Class / Patent application number | Description | Number of patent applications / Date published |
375142000 | Having correlation-type receiver | 43 |
20080205489 | Inductive Communication System with Increased Noise Immunity Using Low-Complexity Transmitter - The invention related to a modulator for a communications system. The modulator comprises a spread spectrum coder, a pulse code modulator having a signal input port connectable to a signal output port of the spread spectrum coder. The modulator performs a robust and error free modulation and coding scheme by using a modified spread spectrum scheme combined with pulse code modulation. The communication system contains a low data rate, noise robust modulation and coding scheme using a very simple transmitter. This results in a very straightforward transmitter circuit, reducing size and costs of the transmitter. | 08-28-2008 |
20080273578 | GNSS RECEIVER WITH CROSS-CORRELATION REJECTION - Radiolocalization receiver having a plurality of correlation taps, and including a module of cross-correlation detection in which spurious correlation terms are detected by statistical analysis of the frequencies of the candidate peaks. The system can restrict further integration to those taps whose frequency is outside the cross-interference signal, or trigger new acquisition of different space vehicles, upon detection of a cross-interference situation. | 11-06-2008 |
20080285630 | METHOD AND APPARATUS FOR REDUCING CODE PHASE SEARCH SPACE - A GPS communication system including a server and a client, each including a GPS receiver, for reducing the code phase search space of the GPS receiver of the client. The communication system includes a transmitter for transmitting timing information from the server to the client to help the client locate a first satellite, and a receiver for using timing differences between the satellites to synchronize and locate other satellites. The code phase search space is reduced by reducing the number of phase hypotheses that must be calculated to establish communication between the server and the client. | 11-20-2008 |
20080298436 | Random Access Collision Detection - A receiver in a communication system correlates incoming signals, which may be sent by several transmitters, with one or more predetermined sequences. The receiver should take the maximum delay spread into account in determining whether a collision between incoming signals has occurred. For example, the receiver may decide that a collision has occurred only if two correlation peaks are separated in time by more than the maximum delay spread. | 12-04-2008 |
20080310482 | Alternative direct sequence spread spectrum symbol to chip mappings and methods for generating the same - Alternative direct sequence spread spectrum symbol to chip mappings and methods for generating the same for use in a direct sequence spread spectrum wireless protocol and embedded in a transceiver chip used by wireless subsystems are provided. The present invention discloses alternative symbol to chip mappings that are orthogonal or nearly orthogonal to the N/2 unused chip sequences defined by a standard transmission protocol. The present invention is advantageous because it provides for an increased number of users and better reliability for wireless subsystems operating in increasingly overcrowded frequency bands. Other advantages of the present invention include a reduction in the negative effects of clear channel assessment including delayed or cancelled signal transmission and interference for wireless subsystems that transmit time-sensitive data. | 12-18-2008 |
20090046766 | Method and system for resolving the acquisition ambiguity and the problem of false lock in tracking BOC(m,n) modulated signals, particularly for satellite positioning/navigation systems - A method and a system for the acquisition and tracking of BOC(m,n) modulated codes, m/n equal to an integer, in which a correlation function is calculated of the BOC(m,n) modulated code received from a remote transmitter with a code w | 02-19-2009 |
20090110034 | SYSTEMS AND METHODS FOR GENERATING SEQUENCES THAT ARE NEAREST TO A SET OF SEQUENCES WITH MINIMUM AVERAGE CROSS-CORRELATION - A method for generating sequences that are nearest to a set of sequences with minimum average cross-correlation is described. Each element of a set of sequences is projected to a nearest constellation point. The set of sequences is converted into a time domain representation. An inverse discrete Fourier Transform (IDFT) is performed on the set of sequences. A cubic metric of each sequence of the set of sequences is evaluated. A sequence is removed from the set if the cubic metric exceeds a threshold. A minimum maximum cross-correlation is obtained for the set of sequences. | 04-30-2009 |
20090207889 | SPREAD SPECTRUM COMMUNICATION METHOD ADN SYSTEM USING VERY WEAK POWER, AND HIGH FREQUENCY RADIO APPARATUS - Provided is a high frequency radio apparatus capable of correcting a frequency of a carrier of the own apparatus in accordance with a frequency of a reception carrier when performing spread spectrum communication using very weak power. A carrier demodulating part demodulates a spread code received from a communication counterpart radio apparatus by using default carrier data, and sends the demodulated spread code to a synchronization timing detecting part. When the synchronization timing detecting part detects the spread code from the carrier demodulated data, a carrier frequency deviation detecting part performs a frequency analysis of the spread code to detect a deviation amount of the carrier frequency. A carrier data generating part generates corrected carrier data based on the detected deviation amount. A DBPSK modulating part uses the corrected carrier data to perform data transmission to the communication counterpart radio apparatus. | 08-20-2009 |
20100061426 | Apparatus and method for correlation in a gps receiver - An apparatus comprising: a first code controller for controlling the storage of a first spreading code portion; a first data input controller for controlling the storage of a first set of input samples; a second data input controller for controlling the storage of a second set of input samples; a combiner arranged to combine a spreading code sample with an input sample and output the resultant combination; a summer for summing said resultant combinations; and a combination controller arranged to control which of the stored first set of input samples or the stored second set of input samples provides said input sample for combination in the combiner. | 03-11-2010 |
20100111140 | Methods, Apparatuses and Computer Program Products for Code Correlation of Multi-Path Spread Spectrum Signals - A method including correlating a code having a first offset with a signal to produce a first correlation result; correlating the code having a second offset with the signal to produce a second correlation result; determining a cost function using the first correlation result and the second correlation result; and adjusting the first offset and the second offset in dependence upon the cost function, wherein the cost function uses a first weighting for the first correlation result and a second, different weighting for the second correlation result. | 05-06-2010 |
20100189163 | METHOD OF PROCESSING A DIGITAL SIGNAL DERIVED FROM A DIRECT-SEQUENCE SPREAD SPECTRUM SIGNAL AND A RECEIVER - Complex digital data values derived from a DSSS signal, in particular, a GNSS signal, are delivered to a general purpose microprocessor at a rate of 8 MHz and chip sums over eight consecutive data values spaced by a sampling length (T | 07-29-2010 |
20100202495 | TRANSMITTER, RECEIVER, WIRELESS COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - A transmitter has a portion that sets a parameter about the transmitter itself based on a parameter made to correspond to a condition for selecting a receiver with which the transmitter communicate with, a portion that generates a spread code based on the set parameter, and a sending portion that spreads transmit-data to form a spread signal by the generated spread code, and that sends the spread signal. The receiver has a portion that receives the signal transmitted by the transmitter, a portion that sets a parameter about the receiver itself based on the parameter made to correspond to the condition, a portion that generates a despread code based on the set parameter, a portion that performs a correlation computation of the received signal and the generated despread code, and a portion that selects a transmitter with which the receiver communicates, based on a result of the correlation computation. | 08-12-2010 |
20100272156 | HUMAN BODY COMMUNICATION SYSTEM AND COMMUNICATION METHOD THEREOF - A human body communication system is provided. The human body communication system includes a transmitter and a receiver. The transmitter transmits a frame including a preamble, which is a Manchester-encoded pseudo noise (PN) code, to the human body. The receiver receives the frame from the human body, performs Manchester-decoding on the frame, performs cross-correlation on the decoding result and the PN code, and performs frame synchronization using the cross-correlation result. Accordingly, clock and data recovery performance is improved. Efficient frame synchronization with reduced computation amount can be provided. | 10-28-2010 |
20100278215 | PROCESSING CODE-MODULATED SIGNALS - A method of processing a received first code-modulated signal, the received first code-modulated signal being a first signal modulated with a first code, to determine at least one of said first code and a delay in the first code-modulated signal, which determines a correlation between the received first code-modulated signal and a second code, the second code being at least substantially a sum of a plurality of further codes. | 11-04-2010 |
20100316092 | SYSTEM AND METHOD FOR DETECTING SPREAD SPECTRUM SIGNALS IN A WIRELESS ENVIRONMENT - An apparatus for detecting a spread spectrum signal in a wireless signal environment includes at least one antenna for receiving spread spectrum signals, such as UMTS signals, from a signal source in the wireless signal environment. In one embodiment, a detection circuit is configured for correlating a code in signal received by the apparatus with a set of possible codes for spread spectrum signals in order to detect the existence of a spread spectrum signal. In another embodiment, a detection circuit is configured for obtaining at least one reference frame of data from a received signal. The detection circuit is further operable for correlating a segment of the reference frame with a repeated segment of at least one subsequent frame of data in order to detect the existence of a spread spectrum signal. A repeater might incorporate such an apparatus wherein the variable gain of the repeater is adjusted based upon the correlation and the detection of a spread spectrum signal. | 12-16-2010 |
20110019719 | ADAPTIVE LINK COMMUNICATIONS USING ADAPTIVE CHAOTIC SPREAD WAVEFORM | 01-27-2011 |
20110032974 | CARRIER FREQUENCY SYNCHRONIZATION DETECTION CIRCUIT AND CORRELATION CALCULATOR - A correlation calculator and carrier frequency synchronization detection circuit are provided that enable a code phase, carrier frequency, and carrier frequency phase match to be detected even if a carrier frequency is greatly displaced. A correlation value calculation section ( | 02-10-2011 |
20110058592 | MULTICARRIER CDMA TRANSMISSION SYSTEM AND TRANSMISSION METHOD - In multicarrier transmission for multiplying transmit data individually by each code constituting orthogonal codes and transmitting each result of multiplication by a prescribed subcarrier, a plurality of different subcarriers are assigned exclusively to each user and each user performs multicarrier transmission of the transmit data by the subcarriers assigned. Further, a base station assigns a plurality of different subcarriers to each user exclusively, applies beam-forming processing on a per-user basis and performs multicarrier transmission of transmit data to each user by the subcarriers assigned. | 03-10-2011 |
20110103430 | Autocorrelation-Based Multi-Band Signal Detection - A receiver device for detecting a multi-band signal, the receiver device comprising a bank of autocorrelation units adapted for separating the multi-band signal into a set of autocorrelation signals, and a sampling stage arranged downstream the bank of autocorrelation units and adapted for sampling the set of autocorrelation signals to thereby select individual signal components for detection. | 05-05-2011 |
20110134965 | RSSI MEASUREMENT MECHANISM IN THE PRESENCE OF PULSED JAMMERS - This disclosure relates to method, device and system for controlling power in a communication system. A plurality of power levels is measured from a received signal that includes a pulsed noise source. The received signal is correlated with a known sequence creating a correlation metric. A signal power is determined based on the correlation metric and the plurality of power levels. An uplink signal is transmitted at a transmit power that is based on the signal power. | 06-09-2011 |
20110194588 | WIRELESS COMMUNICATION SYSTEM AND METHOD OF PROCESSING A WIRELESS SIGNAL - A wireless communication system includes: a frequency down-converting circuit for receiving a wireless signal and for performing frequency down-conversion on the wireless signal to output a frequency down-converted signal; a first training circuit for performing frequency comparison between the frequency down-converted signal and a plurality of candidate carrier signals having different frequencies so as to determine a plurality of selected carrier signals from the candidate carrier signals; a second training circuit for performing phase comparison between the frequency down-converted signal and phases of a pseudo-noise sequence at each of the selected carrier signals so as to determine a matching phase and a matching carrier; and a demodulator for demodulating the frequency down-converted signal according to the matching carrier and the matching phase so as to generate a demodulated signal. | 08-11-2011 |
20110206090 | Method for Optimizing an Acquisition of a Spread-Spectrum Signal from a Satellite by a Mobile Receiver - A method for optimizing the acquisition phase of a spread-spectrum signal by a mobile receiver includes searching for the path having the maximum energy for different frequency assumptions and among all the positive trend paths of said frequencies between two initial and final instants marking the beginning and the end of a coherent signal integration. | 08-25-2011 |
20130022085 | RAPID 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. | 01-24-2013 |
20130028296 | CHIP X2 CORRELATION HYPOTHESES USING CHIP X1 SAMPLES - A UE may store received samples of a wireless signal at cx | 01-31-2013 |
20130034123 | Coherent Interference Detection - A method for detecting coherent interference includes the steps of: (a) receiving a signal at a first frequency, (b) forming a set of cross-correlation results by at least cross-correlating the signal with a first known code for a plurality of code offsets, (c) determining a statistical signature of the cross-correlation results, and (d) deciding, based on the statistical signature, whether non-negligible coherent interference is present within a search bin defined by the combination of the first frequency and the first known code. | 02-07-2013 |
20130114643 | SYSTEM AND METHOD FOR COMMUNICATING IN A LOSSY ENVIRONMENT - A method of wireless communication in a lossy environment entails generating a direct sequence spread spectrum (DSSS) code string that includes a pseudo-noise (PN) sequence followed by instances of shifted PN sequences, where the shifted PN sequences are produced in response to the content of the message. The PN sequence includes a plurality of chips arranged in a first order, and each of the shifted PN sequences includes the plurality of chips arranged in another order. A beacon signal modulated by the DSSS code string is transmitted from a transceiver and received at a receiver within the communication system. Correlation peaks are formed at the receiver, where each correlation peak is associated with one of the PN sequences or one of the shifted PN sequences. Shift values are determined from the correlation peaks and the shift values are decoded to produce the message at the receiver. | 05-09-2013 |
20130136155 | PROCESS 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 subframes 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. | 05-30-2013 |
20130279541 | Method 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. | 10-24-2013 |
20130336366 | Identification and Isolation of Radio Signals for a Wireless Location System - In an overlay, network-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect uplink radio signaling for use in TOA, TDOA and/or AoA positioning methods. In a UMTS, the dual nature of the uplink allows for identification of the correct uplink signal even in the presence of co-channel interference from other UMTS mobile devices. | 12-19-2013 |
20140064338 | PREAMBLE DETECTION USING VECTOR PROCESSORS - In one embodiment, a programmable vector processor performs preamble detection in a wireless communication network. Implementation of preamble detection in the vector processor is made possible by a set of vector instructions that include (i) a circular load instruction for loading vectors of received data, (ii) a correlation instruction for correlating the vectors of received data with vectors of the scrambling code to concurrently generate a plurality of complex correlations, (iii) a partial-transpose instruction for arranging vectors of the complex correlations for use by a Fast Hadamard Transform (FHT) processor, and (iv) an FHT instruction for performing FHT processing on a vector of complex correlations. Implementing preamble detection in the vector processor allows more of the received data to be processed concurrently. As a result, preamble detectors of the disclosure may detect preambles using fewer clock cycles than that of comparable preamble detectors implemented using hardware accelerators. | 03-06-2014 |
20140133522 | Receiver For Use In An Ultra-Wideband Communication System - In an ultra-wideband (“UWB”) receiver, a received UWB signal is periodically digitized as a series of ternary samples. The samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, estimates of the channel impulse response (“CIR”) are developed. When a start-of-frame delimiter (“SFD”) is detected, the best CIR estimate is provided to a channel matched filter (“CMF”) substantially to filter channel-injected noise. | 05-15-2014 |
20140348210 | METHOD AND DEVICE FOR COMPRESSING A WIDE BAND RADIO-NAVIGATION SIGNAL, ASSOCIATED METHOD AND DEVICE FOR CALCULATING THE CORRELATION FUNCTION OF THE SPREADING CODE OF THE SAID COMPRESSED SIGNAL - The invention relates to a method for compressing a wide band satellite radio-navigation signal in order to transmit it on a narrow band channel and to a method for calculating the correlation function of the spreading code of a satellite radio-navigation signal compressed by application of the compression method. | 11-27-2014 |
20150063426 | SYSTEMS AND METHODS FOR PSEUDO-RANDOM CODING - Systems and methods for improving performance in terrestrial and satellite positioning systems are disclosed. Signal processing systems and methods are described for selecting, from among a set of codes, certain codes having desired autocorrelation and/or cross-correlation properties. Systems and methods for generating, encoding, transmitting, and receiving signals using the selected codes are also described. | 03-05-2015 |
20150085899 | CODING IN A POSITIONING SYSTEM - Embodiments describe determining position by selecting a set of digital pseudorandom sequences. The magnitudes of the cross-correlation between any two sequences of the chosen set are below a specified threshold. A subset of digital pseudorandom sequences are selected from the set such that the magnitudes of the autocorrelation function of each member of the subset, within a specified region adjacent to the peak of the autocorrelation function, are equal to or less than a prescribed value. Each transmitter transmits a positioning signal, and at least a portion of the positioning signal is modulated with at least one member of the subset. At least two transmitters of the plurality of transmitters modulate respective positioning signals with different members of the subset of digital pseudorandom sequences. | 03-26-2015 |
20150098491 | INCOHERENT UWB-IR TRANSCEIVING METHOD WITH IMPROVED MULTIPATH-RESISTANCE - There is provided an incoherent UWB-IR communication method by which erroneous demodulation is difficult to occur even in a multipath environment. Thus, the present invention includes an incoherent wireless communication method including a first step of modulating transmission data, a second step of converting the modulated transmission data into pulses and converting the pulses received from the external into reception data, and a third step of demodulating the reception data, wherein the pulses used in the second step includes a plurality of pulse sequences and the plurality of pulse sequences is such that the peaks of cross-correlation values are lower than the peaks of autocorrelation values. | 04-09-2015 |
20150341077 | SYSTEMS AND METHODS FOR PSEUDO-RANDOM CODING - Systems and methods for improving performance in terrestrial and satellite positioning systems are disclosed. Signal processing systems and methods are described for selecting, from among a set of codes, certain codes having desired autocorrelation and/or cross-correlation properties. Systems and methods for generating, encoding, transmitting, and receiving signals using the selected codes are also described. | 11-26-2015 |
20150365129 | TRANSMISSION DEVICE, RECEPTION DEVICE, AND RADIO COMMUNICATION METHOD - A transmitting apparatus includes an OFDM modulator that generates a first modulation symbol by modulating a first information signal using a first modulation scheme, a signal point of the first modulated information signal being arranged at a first position in an in-phase quadrature-phase plane and a second modulation symbol by modulating a second information signal using the first modulation scheme, and by changing a second position at which a signal point of the modulated second information signal is arranged to a third position in the in-phase quadrature-phase plane, wherein the third position is different from the first position. An OFDM modulation signal includes the first modulation symbol and the second modulation symbol, wherein the OFDM modulation signal comprises a plurality of subcarriers. A transmitter transmits the OFDM modulation signal. | 12-17-2015 |
20150372714 | METHOD AND RECEIVER FOR RECEIVING A BINARY OFFSET CARRIER COMPOSITE SIGNAL - A data processor selects a set of BOC correlations in accordance with a BOC correlation function for the sampling period if the primary amplitude exceeds or equals the secondary amplitude for the sampling period. The data processor selects a set of QBOC correlations in accordance with a QBOC correlation function for the sampling period if the secondary amplitude exceeds the primary amplitude for the sampling period. The data processor uses either the BOC correlation function or the QBOC correlation function, whichever with greater amplitude, at each sampling period to provide an aggregate correlation function that supports unambiguous code acquisition of the received signal. | 12-24-2015 |
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