlation value within the search window and determines the detection time of the maximum value. | 12-16-2010 |
| 20100329396 | Interference Detector and Method Thereof - An interference detector receives a data stream including predetermined symbols that include a first data and a second data, between which is a frequency offset. The interference detector includes a correlation apparatus that generates a first correlation result and a second correlation result according to the data stream; a power searching unit, coupled to the correlation apparatus, that generates a first maximum correlation result and a first neighboring power according to the first correlation result, and generates a second maximum correlation result and a second neighboring power according to the second correlation result; and a determining unit, coupled to the power searching unit, that generates a determination result according to the first maximum correlation result, the first neighboring power, the second maximum correlation result and the second neighboring power to indicate existence of interferences. | 12-30-2010 |
| 20110002422 | Apparatus for Detecting Digital Video Signal Parameters and Method Thereof - A method for detecting digital video signal parameters detects an integer carrier frequency offset (ICFO), a pilot pattern and a carrier mode of a signal received by an Orthogonal Frequency-Division Multiplexing (OFDM) communication system. The method includes receiving a first OFDM symbol comprising a plurality of first frequency-domain sub-carriers and a second OFDM symbol comprising a plurality of second frequency-domain sub-carriers; generating a plurality of sub-carrier correlation results according to the first frequency-domain sub-carrier and the second frequency-domain sub-carrier; and determining a maximum sub-carrier correlation result from the plurality of sub-carrier correlation results; and outputting an ICFO, a pilot pattern and a carrier mode corresponding to the maximum sub-carrier correlation result. | 01-06-2011 |
| 20110002423 | METHOD AND DEVICE FOR PROCESSING DATA AND COMMUNICATION SYSTEM COMPRISING SUCH DEVICE - A method and a device are provided for data processing. The data contains symbols and a control parameter is determined based on a correlation property of the symbols of the data. In this manner signal recovery is achieved that is robust against any kind of distortion and is fast enough to track time varying clocking disturbances. Further, a communication system is provided containing such a device. | 01-06-2011 |
| 20110013731 | SPECTRUM SENSING FOR DMB-T SYSTEMS USING PN FRAME HEADERS - This dissertation addresses the intersection of personal wireless technology and computational intelligence. The primary research issue addressed is the organization of radio domain knowledge into data structures processable in real-time that integrate machine learning and natural language processing technology into software radio. The thesis defines and develops the cognitive radio architecture. The features needed in the architecture are derived from cognitive radio use cases. These include inferring user communications context, shaping access-network demand, and realizing a protocol for real-time radio spectrum rental. Mathematical foundations for the knowledge-representation architecture are derived by applying point-set topology to the requirements of the use cases. This results in the set-theoretic ontology of radio knowledge defined in the Radio Knowledge Representation Language (RKRL). The mathematical analysis also demonstrates that isochronous radio software is not Turing-computable. Instead, it is constrained to a bounded-recursive subset of the total functions. A rapid-prototype cognitive radio, CR1, was developed to apply these mathematical foundations in a simulated environment. CR1 demonstrated the principles of cognitive radio and focused the research issues. This led to an important contribution of this dissertation, the cognitive radio architecture. This is an open architecture framework for integrating agent-based control, natural language processing, and machine learning technology into software-defined radio platforms. | 01-20-2011 |
| 20110013732 | RECEIVER AND METHOD - A receiver for detecting and recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols. The receiver comprises a demodulator, symbol synchronization unit, frequency transform processor, and coarse frequency offset detector. The demodulator generates sampled symbols. The symbol synchronisation unit has correlators, which receives the sampled symbols, and a correlation detection processor. Each correlator auto correlates each sampled symbol, and the correlation detection processor determines a start point of each symbol. The frequency transform processor receives the sampled symbols and performs a frequency transform on each symbol. The coarse frequency offset detector includes a pilot data filter, which includes taps corresponding to a value and spacing of the pilot pattern of the symbols and arranged to receive as an input the frequency domain symbols from the frequency transform processor, and a coarse frequency offset detect processor, which is arranged to detect a coarse frequency offset output from the pilot data filter. | 01-20-2011 |
| 20110026648 | METHOD AND SYSTEM FOR INCREASING THE ACCURACY OF FREQUENCY OFFSET ESTIMATION IN MULTIPLE FREQUENCY HYPOTHESIS TESTING IN AN E-UTRA/LTE UE RECEIVER - A mobile device receives a radio frequency (RF) signal comprising a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS). The mobile device performs multiple frequency hypothesis (MFH) testing via multiple MFH branches. A PSS correlation process is performed for each MFH branch. Frequency offset for receiving data is estimated using resulting correlation data. A desired offset is placed in each MFH branch. A baseband signal is frequency offset per MFH branch according to the desired frequency offset before the PSS correlation process. A received PSS is detected based on a maximum PSS correlation over the entire set of MFH branches. A frequency offset is estimated for the MFH branch associated with the detected PSS by combining an associated residual frequency with a corresponding desired offset. The frequency offset estimate is used for baseband signal processing and/or adjusting a reference oscillator frequency at the mobile device. | 02-03-2011 |
| 20110026649 | Technique for determining a frequency offset - A technique for determining a frequency offset between components of a communication network based on a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence is described. A method implementation of this technique comprises a provision of a set of correlation signals at different frequencies, with each correlation signal being indicative of a specific frequency offset hypothesis and comprising the CAZAC sequence. Once a synchronization signal comprising the CAZAC sequence is received, this synchronization signal is correlated with each of the correlation signals to obtain a correlation result for each frequency offset hypothesis. In a next step, at least one of the frequency offset hypotheses is selected based on a comparison of the correlation results. The frequency offset may then be determined based on the at least one selected frequency offset hypothesis. | 02-03-2011 |
| 20110038444 | RECEIVING APPARATUS AND RECEIVING METHOD - Disclosed herein is a receiving apparatus including a first correlation value computation section, an operation section, a second correlation value computation section, a decoding section, and a determination section. | 02-17-2011 |
| 20110051862 | METHODS AND APPARATUS FOR OFDM SYMBOL SYNCHRONIZATION FOR IN-DOOR DIGITAL TV RECEPTION - A received signal comprises a continuous sequence of symbols φ | 03-03-2011 |
| 20110051863 | CHANNEL ESTIMATOR - The channel estimator includes a plurality of correlating sections configured to calculate a plurality of time correlation values between the signal and a plurality of known pattern signals having different code lengths, an analyzing section configured to output a control signal representing a selected period for extracting a preferable correlation output from the output from each of the plurality of correlating sections, and a delay profile generating section configured to output a delay profile obtained by adaptively selecting or combining parts of the outputs from the plurality of correlating sections based on the output from the analyzing section. | 03-03-2011 |
| 20110090995 | SIMULTANEOUS CELL GROUP AND CYCLIC PREFIX DETECTION METHOD, APPARATUS AND SYSTEM - A method, and associated apparatus and system, for simultaneous cell group and cyclic prefix (CP) detection, having the steps of determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the S-SyS signal; and detecting the cell group and CP length by the correlation giving maximum energy. | 04-21-2011 |
| 20110096875 | Adaptive Digital Baseband Receiver - An adaptive digital baseband receiver is described in which operating parameters of the receiver, such as bit-widths and operating frequencies, are determined that achieve a target bit-error-ratio (BER) as a function of received signal-to-noise ratio (SNR) and interference levels in a wireless channel and enable the receiver to consume a minimum amount of power. Over consumption of power may be avoided due to a functional relationship between optimal resolution and input signal conditions. In exemplary embodiments, the adaptive digital receiver is provided that adjusts bit-widths and operating frequency at power efficient levels while meeting a target BER. Simulations can be used to determine a relation between bit-width, operating frequency, and input signal conditions, for example. | 04-28-2011 |
| 20110110470 | FRAME BOUNDARY DETECTION - A method of WLAN frame detection in a received signal, wherein the frame comprises first and second training sequences and the method comprises auto-correlating the signal with a delayed version of itself to establish a first frame boundary estimate based on behaviour of the autocorrelation result due to the inclusion of the first training sequence in the frame, cross-correlating the signal with a copy of the second training sequence at a range of time offsets in order to generate a first cross-correlation profile, classifying the first cross-correlation profile into one of a number of categories, establishing a second frame boundary estimate from the first cross-correlation profile in a manner dependent upon the category assigned to the first cross-correlation profile and determining a refined frame boundary estimate on the basis of a consideration of the first and second frame boundary estimates. Apparatus for performing the method is also described. | 05-12-2011 |
| 20110142182 | MATCHED FILTER CIRCUIT APPARATUS IN THE BASE BAND PROCESS SYSTEM OF THE TERMINAL DEVICE AND METHOD THEREOF - The present invention discloses a matched filtering circuit apparatus in the baseband processing system of the terminal device and method thereof. The circuit apparatus comprises a control unit for controlling the processing procedures of de-scrambling, de-spreading, de-rotating and maximal ratio combining data, the output ports of the control unit connects with a V vector buffer unit, a shift integral selection unit and a coherent integral unit for implementing the matched filtering and data buffer. Due to the application of entirely pipeline design structure, the processes of data buffer and matched filtering can be carried out simultaneously, thus shortening time consumption of the terminal hardware accelerator and effectively improving the operation efficiency of the mobile communication terminal hardware system. | 06-16-2011 |
| 20110150148 | APPARATUS AND METHOD FOR DETECTING SIGNAL IN WIRELESS COMMUNICATION SYSTEM - The apparatus includes a radio frequency (RF) unit configured to arrange a plurality of symbols received through an antenna at a frequency domain, an analog to digital (AD) converter configured to converts the plurality of symbols arranged at the frequency domain to digital symbols, a fast Fourier transform (FFT) unit configured to transform the digital symbols through a fast Fourier transform scheme, a compensator configured to compensate a gain mismatch between an I-channel and a Q-channel of the transformed digital symbols, a mapping unit configured to the compensated digital symbols to a constellation diagram, and a detector configured to correlate the mapped symbols, extract correlation results, and detect a high throughput (HT) signal using the extracted correlation results. | 06-23-2011 |
| 20110150149 | APPARATUS AND METHOD FOR DETECTING PACKET END POINT IN WIRELESS COMMUNICATION SYSTEM - An apparatus for detecting a packet end point in a wireless communication system includes: a signal reception unit configured to receive a signal from an outside, convert the signal into a baseband signal, perform analog-digital conversion of the baseband signal, and perform a digital front end; a storage unit configured to store an output of the signal reception unit; a frequency offset estimation unit configured to estimate a frequency offset using the output of the storage unit; a frequency offset correction unit configured to compensate for a frequency error using the estimated frequency offset; an offset correlation unit configured to calculate correlation of the frequency offset and a cyclic prefix; an auto-correlation operation unit configured to calculate auto-correlation of the cyclic prefix; and a packet end detection unit configured to check a packet end point using the auto-correlation. | 06-23-2011 |
| 20110150150 | DEVICE AND METHOD FOR DETECTING TIMING SYNCHRONIZATION - A timing synchronous detection device includes: a first autocorrelator that performs autocorrelation using a received signal and a first delay signal in which the received signal is delayed; a second autocorrelator that performs autocorrelation using the received signal and a second delay signal in which the received signal is delayed; an average-normalization device that obtains an average value of an output signal of the first autocorrelator and an output signal of the second autocorrelator; a comparator that compares the average value and a threshold value and that outputs, if the average value is larger than the threshold value, the average value; and a maximum value search device that searches for a maximum value of the average values that are output from the comparator. | 06-23-2011 |
| 20110164708 | SYMBOL TIMING METHODS AND APPARATUSES USING THE SAME IN MULTI-CARRIER RECEIVING SYSTEMS - A symbol timing method for a multi-carrier system is provided, including: receiving an input symbol; executing a correlation operation by using a first summation window with a size smaller than a duplicated data to generate a first characteristic signal; determining a first search region according to a first predetermined threshold and the first characteristic signal and searching a local peak value in the first search region; locating a right edge point of the first characteristic signal according to a difference value and the local peak value; obtaining a coarse symbol timing position for a following input symbol according to a predetermined movement and the right edge point; and outputting the coarse symbol timing position to a signal transformation module, wherein signal transformation is executed by the signal transformation module according to the coarse symbol timing position. | 07-07-2011 |
| 20110200150 | WIDEBAND COMMUNICATION FOR BODY-COUPLED COMMUNICATION SYSTEMS - The present invention relates to a communication apparatus, method and computer program product for providing a reception approach in a body-coupled communication system with a switch-based filtering in order to remove low frequency interference without attenuating the wanted digital signal, and a receiver structure that makes use of correlation for both data detection and synchronization in order to suppress the uncorrelated interference without attenuating the wanted signal. | 08-18-2011 |
| 20110249776 | METHOD FOR DETERMINING AS TO WHETHER A RECEIVED SIGNAL INCLUDES A DATA SIGNAL - A method of determining as to whether a received signal includes a data signal is provided. The method provided includes determining a first value based on a cyclic auto-correlation of the received signal and determining a second value based on the cyclic auto-correlation of the received signal. The method provided further includes determining as to whether a received signal includes a data signal based on a comparison of the first value and the second value. | 10-13-2011 |
| 20110249777 | FRAME SYNCHRONIZATION APPARATUS AND METHOD BASED ON DIFFERENTIAL CORRELATION IN COMMUNICATION SYSTEM - A frame synchronization apparatus and method based on differential correlation in a communication system are provided. A correlation analysis is performed by using sync word in a prior search window and a posterior search window for obtaining a plurality of prior-window correlation values and a plurality of posterior-window correlation values, respectively. N maximum correlation values in the correlation values are selected, wherein indexes of the maximum correlation values are I | 10-13-2011 |
| 20110249778 | METHOD AND APPARATUS FOR PACKET DETECTION VIA CROSS-CORRELATION IN THE PRESENCE OF FREQUENCY OFFSET - An apparatus and method for packet detection using cross-correlation in the presence of frequency offset. The method comprises: segmenting a received signal; and cross-correlating each segment with an expected signal. The apparatus comprises a slicer that segments a received signal; and a cross correlator that cross-correlates each segment with an expected signal. | 10-13-2011 |
| 20110255641 | Receiver for Voice Services Over Adaptive Multi-User channels on One Slot - A receiver, in particular a VAMOS receiver, is provided. The receiver is adapted to split the complex-valued baseband signal into its real and imaginary parts. The two branch system thus created is modeled as a real-valued Multiple Input Multiple Output, MIMO, system. The receiver is further adapted to use correlations of the noise, both in time and between branches of a channel to suppress the noise for multi-users in the same channel. In accordance with one embodiment the receiver is adapted to take into account the known symmetries present in a symbol constellation when more than one user exists in the same channel. This is for example the case in adaptive symbol constellation such as an adaptive alpha-QPSK constellation. Using the receiver in accordance with the above can provide the same performance as a joint detection receiver in the presence of Gaussian white noise, while giving better interference suppression than either SAIC or joint detection in the presence of GMSK modulated interference. | 10-20-2011 |
| 20110280348 | Method and Apparatus for Coding Acquisition - The present invention relates to a method and apparatus for code acquisition. The present invention performs variable delay correlation to obtain the peak correlation result which is immune to carrier frequency offset and Doppler. The present invention makes use of a mapping parameter which is immune to sampling frequency offset. In particular, the present invention is applicable to the DTMB standard. | 11-17-2011 |
| 20110286555 | METHOD AND APPARATUS FOR DETECTING PRESENCE OF SIGNAL IN WIRELESS COMMUNICATION SYSTEM BASED ON CR TECHNOLOGY - The present invention relates to a method of detecting the presence of a transmission signal of a transmitter in a reception signal in a wireless communication system based on CR technology. The method includes generating a frequency signal vector using a Fourier transform and a reception signal vector obtained by sampling the reception signal at a certain period, finding an eigenvalue and an eigenvector regarding a matrix, obtaining by approximating a covariance matrix of the frequency signal vector using a vectorized Fourier transform result of all channel impulse responses of the transmission signal linearly modulated, calculating a sufficient statistic on a basis of the frequency signal vector, the eigenvalue, and the eigenvector, finding a threshold which is a criterion for determining signal presence detection on a basis of a preset detection probability or a preset false alarm probability and the eigenvalue, and if the sufficient statistic is determined to be greater than the threshold, determining that the transmission signal exists. | 11-24-2011 |
| 20110286556 | ACQUISITION OF TIMING INFORMATION IN WIRELESS COMMUNICATION SYSTEMS - A method for identifying a reference point in time in a wireless communication system includes: receiving a first repeated sequence of symbols; receiving a second repeated sequence of symbols; performing an autocorrelation between the first and second sequences of symbols; and identifying as the reference point in time an autocorrelation null between the first and second repeated sequences of symbols. Apparatus for identifying a reference point in time in a wireless communication system includes: means for receiving a first repeated sequence of symbols; means for receiving a second repeated sequence of symbols; means for performing an autocorrelation between the first and second sequences of symbols; and means for identifying as the reference point in time an autocorrelation null between the first and second repeated sequences of symbols. Other aspects, features, and embodiments are also claimed and described. | 11-24-2011 |
| 20110299638 | LOGARITHMIC DETECTOR AND METHOD OF PRE-CHARGING AN AVERAGE FILTER ON A LOGARITHMIC DETECTOR - The detector comprises a plurality of detection stages connected to a summator for providing a summation signal as a logarithmic representation of the input signal to a first input of a data slicer and an input of an average filter having an output connected to a second input of the data slicer. The data slicer has a data slicer output for providing an extracted digital data signal in dependence on a comparison of the summation signal and an output signal of the average filter. The average filter receives a first pre-charge voltage and a second pre-charge voltage depending on an output signal of a carrier detector circuit detecting a carrier signal of the input signal. | 12-08-2011 |
| 20110305304 | Signal Reception - A method of receiving a demodulated waveform according to a protocol in which the waveform represents a block of transmitted bits comprising a first group of bits and a second group of bits, the second group of bits being a function of the first group of bits, the method comprising: sampling the demodulated waveform to recover a first group of sample values corresponding to the first group of transmitted bits and a second group of sample values corresponding to the second group of transmitted bits; assigning bit values to reliable sample values of the first group of sample values; generating a set of candidates for a block of bits corresponding to the demodulated waveform, each candidate comprising a first group of candidate bits and a second group of candidate bits, the first group of candidate bits being generated using the assigned bit values and a combination of bit values unique to that candidate in the set of candidates, and the second group of candidate bits being generated by applying the said function to the first group of candidate bits; performing a correlation operation by determining a correlation between each candidate and the recovered first and second groups of sample values to form a correlation value associated with each candidate; and selecting the candidate associated with the correlation value that is indicative of the strongest degree of correlation between a candidate and the first and second groups of sample values to be the block of bits corresponding to the demodulated waveform. | 12-15-2011 |
| 20110317792 | TIMING SYNCHRONIZATION METHOD AND APPARATUS IN A WIRELESS COMMUNICATION SYSTEM - Provided are a timing synchronization method and apparatus in a wireless communication system that may synchronize timing based on channel energy having a low Signal to Noise Ratio (SNR) in a wideband (WB) system. The timing synchronization apparatus in the wireless communication system may capture optimal channel energy by performing a comparison using a timing estimation scheme based on a correlation peak. | 12-29-2011 |
| 20120002762 | SINGLE OR DUAL COMPLEX SUBCARRIER DOWNCONVERSION - A method for subcarrier downconversion and data detection according to one embodiment includes determining whether to use an upper sideband frequency section of a complex downconverter output, a lower sideband frequency section of the complex downconverter output, or both sideband frequency sections of the complex downconverter output; and processing the output corresponding to the selected sideband frequency section or sections based on the determination, wherein the processing includes correlation and data detection. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
| 20120002763 | HALF BIT CORRELATOR COMBINING FOR DATA DEMODULATION - A method for demodulating a data signal according to one embodiment includes processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. A system for demodulating a data signal according to one embodiment includes a correlator module having logic for: processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. Additional systems and methods are also presented. | 01-05-2012 |
| 20120020439 | RECEIVER WITH CHANNEL ESTIMATION CIRCUITRY - The invention concerns receive circuitry for demodulating an input signal received from a transmission channel, the receive circuitry including a frequency interpolation filter arranged to provide channel estimations (Ĥn) of the entire channel, the frequency interpolation filter having at least one filter receiving the pilot frequency channel estimations and performing filtering based on a plurality (Q) of the pilot channel estimations at a time; and a memory arranged to store the filter coefficients for the at least one filter, the coefficients being based on a frequency-domain autocorrelation of a model of the transmission channel, the model representing the time distribution of the channel power of the transmission channel determined independently of the pilot frequency channel estimations, wherein said model is based on a χ | 01-26-2012 |
| 20120020440 | METHOD AND DEVICE FOR DETERMINING SMOOTH WINDOW LENGTH IN CHANNEL ESTIMATION - A method and a device for determining a smooth window length in channel estimation is provided. The method includes: obtaining autocorrelation values of pilot signals, where the autocorrelation values include first autocorrelation values and second autocorrelation values, at least two first autocorrelation values exist, and at least one second autocorrelation value exists; determining a speed range according to symbols of the first autocorrelation values or the symbols of the first autocorrelation values and a ratio value between the second autocorrelation value and one of the first autocorrelation values; and determining the smooth window length according to the speed range. Through the method provided in embodiments of the present invention, the problems caused by a fixed smooth window length may be avoided, and this improves system performance. | 01-26-2012 |
| 20120027135 | SYSTEM AND METHOD FOR SYNCHRONIZATION TRACKING IN AN IN-BAND MODEM - Processing the synchronization of an inband modem to detect sample slip conditions is disclosed. Decision logic reliably detects the sample slip condition while minimizing the number of false alarms. | 02-02-2012 |
| 20120027136 | SYSTEM ACCESS AND SYNCHRONIZATION METHODS FOR MIMO OFDM COMMUNICATIONS SYSTEMS AND PHYSICAL LAYER PACKET AND PREAMBLE DESIGN - A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame. | 02-02-2012 |
| 20120033768 | NON-COHERENT DETECTION APPARATUS AND METHOD FOR IEEE 802.15.4 LR-WPAN BPSK RECEIVER - A non-coherent detection apparatus and method for an IEEE | 02-09-2012 |
| 20120039424 | Receiver and Method for the Reception of a Node by a Receiver in a Wireless Network - In one embodiment, a method includes receiving a radio frequency (RF) signal; synchronizing the received RF signal with a preamble to determine a time base; determining a first energy value of the received RF signal by averaging received signal strength indication (RSSI) values of the received RF signal over a first period of time; determining a second energy value of the received RF signal over a second period of time; determining a difference value between the first energy value and the second energy value; comparing the difference value with a predetermined energy threshold value; determining a quality value of the received RF signal; comparing the quality value of the received RF signal with a predetermined quality threshold value; and, if the difference value exceeds the predetermined energy threshold value or the quality value is below the predetermined quality threshold value, then erasing the time base. | 02-16-2012 |
| 20120045025 | DIVERSITY RECEPTION DEVICE AND DIVERSITY RECEPTION METHOD - A diversity reception device includes branches, a controller and a combining section. Each branch includes a correlation section that generates a correlation signal that represents a correlation between a received signal and a delayed signal or between the received signal and a reference signal, where the correlation signal level disregarding the received signal level, a time position detector that detects time positions at which the level of the correlation signal is at a peak, a demodulation section that demodulates the received signal, and a multiplication section that multiplies the demodulated signal with a weighting factor. The controller controls the weighting factor on the basis of the respective levels of the correlation signals at the detected time positions. The combining section combines, by adding, the respective demodulated signals of the branches subsequent to the demodulated signal of each branch being multiplied with the weighting factor. | 02-23-2012 |
| 20120057662 | BIT CHANGE DETERMINATION METHOD AND BIT CHANGE DETERMINATION DEVICE - A bit change determination method includes performing a correlation operation of a signal received from a satellite and a replica code, segmenting the signal using a bit transition timing of navigation message data and performing a first calculation to calculate the result of the correlation operation for a first period having N (N≧1) continuous unit periods with a bit period of navigation message data as a unit period, performing a second calculation to calculate the result of the correlation operation for a second period having M (M>1) continuous unit periods adjacent to the first period, and determining whether a bit value changes or not at a boundary between the first period and the second period using the first and second calculation results. | 03-08-2012 |
| 20120057663 | Terminal State Management in a Telecommunications Network - A signal transmitted in a radio telecommunications network is received ( | 03-08-2012 |
| 20120057664 | METHOD AND APPARATUS FOR SYMBOL TIMING RECOVERY - Methods and apparatus for symbol timing recovery are provided. Both a coarse symbol timing recovery method and apparatus, and a fine symbol timing recovery method and apparatus are described which can be used jointly for symbol recovery, for example in phase shift keying receivers. The coarse method involves the use of differential correlations and finding the time difference in peak values of the correlation results. The fine method involves interpolation of a received digital signal, followed by filtering and timing error detection. The error detection signal is further filtered and used to control the interpolator. The methods provide for robust symbol timing synchronization. | 03-08-2012 |
| 20120082271 | DETECTING DIGITAL RADIO SIGNALS - In one embodiment, a receiver front end circuit can receive and process multiple radio frequency (RF) signals and output downconverted signals corresponding to these signals. In turn, multiple signal processors can be coupled to this front end. Specifically, a first signal processor can receive and process the downconverted signals to output a first signal obtained from content of a first RF signal, and a second signal processor can receive and process the downconverted signals to output a second signal obtained from content of a second RF signal. In addition, the apparatus may include a detection circuit coupled to the receiver front end circuit to detect presence of at least the second signal and enable the second signal processor responsive to the detected presence. | 04-05-2012 |
| 20120087447 | APPARATUS AND METHOD FOR ESTIMATING HIGH SPEED FREQUENCY OFFSET IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method estimate a high speed frequency offset in a wireless communication system. The apparatus includes a correlator, an accumulator, a phase calculator, and a frequency offset coupler. The correlator performs a first correlation and a second correlation based on a first reference signal and a second reference signal. The accumulator accumulates results of the correlations. The phase calculator calculates a first phase and a second phase from the accumulated first correlation value and the accumulated second correlation value. The frequency offset coupler determines whether a frequency offset deviates from a frequency offset estimate range based on a difference between the first phase and the second phase, and compensates the frequency offset according to the determination result. The apparatus can estimate a frequency offset within an error allowable range under an environment where a terminal moves at high speed. | 04-12-2012 |
| 20120087448 | SYSTEM AND METHOD FOR ACQUISITION OF SIGNALS - A system for processing a received signal having at least one code applied thereto, the received signal having a frequency, the system comprising: first correlator circuitry arranged to correlate the received signal with a first code to provide an output; second correlator circuitry arranged to correlate the received signal with a second code to provide an output, wherein the first code and the second code are different; and processor for processing together the outputs of the first and second correlator circuitry to cancel the frequency. | 04-12-2012 |
| 20120093267 | Method for Unifying Secondary Synchronization Signal Detection and Frame Timing Synchronization - A method for joint secondary synchronization signal detection and frame timing synchronization includes: (1) generating local secondary synchronization sequences SSC | 04-19-2012 |
| 20120099681 | RECEPTION APPARATUS, RECEPTION METHOD, AND PROGRAM - A reception apparatus is disclosed which includes: a detection section configured to detect the presence or absence of spectrum inversion in data transmitted by a multi-carrier transmission system based on whether a known signal can be decoded using that part of the transmitted data which has been transmitted by carriers used for transmitting the known signal; and a correction section configured to correct the data transmitted by the multi-carrier transmission system if the presence of spectrum inversion is detected. | 04-26-2012 |
| 20120099682 | DIVERSITY RECEPTION DEVICE - A diversity reception device includes a power combiner to combine electric powers of OFDM signals, each OFDM signal being received by a first antenna and second antenna, a switch to change connections between branched output-ports of the first and second antennas, in mid-stream of effective symbol periods, the effective symbol periods are assigned respectively in each of symbol periods of the OFDM signals, a receiver to demodulate the OFDM signals, a phase shifter to shift phases of the OFDM signals received by the second antenna, and an arithmetic and control processing circuit to calculate complex correlation coefficient between a guard interval, assigned in each of the symbol periods associated with the first antenna, and a copy-source interval, assigned in each of the symbol periods associated with the second antenna, and to determine rotation angle on the basis of the complex correlation coefficient. | 04-26-2012 |
| 20120114082 | MOBILE WIRELESS TERMINAL DEVICE AND BASE STATION SEARCH METHOD - According to one embodiment, a mobile wireless terminal device includes a receiver detecting a beacon and a communication module detecting a base station identification. The receiver comprises an accumulation module accumulating levels of a sampling received wireless signal to obtain a reception profile, a correlation module detecting a shift amount maximizing a correlation between a present reception profile and a past reception profile, a first detector detecting a beacon, when a difference between the detected shift amount and a default amount is larger than a predetermined amount, in accordance with a difference between a shifted profile by the default amount, and the present reception profile, and a second detector which detects a beacon, when the difference is not larger than the predetermined amount, in accordance with a difference between a shifted profile by the detected shift amount, and the present reception profile. | 05-10-2012 |
| 20120121048 | MULTI-ANTENNA CHANNEL ESTIMATION METHOD BASED ON POLYPHASE DECOMPOSITION - A multi-antenna channel estimation method based on polyphase decomposition includes: receiving frequency domain received signals transformed using discrete fourier transformation (DFT) in pilot symbols; performing phase correction on the frequency domain received signals; performing polyphase decomposition on the frequency domain received signals which are corrected using phase correction and acquiring polyphase signals; performing interpolation on the polyphase signals and acquiring the estimation values of the multi-antenna channel parameters with various linear combinations on each frequency; acquiring decorrelation array based on the pilot structure of the transmission antenna and decorrelating the estimation values of the multi-antenna channel parameters with various linear combination on each frequency using the decorrelation array and acquiring channel parameters of the pilot symbols on each frequency; acquiring channel parameters of data symbols based on the channel parameters of the pilot symbols. With the present invention, the inversion problem in multi-antenna channel estimation is avoided with lower complexity, and results of the multi-antenna channel estimation method become more accurate since the DFT and filtering are performed in the interpolation after polyphase decomposition. | 05-17-2012 |
| 20120128106 | RECEPTION CIRCUIT - A reception circuit is provided which can detect the beginning of data regardless of a preamble or a unique word contained or not in a received signal and regardless of coding systems for received signals. The reception circuit includes a correlation operation portion that performs a correlation operation to generate a correlation signal while sliding one symbol of reference signal in relation to a received signal. The reference signal goes to a high level during a first half symbol period and goes to a low level during a second half symbol period. The reception circuit further includes: a delay portion that outputs a delay signal by delaying the reference signal for a half symbol period in relation to the received signal; and a data beginning timing detection portion that detects a beginning peak timing for the correlation signal as a beginning timing of data contained in the delay signal. | 05-24-2012 |
| 20120134454 | APPARATUS, AND ASSOCIATED METHOD, FOR FILTERING A RECEIVE SIGNAL BY ADAPTIVE OPERATION OF AN INPUT NOISE WHITENING FILTER - Apparatus, and an associated method, for the receive part of a receiving station, such as a mobile station or other transceiver of a cellular communication system. Selection is made of filter characteristics to be exhibited by an adaptive, input noise whitening filter. A noise estimator estimates a noise component of a noise sequence. An autocorrelation estimator estimates the noise-component autocorrelation. A determination is made as to whether the autocorrelation exceeds a threshold. If so, filter characteristics are selected to cause the input noise whitening filter to operate to inject whitening noise into the received sequence. | 05-31-2012 |
| 20120140858 | FINE SYMBOL TIMING ESTIMATION - Systems and methods for fine symbol timing estimation are disclosed herein. In one embodiment, a wireless receiver includes a differential detector, a correlator, a coarse symbol timing estimator, and a fine symbol timing estimator. The differential detector is configured to detect phase differences in a received preamble signal modulated using differential phase shift keying. The correlator is configured to correlate symbol values output by the differential detector against a reference sequence. The coarse symbol timing estimator is configured to generate a coarse symbol timing estimate, and to generate a coarse timing sample symbol index value corresponding to the coarse symbol timing estimate. The fine symbol timing estimator is configured to generate a fine symbol timing estimate that is more accurate than the coarse symbol timing estimate based on the coarse timing sample symbol index value and correlation samples at index values preceding and succeeding the coarse timing sample index value. | 06-07-2012 |
| 20120163514 | PREAMBLE DETECTION AT LOW SIGNAL-TO-NOISE LEVELS - A preamble detector has a correlator outputting for every sample position of the preamble part of an incoming sampled signal stream a score and associated class value; and a multiple cluster unit receiving the class and score output values from the correlator, wherein a first cluster receives output values from the correlator and the following clusters are coupled in series such that each cluster receives output values from the correlator and a preceding cluster and wherein the output values of the correlator and a cluster are processed such that an n-th cluster of the multiple cluster unit, with n>1, accumulates the highest score values of n score values with matching class values. | 06-28-2012 |
| 20120163515 | DEFINING ADAPTIVE DETECTION THRESHOLDS - A wireless device ( | 06-28-2012 |
| 20120177155 | APPARATUS AND METHOD FOR RECEIVING DATA IN COMMUNICATION SYSTEM - Disclosed is an apparatus for receiving data in a communication system, including a receiving unit configured to receive data through a multi-channel in a MIMO (multi-input multi-output) scheme; a calculating unit configured to calculate a receiving power distribution value in each antenna of a multi-antenna and in each channel of the multi-channel, correspondingly to the MIMO scheme, and to generate a receiving synchronization signal using the receiving power distribution value; and a synchronization unit configured to synchronize frames for the data receiving of the receiving unit using the receiving synchronization signal. | 07-12-2012 |
| 20120177156 | CLOCK RECOVERY APPARATUS - The invention relates to a clock recovery apparatus being configured to recover clock information from an input signal. The clock recovery apparatus comprises Fourier transforming means ( | 07-12-2012 |
| 20120201335 | START-UP AUTOMATIC FREQUENCY CONTROL (AFC) METHOD AND APPARATUS - A method and apparatus for use in connection with wireless communication to adjust the frequency of an oscillator to synchronize with a received signal by correlating a synchronization code channel with training sequences to estimate relative offsets which are employed to estimate an error, which is then filtered. The filtered output preferably provides a voltage controlling a voltage controlled oscillator (VCO). The same technique may be employed to control a numeric controlled oscillator (NCO). | 08-09-2012 |
| 20120207253 | METHOD AND APPARATUS FOR PERFORMING CHANNEL ESTIMATION IN A WIRELESS COMMUNICATION SYSTEM - A method and apparatus for performing channel estimation in a wireless communication system, in which a channel estimate of each pilot tone included in adjacent first and second resource allocation blocks is calculated. Channel estimates of first pilot tones are detected, which have a predetermined subcarrier spacing or less from the second resource allocation block, channel estimates of second pilot tones are detected; and which have a predetermined subcarrier spacing or less from the first resource allocation block. The channel estimates of the first and second pilot tones are updated, and channel estimation is then performed using the updated channel estimates. | 08-16-2012 |
| 20120207254 | APPARATUS AND METHOD FOR MMSE CHANNEL ESTIMATION IN CONSIDERATION OF OFFSET COMPENSATION IN WIRELESS COMMUNICATION SYSTEM - A channel estimation method of a channel estimation apparatus in a wireless communication system is provided. The method includes predefining a plurality of weight tables about at least one of a speed and a Carrier to Interference-and-Noise Ratio (CINR) using a correlation value considering offset compensation; selecting a weight table to be used for channel estimation based on at least one of the estimated speed and the CINR, from the plurality of weight tables; and multiplying a pilot channel estimation value and the selected weight table, and performing data channel estimation. | 08-16-2012 |
| 20120213315 | PROCESS FOR ESTIMATING THE CHANNEL IN A OFDM COMMUNICATION SYSTEM, AND RECEIVER FOR DOING THE SAME - MIMO receiver for processing N data streams received by N antennas for a direct-sequence (DS) spread-spectrum wireless communication system comprising:
| 08-23-2012 |
| 20120213316 | PREAMBLE DETECTION WITH UNKNOWN CHANNEL - A system comprises a correlation module that correlates modulated signals with a plurality of preamble sequences and that generates correlation values. A control module selects a largest correlation value from said correlation values and detects one of said preamble sequences in said modulated signals upon determining that a magnitude of said largest correlation value is greater than or equal to a first predetermined threshold. | 08-23-2012 |
| 20120219098 | CONTROLLABLE FILTER TO DIAGONALIZE A TRANSMISSION CHANNEL - The present invention relates to a node ( | 08-30-2012 |
| 20120230453 | CHANNEL ESTIMATION AND SYMBOL BOUNDARY DETECTION METHOD - A channel estimation method for use with a received signal by a receiver is disclosed. The received signal comprises multiple data bursts which are transmitted to the receiver via multiple path channels, with each of the data bursts having a plurality of preamble symbols which are decoded. The channel estimation method includes the following steps: firstly, at least one correlation pattern is generated according to the decoded preamble symbols. Then, a cross correlation of the correlation pattern with the received signal is performed to yield at least one correlation result of channel impulse response (CIR). Wherein, the symbol boundary of the received signal is decided according to the correlation result. | 09-13-2012 |
| 20120243645 | DIGITAL RECEIVER FOR REACTIVE RADIO - A digital receiver is disclosed. In one aspect, the receiver includes a receiving module for receiving packetized data. The receive may further include a first processing module for packet detection having a first programmable processor. The receiver may further include a second processing module for demodulation and packet decoding having a second programmable processor. The receiver may further include a first digital receive controller having a third processor arranged for being notified of detection of data by the first processing module and for activating the second processing module. | 09-27-2012 |
| 20120250806 | NON-PARAMETRIC UPLINK INTERFERENCE CANCELLATION - Aspects of an apparatus and method of wireless communication include detecting, by a base node, at least one path of a transmission corresponding to received samples from a user equipment. Further, the aspects include assigning a bank of correlators around the detected at least one path, and estimating a composite channel impulse response at an output of each correlator of the bank of correlators. Further, the aspects include refining noisy channel estimates, and reconstructing a received signal from the user equipment based on the refined noisy channel estimate of the composite channel impulse response. Additionally, the aspects include canceling the reconstructed received signal from the received samples | 10-04-2012 |
| 20120250807 | SCHEMES FOR DETECTING GUARD INTERVALS IN OFDM SYSTEM - A receiver and method of detecting a guard interval estimate accurately by performing an Nth order polynomial based non-linear quantization on a pre-estimated guard interval in a received Orthogonal Frequency Division Multiplexing (OFDM) signal in a receiver is provided. The pre-estimated guard interval is obtained by performing normalized auto-correlation on the received OFDM signal. The method includes (i) performing a rounding operation on (a) one or more m | 10-04-2012 |
| 20120275550 | METHOD FOR DETECTING S-SCH IN CELL SEARCHING AND RECEIVER USING THE SAME - Disclosed is a method for detecting S-SCH in cell searching including: detecting an m0 value corresponding to an even index in a secondary synchronization channel (S-SCH) signal having an even index; determining an m1 group defined by the m0 value; detecting an m1 value using correlation detection relation within the m1 group; and detecting a group ID using the m0 value and the m1 value. | 11-01-2012 |
| 20120275551 | Correlation Computation Method, Device and System - An aspect of the invention is a signal processing method for correlation computation between received signal samples, code replica and carrier replica. The method is characterized in that the method comprises steps of: mapping ( | 11-01-2012 |
| 20120281791 | FREQUENCY CORRECTION CIRCUIT, RADIO RECEIVING APPARATUS, AND FREQUENCY CORRECTION METHOD - A radio receiving apparatus according to the present invention receives a preamble signal through one frequency band and also detects a periodic symbol timing in a receiving period of a part of a symbol that composes the preamble signal. A frequency correction circuit includes a generating unit, a detecting unit, and a correction unit. The generating unit generates a detection window of a predetermined time width including each of a first and a second symbol timing that are previously determined among the periodic symbol timings in the receiving period of a remaining symbol that composes the preamble signal. The detecting unit sequentially receives a correlation value between the preamble signal and a reference signal and detects a maximum value from the correlation value input during a period when the detection window is opened. The correction unit corrects a frequency deviation of the one frequency band based on the maximum value. | 11-08-2012 |
| 20120281792 | METHOD AND SYSTEM FOR GENERATING TIMED EVENTS IN A RADIO FRAME IN AN E-UTRA/LTE UE RECEIVER - A mobile device coupled to a common system clock receives a signal comprising a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS) in a radio frame. Sample counts are generated for timed events based on corresponding operating bandwidths. The timed events are detected at modulo sample counts of the generated sample counts according to corresponding operating bandwidths. PSS symbol timing determined via the PSS synchronization is aligned to the generated sample counts based on corresponding operating bandwidth. The generated sample counts are bit-shifted relative to the aligned PSS symbol timing for other timed events based on corresponding operating bandwidths. The one or more timed events are determined via performing modulo counting after the bit-shifting. Timing operations are performed at the determined timed events and the determined one or more timed events are refined, accordingly. | 11-08-2012 |
| 20120288040 | Method and Device for Implementing Automatic Frequency Control - The present invention discloses a method and apparatus for implementing automatic frequency control. The method comprises: calculating a correlation value of common pilot symbols in a reception signal of each path and a frequency offset value, calculating a combined frequency offset value according to the frequency offset value of each path, and determining, according to the combined frequency offset value, a frequency offset adjustment value for a voltage controlled oscillator, a frequency offset adjustment value for overall reception signals and a frequency offset adjustment value for the reception signal of each path. Compared with prior art, with the method and apparatus of the present invention, a new method of small-scope frequency offset estimation is selected, which makes frequency offset estimation more accurate; by using CORDIC, hardware resources are saved and calculation accuracy is improved; the stability of system is enhanced by the frequency offset adjustment and control policy. | 11-15-2012 |
| 20120288041 | Method And Apparatus For Frequency Tracking In A Space Time Transmit Diversity Receiver - A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function. | 11-15-2012 |
| 20120294396 | Direct detection of wireless interferers in a communication device for multiple modulation types - Direct detection of wireless interferers in a communication device for multiple modulation types. One or more radios implemented within a communication device is/are operative to receive and process wireless communications. A wireless communication signal is processed to extract symbols there from. Various symbols groups are processed in accordance with correlation processing to identify potential interferers (e.g., other communication devices using common portions of frequency spectra). Alternatively, matched filter processing (e.g., using a Barker matched filter in some embodiments) operates on the various symbol groups to identify some potential interferers. Various combinations of correlation processing and matched filter processing may be employed in other instances (e.g., using any of a desired means of comparison, combining, etc.) in considering interferers identified in accordance with each of these two means. Also, re-identification and re-characterization of possible interferers may be performed subsequently to remove or re-admit frequency spectra for use in communications. | 11-22-2012 |
| 20120294397 | DELAY DETECTOR CIRCUIT AND RECEIVER APPARATUS - The present invention provides a delay detector circuit that delivers performance at low cost and can reduce power consumption, and a receiver apparatus that uses this delay detector circuit. The delay detector circuit according to the present invention performs a part of the decoding processing for decoding data transmitted by a transmitter apparatus based on a received wave. The receiver apparatus according to the present invention uses the delay detector circuit described above. Therefore the delay detector circuit and receiver apparatus of the present invention deliver performance at low cost and can reduce power consumption. | 11-22-2012 |
| 20120328057 | METHOD AND APPARATUS FOR IMPLEMENTING SIGNAL QUALITY METRICS AND ANTENNA DIVERSITY SWITCHING CONTROL - A method for detecting the digital quality of a radio signal includes: receiving a radio signal including a digital portion modulated by a series of symbols each including a plurality of samples; computing correlation points between endpoint samples in cyclic prefix regions of adjacent symbols; and using the correlation points to produce a digital signal quality metric. Receivers that implement the method are also provided. | 12-27-2012 |
| 20130022157 | DIGITAL FRONT-END CIRCUIT AND METHOD FOR USING THE SAME - A digital front-end circuit is disclosed. In one aspect, the circuit includes a filtering block for filtering received data. The filtering block has a first filter branch for filtering the received data in a first frequency band and a second filter branch for filtering the received data in a selected second frequency band. The second filter branch is in parallel with the first filter branch, is programmable and includes a block for resampling the received data. The front-end circuit also includes a circuit for performing synchronization and spectrum sensing on the received data, which is in connection with the output of the filtering block. The front-end circuit also includes a controller block for controlling the filtering block and the synchronization circuit. | 01-24-2013 |
| 20130022158 | CHANNEL ESTIMATION METHOD AND SYSTEM FOR INTER-CARRIER INTERFERENCE-LIMITED WIRELESS COMMUNICATION NETWORK - A method and system for wireless communication channel estimation. A frequency offset hypothesis is determined. An interchannel interference (“ICI”) matrix based on the frequency offset hypothesis is generated. Pilot channel estimates based on the ICI matrix are obtained. A correlation error of the pilot channel estimates to the frequency offset hypothesis is calculated. The correlation error is compared with a predetermined correlation error value. The frequency offset hypothesis is updated and the aforementioned steps are iteratively repeated if the correlation error is greater than the predetermined correlation error value. The pilot channel estimates are used to estimate the wireless communication channel. | 01-24-2013 |
| 20130034194 | RADIO RECEIVER - There is provided a radio receiver including: a first matched filter, a second matched filter, a first frame synchronization determining unit and a first phase determining unit. The first matched filter performs matching processing on the basis of N first tap coefficients and sign information of a received digital signal to obtain first output data. The second matched filter performs matching processing on the basis of M (M is a natural number smaller than the N) second tap coefficients, the sign information and amplitude information of the received digital to obtain second output data. The first frame synchronization determining unit determines a first frame synchronization timing of the received digital signal on the basis of the first output data. The first phase determining unit determines a first phase amount of the received digital signal on the basis of the second output data and the first frame synchronization timing. | 02-07-2013 |
| 20130039450 | METHOD AND ASSOCIATED APPARATUS OF DATA EXTRACTION - Method and associated apparatus of data extraction, including: sampling a signal and obtaining a plurality of sampled values, providing a reference sample quantity when the sampled values transit, providing a unit bit sample quantity according to the reference sample quantity, and corresponding each of the sampled values to each data bit of the signal according to the unit bit sample quantity. | 02-14-2013 |
| 20130051503 | SYSTEM AND METHOD FOR PREDICTING A POSITIVE CORRELATION - A device and method are disclosed for reducing the power consumption of a wireless radio device in establishing a wireless connection by predicting a probability of a positive correlation. The wireless radio device may power up a radio receiver of a connectable device to receive a portion of a sync word from a requesting device, determine a correlation value based on the received portion of the sync word and an expected sync word and if the correlation value is less than a threshold value, power down the radio receiver of the connectable device. Additionally, if the correlation value is greater than a threshold value, the entire sync word may be received from the requesting device and a correlation value may be determined based on the entire sync word and the expected sync word. | 02-28-2013 |
| 20130051504 | COMPENSATING DEVICES AND METHODS FOR DETECTING AND COMPENSATING FOR SAMPLING CLOCK OFFSET - A compensating device for detecting and compensating for a sampling clock offset in a receiver. An SCO detector includes multiple calculation paths and a controller. Each calculation path receives a time domain signal and a hypothetic offset, calculates correlation coefficients between the time domain signal and a delayed version of the time domain signal according to a predetermined delay and the hypothetic offset, calculates correlation coefficient sums according to the correlation coefficients, and extracts a maximum correlation coefficient sum for the hypothetic offset from the correlation coefficient sums. The controller is coupled to the calculation paths for providing different hypothetic offsets to each calculation path and detects the SCO according to the maximum correlation coefficient sums obtained from the calculation paths. An SCO compensator receives the SCO and compensating for the SCO on a signal generated in a signal processing path of a receiver. | 02-28-2013 |
| 20130058442 | WIRELESS RECEIVING APPARATUS AND METHOD - According to one embodiment, a wireless receiving apparatus a calculation module, a detection module and a determination module. The calculation module calculates, for each of modes, correlation values between a received signal and reference signals. The detection module synthesizes the correlation values to generate first correlation value sequences for each of the modes, and to detect at least one second correlation value sequence. The determination module selects a known signal period from the signal periods and a known signal interval from the signal intervals, based on first correlation values included in the second correlation value sequence, and to determine a received signal mode. | 03-07-2013 |
| 20130064333 | WIRELESS RECEIVING APPARATUS AND METHOD - According to one embodiment, a wireless receiving apparatus includes a calculation module, a first determination module and a second determination module. The second determination module determines a length of interleaver blocks by determining whether or not a maximum value of second correlation value sequence is not less than a second threshold value within a first period, the second correlation value sequence being generated by combining third correlation values being between the receiving signal and each of reference signals, and to determine an initial position of the interleaver blocks based on a position of the maximum value. | 03-14-2013 |
| 20130077722 | SIGNAL ACQUISITION SYSTEM - A signal acquisition system efficiently acquires a transmitted signal even at very low power. The system may synchronize to a preamble structure in the transmitted signal and, for example, determine timing parameters that locate the preamble with respect to system timing or other clock references. The system is particularly effective at acquiring weak power signals and is also robust against significant noise and other impairments, and therefore improves the ability of a receiving device that incorporates the signal acquisition system to acquire the signal and establish communication with other devices. | 03-28-2013 |
| 20130094619 | SYSTEMS AND METHODS FOR PACKET DETECTION - Systems, methods, and devices for detecting packets in signals are described herein. The apparatus comprises a receiver configured to receive a signal comprising a plurality of samples. The apparatus comprises circuitry. The circuitry is configured to apply a match filter to the plurality of samples to produce a plurality of blocks of samples, each block comprising a number of samples. The circuitry is configured to correlate a subset of the samples of a first block with a subset of the samples of a second block to produce an output. The circuitry is configured to compare the output to a threshold value to determine whether the signal comprises a data packet. | 04-18-2013 |
| 20130094620 | ESTIMATION OF A MULTIPATH SIGNAL IN A WIRELESS COMMUNICATION SYSTEM - Described herein is a method and system for estimating a time-varying multipath communication channel. The system comprises a receiver for receiving a signal comprising a data packet transmitted over the multipath communication channel. The system also comprises a frequency-domain channel estimator that generates a frequency-domain channel estimate based on the received signal. The system further comprises a time-domain channel modeller that receives the frequency-domain channel estimate and generates an estimate of parameters in a time-domain model of the multipath communication channel. The model characterises the multipath communication channel as a delay line with a plurality of taps, each tap having tap parameters defining a delay, a Doppler and a gain for the tap. The tap parameters are constant over the data packet. | 04-18-2013 |
| 20130129022 | Method and Associated Apparatus of Communication Parameter Detection - A method of communication parameter detection for detecting a temporal length of a guard interval of cyclic messages in a communication is provided. The method includes: searching peaks of an autocorrelation signal in the communication signal, and providing a peak for each cyclic message; sorting a time difference between two consecutive peaks to one of bins of a histogram, and determining the temporal length of the guard interval according to a result of the histogram; while a peak is found, providing a signal average according to an average of the autocorrelation signal over an average calculating period, comparing whether a ratio of the peak to the signal average is greater than a threshold, and accordingly detecting whether the communication signal carries valid information. | 05-23-2013 |
| 20130136216 | RECEPTION DEVICE - There are provided a correlation calculation unit that takes a cross-correlation between a signal from which a DC component of an analog baseband signal is removed, and to which a known fixed DC offset is added, and a known signal, an inter-correlation peak phase difference detection unit that estimates a carrier frequency offset from a peak of the calculated correlation vector, and a residual DC offset estimation unit that estimates a residual DC offset component from a mean value of the sidelobe of the calculated correlation vector. | 05-30-2013 |
| 20130142290 | Method and Apparatus for Modulation and Coding Scheme Adaption in a MIMO System - Method and apparatus for decoding a transmitted signal by a receiver in a MIMO system into a first estimate component for estimating a first signal, a first interference component indicating interference resulting from a correlation relationship among a set of signals to be transmitted, and a first noise component. A base station generates the transmitted signal from the set of signals through a coding process, the coding process defining a correlation relationship amongst the set of signals. The correlation information about the correlation relationship is transmitted to the receiver directly or by a dedicated reference symbol. The decoding is performed by determining a linear receiver filter for the first signal in accordance with the correlation information, and de-correlating the first signal and interferences. | 06-06-2013 |
| 20130142291 | Synchronization Signals Detection - A wireless device correlates received signals with predetermined synchronization signals to produce correlation values. The wireless device identifies a first synchronization signal as a synchronization signal transmitted by a first base station. The wireless device subtracts a processed first synchronization signal from received signals to generate an updated received signal and correlates the updated received signal with a second plurality of predetermined synchronization signals to produce correlation values. The wireless device identifies a second synchronization signal as a synchronization signal transmitted by a second base station based on correlation values. | 06-06-2013 |
| 20130142292 | METHOD AND APPARATUS FOR ESTIMATING FREQUENCY - A method and apparatus for use in connection with wireless communication to adjust the frequency of an oscillator to synchronize with a received signal by correlating a synchronization code channel with training sequences to estimate relative offsets which are employed to estimate an error, which is then filtered. The filtered output preferably provides a voltage controlling a voltage controlled oscillator (VCO). The same technique may be employed to control a numeric controlled oscillator (NCO). | 06-06-2013 |
| 20130148765 | COARSE TIMING ACQUISITION - A coarse timing acquisition technique includes generating a sequence detection indicator. The sequence detection indicator indicates detection of a sequence of repeated symbols in a received signal. The sequence detection indicator is based on a first energy threshold and a normalized moving sum of an autocorrelation signal. The autocorrelation signal is based on the received signal. | 06-13-2013 |
| 20130148766 | SIGNAL DETECTION DEVICE AND SIGNAL DETECTION METHOD - In this signal detection device ( | 06-13-2013 |
| 20130163703 | APPARATUS AND METHOD FOR DETECTING BROADCASTING SIGNAL - Disclosed are an apparatus and a method for detecting a broadcasting signal. The signal detecting apparatus according to the exemplary embodiment of the present invention includes: a reference signal generator outputting a reference signal acquired by performing a correlation calculation between a current sample and a previous sample of a received signal which is an FM signal or a digital radio mondiale plus (DRM+) signal and then normalizing a result of the correlation calculation; and a discriminator detecting a maximum value of the reference signal and judging that the received signal is the FM signal when the maximum value of the reference signal is more than a predetermined threshold. | 06-27-2013 |
| 20130170589 | Filter Offset Compensation - Problems arising from a pre-emphasis filter, particularly an infinite-impulse-response filter, in a signal modulator are solved by detecting sequences of the same bit or symbol in a modulation signal and compensating the corresponding d.c. offset in the signal generated by the pre-emphasis filter without real-time feedback. The amount of offset compensation can be defined during design of the modulator or adjusted or calibrated during production. It is not necessary to change the transfer function of the pre-emphasis filter, but only to correct the d.c. offset of the filter output signal. | 07-04-2013 |
| 20130170590 | Receiver Node and A Method Therein for Compensating Frequency Offset - According to embodiments herein an ambiguity problem when compensating for frequency offset may be solved by compensating a received reference symbol according to two different frequency offset hypotheses; the estimated frequency offset and the a mirrored version of the same. Then by comparing the compensated reference symbol of the different frequency hypotheses with a target reference symbol, which is known at the receiver node | 07-04-2013 |
| 20130177109 | SIGNAL DETECTOR, SIGNAL DETECTION METHOD, AND COMMUNICATION TERMINAL APPARATUS - There is provided a signal detector which includes a correlation emphasis unit configured to generate correlation emphasis signals corresponding to the respective fixed intervals, an autocorrelation matrix generation unit configured to generate an autocorrelation matrix, a noise power estimation unit configured to estimate noise power in the correlation emphasis signals, a noise power matrix generation unit configured to generate, a noise power matrix having noise power components, a noise removal unit configured to remove an influence of noise from the autocorrelation matrix, an eigenvalue calculation unit configured to calculate an eigenvalue of the autocorrelation matrix from which the influence of noise has been removed by the noise removal unit, and a signal judgment unit configured to determine whether a signal transmitted from an external apparatus is included in the received signals. | 07-11-2013 |
| 20130177110 | Mid-Packet Clear Channel Assessment - A mid-packet detection technique is provided that detects a packet with periodic repetitions of a fixed duration at a point in time of the packet other than a start-of-packet pattern, e.g., a preamble, associated with the packet. The process performs packet detection without detecting a preamble and does not require carrier frequency recovery, timing recovery (synchronization) or channel estimation. In one embodiment, a doubly differential matched filter autocorrelation of the received signal is computed and used as a metric for packet detection when the preamble is not observed or to complement preamble detection. The metric is compared to a threshold to indicate detection of a packet. | 07-11-2013 |
| 20130188758 | JOINT SOURCE CHANNEL DECODING USING PARAMETER DOMAIN CORRELATION - Methods, systems, and apparatuses are provided for performing joint source channel decoding in a manner that exploits parameter domain correlation. Redundancy in speech coding and packet field parameters is exploited to generate conditional probabilities that a decoder utilizes to perform joint source channel decoding. The conditional probabilities are based upon correlations of parameters of a current frame with parameters of the same or other frames or historical parameter data. Parameter domain correlation provides significant channel decoding improvement over prior bit domain solutions. Also provided are methods, systems, and apparatuses for utilizing received statistics of monitored data bits from which conditional probabilities are generated to perform channel decoding. The techniques described may be implemented at the decoder side and thus do not interfere with transmission standards. | 07-25-2013 |
| 20130188759 | SYSTEMS AND METHODS FOR COMPOSITE ADAPTIVE FILTERING - Systems and methods are provided for adaptively filtering a signal. A signal is received, and the received signal is filtered to generate an output signal. A difference signal is generated based on a difference between the output signal and a reference signal, and a correlation of the received signal and the different signal is evaluated. Then, a mode is selected between a first adaptive filtering mode and a second adaptive filtering mode based at least in part on the correlation, and the received signal is filtered using the selected adaptive filtering mode. | 07-25-2013 |
| 20130195229 | MULTIPLE CORRELATORS FOR COMMUNICATION DEVICE DETECTION - A receiver unit of a communication device can employ multiple correlators for decoding the access address of a packet received from another communication device. A dynamically determined primary frequency offset is applied to a phase difference signal that is determined from an RF signal that comprises the packet. For each of a plurality of access address decoding chains of the receiver unit, a secondary frequency offset associated with the access address decoding chain is applied to the phase difference signal, the phase difference signal is correlated with a predetermined access address of the communication device, and a resultant correlation output is compared against a correlation threshold. One of the access address decoding chains that generated the correlation output that is greater than the correlation threshold is selected and the packet is demodulated based, at least in part, on the phase difference signal corresponding to the selected access address decoding chain. | 08-01-2013 |
| 20130202068 | WIDEBAND DETECTION OF NARROWBAND TRIGGER SIGNALS - A mechanism can be implemented for reducing the power consumption of a wireless radio device in establishing a wireless connection by utilizing a wideband signal to detect a narrowband trigger signal at a potential narrowband trigger frequency. The wireless radio device may operate a wideband receiver to receive an RF signal. Being aware of the potential narrowband trigger frequencies, the wideband receiver may utilize the received RF signal to detect the presence of a narrowband trigger signal at one of the potential narrowband trigger frequencies. | 08-08-2013 |
| 20130202069 | Frequency Offset Compensation for Multi-carrier Communication Systems - The present disclosure provides a frequency offset compensation technique for use by a multi-carrier receiver. Compared with legacy receiver designs, the technique introduces a new function which correlates various frequency offsets of the different carriers involved in multi-carrier signal transmission and reception. This new function can be coupled with an Automatic Frequency Control (AFC) function which can then utilize the correlation information provided by the new function to achieve significantly better frequency error/offset estimation when the carriers are correlated. As a method aspect, the frequency offset compensation technique comprises the steps of receiving signals modulated on a plurality of carrier frequencies, deriving a frequency offset for each carrier frequency to thereby provide a plurality of frequency offsets corresponding to the plurality of carrier frequencies; correlating these plurality of frequency offsets; and controlling compensation of the frequency offsets based on a result of the correlation. | 08-08-2013 |
| 20130216007 | WIRELESS COMMUNICATIONS DEVICE HAVING TEMPORARY CORRELATION MATRIX WITH TIME INVERSION AND RELATED METHODS - A wireless communications device may include a receiver configured to receive a continuous phase modulation (CPM) signal and a demodulator coupled downstream from the receiver. The demodulator may be configured to generate a CPM correlation matrix based upon an expected CPM signal, and generate a temporary correlation matrix. The temporary correlation matrix may include a first copy of the CPM correlation matrix inverted in time, and a second copy of the CPM correlation matrix. | 08-22-2013 |
| 20130216008 | Method and Associated Apparatus for Determining Signal Timing of Wireless Network Signal - A method for determining signal timing of a wireless network signal is provided. The method includes: performing match-filtering on the wireless network signal transmitted by one or multiple antennas to provide a match value distribution, performing moving averaging on the match value distribution to provide an accumulation distribution, searching a peak of the accumulation distribution to provide a central timing according to a timing at which the peak occurs, and determining the signal timing (e.g., a symbol boundary) of the wireless network signal according to the central timing. | 08-22-2013 |
| 20130230129 | METHOD FOR COARSE FREQUENCY SYNCHRONIZATION IN OFDM RECEIVER - The present invention provides a method for coarse frequency synchronization in an OFDM receiver. Even if the maximum variation of crystal oscillator (X-TAL) frequency disturbance is maximized and most of the variation in crystal oscillator (X-TAL) frequency disturbance is vary small, the estimation or search method of the present invention is capable of rapidly and effectively terminating the estimation of the integral multiple frequency offset (IFO). The integral multiple frequency offset (IFO) candidate is ascendingly increased and descendingly reduced at one value interval. In the estimation IFO, the correlation peak value in the intermediate status is compared to the thresholds, the coarse frequency synchronization (CFS) acquisition directly is ended and ensured when the correlation peak value is greater than the threshold, and a confidence check is not performed when correlation peak value is less than the threshold for considerably reducing the acquisition time of the CFS. | 09-05-2013 |
| 20130235958 | JOINT SPECIAL BURST AND TRANSPORT FORMAT COMBINATION INDEX (TFCI) DETECTION - To detect a special burst sequence, a cross correlation (C) is compared to a square root of an estimated noise variance (σ) in conjunction with a threshold value (Th). In one aspect of the disclosure, the threshold value may include multiple threshold values. The multiple threshold values may be compared to an intensity or level of a special burst metric (C/σ) to facilitate determination of the special burst sequence. For example, when a special burst metric C/σ is greater than a second threshold value (Th | 09-12-2013 |
| 20130243133 | COGNITIVE RADIO COMMUNICATION SYSTEM RECOGNIZING INTERFERENCE BASED ON KNOWN SIGNAL - A cognitive radio (CR) communication apparatus and method is provided. A cognitive radio (CR) communication apparatus includes a signal receiving unit which receives signals from a primary user of a primary system and a secondary transmitter of a secondary system, the received signals including an element associated with at least one known signal of the secondary transmitter, and a determination unit which determines whether a signal of the primary user exists from among the received signals based on the element associated with the at least one known signal. | 09-19-2013 |
| 20130287151 | CONTINUOUS TIME COUNTER - A continuous time counter and method of counting are provided, comprising a sequence of adding stages which build up the output based on the inputs by progressively adding new values to opposite ends of an output stack. The counter provides for fast and reliable continuous time counting operations. | 10-31-2013 |
| 20130294552 | TRANSMITTER, RECEIVER, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - Provided is a transmitter for transmitting signals by means of the STBC method or the DSTBC method, wherein communication is carried out effectively. The transmitter for transmitting signals by means of the STBC method or the DSTBC method has the following configuration. A frame in which synchronization words are arranged at specified positions is used. An encoding means in the transmitter encodes the entire frame to be transmitted including the synchronization words, by means of the STBC method or the DSTBC method. It is also possible to implement a communication system and a communication method for communicating signals by means of the STBC method or the DSTBC method. | 11-07-2013 |
| 20130308730 | Method for Sensing Wireless Microphones Using Augmented Spectral Correlation Function - A method for detecting wireless microphone signals based on an augmented spectral correlation function is provided. The method includes obtaining an augmented spectral correlation function (SCF) of acquired digital signals based on a SCF of the digital signal and a conjugate SCF proposed in the present invention, calculating a statistic, and comparing it with a decision threshold simulated or calculated through a predetermined method to determine whether the digital signal is a wireless microphone signal. With the proposed augmented SCF, the present invention overcomes a difficulty in sensing TV white space, namely, the inability of most existing detection methods to effectively distinguish between narrowband interferences and wireless microphone signals. Meanwhile, the detection method has low algorithm complexity and is easy to implement in real systems | 11-21-2013 |
| 20130315353 | Processing Samples of a Received RF Signal - Apparatus comprises: means configured to obtain a set of plural samples of signals, the set comprising at least one sample for each of L antenna elements of a receiver, where L is an integer greater than two and where the samples are of an RF signal that has been downconverted by a downconversion frequency; means configured, for each antenna element, to perform autocorrelation on the samples relating to that antenna element; means configured to sum the results of autocorrelation for all antenna elements; means configured to convert the summed results into the frequency domain; means configured to determine a maximum value of the summed results in the frequency domain; and means configured to use the determined maximum value to provide an output indicative of an offset between a carrier of the RF signal and the downconversion frequency. Another apparatus comprises: means configured to obtain a set of plural samples of signals, the set comprising k samples for each of L antenna elements of a receiver, where L is an integer greater than two and where the samples are of an RF signal that has been downconverted by a downconversion frequency; means configured, for each antenna element, to convert vectors provided by the samples relating to that antenna element into frequency domain vectors and to square the frequency domain vectors; means configured to sum the squared frequency domain vectors for all antenna elements; means configured to determine a maximum value of the summed results in the frequency domain; and means configured to use the determined maximum value to provide an output indicative of an offset between a carrier of the RF signal and the downconversion frequency. | 11-28-2013 |
| 20130322579 | SYSTEMS AND METHODS FOR FAST AND PRECISE FREQUENCY ESTIMATION - Systems and methods are provided for fast and precise estimation of frequency with relatively minimal sampling and relatively high tolerance to noise. | 12-05-2013 |
| 20130322580 | SYSTEMS AND METHODS FOR FAST AND PRECISE FREQUENCY ESTIMATION - Systems and methods are provided for fast and precise estimation of frequency with relatively minimal sampling and relatively high tolerance to noise. | 12-05-2013 |
| 20130322581 | Matched Filtered Data Samples Processing - The invention relates to apparatuses, methods, a system, computer programs, computer program products and computer-readable media. Matched-filtered samples are conveyed instead of antenna samples, so that data rates in the interface between a remote radio head and the BTS or base band hotel may be lower. For detecting data, the matched filtered data samples are processed by using information on the radio channel. | 12-05-2013 |
| 20130322582 | RECEIVER, RECEIVING METHOD, AND COMPUTER PROGRAM - Provided is a receiving device which, even when a temporary degradation occurs in the propagation path environment during an AFC tracking operation, does not require an initial lead-in operation when the propagation path environment returns to normal and which has lower power consumption and shortened time during which communication is not possible; also provided are a receiving method and a computer program. This receiving device calculates the variance of the phase rotation angle relative to a reference signal, compensating for frequency error if the rotation angle variance is less than a pre-set threshold value (TH), and stopping frequency error compensation if the rotation angle variance is greater than or equal to the threshold value (TH). | 12-05-2013 |
| 20130322583 | CHANNEL ESTIMATION PROCESSING FOR PERFORMANCE IMPROVEMENT IN LOW SNR REGIME - Disclosed is an improved channel estimation by post-processing of the channel response that is generated by a Golay correlator The processing is done using time-domain operations such as gating and filtering. Gating is performed on the estimated channel response taps in order to reduce the noise level. Pre-filtering the channel response through a filter matched to the transmitted pulse-shape improves the probability of detecting the channel peaks. Post-filtering the processed channel impulse response to eliminate the high frequency effects that are added by the windowing and gating operations. | 12-05-2013 |
| 20140003557 | METHOD AND APPARATUS OF CROSS-CORRELATION WITH APPLICATION TO CHANNEL ESTIMATION AND DETECTION | 01-02-2014 |
| 20140003558 | DIVERSITY CONTROL METHOD AND WIRELESS COMMUNICATION APPARATUS | 01-02-2014 |
| 20140003559 | Method And System For Improved Cross Polarization Rejection And Tolerating Coupling Between Satellite Signals | 01-02-2014 |
| 20140023166 | OFDM MODULATION SIGNAL DEMODULATOR, RECEIVING APPARATUS, AND RECEIVING AND DISPLAYING APPARATUS - An OFDM modulation signal receiving apparatus by which a user can generally grasp a reception state of an OFDM modulation signal and take measures to improve the reception quality thereof. The OFDM modulation signal receiving apparatus comprises: an autocorrelation calculating part that calculates an autocorrelation value of an OFDM modulation signal at predetermined periods; an intra-interval total sum value calculating part that sums up comparison result values obtained by comparing the autocorrelation value with at least one threshold in each predetermined interval to calculate an intra-interval total sum value of each predetermined interval; and a selection storage part that stores a piece of autocorrelation level data according to the intra-interval total sum value in each predetermined interval. | 01-23-2014 |
| 20140023167 | METHOD AND DEVICE FOR ESTIMATING GAIN AND PHASE CORRECTION PARAMETERS WHEN RECEIVING AN OFDM MODULATED SIGNAL - Gain and phase correction parameters are estimated by calculating the error between the value of at least one received bin and a probable value of the transmitted bin, and by correlating this error with the conjugate value of the rotationally compensated symmetrized bin. | 01-23-2014 |
| 20140023168 | CROSS-CORRELATION RECEIVER - An embodiment of a receiver is proposed. The receiver includes a buffer element for receiving an input signal continuously, synchronization means for synchronizing the input signal by monitoring a buffer signal corresponding to the input signal within the buffer element at a corresponding monitoring time for determining a complete reception of at least one preamble signal within the buffer signal at a reception time, and by synchronizing the input signal according to the detection of the complete reception of the at least one preamble signal, and extraction means including at least one operative block configurable in an extraction phase for extracting a data signal associated with the at least one preamble signal from the input signal. In an embodiment, the synchronization means shares said at least one operative block with the extraction means; said at least one operative block is configurable in a synchronization phase for synchronizing the input signal. The operative block includes correlation means configurable in the synchronization phase for calculating at each monitoring time a correlation function between the buffer signal and a reference signal corresponding to the preamble signal, detection means configurable in the synchronization phase for detecting a partial reception of a significant portion of the preamble signal at a partial reception time according to the correlation function, and prediction means configurable in the synchronization phase for predicting the reception time according to the partial reception time. | 01-23-2014 |
| 20140029703 | I/Q CALIBRATION TECHNIQUES - A receiver includes a static I/Q calibration block and a correlation/integration block. The static I/Q calibration block is configured to substantially eliminate mismatches between in-phase and quadrature components of a portion of the spectrum having associated I/Q mismatches that are relatively frequency-independent. The correlation/integration block is configured to substantially eliminate mismatches between the in-phase and quadrature components of portions of the spectrum having associated I/Q mismatches that are relatively frequency-dependent in accordance with a pair of signals generated by the static I/C calibration block. | 01-30-2014 |
| 20140029704 | SYSTEM AND METHOD FOR CORRELATING RECEIVED SIGNAL OVER TIME AND FREQUENCY - A system is provided for use with a frequency band including a transmission frequency and a received frequency. The transmission frequency includes a transmission signal having a transmitted unique word therein. The received frequency includes a received signal having a received unique word therein, wherein the received unique word had been received at a received time and at a received phase. The system includes a first sub-correlator, a second sub-correlator and a discrete Fourier transform device. The first sub-correlator can perform a first correlation of only a first portion of the received unique word with a corresponding first portion of the transmitted unique word over a plurality of instances of time and can output a first plurality of sub-correlation values. The second sub-correlator can perform a second correlation of only a second portion of the received unique word with a corresponding second portion of the transmitted unique word over the plurality of instances of time and can output a second plurality of sub-correlation values. The discrete Fourier transform device can perform a discrete Fourier transform over a plurality of frequencies within the frequency band on the first plurality of sub-correlation values and can perform a discrete Fourier transform over the plurality of frequencies within the frequency band on the second plurality of sub-correlation values. The first portion of the received unique word is different from the second portion of the received unique word | 01-30-2014 |
| 20140044222 | METHOD AND DEVICE FOR DETECTING RECEIVED SIGNAL USING MEDIAN ABSOLUTE DEVIATION - A method of detecting a received signal, includes determining correlation between a received signal in a predetermined signal interval and training symbols, and determining a median absolute deviation (MAD) of the received signal in a predetermined reference interval. The method further includes detecting a presence of the received signal based on the correlation and the MAD. | 02-13-2014 |
| 20140050287 | DATA SLICER FOR REDUCING SYSTEM START-UP TIME AND RECEIVER WITH THE SAME - A receiver for reducing a system start-up time includes an antenna, an RF (Radio Frequency) circuit, a demodulation circuit, and a data slicer. The data slicer includes a filter, a comparator, a switch, and a delay generator. The filter filters a demodulated signal so as to generate a threshold level. The comparator has a positive input terminal for receiving the demodulated signal and a negative input terminal for receiving the threshold level. The comparator compares the demodulated signal with the threshold level so as to generate a digital signal. The switch is coupled between the positive input terminal and the negative input terminal. The delay generator determines whether or not to close the switch during a delay time according to an enable signal. | 02-20-2014 |
| 20140056392 | FREQUENCY OFFSET COMPENSATION IMPROVEMENT FOR A LONG TERM EVOLUTION (LTE) SEARCHER - A method and system provide frequency offset compensation in a wireless communication device. A frequency offset compensation module (FOCM) correlates a received reference signal with sub-replica reference sequences to obtain a vector of matched filter output values associated with a time offset identified by a correlation time index value. The FOCM determines a correlation score vector using a combined energy associated with matched filter output values. The FOCM then determines a first phase difference based on matched filter output values corresponding to adjacent sub-replica sequences. The FOCM computes a second phase difference by linearly combining a selected first phase difference and at least one neighbor first phase difference having a second correlation time index value that differs from a first correlation time index value of the selected first phase difference. The FOCM uses the second phase difference to provide compensation for a frequency offset associated with received signals. | 02-27-2014 |
| 20140056393 | Coefficient Calculation Method and Device for Time-Domain Channel Estimation Filter - The present invention provides a method and a device for calculating a coefficient of a time-domain channel estimation filter. The method comprises: acquiring position information and weight information of symbols carrying RS information corresponding to X | 02-27-2014 |
| 20140056394 | SIGNAL DETECTOR DEVICE AND SIGNAL DETECTION METHOD - In a signal detection apparatus, power detection section | 02-27-2014 |
| 20140079163 | TIMING RECOVERY FOR LOW ROLL-OFF FACTOR SIGNALS - A method includes receiving a signal, which carries data in a sequence of symbols that are modulated in accordance with a pulse shape and transmitted in accordance with a timing clock. The received signal is filtered with a matched filter whose response is matched to the pulse shape of the symbols, to produce a filtered signal. The timing clock is initially recovered from the received signal prior to filtering with the matched filter. Upon meeting a predefined condition, a switch is made to recover the timing clock from the filtered signal after filtering with the matched filter. The symbols are demodulated using the recovered timing clock, so as to reconstruct the data. | 03-20-2014 |
| 20140079164 | Full-Range Pilot-Assisted Frequency Offset Estimation for OFDM Communication Systems - A training symbol with two identical halves as well as a pilot-tone at a center frequency is used for both timing synchronization and carrier frequency offset estimation. A timing synchronization is achieved by finding a peak of a cross-correlation function of the two halves in the first symbol. A fraction part of the frequency offset FO is then calculated from a phase difference between the two halves of the first training symbol. Then, the received signal is compensated for the fraction part of FO, and, an integer part of the FO is obtained by counting the shifted positions of the pilot-tone peak in the frequency domain. | 03-20-2014 |
| 20140086369 | CYCLIC SHIFT DELAY DETECTION USING AUTOCORRELATIONS - Systems, apparatus and methods for determining a cyclic shift diversity (CSD) mode are presented. Examples use two different autocorrelations to determine a current CSD mode. Specifically, a delay-based autocorrelation and a cyclic shift-based autocorrelation are each computed then compared to each other, for example, by taking a difference of the two autocorrelations. A multipath signal leads to similar autocorrelations, where as a signal with a CSD mode enabled leads to dissimilar autocorrelations. By examining the number of peaks in the delay-based autocorrelation or the autocorrelation difference, a current CSD mode may be determined. | 03-27-2014 |
| 20140093018 | FREQUENCY OFFSET ESTIMATION METHOD AND ASSOCIATED APPARATUS APPLIED TO MULTI-CARRIER COMMUNICATION SYSTEM - A frequency offset estimation method for a multi-carrier communication system is provided. The method includes: transforming a representation of a reception signal from a time domain to a frequency domain, and generating a plurality of symbols; calculating a correlation of two symbols among the symbols, and obtaining a plurality of correlating complex numbers corresponding to a plurality of subcarriers; generating M number of candidate subcarrier position sets according to a subcarrier position set of a specific signal and M number of candidate frequency offsets; calculating M number of calculated values according to the correlating complex numbers corresponding to the M number of candidate subcarrier position sets; and determining a frequency offset according to the maximum calculated value among the M number of calculated values. | 04-03-2014 |
| 20140093019 | RECEIVER - A receiver for receiving an RF signal transmitting a bit sequence representing a symbol is provided. The receiver includes an oscillator, a counter, at least one state machine and at least one correlator. The oscillator is configured to oscillate dependent on the received RF signal, wherein the oscillator signal is controlled to provide an oscillation signal based on the oscillation during a plurality of subsequent active periods. The counter is configured to provide a counter value describing threshold crossings of the oscillator signal for each of the active periods. The at least one state machine is connected to the counter and configured to output state values, each state value dependent on two subsequent counter values. The at least one correlator is configured to correlate the output state values with a predefined bit sequence and to output a value representing the symbol dependent on the correlation. | 04-03-2014 |
| 20140093020 | WIRELESS COMMUNICATION DEVICE AND METHOD OF DETERMINING REFERENCE SIGNAL - A wireless communication device according to the present invention includes a standard signal holding unit for holding a plurality of standard signals, a correlation value calculation unit for performing a correlation operation between a received signal and the plurality of standard signals, and a reference signal selection unit for determining a reference signal from among the plurality of standard signals on the basis of a correlation operation result obtained by the correlation value calculation unit. When a correlation value peak which provides a maximum value is not detected among a plurality of correlation values obtained by the correlation operation between the received signal and the plurality of standard signals, the reference signal selection unit repeats a predetermined number of times, a process of performing a correlation operation between a new standard signal which is generated so that a head of a data part is located at some midpoint in a predetermined symbol interval and the received signal. | 04-03-2014 |
| 20140098910 | METHOD AND APPARATUS FOR REDUCING THE TIME REQUIRED TO ACQUIRE A GPS SIGNAL - A method of correlating a digital communications signal is described. In an example, a window is defined equal to a portion of an epoch of the digital communication signal. The digital communication signal is then correlated across the window. A determination is made as to whether a correlation peak results from the correlating. Timing parameters are then established for receiving additional digital communication signals in response to presence of the correlation peak. | 04-10-2014 |
| 20140098911 | Adaptive Frequency-Domain Reference Noise Canceller for Multicarrier Communications Systems - A method and apparatus to align data blocks in a data signal and a reference signal to increase cross-correlation between the data signal and the reference signal as compared to the unaligned data and reference signals and cancel interference in the data signal in the frequency-domain under changing conditions and in the presence of the data signal. | 04-10-2014 |
| 20140105334 | Fine Phase Estimation for Highly Spectrally Efficient Communications - A receiver may process a received signal to generate a processed received signal. The receiver may generate, during a sequence estimation process, an estimate of a phase error of the processed received signal. The receiver may generate an estimate of a value of a transmitted symbol corresponding to the received signal based on the estimated phase error. The generation of the estimate of the phase error may comprise generation of one or more phase candidate vectors. The generation of the estimate may comprise calculation of a metric based on the one or more phase candidate vectors. The calculation of the metric may comprise phase shifting the processed received signal based on the estimated phase error resulting in a phase-corrected received signal. The calculation of the metric may comprise calculating a Euclidean distance based on the phase-corrected received signal and one or more symbol candidate vectors. | 04-17-2014 |
| 20140105335 | WIRELESS RECEIVING APPARATUS - A wireless receiving apparatus includes a spurious component extraction unit, and a spurious cancellation unit. The spurious component extraction unit is configured to cancel a desired wave with a multi-antenna configuration, and extract spurious components. The spurious cancellation unit is configured to cancel spurious in received signals by using the spurious components extracted. A first correlation unit in the spurious component extraction unit finds a correlation between an output of the spurious extraction unit and an output of the spurious cancellation unit. | 04-17-2014 |
| 20140112420 | RECEIVING APPARATUS AND METHOD - A receiving apparatus for receiving signals in a transmission system transmitted based on a frame structure including signaling data and payload data. The receiving apparatus includes a receiver configured to receive a transmission signal, a frame demapper configured to demap signaling data blocks and payload data patterns from the frames of the frame structure of the received transmission signal, wherein a signaling data block is assumed to include a number of data corresponding to a number of a signaling data pattern, wherein the signaling data patterns are split into n signaling data portions, n being a positive integer, in which n signaling portions are mapped onto n or less frames, and a demodulation decoder is configured to separately demodulate and decode the signaling data blocks and payload data patterns to obtain signaling data and payload data. | 04-24-2014 |
| 20140119480 | RECEIVER AND METHOD FOR RECEIVING A COMPOSITE SIGNAL - A first signal generator is arranged to generate a first signal. A data storage device is configured to provide a null code. A multiplexer is capable of multiplexing the first signal and the null code consistent with a predetermined time sequence for expression of the null code in a produced precursor signal. A ranging code generator is arranged for generating a ranging code. A mixer is capable of accepting the ranging code and the precursor signal and outputting a locally generated reference signal. After down-conversion and digitization of the received composite signal, the code correlator can correlate the digital received composite signal to the locally generated reference signal to decode at least a first portion of the received composite signal, while leaving a second portion of the received composite signal undecoded. | 05-01-2014 |
| 20140119481 | SYMBOL TIMING RECOVERY WITH MULTI-CORE PROCESSOR - A method of performing timing error detection includes receiving, by a multi-core processor, a data stream and up-sampling the data stream by a plurality of processing cores of the multi-core processor. The up-sampling is performed in parallel by the plurality of processing cores. The method includes selecting one sample per symbol of the data stream to generate a sampled data output. The method also includes performing symbol timing recovery based on the sampled data output to adjust a resampling point. | 05-01-2014 |
| 20140133607 | Method and Mobile Device for Joint Cell Identity Detection and Cell Measurement for an LTE System - The present invention relates to a method and system for communication in a mobile device. First and second OFDM symbols containing first and second received cell-specific reference subcarriers, respectively, are received. First and second received cell-specific reference subcarriers of the first and second OFDM symbols are extracted. A pair of received subcarriers is generated by computing the scalar product of the first received cell-specific reference subcarrier and the conjugate of the second received cell-specific reference subcarrier. A reference sequence is provided, that contains pairs of reference subcarriers for multiple, possible combinations of cell-IDs. The pair of received subcarriers is correlated with each pair of reference subcarriers of the reference sequence to generate cell-specific correlation values associated with each cell-ID of a plurality of cell-specific correlation values. The cell-ID of the strongest cell is determined by searching for the highest correlation value. | 05-15-2014 |
| 20140133608 | HYPOTHESES GENERATION BASED ON MULTIDIMENSIONAL SLICING - A sequence estimation circuit of a receiver may receive a sample of an inter-symbol correlated (ISC) signal corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The sequence estimation circuit may calculate a residual signal value based on the sample of the ISC signal and based on a survivor sequence. The sequence estimation circuit may generate one or more branch vector hypotheses based on the residual signal value, where each of the hypotheses comprises a plurality of symbols. The sequence estimation circuit may generate an estimate of one or more of the plurality of transmitted symbols based on the one or more branch vector hypotheses. | 05-15-2014 |
| 20140133609 | Carrier Selection for Multiple Antennas - A method and apparatus is disclosed to process a received single stream communication signal and/or a multiple stream communication. A communications receiver is configured to receive the received communication signal. A communications receiver determines whether the received communication signal includes a single stream communication signal or a multiple stream communication signal. The communications receiver determines whether a received communication signal complies with a known single stream communications standard. The communications receiver determines whether the received communication signal complies with a known multiple stream communications standard. The communications receiver decodes the received communication signal according to the known single stream communications standard upon determining the received communication includes the signal single stream communication signal. The communications receiver decodes the received communication signal according to the known multiple stream communications standard upon determining the received communication includes the multiple stream communication signal. | 05-15-2014 |
| 20140140449 | COMMUNICATION METHOD AND RECEPTION APPARATUS - An electronic device that digitizes a baseband signal obtained from a received high-frequency signal; specifies a position of a preamble included in the digitalized signal; calculates a square of the preamble; specifies a peak from a value obtained by the square of the preamble; performs a fast Fourier transform (FFT) on the baseband signal using a position of the peak as a start of an FFT window; extracts phases of a plurality of frequency components for phase measurement from the baseband signal which has been subjected to the FFT; obtains a phase difference of the plurality of phases; and obtains a phase correction value of a reception signal using the phase difference and a phase reference. | 05-22-2014 |
| 20140169508 | CARRIER AND SAMPLING FREQUENCY OFFSETS ESTIMATION METHOD AND ASSOCIATED APPARATUS APPLIED TO MULTI-CARRIER COMMUNICATION SYSTEM - An offset estimation apparatus for a multi-carrier communication system is provided. The offset estimation apparatus includes an FFT unit configured to transform a reception signal and to generate multiple symbols, a conjugate multiplier configured to receive and conjugate multiply two consecutive symbols corresponding to predetermined subcarrier indices to generate multiple correlating complex numbers, a powering unit configured to raise the correlating complex numbers by a received exponent to generate multiple powered correlating complex numbers, and a calculation unit configured to estimate a frequency offset according to the powered correlating complex numbers. | 06-19-2014 |
| 20140177764 | LOW POWER PACKET DETECTION EMPLOYING SINGLE ADC - Wireless systems, devices, and methods are presented in which a communications interface unit is configured to receive a wireless signal and includes a first channel path having a first down-converter to generate a first analog baseband signal and a first ADC to generate first digital samples as well as second channel path having a second down-converter that operates at a frequency orthogonal to the first down-converter and generates a second analog baseband signal and a second ADC to generate second digital samples. In addition, a packet detector unit is used to detect a beginning frame of packet data, wherein the second channel path is deactivated until the beginning frame of the packet data is detected and the packet detector detects the beginning frame of the packet data based on only the first digital samples provided by the first channel path. | 06-26-2014 |
| 20140185717 | APPARATUS AND METHOD FOR FRAME SYNC DETECTION - An apparatus includes: first to N−1-th correlation-calculation units correlation-calculating a signal at a position corresponding to an n-th reference cell of a reference symbol in a received symbol and a signal at a position corresponding to an n+1-th reference cell of the reference symbol in the received symbol; a first calculation unit multiplying a result of phase correlation calculation of the n-th reference cell and the n+1-th reference cell by the calculation result of the correlation-calculation units and thereafter, summing up all of the multiplication results to calculate a first sum total; a second calculation unit multiplying a result of phase correlation calculation of an N−n−2-th reference cell and an N−n−1-th reference cell by the calculation result of the correlation-calculation units and summing up all of the multiplying results to calculate a second sum total; and a decider detecting a larger value between the first and the second sum total. | 07-03-2014 |
| 20140233683 | REDUCED STATE SEQUENCE ESTIMATION WITH SOFT DECISION OUTPUTS - A receiver may be operable to receive an inter-symbol correlated (ISC) signal, and generate a plurality of soft decisions as to information carried in the ISC signal. The soft decisions may be generated using a reduced-state sequence estimation (RSSE) process. The RSSE process may be such that the number of symbol survivors retained after each iteration of the RSSE process is less than the maximum likelihood state space. The plurality of soft decisions may comprise a plurality of log likelihood ratios (LLRs). Each of the plurality of LLRs may correspond to a respective one of a plurality of subwords of a forward error correction (FEC) codeword. | 08-21-2014 |
| 20140241472 | FSK/MSK Decoder - A decoder for a modulation scheme is configured to operate close to the radio noise floor. A correlation value may be constantly updated, in an effort to match to a signature to a preamble of a packet. A low clamp value may act as a floor to which a calculated correlation value is set, if it is less than the low clamp value. If a correlation threshold is exceeded, then the correlation value is examined to determine it is a peak value. If the peak is found, power of the preamble is compared to a power threshold that is relative to the radio noise floor. If the power threshold is exceeded, positive correlation is detected. A channel optimizer is used to remove the frequency misalignment. This enables the use of a filter that is approximately equal to the occupied bandwidth of the incoming signal, further rejecting noise and interference. | 08-28-2014 |
| 20140241473 | OFDM SIGNAL RECEIVER AND METHOD FOR RECEIVING OFDM SIGNAL - A Tu delay section delays an analog-to-digital converted OFDM signal S | 08-28-2014 |
| 20140241474 | METHOD AND APPARATUS FOR SPECTRUM SENSING - In accordance with an example embodiment of the present invention the application discloses a method and an apparatus to receive a signal ( | 08-28-2014 |
| 20140270015 | INTER-CARRIER INTERFERENCE PHASE NOISE COMPENSATION BASED ON PHASE NOISE SPECTRUM APPROXIMATION - An approach is provided to compensate for inter-carrier interference caused by phase noise in a transmitted or received signal. The approach involves causing an estimation of one or more phase noise spectrum taps that cause inter-carrier interference in a received signal. The approach also involves causing an approximation of an instantaneous phase noise spectrum by a low order finite impulse response filter based on the estimated one or more phase noise spectrum taps. The approach additionally involves determining a de-convolution filter having two or more filter coefficients for one or more orthogonal frequency-division multiplexing symbols associated with the received signal. The approach further involves causing the de-convolution filter to be matched to the approximated instantaneous phase noise spectrum. The approach also involves causing the inter-carrier interference caused by phase noise to be compensated for based on a de-convolution procedure that applies the de-convolution filter to the one or more orthogonal frequency-division multiplexing symbols. | 09-18-2014 |
| 20140286462 | REDUCING ELECTROMAGNETIC INTERFERENCE IN A RECEIVED SIGNAL - Disclosed are various embodiments for reducing the amount of electromagnetic interference (EMI) that may be present in a received signal. A frequency component for the received component is generated. An EMI frequency, an EMI phase, and an EMI amplitude present in the frequency component are tracked. Cancelling data is generated responsive to the EMI frequency, the EMI phase, and the EMI amplitude present in the frequency component. | 09-25-2014 |
| 20140294127 | Method, Apparatus, Receiver, Computer Program and Storage Medium for Joint Detection - The present invention relates a method, apparatus, receiver, computer program for joint detection. In the method, it is firstly determined if whether a number of original active codes is beyond a predefined threshold or not, and when the number of the original active codes is beyond the predefined threshold and a strong interference code exists in the active codes corresponding to intra-frequency adjacent cells, it is to apply an interference cancellation to a receive signal, cancel MAI caused by a strong interference signal corresponding to the strong interference code, and perform a joint detection by utilizing a matched filtering result of a remaining signal after the interference cancellation for the joint detection. According to at least one embodiment of the present invention, when there is large interference in the intra-frequency adjacent cells and the number of the active codes is beyond a maximum threshold, the joint detection performance is improved. | 10-02-2014 |
| 20140301507 | Highly-Spectrally-Efficient Receiver - A receiver may be operable to receive a QAM-based, inter-symbol correlated (ISC) signal having pilot overhead of 5% at a signal-to-noise ratio (SNR). The receiver may be operable to process the QAM-based, ISC signal to output information at a particular rate with a symbol error rate lower than or equal to 1e-2. The first SNR may be at least 3 dB below a SNR required to achieve the same particular information rate and the same symbol error rate while processing a signal having zero inter-symbol interference. | 10-09-2014 |
| 20140307836 | TUNABLE FILTER FOR LTE BANDS - A tunable filter reduces the total number of filters used in TDD (Time-Division Duplex) communication circuitry. The communication circuitry may include a tunable filter and a first switch associated with the tunable filter. The tunable filter may include a tuning component and a filtering component. The tuning component may be located with the first switch on a first die. The filtering component may be located in a laminate underneath the first switch. Power amplifiers for amplifying transmission signals may be located on a second die, and the second die may be located on the laminate. | 10-16-2014 |
| 20140307837 | METHOD OF SELECTING RECEIVE ANTENNAS FOR MIMO SYSTEMS - A method of performing receive antenna selection is presented. The method executes a determination operation for a set of receive antennas, determines a maximum result of the determination operation for two of the antennas, eliminates one of the two antennas from the set of antennas, and repeats the determination and elimination process until only a predetermined number of antennas remain in the set. The signals from these remaining antennas are then processed. The present invention reduces receiver complexity and cost. | 10-16-2014 |
| 20140334578 | DIGITAL RADIO RECEIVER SYSTEM AND METHOD - Provided is a method of scanning for broadcast services in a broadcast signal to generate a broadcast service list for use with a digital radio receiver system, and the digital radio receiver system used for scanning for broadcast services to generate a broadcast service list. The system utilises spectrum awareness data, which includes data defining one or more frequencies at which broadcast services may be receivable, in order to reduce the number of frequencies to scan such that the overall scan time may be reduced. The data in the spectrum awareness data is a filtered subset of the plurality of frequencies at which the broadcast services may be received, which allows the controller of a digital radio receiver to tune a tuner to only the frequencies that are likely to contain a broadcast service when generating or updating a broadcast service list. | 11-13-2014 |
| 20140355725 | SYSTEM AND METHOD FOR SEARCHING FOR ZADOFF-CHU SEQUENCES DURING A PHYSICAL RANDOM ACCESS CHANNEL SEARCH - A system that includes an interface, a processor; and a hardware accelerator. The hardware accelerator is arranged to perform, for each Zadoff-Chu sequence of at least a first sub-set of the set of Zadoff-Chu sequences, a first hardware accelerator set of operations that includes frequency to time domain conversion to provide third intermediate vector that is associated with the Zadoff-Chu sequence. The processor is arranged to complete the Zadoff-Chu sequence search in response to the third intermediate vector—whereas the hardware accelerator and the processor are arranged to partially search the same Zadoff-Chu sequence at different periods of time. | 12-04-2014 |
| 20140355726 | Methods And Systems For Rapid Detection Of Digital Radio Signals - Systems and methods are disclosed for rapid detection of digital content within received radio frequency (RF) signals. The disclosed embodiments digitize received RF signals and apply a sliding window average to subsampled complex magnitudes for the digital samples to generate subsampled magnitude values. The subsampled magnitude values are then collected over a small number of symbols for the digital content, and the results are analyzed to determine whether or not digital content is present with the received signals. For example, multi-symbol histograms and magnitude ratios determined over multiple symbols can then be utilized to make the determination of whether digital content is present in the received signals. The resulting detection determination can be utilized further to control operations of systems utilizing the disclosed embodiments. The disclosed embodiments can be used, for example, to detect the presence of HD (High Definition) Radio digital content within broadcast channels. | 12-04-2014 |
| 20140362955 | ADAPTIVE IQ IMBALANCE ESTIMATION - A transceiver includes an input node to receive an input signal having in-phase (I) data and quadrature (Q) data, the input signal including several data samples. A correlation module determines an autocorrelation of the in-phase data, an autocorrelation of the quadrature data, a difference between the autocorrelation of the in-phase data and the autocorrelation of the quadrature data, and a cross correlation between the in-phase data and the quadrature data. An averaging module determines an average of the difference between the autocorrelation of the in-phase data and the autocorrelation of the quadrature data, and an average of the cross correlation between the in-phase data and the quadrature data, in which the averages are determined over a specified number of data samples. A compensation module, based on the average difference between the autocorrelation of the in-phase data and the autocorrelation of the quadrature data, and the average cross correlation between the in-phase data and the quadrature data, determines compensated in-phase data and quadrature data having reduced IQ mismatch. | 12-11-2014 |
| 20140376669 | USE OF NEURAL NETWORK BASED MATCHED FILTER FOR FAST RESPONSE TIME IN HIGH-SPEED COMMUNICATIONS CHANNELS - A neural network is used within a receiver to discriminate a large set of input waveforms without using a very large set of conventional matched filters. The neural network is trained under actual line conditions as opposed to the requirement for ideal signals when using matched filters. The finite waveforms are based on digital modulation principles. A best match is made between a received waveform from the noisy channel and that of previously trained waveforms in order to extract data. Neural network based matched filter allows data be discriminated separately for each sub-carrier channel in the receiver. The neural network system allows fast processing and is suitable for high-speed data communications systems. | 12-25-2014 |
| 20140376670 | Method and Apparatus of Cross-correlation with Application to Channel Estimation and Detection - The present disclosure provides for a method and apparatus for efficient cross-correlation between a reference sequence and a received sequence in a wireless communication system. The reference sequence includes a concatenation of sign-adjusted sub-sequences, the sign adjustments determined by a first sign sequence of a set of sign sequences. For example, the reference sequence may be an alternating concatenation of sign-adjusted Golay complementary pair sub-sequences. The received sequence is shifted to provide a plurality of time shifted sequences that are then cross-correlated with the sub-sequences to form a set of partial cross-correlations. The partial cross-correlations are sign-adjusted using the first sign sequence and combined to produce the cross-correlation between the reference sequence and the received sequence. The cross-correlations so produced may be used for channel signature (e.g. PHY-type) identification and/or channel impulse response estimation. | 12-25-2014 |
| 20150049847 | FAST FILTERING FOR A TRANSCEIVER - Techniques for fast filtering for a transceiver are presented. A multidimensional filter processor component (MDFPC) can perform configurations and adaptations of multiple digital filters of a transceiver. The MDFPC can treat multiple, separate filters of a transceiver as a single larger multidimensional filter, and jointly update the multiple filters in a single adaptation operation instead of performing multiple adaptation operations on multiple filters. To facilitate multidimensional filter adaptation, the MDFPC can manage respective cross-correlations associated with the inputs of the filters. The MDFPC can facilitate multidimensional filter adaptation by performing multidimensional filter adaptation in the frequency domain, wherein the adaptation can be performed in parallel for multiple frequency sub-channels. For each frequency sub-channel, the MDFPC can perform a filter adaptation, wherein respective filter adaptation matrices can be generated for respective frequency sub-channels to perform the update to facilitate managing different cross-correlations associated with different frequency sub-channels. | 02-19-2015 |
| 20150071388 | ESTIMATING DOPPLER SHIFT USING PREDEFINED AUTOCORRELATION VECTORS - A method includes holding in a memory of a communication terminal multiple predefined vectors, each including signal autocorrelation values computed for a respective Doppler shift. A signal is received, and empirical autocorrelation values are calculated for the received signal. An actual Doppler shift of the received signal is estimated by selecting, from among the predefined vectors, a vector whose autocorrelation values best match the empirical autocorrelation values of the received signal. | 03-12-2015 |
| 20150071389 | Multi-Mode Receiver for Highly-Spectrally-Efficient Communications - A receiver may be dynamically configurable, during run-time, into a plurality of modes of operation. In a first mode of operation the receiver may demodulate received signals having relative low inter-symbol correlation using a near zero ISI filter and symbol slicing. In a second mode of operation the receiver may demodulate received signals having relatively high inter-symbol correlation using an input filter configured to achieve a desired total partial response and a sequence estimation algorithm. | 03-12-2015 |
| 20150078492 | TRANSMITTING APPARATUS AND METHOD FOR A DIGITAL TELECOMMUNICATION SYSTEM - A transmitting apparatus transmits signals in a digital telecommunication system and a synchronising method is used for synchronizing such signals at a receiving apparatus. The transmitting apparatus prepares for transmission of a reference symbol having at least two repetition patterns, whereby one of the at least two repetition patterns is phase-shifted in relation to the other repetition pattern, and a synchronizing mechanism in the digital telecommunication system uses the reference symbol once received for synchronization. The synchronizing mechanism uses a cross-correlation mechanism to cross-correlate at least one of the two repetition patterns within a correlation window having a predetermined length. | 03-19-2015 |
| 20150110228 | SYNCHRONIZING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXED (OFDM) SYMBOLS IN A RECEIVER - In an embodiment, an apparatus includes a buffer to store incoming orthogonal frequency division multiplexed (OFDM) samples. This buffer is configured to output the OFDM samples according to a read pointer that can be adjusted by a sum value corresponding to a sum of a length of a symbol and a feedback value, to align the read pointer with the symbol. In addition, the apparatus further includes a feedback circuit coupled to the buffer to receive the output OFDM samples and generate the feedback value based at least in part on the output OFDM samples. | 04-23-2015 |
| 20150124913 | CIRCUIT AND METHOD FOR CALCULATING ERROR OF SAMPLING CLOCK, AND SIGNAL RECEIVING CIRCUIT AND METHOD - A method for calculating an error of a sampling clock is provided. The sampling clock is used for sampling a signal to generate a first sample data group and a second sample data group. Each of the first and second sample data groups includes a header having a predetermined sequence. The method includes: performing a correlation operation on the first and second sample data groups with data of the predetermined format to obtain first and second correlation results, respectively; comparing the first and second correlation results to generate a sample data group offset; and generating the error of the sampling clock according to the sample data group offset and a time difference between the first and second sample data groups. | 05-07-2015 |
| 20150131763 | RECEIVING APPARATUS AND METHOD FOR RFID READER - A receiving apparatus for an RFID reader estimates channel coefficients for each of a plurality of receiving antennas based on tag response signals received via a plurality of receiving antennas, compensates the tag response signals received via the plurality of receiving antennas based on the channel coefficients estimated for each of a plurality of channel estimators, combines the compensated tag response signals for each of the plurality of receiving antennas to generate a combined signal, and detect bits in the combined signal. | 05-14-2015 |
| 20150131764 | METHODS, DEVICES AND SYSTEMS FOR RECEIVING AND DECODING A SIGNAL IN THE PRESENCE OF NOISE USING SLICES AND WARPING - A method may comprise receiving and sampling a signal. The signal may encode a data packet. A slice may be generated and stored comprising a pair of values for each of a selected number of samples of the signal representing a correlation of the signal to reference functions in the receiver. The presence of the data packet may then be detected and the detected packet decoded from the stored slices. The generating and storing slices may be carried out as the received signal is sampled. The sampled values of the signal may be discarded as the slices are generated and stored. The slice representation of the signal can be manipulated to generate filters with flexible bandwidth and center frequency. | 05-14-2015 |
| 20150295741 | SIGNAL PROCESSING APPARATUS, SIGNAL PROCESSING METHOD, AND SIGNAL PROCESSING PROGRAM - To obtain a high-quality enhanced signal, there is provided an apparatus including a transformer that transforms a mixed signal, in which a first signal and a second signal coexist, into a phase component for each frequency and one of an amplitude component and a power component for each frequency, a change amount generator that generates a change amount of the phase component at a predetermined frequency by using a series of data with a cross-correlation weaker than that of the phase components and randomness lower than that of random numbers, a phase controller that controls the phase component by using the change amount provided from the change amount generator, and an inverse transformer that generates an enhanced signal by using the phase component having undergone control processing by the phase controller. | 10-15-2015 |
| 20150304131 | RECEIVING APPARATUS, METHOD FOR RECEIVING, AND WIRELESS COMMUNICATION SYSTEM - A receiving apparatus includes an estimator that estimates a channel of a known signal received in the receiving apparatus, and a controller that controls a weight value based on the result of the estimating, the weight value being to be multiplied by a replica signal of the known signal. | 10-22-2015 |
| 20150311931 | METHOD AND SYSTEM FOR MULTIBAND INTERFERENCE MITIGATION WITH MULTIPATH CANCELLATION - A method and apparatus is provided for mitigating multiband self-interference using multipath cancellation. A dual-band transceiver receives an incoming radio-frequency signal that includes a multipath self-interference component generated by the transmission of an outgoing radio-frequency signal. The transceiver creates a plurality of reference signals from the outgoing radio-frequency signal by introducing delay values with respect to the outgoing signal. The transceiver adjusts the amplitude and phase of each of the delayed reference signals and combines the resulting signals with the incoming radio-frequency signal to cancel the self-interference component. The delay values may be determined adaptively. The systems and methods described herein are particularly useful for dual-band transceivers capable of communicating simultaneously using Long-Term Evolution (LTE) wideband signals and Public-Safety Narrowband (PSNB) signals. | 10-29-2015 |
| 20150311946 | SHORT-RANGE ZIGBEE COMPATIBLE RECEIVER WITH NEAR-THRESHOLD DIGITAL BASEBAND - An 8.1 nJ/bit 2.4 GHz receiver with integrated digital baseband supporting Q-QPSK DSSS modulation compliant with the IEEE 802.15.4 standard is presented that targets short-range, Internet of Things applications (IoTs). The sensitivity of a wireless communication receiver in general trades with power consumption. This receiver exploits this tradeoff to achieve a total power consumption of 2.02 mW including ADCs and digital baseband processing, at a sensitivity of −52.5 dBm at 250 Kbps. The energy-efficiency of the radio frequency (RF) front-end alone is nearly two times better than the prior art. The receiver was fabricated in 65 nm CMOS with an area of 0.86 mm | 10-29-2015 |
| 20150312065 | JOINT SEQUENCE ESTIMATION OF SYMBOL AND PHASE WITH HIGH TOLERANCE OF NONLINEARITY - A method and system for a sequence estimation in a receiver, such as for use when receiving a sample of a received inter-symbol correlated (ISC) signal corresponding to a transmitted vector of L symbols, with L being a integer greater than 1, and with symbol L being a most-recent symbol and symbol | 10-29-2015 |
| 20150326334 | System and Method for Cyclostationarity-Based Signal Identification - The present disclosure describes systems and methods for identifying a signal that is a product of two or more other signals. In an embodiment, the presence of a particular signal is determined and identified by applying a cyclostationarity detection technique, such as comparing a cyclic autocorrelation function of a product signal with the cyclic autocorrelation function of at least one of the signals which formed the product signal. | 11-12-2015 |
| 20150333933 | Least Squares Channel Identification for OFDM Systems - An OFDM system generates a channel estimate in the time domain for use in either a frequency domain equalizer or in a time domain equalizer. Preferably channel estimation is accomplished in the time domain using a locally generated reference signal. The channel estimator generates an initial estimate from a cross correlation between the time domain reference signal and an input signal input to the receiver and generates at least one successive channel estimate. Preferably the successive channel estimate is determined by vector addition (or subtraction) to the initial channel estimate. The at least one successive channel estimate reduces the minimum mean square error of the estimate with respect to a received signal. | 11-19-2015 |
| 20150349946 | METHOD OF CREATING AltBOC CORRELATION FUNCTION, METHOD OF TRACKING AltBOC SIGNAL, AND SYSTEM FOR TRACKING AltBOC SIGNAL CROSS-REFERENCE TO RELATED APPLICATIONS - There is provided a method of creating an AltBOC correlation function that includes: receiving an AltBOC signal by a receiver; analyzing a subcarrier of the AltBOC signal into eight partial subcarriers having the same period by the receiver; creating partial correlation functions by correlating each of the eight partial subcarriers with the AltBOC signal by the receiver; and creating a resultant correlation function by combining the partial correlation functions by the receiver. | 12-03-2015 |
| 20160099804 | SIGNAL DIGITIZER AND CROSS-CORRELATION APPLICATION SPECIFIC INTEGRATED CIRCUIT - According to one embodiment, a cross-correlator comprises a plurality of analog front ends (AFEs), a cross-correlation circuit and a data serializer. Each of the AFEs comprises a variable gain amplifier (VGA) and a corresponding analog-to-digital converter (ADC) in which the VGA receives and modifies a unique analog signal associates with a measured analog radio frequency (RF) signal and the ADC produces digital data associated with the modified analog signal. Communicatively coupled to the AFEs, the cross-correlation circuit performs a cross-correlation operation on the digital data produced from different measured analog RF signals. The data serializer is communicatively coupled to the summing and cross-correlating matrix and continuously outputs a prescribed amount of the correlated digital data. | 04-07-2016 |
| 20160099818 | HYPOTHESES GENERATION BASED ON MULTIDIMENSIONAL SLICING - A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on a slicing of the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver. | 04-07-2016 |
| 20160134315 | INTERFERENCE CANCELLATION - A circuit comprises a vector separator circuit to generate a first extracted signal according to (i) a first correlation signal, (ii) a second correlation signal, and (iii) a relative response signal. The first correlation signal corresponds to a first correlation between an input signal and a first test signal. The first test signal has a first frequency, and the input signal includes a first spur having the first frequency. The second correlation signal corresponds to a second correlation between the input signal and a second test signal. The second test signal has a second frequency. The relative response signal corresponds to a relative response of the second frequency in the first correlation signal. | 05-12-2016 |
| 20160149741 | ANTENNA DIRECTION ADJUSTMENT METHOD AND OFDM RECEPTION DEVICE - The present invention makes it possible to maintain the continuity of reception detection level and adjust the direction of a reception antenna even under the condition that the reception electric field is low and clock timing synchronization at a C/N ratio of 0 dB or less is lost. QAM modulation including a pilot carrier has higher correlativity in one symbol (1152 samples) correlation, and differential modulation with no pilot has higher correlativity in effective symbol (1024 samples) correction. Detection circuits are provided separately for the QAM modulation and the differential modulation, and in the differential modulation, autocorrelation with a 1024 FFT clock delay signal is performed. The higher of the respective correlation results is selected in the final stage. | 05-26-2016 |
| 20160164700 | METHOD AND APPARATUS FOR CHANNEL ESTIMATION USING LOCALIZED SINR IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus are disclosed for channel estimation in broadband wireless communication systems by using locally prevailing SINR conditions in the RF channel bandwidth. According to one aspect, the channel estimation method adapts to the local SINR across different parts of the channel bandwidth. This leads to channel estimates that are optimized to SINR conditions prevailing in different parts of the channel bandwidth. The channel estimation method described herein may result in the reduction of channel estimation errors, which in turn may lead to improved performance of a broadband wireless communication system. | 06-09-2016 |
