| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 375149000 | Having specific code synchronization | 34 |
| 20080260007 | Method and Apparatus for Achieving Channel Variability in Spread Spectrum Communication Systems - A method and apparatus are disclosed for modulating a communication signal in a code division multiple access (CDMA) environment using orthogonal N by N Hadamard spread spectrum codes Orthogonal spreading codes are used that have lengths that are not a power-of 2 to provide additional channel variability for various multimedia applications and increase the flexibility of the number of channels/bandwidth relationship. The Hadamard codes are multiples of 4 (4n) and demonstrate a good cross-correlation property, making them very useful in the flexible design of code division multiple access (CDMA) systems. A transmitter encodes each of to N data streams (N not being a power of 2), to be transmitted using a 4n codeword, N | 10-23-2008 |
| 20080260008 | METHODS AND APPARATUS FOR TIME TRACKING USING ASSISTANCE FROM TDM PILOTS IN A COMMUNICATION NETWORK - Methods and apparatus for time tracking using assistance from TDM pilots in a communication network. In an aspect, a method is provided for time tracking in a device operating on a communication network, wherein the device performs a time tracking algorithm. The method includes determining a delay spread, and modifying at least one parameter used by the time tracking algorithm based on the delay spread. In another aspect, an apparatus is provided for time tracking in a device operating on a communication network, wherein the device performs a time tracking algorithm. The apparatus includes computation logic for determining a delay spread, and control logic for modifying at least one parameter used by the time tracking algorithm based on the delay spread. | 10-23-2008 |
| 20080267264 | Low phase noise clock generator for device under test - According to one embodiment, a low phase noise clock generator includes a frequency multiplier using a crystal oscillator, which is configured to receive a reference clock and to generate a multiplied reference clock. The low phase noise clock generator further includes a prescaler module configured to divide down a frequency and significantly reduce phase noise of the multiplied reference clock to generate a low phase noise clock. In one embodiment, a tester can be configured to input the low phase noise clock into the crystal oscillator input of a device under test to accurately test a phase noise of the device under test. | 10-30-2008 |
| 20080304554 | METHOD AND APPARATUS FOR ESTIMATING IMPAIRMENT COVARIANCE MATRICES USING UNOCCUPIED SPREADING CODES - In one of its aspects, the technology concerns a method of processing a signal which includes physical data channels which have been channelized using spreading codes. The method comprises (1) despreading unoccupied spreading codes (e.g., codes which are essentially unobscured by traffic data) included in the signal to obtain unoccupied code despread values, (2) using the unoccupied code despread values to form an impairment covariance matrix; and (3) using the impairment covariance matrix along with a channel estimate to form a processing parameter. The processing parameter can be one of combining sets and a signal quality estimate. In another of its aspects, the technology concerns a coherent, linear equalizer apparatus configured to process a signal which includes physical data channels which have been channelized using spreading codes. The equalizer apparatus comprises plural delay fingers ( | 12-11-2008 |
| 20080310486 | PRAGMATIC ADAPTIVE MRC AND MMSE MIMO-OFDM RECEIVER ALGORITHM - An adaptive receiver algorithm is disclosed, for use in MIMO-OFDM systems. The adaptive receiver algorithm selectively chooses either the MRC technique or the MMSE technique, for optimum receiver performance, depending on the characteristics of the wireless environment. | 12-18-2008 |
| 20090016413 | PSEUDO RANDOM CLOCK GENERATOR - A pseudo random clock generator includes a clock generator for generating a clock signal. A pseudo random code generator receives the clock signal and thereby generating a pseudo random code. A code limiter enables the value of the pseudo random code being unchanged for at least two periods of the clock signal. A logic gate applies a logic operation to the pseudo random code and the clock signal and thereby outputting a pseudo random clock. | 01-15-2009 |
| 20090041095 | METHOD AND APPARATUS FOR FINE FREQUENCY SYNCHRONIZATION IN WIRELESS BROADBAND (WIBRO) SYSTEM WITHOUT USING GLOBAL POSITIONING SYSTEM (GPS) RECEIVER - Provided is a fine frequency synchronization method of a WiBro system, and particularly, a fine frequency synchronization method which measures a spread degree of a received signal of an adjacent subcarrier using orthogonality of PN sequences and thereby estimates a frequency offset, in a base station or a wireless repeater without using a GPS receiver. The fine frequency synchronization method includes: (a) performing despreading on received adjacent subcarrier sequences, using a PN sequence transmitted from a transmitting party; (b) obtaining ratios of correlative values obtained by the despreading; and (c) estimating a frequency offset on the basis of the ratio of correlative values. Accordingly, fine frequency offset estimation with relatively low complexity is possible without using a GPS receiver in a WiBro environment where interference signals of other base stations or repeaters exist. | 02-12-2009 |
| 20090052504 | COMMUNICATION TERMINAL, BASE STATION, AND RECEIVING METHOD - A communication terminal in which a circuit component can measure active sets thereby to reduce the circuit scale. In the terminal, a synchronization base station switch ( | 02-26-2009 |
| 20090213911 | CODE TRACKING LOOP WITH AUTOMATIC POWER NORMALIZATION - The present invention is for a receiver incorporated into User Equipment (UE) or base stations of a code division multiple access (CDMA) communication system. The UE and base station are in communication with one of the plurality of base stations and receives a communication signal through the receiver. The communication signal is correlated using a delay locked code tracking loop, that estimates and tracks a channel delay. The tracking loop comprises a reference code generator and an interpolator for generating timed signal versions in response to said communication. A timed signal correlator, included in the tracking loop for correlating at least two of the timed signal versions with the code reference signal. The result of the correlation is used for generating an error signal. An automatic power normalization loop (APN), that is responsive to the interpolator, generates a power error signal that normalizes the error signal through a normalization circuit. | 08-27-2009 |
| 20090238248 | SPREAD SPECTRUM WITH DOPPLER OPTIMIZATION - A method of compensating for doppler phase errors includes receiving a signal at a receiver wherein the signal is spread using a pseudo-noise code, dividing the signal into a plurality of smaller coherent units and then compensating for induced doppler phase errors by analyzing the plurality of smaller coherent units. Analysis may include producing a plurality of coherent sums by summing across the smaller coherent units and then summing non-coherently the plurality of coherent sums. Analysis may also include demodulating a symbol from the smaller coherent units. A modulation technique may be selected from a plurality of modulation techniques and then be used to encode and transmit a symbol stream. | 09-24-2009 |
| 20090285268 | Signal receiver using data bit search in alternating time segments - A GNSS receiver and method using alternating “A” and “B” time segments for a reception time length of two or more data bits. The GNSS signal in an “A” time period comprising the “A” time segments is integrated for determining “A” magnitudes corresponding to code phase increments and the GNSS signal in a “B” time period comprising the “B” time segments is integrated for determining “B” magnitudes corresponding to code phase increments. A trial-and-error data bit search is performed for depolarizing data bit senses. The code phase increment showing the largest correlation level is used for acquisition of the GNSS signal and/or determination of the location where the GNSS is being received. | 11-19-2009 |
| 20090310653 | HYBRID POLYPHASE AND JOINT TIME-FREQUENCY DETECTION - A demodulator ( | 12-17-2009 |
| 20100027591 | POSITIONING SIGNAL RECEPTION DEVICE AND CONTROL METHOD OF POSITIONING SIGNAL RECEPTION DEVICE - A positioning signal reception device receives a positioning signal transmitted from a position information satellite, and includes: a signal reception portion that obtains a reception signal by receiving the positioning signal; an A/D conversion portion that generates a digital signal by converting the reception signal into a digital form; a filter portion that subjects the digital signal to frequency separation, a characteristic of the filter portion being changeable; a filter characteristic change portion that changes the characteristic of the filter portion according to an operating state of the positioning signal reception device and an external environmental condition of the positioning signal reception device; and a code synchronization establishment portion that establishes synchronization of spreading codes contained in the reception signal. | 02-04-2010 |
| 20100098137 | DETECTION DEVICE OF A SPREADING CODE AND A TIMING, AND A METHOD THEREOF - An A/D converted and inputted signal is stored in a memory. A sliding correlator sequentially reads the signal stored in the memory and despreads this signal. A despreading timing is adjusted and then the candidate for a despreading code is outputted from a code generation circuit. The despreading code outputted at a predetermined timing is used for obtaining a correlation value of signals outputted from the memory, using the sliding correlator. Thus, by storing signals in the memory, fluctuation of a correlation value caused by fading does not occur while specifying a code or detecting a despreading timing. | 04-22-2010 |
| 20100142596 | SYNCHRONIZATION ERROR TRACKING DEVICE AND METHOD THEREOF - Provided is a synchronization error tracking device and method. The method and system estimates and corrects the synchronization error generated by time and frequency offsets during the data transmission interval and uses a module designed for initial synchronization or channel estimation without adding a new correlation operator. Further, a combining mark value and a synchronization position value acquired during the synchronization process are used. | 06-10-2010 |
| 20100166045 | METHOD FOR OBTAINING PRECISE SAMPLING FREQUENCY OF GLOBAL POSITIONING SYSTEM (GPS) - A method for obtaining a precise sampling frequency of a global positioning system (GPS) is applied in a GPS receiver. First, a radio frequency (RF) module of the GPS receiver is used to receive a satellite signal from at least one satellite. Then, a plurality of code delays of the satellite signal is calculated at a fixed time interval, and time differences between all adjacent two code delays among all the obtained code delays are calculated to obtain a plurality of time differences. Next, a mean value of all the obtained time differences is calculated. At last, a ratio between 1000 times of the mean value and the fixed time interval is calculated to obtain an error value, and the error is added to a standard sampling frequency of the RF module to obtain a new sampling frequency. | 07-01-2010 |
| 20100215084 | SIMPLE AND ROBUST DIGITAL CODE TRACKING LOOP FOR WIRELESS COMMUNICATION SYSTEMS - A simple and robust CTL is used for time tracking of multipath components of a spread spectrum signal transmitted over a wireless multipath fading channel. A digital code-tracking loop includes the implementations of despreading early and late data samples by use of a pseudonoise sequence, an error signal output generated by the despreading, and adjustment for a plurality of on-time, early and late samples, a data rate of a control signal provided as a fractional proportion of a data rate of error signals. | 08-26-2010 |
| 20100254437 | SIGNAL PROCESSING APPARATUS, INFORMATION PROCESSING APPARATUS, SIGNAL PROCESSING METHOD, DATA DISPLAY METHOD, AND PROGRAM - In a signal processing apparatus a synchronizer acquires synchronization with the spreading code of an intermediate frequency signal converted from a signal received from a satellite in a global positioning system. A demodulator then demodulates a message contained in the intermediate frequency signal. A measuring unit outputs a primary signal to a predetermined signal line, the primary signal expressing positioning results for the apparatus as measured on the basis of the demodulated message. A secondary signal output unit attaches a predetermined header to a secondary signal and outputs the result to the predetermined signal line, the secondary signal containing at least the intermediate frequency signal, or a signal generated from the intermediate frequency signal. | 10-07-2010 |
| 20100329311 | UPLINK SIGNAL DETECTION IN RF REPEATERS - A method for detecting an IS-95 signal without knowledge of a spreading code for the IS-95 signal is provided. A received baseband signal is rotated through a plurality of phase-shifts. For each phase-shifted baseband signal, an in-phase component or a quadrature component of the phase-shifted baseband signal is realigned. The in-phase and quadrature components are multiplied by a PN short code to partially despread the components. The partially despread in-phase and quadrature components are multiplied and integrated. The integrated despread in-phase and quadrature components are compared to a threshold value. In response to exceeding the threshold value, the received baseband signal is identified as an IS-95 signal. The method may be implemented on a repeater for repeating signals between multiple sources. | 12-30-2010 |
| 20110007782 | RECEIVER, SIGNAL PROCESSING METHOD AND PROGRAM - A receiver includes a receiving unit that receives a signal from a satellite, a frequency conversion-discretization unit that converts the signal received in the receiving unit into an intermediate frequency signal of a frequency bandwidth including 0 Hz, and discretizes the frequency-converted intermediate frequency signal with a predetermined sampling frequency, a filter unit that filters the discretized signal, which is output from the frequency conversion-discretization unit, through a predetermined filter, a synchronization acquisition unit that acquires synchronization of a spreading code in the discretized signal filtered by the filter unit, and a synchronization holding unit that holds the synchronization of the spreading code, which is acquired by the synchronization acquisition unit. | 01-13-2011 |
| 20120027053 | METHOD AND APPARATUS FOR REDUCING MULTI-USER PROCESSING IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes. | 02-02-2012 |
| 20120281734 | High Sensitivity GPS Receiver - A high sensitivity GPS receiver includes an acquisition engine and a tracking engine. The acquisition engine processes GPS satellite data at data rate that is substantially equal to twice the coarse acquisition (CA) code chip rate. This data rate advantageously enables the acquisition engine to process GPS satellite data with relatively less hardware area than traditional GPS acquisition approaches. In one embodiment, the high efficiency acquisition engine may be over-clocked, thereby allowing different phases of a CA code to be correlated quickly. The tracking engine can advantageously process GPS satellite data at a data rate that does not have an integer relationship to the CA code chip rate. | 11-08-2012 |
| 20130003786 | SYNCHRONIZATION ACQUISITION METHOD OF REAL TIME LOCATING SYSTEM - Provided are a method for dynamically acquiring a PN synchronization of a blink signal in a reader according to a channel state when a tag transmits a direct sequence spread spectrum (DSSS) blink signal having a predetermined period and the reader receives the blink signal in a 2.4 GHz RTLS system which complies with an ISO/IEC24730-2 standard, and a method for synchronizing a frame using a preamble. | 01-03-2013 |
| 20130094541 | RECEIVING DEVICE, RECEIVING METHOD, COMPUTER PROGRAM, AND PORTABLE TERMINAL - To provide a receiving device which is capable of reducing average power and peak power by holding pseudo synchronization of a satellite signal during a sleep period. Provided is a receiving device including a receiving unit for receiving a signal from a satellite, a frequency conversion unit for converting a frequency of the received signal into a predetermined intermediate frequency, a synchronization acquisition unit for carrying out synchronization acquisition and for detecting a carrier frequency, and a synchronization holding unit for assigning and setting, per satellite, a phase of the spread code and the carrier frequency to each of a plurality of channels independently provided in a corresponding manner to a plurality of the satellites to synchronously hold the spread code and a carrier and also for demodulating a message included in the intermediate frequency. The synchronization holding unit includes a spreading code generation unit for generating a spreading code synchronized with the spread code, and in a sleep period in which a positioning operation is not carried out, the synchronization holding unit causes only the spreading code generation unit to operate and a counter that the synchronization holding unit refers to also operates. | 04-18-2013 |
| 20130195149 | SIGNAL PROCESSING APPARATUS, INFORMATION PROCESSING APPARATUS, SIGNAL PROCESSING METHOD, DATA DISPLAY METHOD, AND PROGRAM - A mobile electronic device that includes a circuitry configured to acquire synchronization with a spreading code of an intermediate frequency signal that is obtained by converting a frequency of a received signal from a satellite in a global positioning system into a predetermined intermediate frequency, demodulate a message included in the intermediate frequency signal, output a primary signal to a predetermined signal line, and attach a predetermined header to a secondary signal and output the result to the predetermined signal line, and includes a display unit configured to display data corresponding to the primary signal and the secondary signal, such that the primary signal includes results of measuring one of position, velocity, and time of the mobile electronic device based on the message that is demodulated by the circuitry, and that the secondary signal includes the intermediate frequency signal. | 08-01-2013 |
| 20140056333 | Random Non-Cyclical Binary Code Generator - Presented is a random non-cyclical binary code generator for communications systems. A random non-cyclical sequence of integers from a random number generator is extended in length to form an extended integer sequence. This integer set is immediately loaded into a 10-minute epoch memory consistent with 10 minutes of chips. These integers are then synchronously retrieved from memory under GPS time-of-day control. Retrieved integers are immediately converted into pulse pairs of all ones followed by all zeros with each pulse width equal to the integer value in chips. The chips are immediately concatenated to a chipping clock shifting memory wherein each memory location is a unique phase source of the binary code. The memory length in chips is twice the range uncertainty for a 10 MHz chip rate, with the center chip of the shifting memory maintained as the source of universal time synchronized local binary code. | 02-27-2014 |
| 20140185655 | METHOD AND APPARATUS FOR CORRECTING A REFERENCE CLOCK OF A GPS RECEIVER - An approach is provided for correcting a reference clock of a GPS receiver. The approach involves determining one or more frequency offset values. The approach also involves determining one or more codes associated with one or more satellites. The approach further involves determining a second code associated with the one or more satellites. The approach additionally involves determining one or more delay values between the second code and the one or more first codes. The approach also involves determining one or more proportional values based on the one or more delay values and a determined correlation. The approach further involves determining one or more correlation peak values and determining one or more estimated frequency offset error values based on the one or more correlation peak values. The approach additionally involves causing a calibrated reference clock frequency value to change to a recalibrated reference clock frequency value based on the estimated frequency offset error values. | 07-03-2014 |
| 20140321513 | SYSTEMS AND METHODS FOR ENHANCING GNSS NUMERICALLY CONTROLLED OSCILLATORS - Systems and methods for enhancing numerically controlled oscillators are provided. In certain embodiments, a numerically controlled oscillator enhancer includes a desired rate interface configured to receive a desired numerically controlled oscillator rate from an external device and a closest quantized rate identifier configured to identify a closest quantization rate that is closest to the desired numerically controlled oscillator rate. Further, the numerically controlled oscillator enhancer includes a quantization rate corrector configured to identify the quantization rate correction that, when applied to the closest quantization rate, constrains an accumulated quantization error within an error range and a rate output configured to output a corrected quantized numerically controlled oscillator rate. | 10-30-2014 |
| 20150049791 | REACQUISITION METHOD OF A CDMA MODULATED SATELLITE SIGNALS AND RECEIVING APPARATUS IMPLEMENTING THE METHOD - Acquiring a satellite signal, by, receiving a CDMA-modulated signal; generating a plurality of CDMA-type test signals comprising a reference test signal having a first chip duration, and a plurality of test signals delayed/anticipated of a corresponding time offset from the respective test reference signal, less than the chip duration; calculating correlations between the CDMA-modulated signal and the plurality of test signals for obtaining a plurality of correlation results; selecting, based on the correlation results, acquisition parameters associated to a candidate satellite signal; acquiring or rejecting the acquisition parameters selected based on the correlation results. | 02-19-2015 |
| 20150078421 | DEVICE FOR RECEIVING SIGNALS WHICH HAVE CARRIER FREQUENCIES AND CODES - The device for receiving signals which have carrier frequencies and codes, said signals being navigation or communication signals, has multiple individual antennas ( | 03-19-2015 |
| 20150098494 | METHOD OF DETERMINING THE POSITION OF A DEVICE AND A DEVICE THAT IMPLEMENTS THE METHOD - There is provided a method of determining the position of a device using a satellite positioning system, the method comprising (a) operating a satellite positioning system receiver in the device to collect a plurality of sets of signals; and, when the position of the device is to be determined (b) processing a set of signals to determine if the set is likely to contain signals from satellites in the satellite positioning system; and (c) if it is determined in step (b) that the set of signals is likely to contain signals from satellites in the satellite positioning system, processing the set of signals to calculate the position of the device; (d) if it determined in step (b) that the set of signals is not likely to contain signals from satellites in the satellite positioning system, repeating steps (b), (c) and (d) with another set of signals. | 04-09-2015 |
| 20150139281 | SYNCHRONIZATION DEVICE AND SYNCHRONIZATION METHOD THEREOF - A synchronization device and a synchronization method for use in a receiver are provided. The receiver receives a signal from a transmitter. The synchronization device generates a plurality of first pseudo noise codes in sequence according to a first code phase sequence and generates a plurality of second pseudo noise codes in sequence according to a second code phase sequence which is the reverse of the first code phase sequence, simultaneously. Every time a first pseudo noise code and a second pseudo noise code are generated, the synchronization device makes a correlation calculation for the first pseudo noise code, the second pseudo noise code and the signal. The synchronization device further determines a code phase according to the correlation calculations, and synchronizes with the signal according to the code phase. The synchronization method is applied to the synchronization device to implement the operations. | 05-21-2015 |
| 20150312079 | Estimation of CFO Based on Relative Values of Frequency Bins Corresponding to Used Subcarriers of Received Preamble Symbols for OFDM Systems - It is proposed a method for receiving and demodulating an orthogonal frequency division multiplexing signal received through a transmission channel (TC) by a receiver (RCV), comprising demultiplexing said signal to generate time symbols (y | 10-29-2015 |
| 20150341078 | METHODS AND APPARATUS FOR FREQUENCY OFFSET ESTIMATION AND CORRECTION PRIOR TO PREAMBLE DETECTION OF DIRECT SEQUENCE SPREAD SPECTRUM (DSSS) SIGNALS - Methods and apparatus for frequency offset estimation and correction prior to preamble detection of DSSS signals. An integrated circuit is disclosed including a receiver circuit having an input coupled to receive a DSSS signal, the receiver circuit configured to sample the DSSS signal and to output a sequence of digital samples; carrier frequency offset estimation logic configured to perform a carrier frequency offset estimation on the digital samples; carrier frequency correction logic configured to correct the carrier frequency of the sequence of digital samples using the carrier frequency offset estimation and to output a sequence of corrected digital samples; offset quadrature phase shift keying (O-QPSK) demodulation logic configured to perform demodulation on the corrected digital samples and further configured to output symbols corresponding to the corrected digital samples; and preamble identification configured to identify and detect a preamble sequence in the symbols. Additional methods and apparatus are disclosed. | 11-26-2015 |
