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Correlation-type receiver

Subclass of:

375 - Pulse or digital communications

375130000 - SPREAD SPECTRUM

375140000 - Direct sequence

375147000 - Receiver

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DocumentTitleDate
20090034589MULTIPLE BRANCH PSYNC DETECTION MODULE - A wireless terminal is operable to receive a Wideband Code Division Multiple Access (WCDMA) signal from a base station and includes clock circuitry, a wireless interface, and a Primary Synchronization (PSYNC) module. The clock circuitry generates a wireless terminal clock using a wireless terminal oscillator. The wireless interface receives the WCDMA signal, which is produced by the base station using a base station clock that is produced using a base station oscillator that is more accurate than the wireless terminal oscillator. The PSYNC module includes a plurality of PSYNC correlation branches. Each PSYNC correlation branch phase rotates the WCDMA signal based upon a respective frequency offset, correlates the phase rotated WCDMA signal with a Primary Synchronization Channel (PSCH) code over a plurality of sampling positions, and produces PSYNC correlation energies based upon the correlations for each of the plurality of sampling positions.02-05-2009
20090196331Signal processing unit and wireless communication device - A signal processing unit and a wireless communication device are provided for making it possible to detect a frequency by means of a small scale operation circuit in a short time. The signal processing unit and the wireless communication device are comprised of a carrier data generating unit; a carrier demodulation unit; a matched filter unit that divides carrier demodulated data into a plurality of portions, carries out despread processing and accumulating operation processing as partial correlation processing, further carries out full addition processing for the partial correlation processing result, and outputs correlation detected data; a correlation peak detecting unit that detects a correlation peak from the correlation detected data and outputs correlation peak position information; a coarse frequency deviation detecting unit that outputs a frequency deviation amount with respect to the carrier demodulated data to the carrier data generating unit; and a fine frequency deviation detecting unit that outputs a fine frequency deviation amount from the correlation detected data and the correlation peak position information to the carrier data generating unit.08-06-2009
20080260009Combine Time Multiplexed Pilot (TMP) Derotation with Descrambling and Despreading in Data Correlators Used by Rake Receivers - The invention provides a code modification circuit for receiving a descrambling/dispreading code at a first input pair thereof and a pilot derotation code at a second input pair thereof, and arranged to combine the codes to form a combined code for providing to a correlator such that the correlator can recover data or a pilot signal from an input sequence supplied thereto.10-23-2008
20100158081Memory reduction in GNSS receiver - Radiolocalization receiver with a massively parallel array of correlators, comprising a data compression module (06-24-2010
20100074308GNSS SIGNAL PROCESSOR - A signal processor for GPS or other GNSS radiolocalization systems, includes a RAM pre-correlation buffer which is filled in sync with the code NCO, thus all sample alignment in the buffer is fixed The device further includes an amplitude compressor to limit the size of the buffer memory and is optimized to provide data to the following DFT unit in small bursts that can be processed in real time without the need for intermediate buffers. Thanks to these features the processor limits the amount of fast intermediate memories, is simpler and has lowerpower consumption.03-25-2010
20130039392Satellite Signal Acquisition - A technique for reducing the dwell time in acquiring a satellite signal is provided. The technique minimizes the dwell time in searching for a satellite signal in cells of a search space by comparing the peak-power-to-average ratio (PAPR) to one or more thresholds at one or more intermediate points during the search in a code phase/Doppler frequency bin. The comparison is then used to determine whether to continue the search in a current code phase/Doppler frequency bin or to continue to the next code phase/Doppler frequency bin.02-14-2013
20100046589GPS M-CODE RECEIVER TRACKING SYSTEM - An m-code GPS receiver receives m-code GPS communication signals having a multimodal autocorrelation, using an m-code mode identifier unambiguously determining a mode value of one of the m-code modal peaks coherently aligned to a coherent unimodal detected envelope, based on sequential probability estimation in an m-code envelope tracking filter using filter residual estimation or with a coherent m-code and c/a-code tracking filter also based on filter residual estimation, for generating m-code phase errors, for unambiguous and precise m-code code phase tracking in closed feedback loops, for preferred use in navigation systems.02-25-2010
20100103988DEVICE FOR RECEIVING SATELLITE SIGNALS INCLUDING A PHASE LOOP WITH DELAY COMPENSATION - The general field of the invention is that of devices for receiving radio-navigation signals by satellite, said received signals being transmitted at a carrier frequency, said device including at least means for generating a local signal at a local frequency and a tracking device including a feedback loop called carrier loop for phase-locking the local frequency on the carrier frequency, said loop including a hardware portion and a software portion. The software portion performs the functions of discrimination of the phase of the correlated signal and filtering of said phase. In the various devices according to the invention, the software portion also includes correlation functions mainly dependent on the linear variation coefficients between the local phases φ04-29-2010
20100103989Robust Low-Frequency Spread-Spectrum Navigation System - Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.04-29-2010
20100040118Methods And Apparatus For Reducing A Sampling Rate During A Sampling Phase Determination Process - An electronic circuit includes control circuitry, an analog-to-digital converter which includes a sampler, a pseudorandom noise (PN) generator configured to produce a PN signal, and a plurality of n correlators. The control circuitry is configured to control the sampler, in a sampling phase determination process, to sample a signal at a sampling period of T±T/n (where T is a symbol or chip period of the signal, and n is the number of phases of the sampled signal where n≧4) for outputting a sample set for each one of n phases of the sampled signal. Each correlator has a first input configured to receive one of the sample sets associated with a corresponding one of the n phases of the sampled signal, a second input configured to receive the PN signal, and an output which provides a correlation result from a correlation process between the sample set and the PN signal. The control circuitry is further configured to identify, from the correlation results, one of the phases associated with the optimal correlation result. The control circuitry is then configured to control the sampler, in a communication mode, to sample a received signal at a sampling period of T at the phase associated with the optimal correlation result, for use in recovering user or signaling information from the received signal.02-18-2010
20100040117CORRELATION PEAK LOCATION - Apparatus for determining a location of a peak in correlation output samples, the apparatus being arranged to receive samples from at least one correlator over a plurality of symbol time periods; combine samples from a period that is longer than the symbol time period into combined samples; and determine the position of a peak in the combined samples.02-18-2010
20100329313PROCESSOR FOR USE AS A PATH SEARCHER OF A SPREAD SPECTRUM RECEIVER AND A METHOD OF OPERATION OF THE PROCESSOR - A path searcher for use in a spread spectrum receiver, including a correlator for correlating a received signal in different time positions with a reference code to select for further processing time positions of the signals showing the strongest correlations, wherein the correlator is operable to obtain a correlation energy result for each time position in a set of possible time positions, a comparator for comparing the correlation energy results with each of a plurality of energy thresholds and a recorder for recording data indicating time positions for correlation energy results which are not less than the respective thresholds in different groups corresponding to the respective thresholds. Also described is a semiconductor device and a receiver incorporating the path searcher and a method of operation of the path searcher.12-30-2010
20130089121METHOD OF DEMODULATING MDCM SIGNAL USING HARD DECISION AND METHOD OF DEMODULATING MDCM SIGNAL USING SOFT DECISION - A method of demodulating a modified dual carrier modulation (MDCM) signal using hard decision includes generating real symbol vector candidates and imaginary symbol vector candidates which correspond to an MDCM signal pair; calculating a first norm between a real part of the MDCM signal pair and each of the real symbol vector candidates and determining as a real symbol vector a real symbol vector candidate that has the minimum first norm among the real symbol vector candidates; and calculating a second norm between an imaginary part of the MDCM signal pair and each of the imaginary symbol vector candidates and determining as an imaginary symbol vector an imaginary symbol vector candidate that has the minimum second norm among the imaginary symbol vector candidates.04-11-2013
20090161736SYSTEM AND METHOD FOR FAST CODE PHASE AND CARRIER FREQUENCY ACQUISITION IN GPS RECEIVER - A GPS receiver acquires carrier frequency and Gold code phase using short segments of a received GPS signal. In one embodiment, a 1-ms segment of the GPS signal is transformed to the frequency domain. This is multiplied by a frequency representation of the Gold code. The resulting product is converted to the time domain, and a peak is detected. The location of the peak corresponds to the code phase. If no peak is located, the carrier frequency is changed. Full- and half-bin steps in carrier frequency are considered. Processing gain is achieved by using longer segments of the input signal, for example 4 or 16 ms and integrating 1-ms segments. Considerations are provided for compensating for the effects of a transition, should it occur in the short segment of the GPS signal being processed. Integrations can be performed using non-coherent and coherent techniques. Adjustments are made for non-integral millisecond segment lengths.06-25-2009
20090304051METHOD 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.12-10-2009
20090041096EFFICIENT SYNCHRONIZATION OF A SPREAD SPECTRUM SIGNAL IN THE PRESENCE OF DELAY AND FREQUENCY UNCERTAINTY - Implementations for the synchronization of a spread spectrum signal in the presence of delay and frequency uncertainty. According to one embodiment, there is a signal processing technique that combines coherent integration with a Fast Fourier Transform (FFT). Coherent integration with the direct sequence code is achieved through the use of shift registers, code modulators, and integrators, and applied to subsequences of the spreading code. Subsequences can then be combined via an FFT to achieve further coherent integration and to simultaneously deal with frequency uncertainty.02-12-2009
20110013675METHOD OF RECEPTION AND RECEIVER FOR A RADIO NAVIGATION SIGNAL MODULATED BY A CBOC OR TMBOC SPREAD WAVEFORM - To receive a radio navigation signal modulated by a modulation waveform, the modulation waveform comprising a component BOC(n01-20-2011
20090268789LOW I/O BANDWIDTH METHOD AND SYSTEM FOR IMPLEMENTING DETECTION AND IDENTIFICATION OF SCRAMBLING CODES - A system for detecting and identifying the identity of a base station or cell which transmits a scrambling code is provided. According to one aspect of the system, the system is used to perform scrambling code detection of eight (8) primary cells (each scrambling code's X-component being spaced sixteen (16) chips apart) in a group. According to another aspect of the system, a single scrambling code generator is used to generate a master scrambling code. The master scrambling code is then used to create individual scrambling codes which are used in correlation with received signals to detect in parallel which one of the eight (8) possible primary cells in the group transmitted the received signals. According to yet another aspect of the system, each of the correlators maintains a corresponding X-component segment of the master scrambling code. For every sixteen (16) chips, a new X-component segment of the master scrambling code is introduced into one of the correlators, a X-component segment of the master scrambling code is dropped from another correlator, and X-component segments of the master scrambling code are sequentially shifted or propagated through the remaining correlators; and concurrent correlations are performed by the correlators using their respective corresponding X-component segments of the master scrambling code and newly received signals.10-29-2009
20090268788SYSTEM AND/OR METHOD FOR DETECTING MULTI-TONE JAMMING - The subject matter disclosed herein relates to a system and method for processing a signal received from a satellite positioning system (SPS) in the presence of a multi-tone jammer. In one particular implementation, processing of a signal may be altered in response to detection of one or more conditions.10-29-2009
20130064270METHOD AND APPARATUS FOR ACQUISITION, TRACKING, AND SUB-MICROSECOND TIME TRANSFER USING WEAK GPS/GNSS SIGNALS - A method and apparatus provide high-sensitivity GPS/GNSS signal acquisition in a stationary GPS/GNSS receiver. The uncertainty in frequency due to apparent Doppler shift is partitioned into a plurality of contiguous frequency bins, and the uncertainty in location of navigation data bit boundaries is partitioned into equally spaced trial bit boundary locations. For each combination of the trial bit boundary location and the frequency bin, a signal block of captured complex baseband signal is Doppler-compensated using a phase rotator, and then synchronously summed with a periodicity of one period of C/A code so as to produce a compressed sample block having N samples. Each compressed sample block is cross-correlated with one period of reference C/A code to produce an N-value correlation function. A predetermined number of magnitudes of the N-value correlation functions are stack-accumulated into an array with precession compensation so as to find a correlation peak having the largest value.03-14-2013
20100027594METHOD AND SYSTEM FOR APPLYING VITERBI TYPE PSK DEMODULATION FOR OPTIMUM CORRELATION OF GPS SIGNALS - A method and system of improving sensitivity in the demodulation of a received signal over an arbitrary measurement time epoch, the method comprising the steps of: correlating the received signal in a coherent fashion; and utilizing a Viterbi phase state keying trellis demodulation with a variable resolution of phase states over 360.degree. to demodulate the radio frequency phase trajectory of the signal throughout the measurement time epoch; and the system comprising a receiver for receiving a direct sequence spread spectrum signal, the receiver comprising: an antenna for receiving the direct sequence spread spectrum signal; a downconverter for downconverting the received signal, producing a downconverted signal; an analog to digital converter (02-04-2010
20090010314Cdma Receiving Device, and Path Searching Method - Upon receiving an instruction to open a radio link, a path management unit (01-08-2009
20120114019RANGE EXTENSION TECHNIQUES FOR A WIRELESS LOCAL AREA NETWORK - Techniques for extending transmission range in a WLAN are described. In an aspect, a receiving station determines the frequency error between a transmitting station and the receiving station based on one or more initial packet transmissions and corrects this frequency error for subsequent packet transmissions received from the transmitting station. The residual frequency error is small after correcting for the frequency error and allows the receiving station to perform coherent accumulation/integration over a longer time interval to detect for a packet transmission. The longer coherent accumulation interval improves detection performance, especially at low SNRs for extended transmission range. The techniques may be used whenever the receiving station knows the identity of the transmitting station, e.g., if the subsequent packet transmissions are scheduled. Other aspects, features, and embodiments are also claimed and described.05-10-2012
20080317103METHOD AND APPARATUS FOR RECEIVING PLURALITY OF DATA SIGNALS - A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector.12-25-2008
20100135367Adaptive Correlation for Detection of a High-Frequency Signal - Embodiments related to acquisition, detection, and processing of a high-frequency signal are described and depicted.06-03-2010
20090074039GMSK SPREAD MODULATION RECEIVER - A technique for receiving spread spectrum GMSK signals that demodulates Gaussian Minimum Shift Keying transmissions involving a sequence of data symbols, a spread spectrum code comprising a sequence of spread spectrum chips, a sequence of pre-modulation chips combining the sequence of data symbols with the spread spectrum chips, wherein for each data symbol, at least one of the pre-modulation chips is generated by taking into account at least the data symbol and at least one of the spread spectrum chips.03-19-2009
20110280286Detecting Data Symbols - In one embodiment, a method includes generating a set of sequences of chip values and calculating a correlation between a demodulated signal and each one of two or more of the sequences. Each of the correlations has an absolute value, and one of the correlations has a highest absolute value. The method includes selecting the one of the sequences with the correlation having the highest absolute value; identifying a sequence index corresponding to the selected one of the sequences; and, for each of one or more data symbols in the demodulated signal, determining a value of the data symbol based on the sequence index corresponding to the selected one of the sequences.11-17-2011
20090207891MULTIPATH DETECTION FOR RECEIVED SPS SIGNAL - The subject matter disclosed herein relates to detecting and/or estimating multipath signals. For an example, a signal comprising at least one binary offset carrier (BOC) modulation signal is received. The BOC modulation signal is modulated with a pseudorandom noise sequence comprising a plurality of chips, wherein each of said chips has a set interval. In another aspect, the received signal is correlated with portions of the plurality of chips to provide a power signal. The portions of chips are less than the set interval. In a further aspect, presence of a multi-path signal in the received signal is detected. The detection of multipath is based, at least in part, on one or more characteristics of the power signal.08-20-2009
20100027592TECHNIQUE FOR SEARCHING FOR A PREAMBLE SIGNAL IN A SPREAD SPECTRUM SIGNAL USING A FAST HADAMARD TRANSFORM - In one embodiment, a method for demodulating and searching for a preamble signal containing a complex phasor signal is disclosed. The complex phasor is demodulated using a phasor-rotated fast transformer. A received signal is correlated with a spreading code to produce a correlated signal. The correlated signal is coherently accumulated to produce a coherently accumulated signal. A first phasor-rotated signal transformation is performed on a real component of the coherently accumulated signal, and a second phasor-rotated signal transformation is performed on an imaginary component of the coherently accumulated signal. Finally, the signal power of the transformed real and imaginary components of the coherently accumulated signal is determined.02-04-2010
20100027593METHOD AND DEVICE FOR RECEIVING A BOC MODULATION RADIO-NAVIGATION SIGNAL - Disclosed is a receiver and a method for receiving a radio-electric navigation signal modulated by a carrier at a frequency f02-04-2010
20090141779MULTIPATH SIGNAL DETERMINATION METHOD, SIGNAL SUITABILITY DETERMINATION METHOD, POSITIONING OPERATION METHOD, PROGRAM, AND MULTIPATH SIGNAL DETERMINATION CIRCUIT - A multipath signal determination method includes carrying out correlation operation between a received signal of a positioning signal spread-modulated with a spread code and a replica signal of the spread code with respect to each of IQ components at a predetermined sampling phase interval, and determining whether the received signal is a multipath signal or not, in accordance with a plot position in the case where each correlation value in each of the sampling phases is sequentially plotted on an IQ coordinate.06-04-2009
20090141778SYSTEMS AND METHODS FOR PROCESSING SPREAD SPECTRUM SIGNALS - Systems and methods are disclosed for processing at least two spread spectrum signals that at least partially overlap in time and in frequency. A main correlator bank with a trip detection component can determine a PN code phase for each of the spread spectrum signals that are associated with a PN code signal. The signals may at least partially overlap in time and in frequency. The PN code phases can be determined by comparing the signals to internally generated PN code phases. Based on the comparison, trips associated with the code phases are detected. The PN code phase for each signal can be used to extract a data signal from the signal. The data signals can be outputted.06-04-2009
20110206093SIGNAL ACQUISITION METHOD AND SIGNAL ACQUISITION APPARATUS - A signal acquisition method includes: performing a correlation operation for a satellite signal received from a positioning satellite; frequency-analyzing a result of the correlation operation over a predetermined time which is equal to or longer than a bit length of navigation message data carried by the satellite signal; extracting a power value in a predetermined frequency which includes at least a specific frequency determined according to the bit length, from a result of the frequency analysis; and acquiring the satellite signal using the extracted power value.08-25-2011
20090310654MULTIPLE CORRELATION PROCESSING IN CODE SPACE SEARCH - Methods and apparatus for code phase processing in a wireless communication device are described herein. A wireless device performs code phase search on a pseudo random code spread signal received over a wireless channel. A correlator correlates the received signal to a plurality of code phases in each of a plurality of frequency hypothesis. A maximum peak and a second peak are determined from the correlation results. Cross correlation processing is performed on the maximum peak and the maximum peak is discarded in favor of the second peak for position processing based on the results of the cross correlation.12-17-2009
20090207892Receiving device for spread spectrum communication - A receiving device for spread spectrum communication includes a phase determining unit and a data demodulating unit. The receiving device receives a signal spread and modulated with first spreading code. The phase determining unit calculates a cross correlation between the received signal and a second spreading code and determines a phase P(0) of the received signal based on the cross correlation. The data demodulating unit synchronizes the phase P (0) and the first spreading code and despreads and demodulates the received signal with the first spreading code. The number of components in each of the first spreading code and the second spreading code is an integer greater than or equal to 2.08-20-2009
20090262789METHOD AND APPARATUS FOR PERFORMING SIGNAL CORRELATION USING HISTORICAL CORRELATION DATA - A method and apparatus for estimating a satellite signal parameter in a satellite positioning system receiver is described. In an example, a plurality of correlation results between a satellite signal and a reference signal is generated in response to a command from a processor. At least one satellite signal parameter is estimated from the plurality of correlation results using a co-processor integrated within the satellite positioning system receiver. The at least one satellite signal parameter is then provided to the processor.10-22-2009
20090274198DETERMINATION OF ACTIVE SPREADING CODES AND THEIR POWERS - The present invention relates to a method and a device for detecting active spreading codes for a signal in a communication system and estimating power of the active spreading codes. Further, the present invention ensures efficient interference cancellation. Multiple correlations are performed at a single level of a spreading code tree, the produced output samples are then observed at this level during a defined period, and a decision for the activity and power is met for all existing codes via extracting and processing information from these samples. At the correlation step, unitary fast Walsh Hadamard transformation is performed at practically the highest spreading factor in the system.11-05-2009
20110206092SIGNAL ACQUISITION METHOD AND SIGNAL ACQUISITION APPARATUS - A signal acquisition method includes: performing a correlation operation for a received satellite signal, the satellite signal being transmitted from a positioning satellite; frequency-analyzing a result of the correlation operation over a predetermined time which is equal to or longer than a bit length of navigation message data carried by the satellite signal; extracting a power value in each frequency in which the power value satisfies a predetermined power condition, from a result of the frequency analysis; and acquiring the satellite signal using the extracted power value.08-25-2011
20080212657ITERATIVE DETECTION AND DECODING FOR A MIMO-OFDM SYSTEM - Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs). Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and “dual-maxima” approximation.09-04-2008
20080212656EQUALIZED MODULATION DEMODULATION (MODEM) FORMAT SELECTABLE MULTI ANTENNA SYSYTEM - Method and process for receiving, demodulating, equalizing and processing of Modulation Demodulation Format Selectable (MFS) received signal, received from two or more than two antennas and from diversity receivers. Baseband processing filtering and adaptively equalizing demodulated signals and providing filtered equalized burst operated Time Division Multiplexed (TDM) cross-correlated in-phase and quadrature phase signal, spread spectrum Code Division Multiple Access (CDMA) signal and Orthogonal Frequency Division Multiplexed (OFDM) signals. Demodulation of peak limited cross-correlated OFDM signals. Demodulation and adaptive equalization of receive filtered signal, wherein the received filtered signal is mis-matched to transmit filtered signal. Process for receiving and demodulating MFS signals received from modulated linearly amplified and transmit filtered modulated non-linearly amplified (NLA) signal transmitters. Demodulation and processing of cross-correlated TDM, spread, spectrum and OFDM signals.09-04-2008
20110206091Method for Reconstructing the Characteristics of Transmitted CDMA Waveforms - A waveform reconstruction system and method for using the same are disclosed. The system includes an RF down-converter that receives a signal and outputs a down-converted signal. A demodulator demodulates the down-converted signal to generate a recovered digital data stream. A pattern detector detects a predetermined pattern in the recovered digital data stream. A delay generator delays the down-converted signal and outputs a delayed copy thereof. A signal processing circuit combines the delayed copy with previously received delayed copies of the down-converted signal to reconstruct an averaged waveform from the plurality of delayed copies having the predetermined pattern.08-25-2011
20100061427Method Of Processing Positioning Signals, In Particular For Indoor Applications - A method of processing positioning signal constituted by a superposition of individual signals generated by a plurality of emitters, in particular satellite emitters, comprising:—a first step of coarse acquisition of said individual signals, comprising correlation of the received positioning signal with locally generated replicas of said individual signals;—a step of identifying spurious correlation peaks induced by interferences; and—a step of estimating the code delays and the carrier frequency shifts of the acquired individual signals which are not affected by said interferences. According to preferred embodiments of the invention, the method can also comprise:—a refining step of determining more accurate estimates of said code delays and carrier frequency shifts; and—a step of interference cancellation. The method of the invention is particularly suitable to indoor positioning applications.03-11-2010
20090168853CORRELATION CALCULATION PROCESS EXECUTION METHOD, CONTROL CIRCUIT, SIGNAL PROCESSING CIRCUIT, AND POSITION CALCULATION DEVICE - A correlation calculation process execution method utilizes a first mode and a second mode as a positioning mode that performs a correlation calculation process on a received signal of a positioning signal that is spread-modulated by a spreading code and a signal replica of the spreading code, the first mode being a mode in which correlation values are averaged in a first mode process period to output a correlation value, and the second mode being a mode in which correlation values are integrated in a second mode process period to output a correlation value, the method including repeating the first mode and the second mode while setting an intermediate time of the first mode process period to be the same as an integration reference time of the second mode process period, and variably setting a ratio of an ON/OFF period in at least one period of the first mode process period and the second mode process period.07-02-2009
20090168851A CORRELATOR SUM METHOD FOR SPREAD SPECTRUM SIGNAL RECEIVERS - The present invention provides systems and methods for faster acquisition and more stable tracking of spread spectrum signals with lower computational load requirements. Instead of the present day practice of using only the Prompt correlator, the systems and methods of the invention use the sum of the powers of all the correlators of a channel to determine the acquisition or tracking of the signal. These systems and methods improve the signal acquisition speed resulting in a reduced Time-To-First-Fix (TTFF). Further, these systems and methods improve the acquisition and tracking sensitivity of the receiver.07-02-2009
20080279260LOW POWER CONSUMPTION GNSS RECEIVER AND METHOD THEREOF - Disclosed is a low power consumption GNSS receiver by adaptively adjusting clock frequency. A correlator performs correlations to signals received from the channels with a correlator clock frequency. A DSP controls the correlator clock frequency according to a correlator load to performing correlations. The DSP calculates and adjusts code phases and Doppler frequencies for the signals in turn with a DSP clock frequency. The DSP controls the DSP clock frequency according to an accumulated throughput of calculation and adjustment or a predetermined threshold number of channels. The DSP controls the RF power according to the correlator load. A microprocessor processes a measurement result of the calculation and the adjustment for obtaining position information with a microprocessor clock frequency. The microprocessor controls the microprocessor clock frequency according to an accumulated progress of processing the measurement result. Accordingly, reducing power consumption for the GNSS receiver can be realized.11-13-2008
20080285632DECODING OF THE OVERHEAD CHANNELS OF THE GEO SATELLITE REVERSE LINK - A power efficient technique is used to demodulate the coded overhead channels of a GEO satellite uplink. A coherent receiver used in a wireless communication system is able to determine the information conveyed in the overhead channel, by effecting channel estimates from codewords extracted from a pilot signal. A valid set of codewords is established. Pilot symbols are extracted from a pilot signal and a channel estimate is made from the pilot signal. Codewords in the set of valid codewords are correlated and a channel phase ambiguity in the signals is removed and a codeword with the largest correlation is chosen. The chosen codeword is used to create a revised channel estimate.11-20-2008
20080279261CORRELATION COPROCESSOR - Apparatus and method for providing correlation in a CDMA receiver. A Generic Correlation Coprocessor comprises one or more correlation blocks. Each correlation block comprises a correlation input buffer coupled to one or more correlators. The correlators are coupled to an interpolator input buffer and to a correlator output buffer. One or more interpolators are coupled to the interpolation input buffer and to the correlation output buffer. The correlators correlate the received signal with PN codes to produce a correlated signal. The correlated signal is stored in the correlator output buffer and/or the interpolation input buffer, and provided from the interpolation input buffer to the one or more interpolators. The one or more interpolators interpolate the correlated signal to produce an interpolated signal. The interpolated signal is stored in the correlator output buffer. Signals are provided from the correlator output buffer to other receiver processing systems.11-13-2008
20080205494UNBIASED CODE PHASE DISCRIMINATOR - A feedback control law steers a reference phase that tracks the phase of a received code sequence. The reference phase clocks a track-reference signal consisting of a series of correlation kernels, over which data is extracted and then summed in various combinations. The correlation kernels are designed in such a manner that errors caused by multipath are eliminated or substantially reduced. Furthermore, the areas of the correlation kernels are balanced across level-transitions of a code and non-transitions to eliminate phase biases when tracking specific satellites. Extra care must be taken to balance the correlation kernels in this manner due to a little known aspect of GPS C/A codes. Specifically, not all C/A codes have the same ratio of level-transitions to non-transitions as has been assumed in prior art.08-28-2008
20080205493Multipath Processing for GPS Receivers - A GPS receiver system determines the presence of trackable signals at code delays less than the prompt delay being tracked for a particular signal and changes the prompt delay to correspond to the smallest code delay having a trackable signal. Trackable signals at large code delays are multipath signals and may be separately tracked to aid in dead reckoning. The trackable signals at code delays not adjacent to the current tracked prompt delay may be tracked in the same channel as the prompt delay so that all satellite channels are continuously evaluated for multipath signals being tracked or a non-satellite specific channel may be used to sequentially step through the satellite signals to evaluate multipath on a satellite by satellite basis.08-28-2008
20080267265Robust Multicode Detector for HSDPA - Detecting a symbol of interest comprises despreading a received signal to obtain despread values corresponding to the symbol of interest and to one or more interfering symbols, combining the despread values to generate combined values for the symbol of interest and the interfering symbols, computing spreading waveform correlations between the spreading waveform for the symbol of interest and the spreading waveforms for the interfering symbols, computing interference rejection terms representing the interference present in the combined value for the symbol of interest attributable to the interfering symbols based on the spreading waveform correlations, and generating an estimate of the symbol of interest by combining the combined values with the interference rejection terms. The interference rejection terms are computed by scaling the spreading waveform correlations by corresponding signal powers and compensating the estimates for noise. This provides a robust interference model that avoids numerical problems associated with conventional joint detection.10-30-2008
20090052505METHOD AND DEVICE FOR RECEIVING A DEGRADED RADIONAVIGATION SIGNAL - The invention relates to a method of receiving a radionavigation signal. Over a first determined time correlations of the sampled signal received are calculated with a locally generated code of period T. The signal is received and the code is shifted with respect to one another from one correlation to the next correlation. Over the determined time, the signal is shifted from one correlation to the next, the code being fixed.02-26-2009
20100272161METHOD AND APPARATUS FOR PERFORMING FREQUENCY SYNCHRONIZATION - A method and apparatus for performing frequency analysis of sub-epoch correlations to estimate an unknown frequency of a received signal is provided. The method includes forming a sequence of correlation values from a plurality of correlations performed over a period less than a repeating period of a code, and analyzing the sequence of correlation values to estimate the frequency that is used to receive a signal comprising the code.10-28-2010
20090161735Direct sequence spread spectrum device and method for communication therewith - The communication device according to the present invention is a direct sequence spread spectrum device that performs a communication by using multiple different spread codes for multiple symbols. The direct sequence spread spectrum device according to the present invention includes: a correlation unit that calculates a correlation between each of the multiple different spread codes and a received signal spread by each of the multiple different spread codes, and that outputs a correlation degree for each of the spread codes; and a determination unit that demodulates the received signal to a symbol based on a value of the correlation degree for each of the spread codes.06-25-2009
20090129449RECEIVED SIGNAL DETERMINATION METHOD, POSITIONING DEVICE, AND ELECTRONIC INSTRUMENT - A received signal determination method includes: receiving a positioning signal; performing correlation calculations on the received positioning signal using a code replica of one spreading code among the plurality of spreading codes; selecting a total peak value and a remote peak value, the total peak value being a first maximum correlation value among correlation values obtained by the correlation calculations, and the remote peak value being a second maximum correlation value among correlation values apart from a phase of the total peak value by a phase equal to or greater than a given phase; changing a threshold value condition for the total peak value based on the remote peak value; and determining whether or not the received positioning signal is spread-modulated with the one spreading code by determining whether or not the total peak value satisfies the threshold value condition.05-21-2009
20090185604POSITIONING METHOD, PROGRAM THEREOF, AND POSITIONING DEVICE - A positioning method includes (a) executing a cumulative addition for either one of the polarities on each of an I Q components of a received positioning signal, which is spread-modulated with a spread code reversed in polarity by navigation data, (b) calculating sum of squares of the result of the cumulative addition, (c) calculating correlation between the sum of squares and a replica code of the spread code, and (d) executing a positioning calculation of the present location based on the result of the correlation calculation.07-23-2009
20090022212CDMA RECEIVING APPARATUS AND CDMA RECEIVING METHOD - A CDMA receiving apparatus 01-22-2009
20090252202METHOD AND APPARATUS FOR ENHANCED DECODING IN MULTI-BAND ULTRA-WIDEBAND COMMUNICATIONS - A data transmission and reception method includes transmitting a plurality of position data bits and a amplitude bits with each of the pulses. The method also includes decoding the position bits and the amplitude bits. An ultra-wideband (UWB) system is also described.10-08-2009
20090052506Acquisition of a Code Modulated Signal - The invention relates to the acquisition of a code modulated signal, wherein a first set of correlation results for correlations between the code modulated signal and a first replica code with different code phases and a second set of correlation results for correlations between the code modulated signal and a second replica code with different code phases are available. In order to achieve a high sensitivity, results from both sets of correlation results are combined, wherein correlation results used in the combination are selected based on information on a relative difference between a correct code phase for both replica codes. Then, it is determined based on the combination whether at least one of the sets of correlation results comprises a correlation result representing the correct code phase for the first replica code or the second replica code, respectively.02-26-2009
20090147835RECEIVER AND TRANSMITTER FOR USE IN A SATELLITE NAVIGATION SYSTEM - A receiver is provided for use with a satellite navigation system comprising a constellation of multiple satellites. Each satellite transmits a signal incorporating a spreading code. The receiver includes at least one code storage unit that includes combinatorial logic for storing a memory code comprising a fixed pattern of bits including address decoding, wherein the stored memory code corresponds to a spreading code incorporated into a signal transmitted from a satellite. The receiver further includes a correlator for performing a correlation between an incoming signal and the stored spreading code from the one code storage unit.06-11-2009
20090245332Correlator And Ultrawideband Radio Receiving Apparatus Incorporating The Same - A correlator (i.e., a despreading filter) and an ultrawideband radio receiving apparatus that incorporates the correlator are provided. In one embodiment, a correlator multiplies a plurality of output signals output by a plurality of delay elements that are series-connected by a predetermined coefficient of either +1 or −1 and then sums the plurality of output signals, the delay element including a delay line and an amplifier; the delay line being configured by serially connecting a plurality of delay-line elements, each of the delay-line elements being a low pass filter that has an inductor and a capacitor; the amplifier being connected to an output of a last-stage delay-line element of the series-connected delay-line elements so as to perform impedance matching with respect to the delay line; an output of the amplifier being connected to a subsequent circuit so as to perform impedance matching with respect to the subsequent circuit, such that a loss of the delay line is compensated for and an output voltage of the delay element is made equal to an input voltage of the delay element.10-01-2009
20090257479USE OF CORRELATION COMBINATION TO ACHIEVE CHANNEL DETECTION - Combinations of correlation results are used to achieve detection of multiple coded signals at a receiver in a wireless communications system. The code applied to signals includes a lower rate code and a higher rate code. The lower rate code is a nested or tiered code such that it comprises at least two code sequences of the higher rate code. The received coded signal is correlated with the higher rate code using a single higher rate correlator to provide a higher rate code correlation result. The higher rate code correlation results are fed to two or more lower rate code correlators that combine multiple higher rate code correlation results, each using a different lower rate code, to provide corresponding lower rate code correlation results. The presence of at least one coded signal or mutually exclusive coded signals can be determined from the lower rate code correlation results.10-15-2009
20110129002METHOD FOR THE ACQUISITION OF RADIONAVIGATION SIGNALS CARRYING SPREADING CODE WITH A QUASI-INFINITE PERIOD - A method for the acquisition of a radionavigation signal carrying a spreading code with a quasi-infinite period, where the signal is sampled in baseband on a delay line and correlated with a local spreading code replica, the sampled signal is shifted on the delay line from one correlation to the other, where in order to correlate the signal with the local replica of the code, a plurality of sequences of the spreading code are generated, the code sequences being of the same duration, equal to the duration of the signal sampled on the delay line, and associated with the consecutive time ranges in the temporal alignment search space, where each of the code sequences is correlated with the signal sampled in a respective correlation operation, the correlation operations being executed in parallel for the different sequences of code.06-02-2011
20110129003METHOD FOR ACQUIRING SATELLITE SIGNAL AND SATELLITE SIGNAL RECEIVING DEVICE - Methods and apparatuses for acquiring a satellite signal includes generating a differential code using first, second and third segments of a satellite signal received from a positioning satellite, obtaining a correlation value by performing a correlation using the differential code and a replica of the spreading code, and acquiring the satellite signal using the correlation value. The differential code is generated by performing a differential operation on a spreading code from the positioning satellite.06-02-2011
20090310655SEARCH FREQUENCY CORRECTION METHOD, POSITIONING METHOD, PROGRAM, AND RECEIVING APPARATUS - A search frequency correction method includes: obtaining correlation values by correlating between a received signal that is modulated by direct sequence spread spectrum modulation and a replica code of a spread code with respect to I and Q components at a predetermined search frequency, obtaining accumulated correlation values by accumulating the correlation values of each polarity inversion interval with respect to the I and Q components, calculating a plurality of combinations of the accumulated correlation values in both signs, selecting one of the combinations based on the calculation results of the respective combinations, and correcting the search frequency based on a time variation of an IQ phase represented by the accumulated correlation values of the one of the combinations.12-17-2009
20100254438LOW COMPLEXITY ACQUISITION METHOD FOR GNSS - A low complexity acquisition method and a receiver implemented such a method are disclosed. In the present invention, a cyclical shifted-and-combined (CSC) code is generated by intercepting sub-codes from a full code and combining the sub-codes with an equal gain. The CSC code is correlated with a received signal to find a candidate peak. The other candidate peak(s) can be deduced accordingly. Thus, hypotheses can be significantly reduced. A true peak can be easily and rapidly found by verifying the candidate peaks.10-07-2010
20110129001MULTIPLE-MODE CORRELATOR - Methods and apparatuses are provided for implementing a multiple-mode correlator within a receiver. The multiple-mode correlator may include at least one pre-multiplier portion and a plurality of correlation portions that selectively process multiply result signals from the pre-multiplier portion.06-02-2011
20090285269PHY Preamble Format for Wireless Communication System - A system and method of extracting data from data packets transmitted over a wireless network includes receiving a data packet having a preamble portion and a payload portion. The preamble portion is cross correlated with a first known spreading sequence to generate a first timing signal and the preamble portion is cross correlated with a second known spreading signal to generate a frame timing signal. An impulse is detected in the first timing signal and a first timing parameter is set based upon the detected impulse in the first timing signal. An impulse is detected in the frame timing signal and a frame timing parameter is set based upon the detected impulse in the frame timing signal. Data is extracted from the received payload portion according to the first timing parameter and the frame timing parameter.11-19-2009
20120033716TIME-SETTING IN SATELLITE POSITIONING SYSTEM RECEIVERS - Techniques are provided which may be implemented using various methods and/or apparatuses in a receiver and/or other like device to determine an SPS time using SPS signals based on a correlation process. A verification process may be performed, for example, that verifies a maximum peak in comparison with other peak information resulting from the correlation process, for example, by considering a ratio of a maximum peak to a next maximum peak. A time-setting algorithm may be selected, for example, based, at least in part, on a time uncertainty and/or on a type of demodulation performed on the SPS signal. The time-setting algorithm may operatively control one or both of the correlation and/verification processes in a desired manner given the time uncertainty and/or type/mode of demodulation performed.02-09-2012
20090110037CHANNEL ESTIMATION FOR TIME DIVISION DUPLEX COMMUNICATION SYSTEMS - A plurality of communication bursts are used to communicate data in a shared spectrum in a time slot of a time division duplex communication system. Each burst has an associated midamble sequence of a set of known sequences. A wireless communication apparatus has a receiver component configured to receive the plurality of communication bursts and to define a received vector corresponding to the received bursts. A channel estimator is provided that is configured to estimate channel information of the plurality of communication bursts by constructing a block matrix having a plurality of identical right circulant matrix blocks using the known midamble sequences and the received vector. A data detector then recovers data from the received communication bursts using the estimated wireless channel information.04-30-2009
20100329312Wideband Correlation Mode Switching Methods And Apparatuses - Methods and apparatus are provided for use in devices operatively enabled to perform waveform correlation result processing.12-30-2010
20110243199GNSS Receiver and Method for GNSS Memory Code Generation - A GNSS receiver and method for GNSS memory code generation are disclosed. The GNSS receiver comprises a buffer, a correlator, and a selector. The buffer receives and stores a plurality of first code segments. Each of the first code segment is at least a portion of a memory code. The selector selects a selecting window of the first code segments stored in the buffer as a second code segment according to the code phase selection signal. The correlator calculates a correlation between a received GNSS signal and the second code segment.10-06-2011
20090016414Ultratight coupling prefilter detection block - An observation lock detector block receives I&Q correlations and generates error measurement vectors, each including phase, frequency, code, pseudorange, and covariance residual estimates, and generates validity indicator and confidence indicator vectors, one of which error measurement vectors is an output as a selected error measurement vector with a respective validity indicator and confidence indicator vector, both of which selected vectors are communicated to a navigation solution processor in a ultratightly coupled navigation system for providing improved estimations of a navigation solution, the indicators indicating the usefulness of measurement errors, the prefilter detector block comprising discriminators, sequential filters, observation lock detectors and a measurement selector for selecting measurement vector based on phase, frequency, and code discriminations, the measurement errors being residual estimates that are indicated as valid or invalid for dynamic propagation of the residuals in a navigation receiver for improved performance, especially in low signal-to-noise environments, such as, for use in an ultratight GPS navigation system.01-15-2009
20100254440METHOD AND APPARATUS FOR RECEIVING PLURALITY OF DATA SIGNALS - A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector.10-07-2010
20090154532APPARATUS AND METHOD FOR RECEIVING SIGNAL FOR EXTENT LIMITATION OF TIMING SYNCHRONIZATION IN MB-OFDM UWB SYSTEM - The present invention relates to an apparatus and a method for receiving signal for extent of timing synchronization in MB-OFDM UWB System. The invention divides the digital samples completed of sampling twice as much as minimum sampling clock required to restore the MB-OFDM received signal into ODD data path and EVEN data path, executes the packet detection and timing synchronization for each of divided path and selects the data of path with larger cross correlation value at the timing synchronization point to secure the stable receiving performance in system environment with severe frequency offset and prevent the FTT window shift within preamble section through adding minimum hardware and structural change without increasing the system clock.06-18-2009
20090028223SIGNAL RECEIVER AND METHOD FOR ESTIMATING RESIDUAL DOPPLER FREQUENCIES OF SIGNALS THEREOF - The invention provides a signal receiver. The signal receiver comprises a code removal module, a carrier removal module, a Fast Fourier Transformation (FFT) module, and a signal processor. The code removal module removes a pseudo random noise code from a first signal to obtain a second signal. The carrier removal module generates a carrier signal with a frequency of an estimated carrier frequency, generates at least one delta carrier signal with a frequency of the carrier frequency plus a delta frequency, removes the carrier signal from the second signal to obtain a third signal, and removes the delta carrier signal from the second signal to obtain a fourth signal. The FFT module derives a series of first FFT values from the third signal, and derives a series of second FFT values from the fourth signal. The signal processor estimates the carrier frequency of the second signal to obtain the estimated carrier frequency, determines the delta frequency for the carrier removal module, estimates a residual Doppler frequency of the third signal according to both the first FFT values and the second FFT values, and adjusts the estimated carrier frequency according to the residual Doppler frequency to eliminate distortion from residual Doppler effects from the third signal. The delta frequency is lower than a frequency resolution of the FFT module.01-29-2009
20100124255METHOD AND SYSTEM FOR MAINTAINING INTEGRITY OF A BINARY OFFSET CARRIER SIGNAL - Embodiments of the present technology recite a method and system for maintaining integrity of a binary offset carrier (BOC) signal. In one embodiment, a first correlator is configured for multiplying a timing signal with an internally generated pseudo-random noise (PRN) signal to create a reference signal. The first correlator is further configured for combining the reference signal with a received PRN signal and outputting a first correlation function based upon the combining. A second correlator is configured for multiplying the internally generated PRN signal with the received PRN signal and for outputting an integrity correlation function. A comparison component is configured for determining the offset of the reference signal relative to the received PRN signal based upon a comparison of the integrity correlation function with the first correlation function.05-20-2010
20100208775LOW COST, HIGH PERFORMANCE GPS/GNSS RECEIVER ARCHITECTURE - A low-cost GPS/GNSS receiver receives a satellite signal at an RF frequency (fRF). The GPS/GNSS receiver includes a front end section for receiving the satellite signal and generating a digital complex signal having a first bandwidth, the received satellite signal being converted into a complex signal before digitizing, a signal capturing section for searching for and acquiring the satellite signal, the signal capturing section including a capture memory, a baseband processor for tracking the acquired satellite signal, and a signal splitter coupled to the front end section. The signal splitter splits the digital complex signal into two bandwidths, by generating a narrowband digital complex signal having a second bandwidth substantially smaller than the first bandwidth. The signal splitter provides the narrowband digital signal to the capture memory and the wider first bandwidth digital complex signal to the baseband processor.08-19-2010
20110150047METHOD AND SYSTEM FOR EFFICIENT DSSS FFT PROCESSING EMPLOYING PRIME FACTOR DECOMPOSITION - A direct-sequence spread spectrum (DSSS) receiver may be operable to process signal samples in frequency domain utilizing a prime factor fast Fourier transform (FFT) circuit and a pseudorandom noise (PRN) code. The DSSS receiver may be operable to transform the signal samples into FFT signal samples using the prime factor FFT circuit, transform the PRN code into a FFT PRN code using the prime factor FFT circuit and multiply the FFT signal samples with the FFT PRN code using the prime factor FFT circuit. The DSSS receiver may be operable to inversely transform the multiplied FFT signal samples into correlated signal samples using a prime factor inverse FFT (IFFT) implemented by the prime factor FFT circuit. The prime factor FFT circuit may comprise a prime length FFT core, a FFT memory, a register bank, a switch, a multiplier and a FFT controller.06-23-2011
20100260239COMMUNICATION SYSTEM, SIGNAL PROCESSING METHOD, SIGNAL PROCESSING DEVICE, AND MOVABLE BODY - A communication system includes: a sampling section that samples a reception signal; a preprocessing execution section that acquires a sampling value, which is obtained by the sampling section, while executing preprocessing for performing a Fast Fourier Transform in a divided manner; and a Fast Fourier Transform section that performs the Fast Fourier Transform in the divided manner on the basis of an output acquired from the processing execution section.10-14-2010
20110176582COMMUNICATION DEVICE WITH TESTING - Communication devices and methods are disclosed, wherein a test signal is generated at a first frequency and a higher harmonic of said test signal is received and processed at a second frequency higher than said first frequency.07-21-2011
20100278220PROCESS FOR SUB-MICROSECOND TIME TRANSFER USING WEAK GPS/GNSS SIGNALS - Sub-microsecond time transfer in a GPS/GNSS receiver using a weak GPS/GNSS signal is provided. The digitized complex baseband signal and the generated PN code are cross-correlated for each code period so as to output a complex correlation value at each code epoch of the generated PN code, where a sequence of the output correlation values form a data stream representing the navigation message. Bit synchronization generates bit sync pulses at bit boundaries. The location of a target segment having a known sequence at a known bit location in the navigation message is detected by searching through a plurality of sub-frames and accumulating search results for the plurality of subframes. Transmission time of the target segment is determined from the detected location of the target segment, with a certain time ambiguity. Accurate local time is determined by solving the time ambiguity using approximate time obtained from an external source.11-04-2010
20090185603Differentiated Linear Equalization at Communication Base Stations - The teachings presented herein improve the processing of individual signals of interest included in a received composite signal by computing combining weights and/or signal quality estimates for each signal of interest, e.g., for linear equalization, based on either shared or non-shared correlation estimates. As a non-limiting advantage, the use of shared correlation estimates reduces computational loading as compared to the processing load that would be needed for computing non-shared correlation estimates for all signals of interest. As a further non-limiting advantage, the conditional use of shared and non-shared correlation estimates provides for the use of non-shared correlation estimates where signal characteristic(s) of one or more of the signals of interest warrant such usage, e.g., for one or more high-rate signals of interest.07-23-2009
20100309960SIGNAL ACQUISITION/TRACKING METHOD AND CORRELATOR FOR THE SAME - A Doppler frequency searching method and correlator are disclosed. In the present invention, before Doppler frequency removal, a received signal is converted into digital form having a first sampling rate. Then the signal is down-sampled to have a low sampling rate. The Doppler frequency searching is done by stages. Each stage is in charge of a portion of the Doppler frequency to be removed. The sampling rate can be further reduced in each stage. Each stage can have at least one Doppler frequency removal unit sharing the portion of Doppler frequency that the stage is to remove. Power consumption is reduced since Doppler frequency removal is executed with low sampling rate.12-09-2010
20100309959METHOD AND APPARATUS FOR CONSTANT ENVELOPE DEMODULATION - Certain aspects of the present disclosure relate to a method for demodulating CPM modulated signals transmitted in a wired or wireless communication system using a linear modulation model consisting of a linear superposition of time pulses modulated using pseudo-PSK pulses.12-09-2010
20080205492JOINT DE-SPREADING AND FREQUENCY CORRECTION USING A CORRELATOR - A correlator (08-28-2008
20100284444METHOD AND APPARATUS FOR PACKET ACQUISITION - Certain aspects of the present disclosure relate to a method for acquisition of a received spread spectrum signal transmitted over a wired or wireless medium.11-11-2010
20100166046Method of processing a digital signal derived from a direct-sequence spread spectrum signal - In a GNSS receiver data sequences derived from a digital signal each with an internally generated correlation sequence derived from a basic sequence and mixed with frequency signals corresponding to various Doppler frequencies and in various phase positions with respect to the data sequence are correlated and the correlation values evaluated. In difficult conditions, e.g., RF levels of the signal of −145 dBm and less, correlation values produced with the same correlation sequence and phase position but with a plurality of data sequences are evaluated together in that, in an evaluator (07-01-2010
20100166047METHOD FOR DETECTING SATELLITE NAVIGATION RECEIVED SIGNAL AND APPARATUS THEREOF - Provided are a method for detecting a received signal and an apparatus for detecting a satellite navigation received signal using the same. The present invention provides cells where a correlation value obtained through parallel signal detection is a predetermined signal detection threshold value or more are selected and time domain correlation is performed on the cells so that the correlation value is verified. The cells having the predetermined verified threshold value or more are detected as a final received signal.07-01-2010
20090175319APPARATUS FOR AND METHOD OF MAKING PULSE-SHAPE MEASUREMENTS - A receiver includes a pre-correlation filter that forms an image of the average chip shape of a received signal over a specified period of time. The filter includes an array of complex accumulation registers that accumulate measurements that are associated with signal samples from specific ranges of locations, or code chip phase angles, along a spread-spectrum chip. Using the accumulated measurements, the receiver estimates the location of the chip transitions in a direct path signal component. The receiver may thereafter change the starting point, size and number of ranges, such that the accumulation registers accumulate more detail from the chip edges. The receiver in addition may compare the accumulated measurements with a reference pulse shape to determine if any interference is present in the received transmission that will distort ranging information calculated from the received signal.07-09-2009
20100020856DATA DETECTION FOR CODES WITH NON-UNIFORM SPREADING FACTORS - A plurality of communication signals is received. Each communication signal has an associated code. At least two of the communication signals has a different spreading factor. The associated codes have a scrambling code period. A total system response matrix has blocks. Each block has one dimension of a length M and another dimension of a length based on in part M and the spreading factor of each communication. M is based on the scrambling code period. Data of the received plurality of communication signals is received using the constructed system response matrix.01-28-2010
20110216812APPARATUS AND METHOD FOR PERFORMING DELAY-LOCKED LOOP OPERATION ON RECEIVING SIGNAL - A method for performing delay locked looping upon a received signal which reduces the asymmetry of auto-correlation function resulting from sampling is provided. The received signal is a spread spectrum code signal, and the method includes: generating a plurality of replica spread spectrum code signals according to an estimated code phase delay and phase spacing, the replica spread spectrum code signals having phases respectively different from the phase of the received signal; calculating a spread spectrum code error statistics signal according to the replica spread spectrum code signals and the received signal; and adjusting the estimated code phase delay according to the spread spectrum code error statistics signal and a phase difference between a sampled point of at least one replica spread spectrum code signal and a corresponding signal transition point.09-08-2011
20110216811METHODS AND APPARATUSES FOR DEMODULATING MULTIPLE CHANNEL SATELLITE POSITIONING SYSTEM SIGNALS - Methods and apparatuses are provided which may be enabled within and/or for use with a Satellite Positioning System (SPS) receiver and/or other like apparatuses or device(s) to demodulate a first channel portion of a multiple channel SPS signal based, at least in part, on a second channel portion of the multiple channel SPS signal.09-08-2011
20100254439Method of Resolving Ambiguity, Method of Location of a Receiver by Radionavigation Comprising an Ambiguity Resolution Step and Location Receiver - Method of resolving ambiguity for determining the main peak of the autocorrelation function of signals transmitted by a set of satellites and received by a receiver of a radionavigation system, a signal received originating from a satellite comprising two received spectral components right and left, the said method comprising the following steps: 10-07-2010
20110103432ENHANCED CROSS CORRELATION DETECTION OR MITIGATION CIRCUITS, PROCESSES, DEVICES, RECEIVERS AND SYSTEMS - A receiver (05-05-2011
20120170618Ultra wideband time-delayed correlator - The present invention is for a method and apparatus to improve an Ultra Wideband (UWB) digital receiver's performance sensitivity. A transmitted signal stream has each data bit having multiple identical modulated pulses separated by a constant time interval. The received signal stream is duplicated to create a second signal stream of identical modulated pulses to the original signal stream. The duplicated signal stream is delayed by the constant time interval between identical modulated pulses and the two signal streams correlated to form one signal stream which is detected to improve the sensitivity of the receiver.07-05-2012
20110007783METHOD AND APPARATUS FOR ACQUISITION, TRACKING, AND SUB-MICROSECOND TIME TRANSFER USING WEAK GPS/GNSS SIGNALS - A method and apparatus provide high-sensitivity GPS/GNSS signal acquisition in a stationary GPS/GNSS receiver. The uncertainty in frequency due to apparent Doppler shift is partitioned into a plurality of contiguous frequency bins, and the uncertainty in location of navigation data bit boundaries is partitioned into equally spaced trial bit boundary locations. For each combination of the trial bit boundary location and the frequency bin, a signal block of captured complex baseband signal is Doppler-compensated using a phase rotator, and then synchronously summed with a periodicity of one period of C/A code so as to produce a compressed sample block having N samples. Each compressed sample block is cross-correlated with one period of reference C/A code to produce an N-value correlation function. A predetermined number of magnitudes of the N-value correlation functions are stack-accumulated into an array with precession compensation so as to find a correlation peak having the largest value.01-13-2011
20090168852CODE PHASE ERROR ESTIMATING METHOD, CODE PHASE CALCULATING METHOD, PROGRAM, CODE PHASE ERROR ESTIMATING DEVICE, AND CODE PHASE CALCULATING DEVICE - A code phase error estimating method includes: calculating correlation for I and Q components of a reception signal of a spread modulated positioning signal which is unique to each positioning satellite and a replica signal of the spread code; judging code phase based on the result of the correlation calculation; calculating a ratio between a first correlation value for a third correlation value and a second correlation value for the third correlation value, wherein the first correlation value being a correlation value at the code phase, the second correlation value being a correlation value at a phase shifted from the code phase by X chip (007-02-2009
20090304050Method in a CDMA Receiver Using Hardware and Software in Acquisition, Tracking and Hosting - A method including: using both dedicated circuitry and a programmable processor system for acquisition of a communication channel; and using the dedicated circuitry for tracking the acquired communication channel while using the programmable processor system for hosting an application that uses information dependent upon data dependent on the acquired communication channel.12-10-2009
20110103433RAPID ACQUISITION METHODS AND APPARATUS FOR GPS SIGNALS - A method and apparatus for receiving a signal from transmitters such as GPS satellites, for fixing the location of the receiver. Each of the transmitted signals includes a unique periodically-repeating sequence. A received signal is stored by the receiver for at least two repetitions of the periodically-repeating sequence. FFT operations are performed, and the resulting data frequency samples are pruned responsive to a hypothesized residual frequency, a procedure which significantly reduces the total number of subsequent calculations and therefore significantly reduces processing time. A correlation series is determined from the pruned samples and reference frequency samples corresponding to a hypothesized transmitter. If a match is found in the examination of this series, a code phase offset is determined; if not the process is repeated with another hypothesized residual frequency. Multiple correlation series similarly obtained may also be incoherently combined prior to this examination. The apparatus and method disclosed herein is particularly useful for combined position location and communication systems, especially those that are unsynchronized, such as assisted GPS (“A-GPS”) utilized on GSM and UMTS cellular telephone systems.05-05-2011
20120134392CROSS CORRELATION DETERMINATION METHOD AND CROSS CORRELATION DETERMINATION DEVICE - A cross correlation determination method includes: executing a first decoding of decoding a navigation message included in a received satellite signal using a first replica code and a second decoding of decoding the navigation message using a second replica code; and determining the occurrence of a cross correlation using the result of the first decoding and the result of the second decoding.05-31-2012
20100246644SYSTEMS, COMPUTER PROGRAM PRODUCTS, AND METHODS USING CARRIER PHASES TO DETECT MULTIPATH SIGNALS - A multipath detector includes an RF module receiving multiple signals, and a correlator module receiving the signals from the RF module. The correlator module correlates the signals to create a composite ACF, and produces samples of the composite autocorrelation function (ACF). The samples are time delayed relative to each other. The multipath detector also includes a carrier phase processor that receives the samples and estimates carrier phases associated with each of the samples. The carrier phase processor employs the estimated carrier phases to determine if one of the signals is subject to a multipath delay.09-30-2010
20100246645APPARATUS FOR AND METHOD OF MAKING PULSE-SHAPE MEASUREMENTS - A receiver includes a pre-correlation filter that forms an image of the average chip shape of a received signal over a specified period of time. The filter includes an array of complex accumulation registers that accumulate measurements that are associated with signal samples from specific ranges of locations, or code chip phase angles, along a spread-spectrum chip. Using the accumulated measurements, the receiver estimates the location of the chip transitions in a direct path signal component. The receiver may thereafter change the starting points, sizes and numbers of ranges, such that the accumulation registers accumulate more detail from the chip edges. The receiver in addition may use the accumulated measurements from selected registers and/or selected groups of registers, to produce the correlation values that are needed to perform one or more correlation techniques and/or one or more multipath mitigation techniques. As appropriate, the sizes and/or starting points of the bins, and/or the selections of the bins for the various groupings may be altered, to change the spacings, locations, and so forth to which correlation values correspond.09-30-2010
20120076177SYSTEM AND/OR METHOD FOR DETECTING MULTI-TONE JAMMING - The subject matter disclosed herein relates to a system and method for processing a signal received from a satellite positioning system (SPS) in the presence of a multi-tone jammer. In one particular implementation, processing of a signal may be altered in response to detection of one or more conditions.03-29-2012
20100232478Receiver for spread spectrum communication - A receiver for spread spectrum communication includes a receiver for receiving a wireless signal, a demodulator for demodulating the wireless signal into a spread spectrum signal, a correlation value calculator for calculating a correlation value between the spread spectrum signal and a spreading code having a predetermined number of chips, a synchronization detector for detecting a synchronization point between the spread spectrum signal and the spread signal based on the correlation value, a despreading device for despreading the spread spectrum signal based on the synchronization point, a noise level detector for detecting a noise level of the wireless signal, and a code number setting device for determining the number of chips of the spreading code in such a manner that there is a positive correlation between the noise level and the number of code portions.09-16-2010
20090022211METHOD AND DEVICE FOR CORRELATING A SIGNAL, IN PARTICULAR AN ULTRA WIDEBAND SIGNAL - The waveform of the signal varies according to the distance at which the signal was emitted, and several correlation signals are defined and correspond respectively to at least part of several sampled waveforms of the signal respectively emitted at several distances of different values so that the sum of the maxima of intercorrelations performed respectively between the various correlation signals and the various sampled waveforms is substantially constant over an interval including all the values of the distances. The correlation processing includes several elementary correlation processings respectively performed with the correlation signals and each delivering initial correlation values, as well as a summation of the homologous initial correlation values respectively delivered by the elementary correlation processings so as to obtain the correlation values.01-22-2009
20130010837SIGNAL PROCESSING METHOD, CORRELATOR, SOFTWARE SIGNAL RECEIVER BY USING CODE CYCLE - Disclosed are a signal processing method using a code cycle, a correlator, and a software signal receiver. An exemplary embodiment of the present invention provides a signal processing method of a satellite navigation signal, including: a frequency generating step generating a predetermined frequency component for removing a frequency component of sample data; a code generating step generating a predetermined code component for removing a code component of the sample data and increasing a sample count when the predetermined code component is generated; and a correlation value generating step, if the sample count is equal to a count per unit time, generating a correlation value between the generated predetermined frequency component and the generated predetermined code component by reading a sample data block.01-10-2013
20080247443Method and system for implementing a system acquisition function for use with a communication device - A system acquisition module and corresponding method for facilitating PN code searching which has a PN sequence generator configurable to generate a plurality of PN sequences. The module and method also includes computational units configurable to correlate each received signal sample of a plurality of received signal samples with a corresponding PN sequence of the plurality of PN sequences, and further configurable to provide other hardware resources. A number of computational units from the plurality of computational units are selectively configured to correlate the received signal samples with the PN sequences—the number depending upon availability of the plurality of computational units from providing the other hardware resources. In another embodiment, a communication device having a system acquisition function is provided which includes the system acquisition module and a receiver configured to receive signals, where a plurality of configurable computational units are selectively configurable to implement the PN sequence generator.10-09-2008
20080232441Method of processing a digital signal derived from an analog input signal of a GNSS receiver, a GNSS receiver base band circuit for carrying out the method and a GNSS receiver - An acquisition unit of a GNSS receiver base band circuit comprises a correlator (09-25-2008
20130142221HIGH PERFORMANCE WINDOW SEARCHER FOR CELL MEASUREMENT - Disclosed are various embodiments involving a window searcher for cell measurement. A window search is configurable and scalable as to a number of scrambling codes to be searched in parallel over a window span for each scrambling code. A received signal is descrambled. A coherent accumulation is performed on the descrambled received signal at a first subchip resolution to produce a coherent accumulation result. The coherent accumulation result is interpolated to a second subchip resolution. A non-coherent accumulation is performed on the descrambled received signal at the second subchip resolution based at least in part on the interpolated coherent accumulation result.06-06-2013
20130177045METHOD OF CAPTURING SATELLITE SIGNAL AND DEVICE FOR CAPTURING SATELLITE SIGNAL - Every k (k≧2) sampling values of sampling values in a time series obtained by sampling reception signal from GPS satellite are selected, and addition-subtraction of the selected k sampling values is performed by changing the combinations of addition and subtraction. Using addition-subtraction results of a combination corresponding to time-series change in code values of a replica code from among the combinations of addition and subtraction, a correlation result of the reception signal and the replica code is calculated. The satellite signal of the GPS satellite is acquired using the correlation result.07-11-2013
20130177046METHOD OF CAPTURING SATELLITE SIGNAL AND DEVICE FOR CAPTURING SATELLITE SIGNAL - A method of acquiring a satellite signal includes calculating a correlation result of a reception signal from a GPS satellite and a replica code using an output value of one adder-subtractor for a combination of addition and subtraction corresponding to time-series change in code values of the replica code from among a plurality of adder-subtractors for addition-subtraction of sampling values obtained by sampling the reception signal in a time series with different combinations of addition and subtraction, and acquiring the satellite signal of the GPS satellite using the correlation result.07-11-2013
20120250733METHOD AND APPARATUS FOR RAPID ACQUISITIONS OF GPS SIGNALS IN SPACE APPLICATIONS - A global positioning system (GPS) receiver that is configured to rapidly acquire GPS signals in space applications and a method for rapidly acquiring GPS signals in space applications is disclosed. In an embodiment, the GPS receiver includes, but is not limited to, a GPS signal acquisition component comprising a time domain correlation module. The GPS signal acquisition component is adapted to acquire a GPS signal by receiving data from the GPS signal and processing the data to detect the GPS signal.10-04-2012
20110235687SIGNAL ACQUISITION METHOD, SIGNAL ACQUISITION APPARATUS AND ELECTRONIC DEVICE - A signal acquisition method includes: frequency-converting the frequency of a reception signal which is a satellite signal received from a positioning satellite into a specific frequency corresponding to a bit length of navigation message data carried by the satellite signal; performing a first correlation operation according to a signal of the frequency-converted specific frequency; integrating results of the first correlation operation over a predetermined time longer than the bit length; and acquiring the satellite signal using the integrated results.09-29-2011
20080298440Method and Apparatus for Implementing Seek and Scan Functions for an FM Digital Radio Signal - A method for detecting a digital radio signal includes the steps of receiving the digital radio signal, developing a correlation waveform having a peak that corresponds to a symbol boundary, normalizing the correlation waveform, calculating a peak value of the normalized correlation waveform, and dwelling on the received digital radio signal when the peak value exceeds a predetermined threshold. A receiver that performs the method is also provided.12-04-2008
20090213912MULTIPATH MITIGATION GNSS RECEIVER - An improved GNSS or GPS receiver with a code-tracking loop comprising a plurality of correlators, arranged to extract a plurality of samples of the autocorrelation function of the C/A code, and a discriminator performing linear regression on both sides of the autocorrelation peak, to determine the autocorrelation peak position at the crossing point of two straight lines. The lines are independently adapted to the sides of the correlation peak and, therefore, the receiver can handle well multipath situations, in which the correlation peaks are distorted.08-27-2009
20100316095SYSTEMS, METHODS, AND APPARATUS FOR JAMMER REJECTION - A method according to an embodiment obtains a list of peaks for each of a number of frequency hypotheses. Each peak has an energy result and corresponds to a code phase hypothesis. Embodiments include methods and apparatus that may be used in identifying a location of a signal (such as a GPS signal) in a two-dimensional search space. Location information may be further applied to operations such as signal acquisition, signal tracking, position location of a receiver, and timing operations such as the synchronization of one or more other processes.12-16-2010
20100316094FLEXIBLE AND IN-BAND SIGNALING FOR NESTED PREAMBLE - A multi input multi output (MIMO) receiver is disclosed for transmitting and receiving packets having a preamble format of a packet of information and having a short training sequence (STS), a long training sequence (LTS) and signal (SIG) for training receivers, in accordance with an embodiment of the present invention. The packets having a preamble format for allowing data to be piggy-backed, e.g. transmitted and received using the physical layer rather than the transport layer of networking layers.12-16-2010
20130156073RECONFIGURABLE CORRELATOR FOR A NAVIGATION SYSTEM - Systems and methods are provided for a correlator system. The system includes a plurality of numerically controlled oscillators and a multiplier configured to receive an input stream representing a received signal. A carrier multiplexer is configured to select between respective outputs of at least two of the plurality of numerically controlled oscillators and provide the selected output to the multiplier. A code generator is configured to provide a replica code. A delay component is configured to provide a delayed code from the replica code. A code multiplexer is configured to selectively provide each of the delayed code and the replica code to the multiplier.06-20-2013
20120281735Satellite-Based Positioning System Reception Device Comprising a Function for Detecting False Lock-Ons - A satellite-based positioning system reception device comprises a function for detecting false lock-ons based on a linear combination of complex signals arising from correlation pathways between a signal received from a satellite and a prompt local code and a plurality of local codes shifted by determined delays with respect to the prompt local code. An advantage is that the function for detecting false lock-ons makes it possible to remedy the false lock-ons due to multi-path phenomena.11-08-2012
20120281736SIGNALS, SYSTEM, METHOD AND APPARATUS - Embodiments of the present invention provide a method to produce a modulation signal comprising combining at least two modulation signals, for example, BOCs or derivatives thereof, having portions (chip or a number of chips) thereof with respective relative phases or states ({++,−−} and {+−,−+}) selected such that the average of a plurality of said portions at least reduces cross spectral terms of the composite complex spectrum of said at least two modulation signals.11-08-2012
20130182748Method and Apparatus for Radio Synchronization Detection in a Rake Receiver - Enhanced reception in a communication system is achieved by performing radio synchronization (SYNC) detection after multipath signal components are combined via a Rake combiner. In a communication system comprising a transmitter and a receiver, plural multipath signal components of a signal transmitted by the transmitter are received by the receiver. The plural multipath signal components are correlated with a known spreading code (e.g. a PN code). The correlated multipath signals are analyzed to identify plural correlation peaks and those correlation peaks that exceed a multipath threshold are selected. The selected correlation peaks are combined (i.e., coherently combined) to produce a combined signal. A synchronization event is declared when the combined signal exceeds an adjusted synchronization threshold and the combined signal is then decoded.07-18-2013
20110310935RECEPTION OF SPREAD SPECTRUM SIGNALS - A method and apparatus for improving speed of acquisition of spread spectrum signals in a satellite navigation system. The method includes receiving signals including the spread spectrum signal having a first spreading code, performing a correlation between the received signals and a composite code, the composite code including a superposition of the first spreading code and a second spreading code, detecting a plurality of peaks of the correlation, identifying at least one of the plurality of peaks that relates to the spread spectrum signal, and detecting the spread spectrum signal based on the at least one identified peak.12-22-2011
20130208767RECEIVER FOR DETECTION AND TIME RECOVERY OF NON-COHERENT SIGNALS AND METHODS OF OPERATING SAME - A method for processing a signal having a plurality of codes. The method includes receiving the signal at a receiver and removing a carrier signal from the signal. The method further includes isolating a data stream from the carrier signal and determining timing of the plurality of codes. The plurality of codes is filtered to separate from the plurality of codes in the data stream a particular code for each plurality of codes that correlates to the received signal.08-15-2013

Patent applications in class Correlation-type receiver

Patent applications in all subclasses Correlation-type receiver