Entries |
Document | Title | Date |
20080205554 | Demodulation method utilizing delayed-sampling technique - A demodulation method utilizing delayed-sampling technique, comprising steps of: obtaining a signal processed by a limiting amplifier as an input signal; transferring the input signal via two paths, by one of which the input signal is directly sent to an input end of a delayed sampler, and by the other of which the input signal is sent to a delay line for generating and outputting time delayed signal; sampling the signal transferred via the delay line to generate a group of sampled data; and converting the sampled data by a thermometer-to-binary converter into a group of binary codes, which is input into data decision circuitry to be processed into recovered base-band data. | 08-28-2008 |
20090028272 | DIGITAL BROADCASTING SYSTEM AND METHOD OF PROCESSING DATA THEREOF - A digital broadcasting system and data processing method are disclosed, which are highly resistant to channel changes and noise. The present invention includes receiving a broadcast signal having mobile service data and main service data multiplexed with each other from at least one parade, demodulating the broadcast signal, acquiring program table information describing at least one service included in at least one ensemble from the demodulated broadcast signal and decoding the mobile service data associated with a first service using a program table information transport unit in the acquired program table information. | 01-29-2009 |
20090046814 | IN-PHASE SIGNAL AND QUADRATURE SIGNAL GENERATOR OF MULTI-PORT NETWORK - An in-phase signal and quadrature signal generator of multi-port network can generate an in-phase (I) signal and a quadrature (Q) signal using a matrix according to a rate of powers detected from signals from a multi-port network. | 02-19-2009 |
20090086850 | METHOD AND SYSTEM FOR A RECEIVER WITH UNDERSAMPLING MIXING USING MULTIPLE CLOCK PHASES - Methods and systems for a receiver with undersampling mixing using multiple clock phases are disclosed and may include undersampling a received wireless signal utilizing multiple undersamplers and clocking each of the undersamplers with a separate clock signal. Each of the clock signals may be at a sampling frequency but with a different phase angle. The difference of the phase angle between each of the clock signals may be adjusted and may be determined by the number of undersamplers. A gain ratio may be configured for two signals summed to generate each of the clock signals for the phase angle adjusting. The two signals may include in-phase and quadrature signals. Each of the summed signals may be normalized utilizing limiters. The sampling frequency may be an integer sub-harmonic of the received signal. The undersamplers may include track and hold or sample and hold circuits. | 04-02-2009 |
20090103655 | SIMPLIFIED DE-ROTATION IN DIGITAL FM DEMODULATOR ARCHITECTURES - The present invention relates to a digital receiver for FM signals, in particular to a new demodulator structure and demodulating method, by which according to a first aspect of the invention the usual complex de-rotation process is reduced to a simple addition/subtraction. According to a second aspect of the invention, the requirements for the sampling frequency necessary for processing the demodulator signals are reduced substantially. | 04-23-2009 |
20090147886 | Adaptive IQ Alignment Apparatus - A method and apparatus for aligning I- and Q-signals in a quadrature receiver based on an squared signal. A correction is evaluated in an iterative manner by finding an average of the squared signal. The average squared signal may be the received signal, in which case the iterations are applied in a feed forward manner. Alternatively, the average squared signal is the aligned signal in which case the iterations are applied in a feed back manner. The correction may include the evaluation of an normalisation or, in the feed back case, this can be implicitly included in the manner in which the iteration is applied. Various parameters to the iteration can be set to accommodate the operating environment of the receiver and characteristics of the received signal. | 06-11-2009 |
20090190695 | DECODING DEVICE AND METHOD, RECEIVING DEVICE AND METHOD, AND PROGRAM - Disclosed herein is a decoding device that decodes demodulated data obtained by demodulating a quadrature modulated signal arising from digital modulation of a carrier and detects synchronization, the decoding device including, a decoder configured to decode first demodulated data that is the demodulated data obtained by demodulating the quadrature modulated signal and is composed of in-phase axis data and quadrature axis data, and decode second demodulated data obtained by interchanging the in-phase axis data and the quadrature axis data of the first demodulated data, and a synchronization detector configured to detect a boundary between predetermined information symbol sequences from first decoded data obtained by decoding the first demodulated data and detect the boundary from second decoded data obtained by decoding the second demodulated data, the synchronization detector selecting and outputting one of the first decoded data and the second decoded data based on a result of the detection of the boundary. | 07-30-2009 |
20090262864 | SYMMETRICAL DATA SIGNAL PROCESSING - In a digital communications receiver configured to receive, via a communications channel, a received first signal representing a sequence of symbols, each symbol being encoded to be representative of data bits, a method of processing the received signal includes adjusting a magnitude, filtering, and applying cyclic prefix restoration, to the received signal to produce a second signal, converting the second signal from time domain to frequency domain to produce a frequency domain signal, and determining a first quantity of values representing a first portion of the symbols by evaluating a relationship of channel values representing characteristics of the communications channel and a second quantity of values representing a portion of the frequency domain signal, the first quantity being smaller than the second quantity. | 10-22-2009 |
20100008449 | FREQUENCY DEPENDENT I/Q IMBALANCE ESTIMATION - A receiver estimates I/Q imbalance in I and Q input signals using circuitry to separate different frequency components of the I and Q input signals, and estimation circuitry arranged to estimate I/Q imbalance at the different frequency bands. The separating of the bands may be carried out in the frequency domain, and may involve combining corresponding values representing corresponding negative and positive frequency bands, and converting the separated frequency domain representations to a time domain representation before the estimation. The estimated imbalance may be used to correct the I and Q signals at the different frequency bands. | 01-14-2010 |
20100014613 | DEMODULATION OF A DIGITALLY FREQUENCY-MODULATED ANALOG RECEIVED SIGNAL BY EVALUATION OF THE TIME INTERVALS BETWEEN THE ZERO CROSSINGS - A detector for zero crossings and a counter which is connected to it are used to determine the time intervals between the zero crossings of the received signal or of an intermediate-frequency signal which is produced from the received signal, and for detection of the digital signal data. In this case, a sequence of determined zero crossing intervals can be stored in digital form in a shift register chain, and can be compared in a classification device with previously stored interval sequences. Furthermore, a frequency offset can be determined by averaging the zero crossing intervals and can be compensated for by suitable selection or modification of the previously stored interval sequences, in which case the latter can also be used during the synchronization phase. The synchronization process may, furthermore, be assisted by payload data identification. | 01-21-2010 |
20100061487 | ADAPTIVE RECEIVER FOR HIGH-ORDER MODULATED SIGNALS OVER FADING CHANNELS - An adaptive receiver to provide reliable estimates of the symbols for the high-order MQAM and MPSK modulated signals received in the presence of amplitude fading and phase dynamics induced due to time-varying atmospheric or terrestrial multipath fading encountered in wireless communication channels. The adaptive receiver encompasses an adaptive tracking loop comprised of adaptive channel fade envelope estimator derived from the high-order modulated signal, a novel phase detector to separately estimate the phase due to the fading channel and the reference oscillator from that due to the data modulation present in the received signal without the need of any pilot symbol or pilot carrier, and a Kalman filter, a fixed-lag smoother and a smoothed symbol detector. | 03-11-2010 |
20100098191 | METHODS AND SYSTEMS FOR PROGRAMMABLE DIGITAL UP-CONVERSION - Methods and apparatus are described herein that make use of complex tuning, the inherently repetitive nature of sampled signals, and programmable digital filtering to create a flexible digital up-conversion system that utilizes a digital-to-analog converter (DAC) with a fixed effective sample rate while still being adapted for tunability over a wide frequency range. With a knowledge of the fixed effective sample rate of the DAC and a desired frequency of up-conversion and combining complex tuning at baseband and up-sampling by a factor of N with a programmable passband filter configured to select one of a plurality of signal images resulting from the up-sampling, it is possible to translate a baseband input signal to a wide range of frequencies above or below F | 04-22-2010 |
20100111230 | RECEIVER CAPABLE OF COMPENSATING FOR MISMATCH OF I SIGNAL AND Q SIGNAL AND COMMUNICATION SYSTEM INCLUDING THE SAME - A receiver includes a frequency converter configured to generate a I signal and a Q signal from each band of a multiband signal and a mismatch compensator configured to estimate a mismatch of the I signal and the Q signal for each of the bands of the multiband signal and store at least one compensation value to compensate for the estimated mismatch. The frequency converter compensates for the mismatch of the I signal and the Q signal based on the at least one compensation value. | 05-06-2010 |
20100119011 | SYSTEM AND METHOD FOR TUNING FM SYNTHESIZER - A device is provided for dividing a clock signal by even and odd integers. The device includes a divider, a delay portion and a duty cycle corrector. The divider is arranged to receive the clock signal and can divide the clock signal and output a divided clock signal. The delay portion can output a delayed signal based on the divided clock signal. The duty cycle corrector can output a first signal based on the delayed signal and the divided clock signal. | 05-13-2010 |
20100150270 | SIGNAL PROCESSING CIRCUIT AND RECEIVER USING THE SAME - A signal processing circuit includes a decimation filter which down-samples over-sampled first three-phase digital signals to obtain second three-phase digital signals, and a converter which subjects the second three-phase digital signals to a three-phase to IQ conversion, and obtains orthogonal digital signals. | 06-17-2010 |
20100195770 | SIGNAL DECOMPOSITION, ANALYSIS AND RECONSTRUCTION APPARATUS AND METHOD - The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method. | 08-05-2010 |
20100316168 | Methods and systems to discriminate betwen PSK and FSK signals - Methods and systems are disclosed herein for discriminating phase-shift-key (PSK) modulated signals from frequency-shift-key (FSK) modulated signals in received signal streams. First, a bit frequency analysis is applied to a digital signal stream representing the received signal stream. The bit frequency analysis computes bit frequencies for bit segments within the digital signal stream. These bit frequencies are then summed in an array to form a bit frequency histogram. Second, a bit phase analysis is applied to the digital signal stream. The bit phase analysis computes bit phases for bit segments within the digital signal stream. These bit phases are then summed in an array to form a bit phase histogram. Spikes within the bit frequency and bit phase histograms can be used to determine whether the received signal stream includes FSK or PSK signals. An enhanced bit phase analysis can also used, if needed. | 12-16-2010 |
20110007848 | METHOD FOR CALIBRATING IQ MATCHING OF RECEIVER - A method and system for calibrating the mismatch between I data and Q data of a receiver is disclosed. The receiver includes an amplifier, first and second mixers coupled to the amplifier, an oscillator for driving the first and second mixers; and first and second filters coupled to the first and second mixers. The method comprises turning off the amplifier; and injecting a signal into the first and second mixers. The method also requires measuring the amplitude and phase information of the I and Q data from the first and second mixers based upon the injected signal to provide mismatch information and utilizing the mismatch information to compensate the I data and the Q data during normal operating mode. In a method and system in accordance with an embodiment, the IQ mismatch of a receiver can be measured and compensated. This allows direct-conversion architecture, which is known to have IQ mismatch problem, to be used. Furthermore, if this calibration method is applied to other receiver architectures, the yield loss due to IQ mismatch can be minimized. | 01-13-2011 |
20110069787 | Apparatus and Method for Processing Multi-Channel Signals and Multi-Channel Receiver Using the Same - Disclosed is a multi-channel signal receiver technology. An RF front-end in an RF receiver receiving at least two RF signals with different transmission bandwidths includes: at least two RF tuners receiving, amplifying, and frequency-converting the at least two RF signals, respectively; a switch selecting one of signals output from the at least two RF tuners; a channel filter eliminating interference signals included in a signal output from the switch, and passing a signal of a transmission band; an ADC converting the signal output from the channel filter into a digital signal; a fixed sampling frequency generator generating and transferring a fixed sampling frequency to the ADC. | 03-24-2011 |
20110129039 | SIGNAL RECEIVING APPARATUS AND SIGNAL PROCESSING METHOD - According to one embodiment, a signal receiving apparatus includes a first setting module, a calculator, a detection module, a generator, and a determination module. The first setting module is configured to set a rising or falling of an arbitrary high pulse as a starting point. The calculator is configured to calculate a sampling period based on intervals between a plurality of high pulses. The detector is configured to set a multiple of the sampling period from the starting point as reference points and to detect positions where the plurality of high pulses are generated from each of the reference points. The generator is configured to generate a histogram for the positions where the plurality of high pulses are generated. The determination module is configured to determine positions obtained by adding a value of a peak in the histogram to each of the reference points as sampling points. | 06-02-2011 |
20110274216 | CONTINUOUS PHASE MODULATION FOR SATELLITE COMMUNICATIONS - A new coded continuous phase modulation (CPM) scheme is proposed to enhance physical layer performance of the current DVB-RCS standard for a satellite communication system. The proposed CPM scheme uses a phase pulse design and combination of modulation parameters to shape the power spectrum of CPM signal in order to improve resilience to adjacent channel interference (ACI). Additionally, it improves error rate performance at both high and low frame error rates using low complexity binary convolutional codes and S-random bit interleaving. Phase response using the proposed CPM scheme is a weighted average of the conventional rectangular and raised-cosine responses and provides optimum response to minimize frame error rate for a given data rate. | 11-10-2011 |
20120288033 | RECEIVING APPARATUS FOR HIGH FREQUENCY IMAGING SYSTEM - A receiving apparatus, a receiving method, and an imaging apparatus and method, adapted to receive high frequency image signals. The apparatus includes two or more receiver channels, each receiver channel including an antenna pattern including plural antenna elements to receive high frequency image signals, a receiving mechanism to process the high frequency image signals received by the antenna elements into baseband signals, an analog-to-digital conversion mechanism to convert the baseband signals from the receiving mechanism into digital signals, a phase shifting mechanism to phase shift the digital signals, and a combining mechanism to combine the phase shifted digital signals from the receiver channels into combined signals. | 11-15-2012 |
20120314813 | WIRELESS TRANSMISSION SYSTEM - A wireless data transmitter including: a data modulator adapted to modulate a data signal based on a frequency signal; and at least one antenna adapted to wirelessly transmit the modulated data signal and the frequency signal independently. | 12-13-2012 |
20130216004 | RECEIVER HAVING INPHASE-QUADRATURE IMBALANCE COMPENSATION AND INPHASE-QUADRATURE IMBALANCE COMPENSATION METHOD THEREOF - A receiver having Inphase-Quadrature (I-Q) imbalance compensation and an I-Q imbalance compensation method thereof are provided. The receiver calculates a cross-ratio parameter according to a first ideal receiving value and a first ideal conjugate receiving mirror of a first receiving signal and a second ideal receiving value and a second ideal conjugate receiving mirror of a second receiving signal. The receiver calculates an I-Q imbalance compensation parameter according to the cross-ratio parameter, the first ideal receiving value, the first ideal conjugate receiving mirror, the second ideal receiving value, the second ideal conjugate receiving mirror, the first receiving signal and the second receiving signal. The receiver compensates a third receiving signal according to the I-Q imbalance compensation parameter. | 08-22-2013 |