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Correlative or matched filter

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375 - Pulse or digital communications

375316000 - RECEIVERS

375340000 - Particular pulse demodulator or detector

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DocumentTitleDate
20080232514GPS signal acquisition circuit - A GPS signal acquisition circuit includes a correlation engine, a decimator, a coherent integrator and an incoherent integrator. An over sampled GPS signal is fed into and processed by the correlation engine. The processed signal is sent to the decimator. The decimator generates an output for every M input from the correlation engine. When the decimated correlation engine output is processed in subsequent coherent and incoherent accumulations, the size of the memory required for high-sensitivity signal processing is greatly reduced. Therefore, the production cost can be lowered significantly.09-25-2008
20090185646ESTIMATING FREQUENCY SHIFT - Techniques, systems and apparatus are described for estimating a frequency shift. An apparatus for estimating a frequency shift includes a fast Fourier transform unit to transform a signal of a time domain into a frequency domain and output fast Fourier transform symbols. A complex conjugate multiplier is in communication with the fast Fourier transform unit and output a continual pilot correlation between every two of the fast Fourier transform symbols output from the fast Fourier transform unit. A correlation memory unit is in communication with the complex conjugate multiplier to store the continual pilot correlation output from the complex conjugate multiplier. An adder is in communication with the correlation memory unit to add the continual pilot correlations stored in the correlation memory unit and generate an output signal comprising estimated values of the frequency shift.07-23-2009
20090196383CORRELATION APPARATUS AND METHOD FOR FREQUENCY SYNCHRONIZATION IN BROADBAND WIRELESS ACCESS COMMUNICATION SYSTEM - A correlation apparatus and method for frequency synchronization are provided. A frequency synchronization method of a receiver in a broadband wireless access communication system includes acquiring a highest correlation value by conducting a differential correlation of a variable interval between a received signal and a reference signal and performing a frequency synchronization according to the highest correlation value.08-06-2009
20100008451Symbol Detection in a MIMO Communication System - Circuits are provided for detecting symbols transmitted from multiple transmitting antennas to multiple receiving antennas. A circuit includes distance blocks, selectors, and an identifier block. Each distance-block includes at least one sub-block, and each sub-block inputs a candidate for a corresponding transmitting antenna. The sub-block determines partial distances for pairings of the candidate and each symbol in a constellation from a partial distance of the candidate and signals received at the receiving antennas. At least one selector assigns each pairing for each candidate for a corresponding transmitting antenna to a bin having a range that includes the partial distance of the pairing. The selector selects candidates for a successive transmitting antenna from the bins having the smaller ranges. The identifier block selects a final candidate that is one of the pairings for a last transmitting antenna having a smaller partial distance.01-14-2010
20090122927RECEIVER FOR WIRELESS COMMUNICATION NETWORK WITH EXTENDED RANGE - Techniques for detecting and demodulating a signal/transmission are described. Signal detection is performed in multiple stages using different types of signal processing, e.g., using time-domain correlation for a first stage, frequency-domain processing for a second stage, and time-domain processing for a third stage. For the first stage, products of symbols are generated for at least two different delays, correlation between the products for each delay and known values is performed, and correlation results for all delays are combined and used to declare the presence of a signal. For demodulation, the timing of input samples is adjusted to obtain timing-adjusted samples. A frequency offset is estimated and removed from the timing-adjusted samples to obtain frequency-corrected samples, which are processed with a channel estimate to obtain detected symbols. The phases of the detected symbols are corrected to obtain phase-corrected symbols, which are demodulated, deinterleaved, and decoded.05-14-2009
20090122926DATA THROUGHPUT IN AN INTERFERENCE-RICH WIRELESS ENVIRONMENT - Systems and methods for improving data throughput in an interference-rich wireless environment are described herein. Some illustrative embodiments include a method including receiving a modulated radio frequency (RF) signal including a message packet, identifying a preamble of the message packet generating a correlated preamble by combining the message packet preamble with a correlation sequence corresponding to an expected preamble, determining a characteristic of a correlated signal representing the correlated preamble, comparing the determined characteristic of the correlated signal to a first threshold value, and discarding the message packet if the determined characteristic of the correlated signal is below the first threshold value.05-14-2009
20100074379Tuning replica generation methods and apparatus for their most optimum performance in processing transient signals - The embodiments of the present invention are most optimum methods and apparatus for processing transient (pulsed, non-cooperative, non-reproducible, complex, or simultaneous) signals; in particular, for their unbeatable vigor in passive source identifications; for their ultra precision transient spatial range and Doppler measurements; for their supreme powers in rejection noise and interference contamination; for their utmost abilities in deciphering random, chaotic, turbulent, explosive, thermo nuclear, and other countless transient phenomena. In particular, an embodiment of the present invention is an apparatus for processing transient signals that uses replica generations and which comprises: (a) a signal receiving apparatus which receives one or more signals having transient in nature, at least one of them cannot be repeatedly produced or is a signal of opportunity, and the signals have pulse lengths ranging from less than tenth of a picosecond to higher than several microseconds, and frequency widths from less than 0.10 MHz to higher than 40 GHz; (b) a tuning apparatus which accepts signals from the receiving apparatus as inputs, tunes one or more of these signals in response to a requirement of interest, where the requirement of interest includes, but not limited to, shortening or elongating the one or more of signals; (c) a replica generation apparatus, which accepts signals from the tuning apparatus as inputs, and outputs a train of replica pairs, where relative separations between two members in the replica pairs are same or different; (d) an integration apparatus which performs correlation integrations that is to correlate between two members in the replica pairs and to convert the train of replica pairs into a baseband signal.03-25-2010
20130077722SIGNAL ACQUISITION SYSTEM - A signal acquisition system efficiently acquires a transmitted signal even at very low power. The system may synchronize to a preamble structure in the transmitted signal and, for example, determine timing parameters that locate the preamble with respect to system timing or other clock references. The system is particularly effective at acquiring weak power signals and is also robust against significant noise and other impairments, and therefore improves the ability of a receiving device that incorporates the signal acquisition system to acquire the signal and establish communication with other devices.03-28-2013
20130039450METHOD AND ASSOCIATED APPARATUS OF DATA EXTRACTION - Method and associated apparatus of data extraction, including: sampling a signal and obtaining a plurality of sampled values, providing a reference sample quantity when the sampled values transit, providing a unit bit sample quantity according to the reference sample quantity, and corresponding each of the sampled values to each data bit of the signal according to the unit bit sample quantity.02-14-2013
20130034194RADIO RECEIVER - There is provided a radio receiver including: a first matched filter, a second matched filter, a first frame synchronization determining unit and a first phase determining unit. The first matched filter performs matching processing on the basis of N first tap coefficients and sign information of a received digital signal to obtain first output data. The second matched filter performs matching processing on the basis of M (M is a natural number smaller than the N) second tap coefficients, the sign information and amplitude information of the received digital to obtain second output data. The first frame synchronization determining unit determines a first frame synchronization timing of the received digital signal on the basis of the first output data. The first phase determining unit determines a first phase amount of the received digital signal on the basis of the second output data and the first frame synchronization timing.02-07-2013
20130188759SYSTEMS AND METHODS FOR COMPOSITE ADAPTIVE FILTERING - Systems and methods are provided for adaptively filtering a signal. A signal is received, and the received signal is filtered to generate an output signal. A difference signal is generated based on a difference between the output signal and a reference signal, and a correlation of the received signal and the different signal is evaluated. Then, a mode is selected between a first adaptive filtering mode and a second adaptive filtering mode based at least in part on the correlation, and the received signal is filtered using the selected adaptive filtering mode.07-25-2013
20100111236COURSE TIMING SYNCHRONIZATION - A system for determining the burst start timing of a signal includes logic configured to receive the signal, generate correlation moduli and generate a first timing output based on the correlation moduli. The logic may also be configured to receive operating mode information and timing information and generate search controls. The logic may further be configured to identify a maximum of the correlation moduli using the search controls and determine a second timing output associated with the maximum correlation modulus. The second timing output represents a more accurate approximation of a burst start time than the first timing output.05-06-2010
20090154611METHODS AND APPARATUS FOR LOW OVERHEAD MSK DECODING - Methods and apparatus for receiving a signal having a intermediate frequency (IF), sampling the IF signal at a selected sampling frequency, correlating the sampled IF signal with a preamble signal, determining a correlation peak for the correlated signals, identifying chips of the preamble signal based upon the correlation peak, and decoding the IF signal to obtain and store information encoded in the IF signal.06-18-2009
20090154610GUARD INTERVAL ANALYSIS METHOD AND APPARATUS - A receiver circuit processes a received signal to determine information regarding a guard interval therein. The receiver circuit typically forms digital samples from the received signal; generates a correlation function with peaks at positions that are determined by the size of the guard interval and a position of the guard interval within the received signal. The receiver circuit includes one or more comb filters, each corresponding to a possible guard interval size, each receiving a series of locations at which the correlation function exceeds a predetermined threshold, and each producing an output that provides information about the guard interval size and/or position. This advantageously allows the receiver circuit to determine the guard interval size quickly, for example, even in the case of received signals with relatively low signal-noise ratio.06-18-2009
20090154609APPARATUS AND METHOD FOR SELECTING CORRELATION SCHEME BASED ON CARRIER FREQUENCY ERROR - Provided is a correlation scheme selecting apparatus and method that can acquire initial synchronization efficiently by calculating frequency error criterion threshold between correlation schemes and selecting a correlation scheme for each region when a correlation value is calculated for initial sync in a communication system with carrier frequency errors. The method for selecting a correlation scheme based on a carrier frequency error includes: calculating mis-detection probability values based on a normalized frequency offset for each correlation scheme; determining as a frequency-error criterion threshold a crossing point of graphs of the calculated mis-detection probability values for each correlation scheme; and selecting a correlation scheme based on the determined frequency-error criterion threshold.06-18-2009
20090285338BANK OF CORRELATORS FOR SETS OF GCL SEQUENCES - A method for correlation of an input signal in a receiver is disclosed as well as a receiver and a communication system for implementing the method. The input signal is correlated with Generalized Chirp-Like (GCL) sequences being derived from a single Zadoff-Chu sequence modulated with at least two modulation sequences. The method includes at least the steps of processing samples of the input signal in a first delay line, in a Discrete Fourier Transform (DFT) circuit and in a second delay line. According to the invention, a multiplication of samples of the input signal with elements of modulation sequences corresponding to the at least two modulation sequences being used for deriving the GCL sequences is performed in a step after the processing in the first delay line. Then a DFT processing is performed using a DFT circuit.11-19-2009
20100142659SYSTEM AND METHOD FOR FFT WINDOW TIMING SYNCHRONIZATION FOR AN ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXED DATA STREAM - A system and method for determining an FFT window location for reception of an OFDM signal received over a transmission channel. The OFDM signal includes a plurality of symbols each having a guard interval. The system includes a correlation module that determines a location of maximum correlation in a first symbol, an FFT module to perform an FFT on the OFDM signal based upon an initial FFT window location, and an adjustment module. The adjustment module determines a plurality of permissible echo location options based upon the initial FFT window location, selects a permissible echo location option that corresponds most closely to the location of maximum correlation, and adjusts the initial FFT window location based upon the selected permissible echo location option so that the adjusted FFT window location includes substantially all of a useful symbol length of the first symbol while a maximum number of echoes are included within the guard interval of the first symbol.06-10-2010
20080232515METHOD AND APPARATUS FOR GENERATING TRAINING SEQUENCE CODES IN A COMMUNICATION SYSTEM - A method and apparatus for generating training sequence codes in a communication system. In the method, a pair of sequences A and B having cross-correlation properties as well as autocorrelation properties are generated, and protection sequences A′ and B′ are generated by copying last L symbols of the sequences A and B, respectively. The training sequence codes are generated by locating the protection sequences A′ and B′ in the most significant positions (MSPs) of the sequences A and B. The training sequence codes can be extended and applied to 16-QAM and 32-QAM used in a GERAN system, and the use of such training sequence codes enables data to be efficiently transmitted/received without performance deterioration in a GERAN system.09-25-2008
20130051504COMPENSATING DEVICES AND METHODS FOR DETECTING AND COMPENSATING FOR SAMPLING CLOCK OFFSET - A compensating device for detecting and compensating for a sampling clock offset in a receiver. An SCO detector includes multiple calculation paths and a controller. Each calculation path receives a time domain signal and a hypothetic offset, calculates correlation coefficients between the time domain signal and a delayed version of the time domain signal according to a predetermined delay and the hypothetic offset, calculates correlation coefficient sums according to the correlation coefficients, and extracts a maximum correlation coefficient sum for the hypothetic offset from the correlation coefficient sums. The controller is coupled to the calculation paths for providing different hypothetic offsets to each calculation path and detects the SCO according to the maximum correlation coefficient sums obtained from the calculation paths. An SCO compensator receives the SCO and compensating for the SCO on a signal generated in a signal processing path of a receiver.02-28-2013
20130051503SYSTEM AND METHOD FOR PREDICTING A POSITIVE CORRELATION - A device and method are disclosed for reducing the power consumption of a wireless radio device in establishing a wireless connection by predicting a probability of a positive correlation. The wireless radio device may power up a radio receiver of a connectable device to receive a portion of a sync word from a requesting device, determine a correlation value based on the received portion of the sync word and an expected sync word and if the correlation value is less than a threshold value, power down the radio receiver of the connectable device. Additionally, if the correlation value is greater than a threshold value, the entire sync word may be received from the requesting device and a correlation value may be determined based on the entire sync word and the expected sync word.02-28-2013
20100266075INFRARED SIGNAL DECODE CIRCUIT AND INFRARED SIGNAL DECODE METHOD - According to one embodiment, an infrared signal decode circuit includes: a comparator; a correlation signal generator generating a sum of a first detection signal and a second detection signal as a correlation signal, the first detection signal being obtained by performing an absolute value calculation on a first correlation signal, the second detection signal being obtained by performing an absolute value calculation on a second correlation signal, the first correlation signal corresponding to a correlation between a binary signal and a first reference signal with a frequency substantially identical to a base frequency of a subcarrier of an infrared signal, the second correlation signal corresponding to a correlation between the binary signal and a second reference signal with a phase that differ from a phase of the first reference signal by 90 degrees; and a decoder binarizing the correlation signal generated by the correlation signal generator.10-21-2010
20090304128Packet Detection Apparatus and Method, Wireless Communication Apparatus and Method, and Computer Program - A packet detection apparatus detects a packet from a received signal by using a preamble containing an established, repeating training sequence. A first autocorrelation calculator computes a first autocorrelation of the received signal over a first interval. A first determining unit determines packet discovery by comparing the first autocorrelation to a first autocorrelation threshold value. A second autocorrelation calculator computes a second autocorrelation of the received signal over a second interval equivalent to the interval length for packet discovery announcement. A second determining unit determines packet discovery announcement by comparing the second autocorrelation to a second autocorrelation threshold value lower than the first autocorrelation threshold value.12-10-2009
20090304127NARROW BAND RECEIVER - An RF receiver comprises a signal processor arranged to perform a method of decoding data contained within a signal that comprises a set of slots, at least one said slot comprising a preamble portion and a payload portion and being transmitted at a predetermined transmission frequency. The signal processor is arranged to perform a first process to derive timing data from the preamble portion and perform a second process to extract information from the payload portion, the second process being triggered from said timing data derived from the first process. The preamble portion comprises at least a first sequence of data and a second sequence of data, and the second sequence is the inverse of the first sequence. In preferred embodiments the first process comprises identifying a transition between said first and second sequences of data and deriving said timing data from the identified transition.12-10-2009
20090304126OFDM Communication Device and Guard Interval Length Decision Method - Even if background noise is present, it is possible to control a guard interval length so that a minimum required SINR can be obtained. An OFDM communication device (12-10-2009
20090103667Methods for Modified Signal Acquisition for OFDM Schemes - This invention relates to methods for determining coarse symbol timing and mode detection by using CP correlation-based techniques. In particular, this invention relates to methods for determining symbol timing, frame timing, and system mode for signal acquisition, comprising the steps of: detecting symbol timing and system mode based on cyclic prefix correlation; and determining a null symbol as a function of a pre-defined number of consecutive symbols and using said null symbol to determine frame timing.04-23-2009
20120219098CONTROLLABLE FILTER TO DIAGONALIZE A TRANSMISSION CHANNEL - The present invention relates to a node (08-30-2012
20090041167Demodulator, Receiver, and Demodulation Method - In an OFDM receiver with a diversity configuration having a plurality of demodulation modules, to perform FFT window position recovery and clock recovery, the gain values calculated by the AGC units (02-12-2009
20090092206WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD USING PLURAL COMMUNICATION CHANNELS HAVING DIFFERENT BANDWIDTHS - A wireless communication apparatus includes a measuring unit, a matched filter, and a control unit. The measuring unit measures an electric power of a received signal. The matched filter is capable of operating as a first filter and a second filter for the received signal. The first and second filters detect a frame in a first and second communication channel, respectively. The second communication channel uses a frequency band including a frequency bands used in the first and third communication channel. The control unit determines whether or not the frame exists in the third communication channel according to a detection result of the measuring unit and the matched filter. The control unit operates the matched filter as the first filter when the frame exists in the third communication channel and operates the matched filter as the second filter when the frame does not exist in the third communication channel.04-09-2009
20130058442WIRELESS RECEIVING APPARATUS AND METHOD - According to one embodiment, a wireless receiving apparatus a calculation module, a detection module and a determination module. The calculation module calculates, for each of modes, correlation values between a received signal and reference signals. The detection module synthesizes the correlation values to generate first correlation value sequences for each of the modes, and to detect at least one second correlation value sequence. The determination module selects a known signal period from the signal periods and a known signal interval from the signal intervals, based on first correlation values included in the second correlation value sequence, and to determine a received signal mode.03-07-2013
20110013732RECEIVER AND METHOD - A receiver for detecting and recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols. The receiver comprises a demodulator, symbol synchronization unit, frequency transform processor, and coarse frequency offset detector. The demodulator generates sampled symbols. The symbol synchronisation unit has correlators, which receives the sampled symbols, and a correlation detection processor. Each correlator auto correlates each sampled symbol, and the correlation detection processor determines a start point of each symbol. The frequency transform processor receives the sampled symbols and performs a frequency transform on each symbol. The coarse frequency offset detector includes a pilot data filter, which includes taps corresponding to a value and spacing of the pilot pattern of the symbols and arranged to receive as an input the frequency domain symbols from the frequency transform processor, and a coarse frequency offset detect processor, which is arranged to detect a coarse frequency offset output from the pilot data filter.01-20-2011
20110013731SPECTRUM SENSING FOR DMB-T SYSTEMS USING PN FRAME HEADERS - This dissertation addresses the intersection of personal wireless technology and computational intelligence. The primary research issue addressed is the organization of radio domain knowledge into data structures processable in real-time that integrate machine learning and natural language processing technology into software radio. The thesis defines and develops the cognitive radio architecture. The features needed in the architecture are derived from cognitive radio use cases. These include inferring user communications context, shaping access-network demand, and realizing a protocol for real-time radio spectrum rental. Mathematical foundations for the knowledge-representation architecture are derived by applying point-set topology to the requirements of the use cases. This results in the set-theoretic ontology of radio knowledge defined in the Radio Knowledge Representation Language (RKRL). The mathematical analysis also demonstrates that isochronous radio software is not Turing-computable. Instead, it is constrained to a bounded-recursive subset of the total functions. A rapid-prototype cognitive radio, CR1, was developed to apply these mathematical foundations in a simulated environment. CR1 demonstrated the principles of cognitive radio and focused the research issues. This led to an important contribution of this dissertation, the cognitive radio architecture. This is an open architecture framework for integrating agent-based control, natural language processing, and machine learning technology into software-defined radio platforms.01-20-2011
20090268856DEMODULATION DEVICE, DEMODULATION DEVICE CONTROL METHOD, DEMODULATION DEVICE CONTROL PROGRAM, AND RECORDING MEDIUM WITH RECORDED DEMODULATION DEVICE CONTROL PROGRAM - This demodulation device receives and demodulates a digital broadcast wave. This demodulation device includes an RF search control unit (10-29-2009
20090268855SIGNAL RECEIVING APPARATUS, SIGNAL RECEIVING METHOD AND SIGNAL RECEIVING PROGRAM - A signal receiving apparatus for receiving signals is provided. The signal receiving apparatus includes a correlation-value computation section configured to sequentially compute a correlation value representing a correlation between the received signal and a series of known symbols while sliding the series of known symbols for every symbol included in the received signal, a maximum-value detection section configured to detect a largest correlation value among the correlation values computed by the correlation-value computation section for one frame of the received signal, and a correlation-value storage section configured to store each of the correlation values at one of a predetermined number of storage locations, before and after the largest correlation value is detected by the maximum-value detection section.10-29-2009
20100091916ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYNCHRONIZATION - Embodiments are directed to first and second OFDM pilot symbols. The first and second pilot symbols may have first and second sets, respectively, of allowed, forbidden, and active carrier frequencies. The second sets of carrier frequencies may be formed by frequency shifting the respective first sets by a predetermined frequency, such as the frequency difference between adjacent carriers. An embodiment is directed to frequency translating part of a first received pilot symbol by one carrier interval in a first direction, frequency translating part of a second received pilot symbol by one carrier interval in a second direction that is opposite from the first direction, and forming a correlation by multiplying the frequency translated parts of the first and second pilot symbols by complex conjugates of parts of the pilot symbols upon which frequency translation has not been performed, and summing the multiplication results.04-15-2010
20100091915METHODS AND SYSTEMS FOR MIMO PREAMBLE DETECTION - Certain embodiments of the present disclosure allow for detection of a transmitted preamble sequence by processing a correlation of a received signal and a preamble hypothesis in a way that exploits the good correlation properties of the known set of preamble sequences. For certain embodiments, the highest peaks of the correlation output may be compared across all preamble hypotheses to decide which preamble sequence is transmitted.04-15-2010
20130064333WIRELESS RECEIVING APPARATUS AND METHOD - According to one embodiment, a wireless receiving apparatus includes a calculation module, a first determination module and a second determination module. The second determination module determines a length of interleaver blocks by determining whether or not a maximum value of second correlation value sequence is not less than a second threshold value within a first period, the second correlation value sequence being generated by combining third correlation values being between the receiving signal and each of reference signals, and to determine an initial position of the interleaver blocks based on a position of the maximum value.03-14-2013
20090232258DEVICE AND METHOD FOR DEMODULATING CONTROL SIGNALS - A device performs demodulation of control signals from multiple radio terminals, based on the correlations in the frequency domain between a predetermined code and the orthogonalized control signals and reference signals of the multiple radio terminals obtained by cyclic shifts of the predetermined code. The device includes: a demultiplexer which demultiplexes a reference signal component and a control signal component based on a correlation profile; a path detector which detects a path location or path locations for each radio terminal based on the power values of the reference signal components; extractor which extracts the correlation values of the reference signal components and the correlation values of the control signal components, respectively; and RAKE combiner which combines the extracted values.09-17-2009
20130163703APPARATUS AND METHOD FOR DETECTING BROADCASTING SIGNAL - Disclosed are an apparatus and a method for detecting a broadcasting signal. The signal detecting apparatus according to the exemplary embodiment of the present invention includes: a reference signal generator outputting a reference signal acquired by performing a correlation calculation between a current sample and a previous sample of a received signal which is an FM signal or a digital radio mondiale plus (DRM+) signal and then normalizing a result of the correlation calculation; and a discriminator detecting a maximum value of the reference signal and judging that the received signal is the FM signal when the maximum value of the reference signal is more than a predetermined threshold.06-27-2013
20100226462RECEIVING APPARATUS AND METHOD WITH NO OVERSAMPLING ANALOG TO DIGITAL CONVERSION - The present invention relates to a receiving apparatus for receiving signals in a wireless communication system, in which the signals comprise a dedicated channel estimation sequence, comprising an analog to digital converter adapted to convert received signals into digital samples with a sampling rate identical to a symbol rate of the received signals, a channel estimation means adapted to perform a channel estimation on the basis of the dedicated channel estimation sequence comprised in a digital samples of the received signals, an evaluation means adapted to evaluate the channel estimation result from the channel estimation means, and a control means adapted to control a phase of the sampling rate of the analog to digital converter on the basis of an evaluation of the channel estimation result.09-09-2010
20110280348Method and Apparatus for Coding Acquisition - The present invention relates to a method and apparatus for code acquisition. The present invention performs variable delay correlation to obtain the peak correlation result which is immune to carrier frequency offset and Doppler. The present invention makes use of a mapping parameter which is immune to sampling frequency offset. In particular, the present invention is applicable to the DTMB standard.11-17-2011
20090245436Systems and Methods For Sending An Acknowledgement Message In A Wireless Communication System - A method for sending an acknowledgment message in a wireless communication system is disclosed. A first signal is received before receiving a second signal from a transmitter. Decoded first data is extracted from the first signal. A third signal is produced by encoding and modulating the decoded first data. The second signal is demodulated to produce second symbols. The third signal and the second symbols are correlated.10-01-2009
20090028275FRAME-BASED CARRIER FREQUENCY AND PHASE RECOVERY SYSTEM AND METHOD - Header information is used to facilitate coarse frequency and frame recovery. The coarse frequency and frame recovery is thereafter utilized to perform adaptive phase and frequency synchronization on a frame-by-frame basis.01-29-2009
20090207951Apparatus and Method for Processing Signal Using Single Correlator - An apparatus and method for processing a signal using a single correlator are provided. The apparatus may include a first storage unit storing satellite signal samples, a correlator receiving the satellite signal samples stored in the first storage unit in units of at least two satellite signal samples and performing correlation, and a controller storing the satellite signal samples received from an RF terminal in the first storage unit and controlling the correlator based on a predetermined control value. Accordingly, it is possible to ensure speed and performance even when tracking a plurality of satellite signals using a single correlator.08-20-2009
20120288041Method And Apparatus For Frequency Tracking In A Space Time Transmit Diversity Receiver - A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function.11-15-2012
20120288040Method and Device for Implementing Automatic Frequency Control - The present invention discloses a method and apparatus for implementing automatic frequency control. The method comprises: calculating a correlation value of common pilot symbols in a reception signal of each path and a frequency offset value, calculating a combined frequency offset value according to the frequency offset value of each path, and determining, according to the combined frequency offset value, a frequency offset adjustment value for a voltage controlled oscillator, a frequency offset adjustment value for overall reception signals and a frequency offset adjustment value for the reception signal of each path. Compared with prior art, with the method and apparatus of the present invention, a new method of small-scope frequency offset estimation is selected, which makes frequency offset estimation more accurate; by using CORDIC, hardware resources are saved and calculation accuracy is improved; the stability of system is enhanced by the frequency offset adjustment and control policy.11-15-2012
20110299638LOGARITHMIC DETECTOR AND METHOD OF PRE-CHARGING AN AVERAGE FILTER ON A LOGARITHMIC DETECTOR - The detector comprises a plurality of detection stages connected to a summator for providing a summation signal as a logarithmic representation of the input signal to a first input of a data slicer and an input of an average filter having an output connected to a second input of the data slicer. The data slicer has a data slicer output for providing an extracted digital data signal in dependence on a comparison of the summation signal and an output signal of the average filter. The average filter receives a first pre-charge voltage and a second pre-charge voltage depending on an output signal of a carrier detector circuit detecting a carrier signal of the input signal.12-08-2011
20090257532Determining Burst Transmission Signals - Described are computer-based methods and apparatuses, including computer program products, for determining burst transmission signals. A receiver receives radio frequency data from a data source through a network. The receiver converts the radio frequency data to digital data. The receiver converts the digital data to baseband data. The receiver generates a correlation magnitude from the baseband data based on one or more correlation templates. The receiver determines one or more statistics based on the correlation magnitude and stored statistics. The receiver determines the presence of a burst transmission signal based on a comparison of a threshold value computed as a function of the statistics and the correlation magnitude. If the correlation magnitude exceeds the computed threshold, the receiver demodulates the burst transmission signal to packet data and transmits the packet data to a server.10-15-2009
20110286556ACQUISITION OF TIMING INFORMATION IN WIRELESS COMMUNICATION SYSTEMS - A method for identifying a reference point in time in a wireless communication system includes: receiving a first repeated sequence of symbols; receiving a second repeated sequence of symbols; performing an autocorrelation between the first and second sequences of symbols; and identifying as the reference point in time an autocorrelation null between the first and second repeated sequences of symbols. Apparatus for identifying a reference point in time in a wireless communication system includes: means for receiving a first repeated sequence of symbols; means for receiving a second repeated sequence of symbols; means for performing an autocorrelation between the first and second sequences of symbols; and means for identifying as the reference point in time an autocorrelation null between the first and second repeated sequences of symbols. Other aspects, features, and embodiments are also claimed and described.11-24-2011
20110286555METHOD AND APPARATUS FOR DETECTING PRESENCE OF SIGNAL IN WIRELESS COMMUNICATION SYSTEM BASED ON CR TECHNOLOGY - The present invention relates to a method of detecting the presence of a transmission signal of a transmitter in a reception signal in a wireless communication system based on CR technology. The method includes generating a frequency signal vector using a Fourier transform and a reception signal vector obtained by sampling the reception signal at a certain period, finding an eigenvalue and an eigenvector regarding a matrix, obtaining by approximating a covariance matrix of the frequency signal vector using a vectorized Fourier transform result of all channel impulse responses of the transmission signal linearly modulated, calculating a sufficient statistic on a basis of the frequency signal vector, the eigenvalue, and the eigenvector, finding a threshold which is a criterion for determining signal presence detection on a basis of a preset detection probability or a preset false alarm probability and the eigenvalue, and if the sufficient statistic is determined to be greater than the threshold, determining that the transmission signal exists.11-24-2011
20090220035APPARATUS FOR EQUALIZING CHANNEL IN FREQUENCY DOMAIN AND METHOD THEREFOR - Provided is an apparatus for channel equalization in frequency domain, including: a channel estimation unit for estimating a channel on received signal from outside, a channel matched filter for changing channel characteristic of the channel estimated by the channel estimation unit and the received signal to channel characteristic to meet condition required for noncausal filtering, a noncausal filter for changing the channel characteristic changed by the channel matched filter from nonminimum phase channel to minimum phase channel, a reverse channel calculation unit for calculating a reverse of the channel changed by the non-causal filter in frequency domain, and a frequency domain equalization unit for performing channel equalization with respect to the channel changed by the noncausal filter in the frequency domain by using the reverse obtained by the reverse channel calculation unit as coefficients of the frequency domain equalization apparatus.09-03-2009
20080310561SIMPLIFIED RACH PREAMBLE DETECTION RECEIVER - A low complexity RACH preamble detector is described herein. The RACH preamble detection algorithm uses the peak detection of the time domain correlation function through frequency domain processing. The frequency domain processing considers the reference signals generated directly from frequency domain CAZAC sequence or time domain CAZAC sequence with DFT conversion. A low-complexity poly-phase LPF along with down sampling is implemented before the FFT to reduce the required length of the long FFT operation N-folded.12-18-2008
20100027724RECEIVER AND RECEIVING METHOD - Quick resumption of reproduction of received data is achieved with low cost. A receiver for receiving an OFDM signal has a demodulation unit and a transmission mode control unit. The demodulation unit performs, on a received signal, demodulation and detection of establishment of synchronization in accordance with a transmission mode that is a combination of an FFT mode and a guard interval, and outputs a synchronization establishment signal indicating an obtained result of the detection of establishment of synchronization. The transmission mode control unit holds an FFT mode and a guard interval adopted when the synchronization establishment signal indicates establishment of synchronization, and outputs a combination of the held FFT mode and the held guard interval as the transmission mode to be used in the demodulation unit.02-04-2010
20100128823DOPPLER FREQUENCY ESTIMATING DEVICE, RECEIVING DEVICE, RECORDING MEDIUM AND DOPPLER FREQUENCY ESTIMATING METHOD - A device of an example of the invention comprises a first section which performs IFFT for a channel estimation value obtained by channel estimation to obtain a channel impulse response, a second section which selects paths that belong to a group having a large element based on elements of paths for the channel impulse response, a third section which calculates autocorrelation values by time averaging for each of the paths selected by the second section, a fourth section which obtains an ensemble average value of the autocorrelation values by time averaging obtained by the third section, and a fifth section which obtains a Doppler frequency associated with the ensemble average value based on a characteristic of a relationship between an autocorrelation value and an Doppler frequency and the ensemble average value.05-27-2010
20100119018Method And Apparatus For Frequency Tracking In A Space Time Transmit Diversity Receiver - A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed herein. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function.05-13-2010
20090285339Apparatus for Generating Spreading Sequences and Determining Correlation - An apparatus includes a signal generator to output one of a first sequence or a second sequence and to augment sequences with cover codes, such that a sum of out-of-phase aperiodic autocorrelation coefficients of the first sequence and the second sequence of is zero, a physical layer preamble controller to control the signal generator to generate a preamble of a data unit, including a short training field (STF) formatter to cause the signal generator to generate an STF for use in at least frame synchronization, and a long training field (LTF) formatter to cause the signal generator to generate an LTF for use in at least channel estimation, such that the STF formatter controls the signal generator to include the first sequence in a last portion of the STF, and the LTF formatter controls the signal generator to include the second sequence in a beginning portion of the LTF.11-19-2009
20090213968Method and apparatus to detect random access channel preamble - A method (and operation of a computer program) includes receiving a signal over a wireless channel; correlating the received signal with a reference sequence and providing a correlation output; processing the correlation output to detect a presence of a first predetermined preamble sequence using a main correlation peak and two first order frequency shift peaks and nulling second and higher order frequency shift peaks from the correlation output prior to further processing the correlation output to detect a presence of a second predetermined preamble sequence. Apparatus that embody the method are also disclosed.08-27-2009
20090207950MODULATION SCHEME ESTIMATION APPARATUS AND METHOD - A modulation scheme estimation apparatus includes a receiving unit receiving a first signal, a generation unit generating a plurality of first phase amounts, an acquisition unit acquiring a plurality of multiplication signals by multiplying the first signal by each of the first phase amounts, an extraction unit extracting a plurality of second signals corresponding to respective direct-current components of third signals obtained by subjecting the multiplication signals to Fourier transform, a first computation unit computing a plurality of sums, each of which is a sum of each of the multiplication signals and a corresponding one of the second signals, a second computation unit computing a plurality of absolute values of the sums, and a first identifying unit identifying a modulation scheme corresponding to one of the absolute values which has a highest similarity with respect to reference values associated with modulation schemes.08-20-2009
20090207949TRANSMITTER IDENTIFICATION INFORMATION SIGNAL DETECTION APPARATUS AND METHOD - A transmitter identification information (TII) signal detection circuit is suitable for an orthogonal frequency division modulation system. A TII signal detection circuit receives a TII signal and conducts a cross-correlation calculation on the TII signal and a phase reference symbol (PRS) so as to obtain a present cross-correlation result, and then, sums the cross-correlation results obtained by conducting cross-correlations on AVE_TF_NUM-08-20-2009
20130216008Method and Associated Apparatus for Determining Signal Timing of Wireless Network Signal - A method for determining signal timing of a wireless network signal is provided. The method includes: performing match-filtering on the wireless network signal transmitted by one or multiple antennas to provide a match value distribution, performing moving averaging on the match value distribution to provide an accumulation distribution, searching a peak of the accumulation distribution to provide a central timing according to a timing at which the peak occurs, and determining the signal timing (e.g., a symbol boundary) of the wireless network signal according to the central timing.08-22-2013
20090161800METHOD AND APPARATUS FOR PACKET DETECTION - A present invention provides a method and an apparatus for packet detection. The packet detection method with adaptive strategy includes several stages, and each stage has different parameter setting for packet detection. The method provides the packet detection apparatus with adaptive advantage to adapt various channel environments. The method and an apparatus for packet detection can effectively promote the success probability to detect packets.06-25-2009
20090279646Wireless communication device - A wireless communication device is provided to carry out correlation peak detection processing properly and efficiently in intermittent receiving unit. If a correlation peak is not detected in a first period in which a correlation peak detecting unit detects the correlation peak at a default frequency and a first frequency in a detecting period of a coarse frequency deviation detecting unit in the first period, a control unit makes the correlation peak detecting unit carry out the peak detection at the first frequency in a second period. If the correlation peak is detected in the correlation peak detecting unit and a second frequency is detected in a detecting period of a fine frequency deviation detecting unit in the first period, the control unit makes the correlation peak detecting unit carry out the peak detection at the first and second frequencies in a third period.11-12-2009
20100278288CHANNEL ESTIMATION METHOD AND SYSTEM FOR INTER-CARRIER INTERFERENCE-LIMITED WIRELESS COMMUNICATION NETWORK - A method and system for wireless communication channel estimation. A frequency offset hypothesis is determined. An interchannel interference (“ICI”) matrix based on the frequency offset hypothesis is generated. Pilot channel estimates based on the ICI matrix are obtained. A correlation error of the pilot channel estimates to the frequency offset hypothesis is calculated. The correlation error is compared with a predetermined correlation error value. The frequency offset hypothesis is updated and the aforementioned steps are iteratively repeated if the correlation error is greater than the predetermined correlation error value. The pilot channel estimates are used to estimate the wireless communication channel.11-04-2010
20090290662METHOD FOR GENERATING A REFERENCE SIGNAL SEQUENCE USING GROUPING - Method for generating reference signal sequence using grouping is explained. In this method, base sequences are grouped such that each group contains at least one base sequence of each length, so UE(s) can use various length sequences as a reference signal. And in this method, inter cell interference caused by using various length sequence as a reference signal sequence can be minimized by grouping sequences having the high cross correlation relation.11-26-2009
20090290661DETECTION OF TIME-DOMAIN SEQUENCES SENT ON A SHARED CONTROL CHANNEL - Techniques for sending and receiving signaling messages in a control segment are described. The control segment may be sent with CDM in multiple OFDM symbols. At a receiver, a received sequence is obtained for the control segment. A time-domain signaling sequence is generated based on a signaling message hypothesized to have been sent in the control segment. A correlating sequence is generated based on the signaling sequence. In one design, the signaling sequence is partitioned into multiple sub-sequences, one sub-sequence for each symbol period in which the control segment was sent. Each sub-sequence is cyclically shifted by an amount determined by a channel tap delay. The correlating sequence is then formed by concatenating all of the cyclically shifted sub-sequences. The correlating sequence may also be generated in other manners. The received sequence is correlated with the correlating sequence to determine whether the signaling message was sent in the control segment.11-26-2009
20090296862RECEIVING APPARATUS AND RECEIVING METHOD - A receiving apparatus that can properly determine the position of an effective symbol included in a received signal is provided. A receiver acquires a signal from a sending apparatus that transmits a signal into which a guard interval which is a replica of at least part of an effective symbol is inserted between the effective symbol and another effective symbol. A timing detector finds a correlation between the received signal and a signal obtained by shifting the received signal in a time direction, detects timing at which a maximum correlation value is obtained, and determines that timing which is predetermined time (>12-03-2009
20110200150WIDEBAND COMMUNICATION FOR BODY-COUPLED COMMUNICATION SYSTEMS - The present invention relates to a communication apparatus, method and computer program product for providing a reception approach in a body-coupled communication system with a switch-based filtering in order to remove low frequency interference without attenuating the wanted digital signal, and a receiver structure that makes use of correlation for both data detection and synchronization in order to suppress the uncorrelated interference without attenuating the wanted signal.08-18-2011
20100061493SYNCHRONIZATION CIRCUIT AND SYNCHRONIZATION METHOD, WIRELESS COMMUNICATION DEVICE AND WIRELESS COMMUNICATION METHOD, AND COMPUTER PROGRAM - A synchronizing circuit comprising: a coarse synchronizing circuit which determines temporary reception timing using a preamble consisting of a repetition of known training signals added to a reception packet; a synchronization candidate timing control section which sets up multiple synchronization candidates based on the temporary reception timing and controls synchronization of received signal s in each of the multiple synchronization candidates; a signal quality monitoring section which monitors signal quality of the received signal s synchronized in each of the multiple synchronization candidates; and a synchronization candidate selecting section which selects one of the synchronization candidates as a final reception timing based on a monitoring result of the signal quality in the signal quality monitoring section.03-11-2010
20100061492Reduced Frequency Data Processing Using a Matched Filter Set Front End - Various embodiments of the present invention provide systems and methods for reduced clock rate data processing. As an example, a circuit is disclosed that includes a matched filter bank that receives a series of symbols at a rate corresponding to a sample clock. The matched filter bank includes a first matched filter tuned to detect a first bit sequence in the series of symbols and to assert a first symbol proxy upon detection of the first bit sequence, and a second matched filter tuned to detect a second bit sequence in the series of symbols and to assert a second symbol proxy upon detection of the second bit sequence. The circuit further includes a detector circuit that processes a series of symbol proxies including the first symbol proxy and the second symbol proxy at a rate corresponding to a reduced rate clock. The reduced rate clock is the sample clock divided by a factor.03-11-2010
20090168928Data Slicer Reference Generator For Multiple Burst Data Signals - A slice level reference generator and method for performing improved data slicing operations when gaps are present in a data stream is disclosed that involves applying a nominal reference signal to the comparator the during signal gaps. In one embodiment, a receiver circuit includes a slice level detector and a comparator that operate in a conventional manner, and control circuitry that utilizes a signal detector and a switch to store a slice level reference signal generated by the slice level detector during a first signal burst, and to apply the stored reference signal to the comparator during signal gaps. In one embodiment a timer circuit is used to detect signal gaps. In another embodiment a predetermined fixed reference signal is applied to the comparator during signal gaps.07-02-2009
20080273634Parallel preamble search architectures and methods - The present invention provides architectures and methods which enables faster and more power efficient detection of channel parameters used by a communication system. Various parallel preamble correlator structures are able to perform searches for multiple preambles in parallel. The received samples are correlated with different delays between the samples corresponding to the different possible channel parameters that may be used by the communication system. Processing elements used in the preamble search may be shared among the parallel preamble search sections of a given architecture to reduce costs and power consumption. Decimation and filtering may also be used to reduce the interference from adjacent channels.11-06-2008
20080273633METHOD AND DEVICE FOR ENHANCING SIGNAL DETECTION IN A FREQUENCY SELECTIVE FADING CHANNEL - A method and system are provided for enhanced signal detection in a frequency selective fading channel. Improved signal detection is realized by replacing single matched filters with multiple matched filters. The single matched filter spectrum is partitioned by frequency into M matched filter groups, where M is a positive integer greater than one. The filter bandwidth of each of the M matched filters is less than the bandwidth of the single matched filter from which they are derived. The M matched filters are provided to filter in parallel fashion the input signal into M sub-spectrums of the signal. The input signal is filtered through the M matched filters and also sent to the energy detector. The matched filter outputs are combined and the received signal is detected using the combined output and the energy in the received signal.11-06-2008
20100034326Receiver for receiving data symbols having a symbol period - A receiver and method for receiving symbols having a symbol period with duration SP comprising. N antenna signals are selected equally in time over a symbol period to obtain a combined antenna signal. An autocorrelation is performed on the combined antenna signal to obtain a combined signal. The combined signal is split into the corresponding antenna signal parts and subjected to an integration function. The output of the integration function is used the select the antenna signal with the best signal quality. The invention enables to perform an efficient antenna diversity circuit, which can partially be used for simultaneously preamble detection and frequency offset estimation.02-11-2010
20080304602DIGITAL BROADCASTING SYSTEM AND METHOD OF PROCESSING DATA - A digital broadcast system including a broadcast receiving system and data processing method are disclosed. In the broadcast receiving system receiving broadcast signals, the broadcast receiving system includes a transmission parameter decoding unit, a known sequence detector, and a burst controller. The transmission parameter decoding unit detects information on a burst of a received signal from broadcast data having main service data and mobile service data multiplexed therein within a field of the received signal and outputs the detected information on the burst. The known sequence detector receives burst information from the transmission parameter decoding unit and uses the received burst information and known data position information included in the received data, so as to output burst control information. The burst controller uses the burst control information to control power supply of the broadcast receiving system.12-11-2008
20120294397DELAY DETECTOR CIRCUIT AND RECEIVER APPARATUS - The present invention provides a delay detector circuit that delivers performance at low cost and can reduce power consumption, and a receiver apparatus that uses this delay detector circuit. The delay detector circuit according to the present invention performs a part of the decoding processing for decoding data transmitted by a transmitter apparatus based on a received wave. The receiver apparatus according to the present invention uses the delay detector circuit described above. Therefore the delay detector circuit and receiver apparatus of the present invention deliver performance at low cost and can reduce power consumption.11-22-2012
20120294396Direct detection of wireless interferers in a communication device for multiple modulation types - Direct detection of wireless interferers in a communication device for multiple modulation types. One or more radios implemented within a communication device is/are operative to receive and process wireless communications. A wireless communication signal is processed to extract symbols there from. Various symbols groups are processed in accordance with correlation processing to identify potential interferers (e.g., other communication devices using common portions of frequency spectra). Alternatively, matched filter processing (e.g., using a Barker matched filter in some embodiments) operates on the various symbol groups to identify some potential interferers. Various combinations of correlation processing and matched filter processing may be employed in other instances (e.g., using any of a desired means of comparison, combining, etc.) in considering interferers identified in accordance with each of these two means. Also, re-identification and re-characterization of possible interferers may be performed subsequently to remove or re-admit frequency spectra for use in communications.11-22-2012
20080267324Impulse Radio Communication Device - An impulse radio communication device includes a wave detector for generating a detected signal, a switching section for selecting either a received signal or the detected signal in accordance with an external control signal and outputting it as a demodulation target signal, a reference waveform generating section synchronized with the demodulation target signal and generating a reference waveform signal having a different waveform in accordance with the external control signal, a demodulator for generating a demodulated signal from the demodulation target signal in accordance with the reference waveform signal, and a decoding section for decoding received data from the demodulated signal. This impulse radio communication device switches the demodulation target signal and the reference waveform signal simultaneously in accordance with a receiving and synchronizing state. This makes it difficult that synchronization is pulled in a correlation position having low electric power, and can reduce a acquisition time.10-30-2008
20080240307SINGLE CARRIER HIGH RATE WIRELESS SYSTEM - The present invention relates to a signal generator and signal processor for single carrier wireless communication systems with frequency domain equalizer, which are operable to use pseudorandom-noise sequences for cyclic prefix. The different arrangements and examples of said pseudorandom-noise sequences could be used for coarse timing synchronization, channel estimation, carrier synchronization, signal-noise-ration estimation and channel equalization.10-02-2008
20080240306CORRELATION DEVICE FOR PERFORMING CORRELATION ON A RECEIVED GLOBAL NAVIGATION SATELLITE SYSTEM SIGNAL AND METHOD FOR SAME - The invention provides a correlation device performing correlation on a received Global Navigation Satellite System (GNSS) signal. The correlation device comprises a first decimation module, a second decimation module, and a correlation module. The first decimation module decimates a plurality of samples of the received GNSS signal to obtain a plurality of decimated samples. The second decimation module decimates a plurality of code bits of a locally generated replica code to obtain a plurality of decimated code bits. The correlation module correlates the decimated samples with the decimated code bits to obtain a plurality of correlation results, thus achieving a coarse correlation between the received GNSS signal and the locally generated replica code.10-02-2008
20100142657SELECTION SCHEME FOR SELECTING A PEAK IN A CORRELATION SIGNAL - A method and associated module for selection of a maximum peak in a correlation signal corresponding to the correlation between a code periodically transmitted by a transmitter, and an input signal received by a receiver on a radio channel, includes a selection criteria which is the time recurrence of the same position of peaks of correlation, taking into account a margin around the peak position compensating for a drift due to a frequency offset between the receiver and the transmitter.06-10-2010
20090129520DIGITAL SIGNAL RECEIVING APPARATUS - A digital signal receiving apparatus includes: detection-judging portion judging a possible presence of a desired signal when a signal level of a smoothed signal is greater than a reference level; wherein said first smoothed signal and said second smoothed signal are compared in order to generate a detection signal representing a judgment of a possible presence of a desired signal, said second smoothed signal having a convergence speed slower than that of the first smoothing filter, a filter controlling portion switching an adaptive filter from an adaptive mode to a non-adaptive mode when the detection-judging portion judges the possible presence of the desired signal and switching from the non-adaptive mode to the adaptive mode when the detection-judging portion judges the absence of the desired signal; a limiting portion limiting a signal level of an auto-correlation signal to the signal level of the smoothed signal; and a demodulating portion demodulating the auto-correlation signal having the signal level limited by the limiting means so as to generate a demodulated signal, wherein the input to the demodulator is limited to the level of a smoothed signal, said smoothed signal being generated from the input of the detection judging portion.05-21-2009
20080317174RECEIVER AND RECEIVING METHOD - When a correlation judging circuit judges that the correlation degree between r pulses in a reception signal and a generated substantially the same template as the r pulses is small, a pulse number adjusting circuit outputs a pulse number signal representing s pulses in place of the r pulses, and a template generating circuit generates the substantially the same template as the s pulses, whereby the correlation judging circuit judges the correlation degree between the r pulses in the reception signal and the generated substantially the same template as the s pulses. Accordingly, even when a confronted transmitter changes the number of pulses contained in a reception signal, synchronization capture of the reception signal can be established.12-25-2008
20100002812MULTI-ANTENNA WIRELESS RECEIVER CHAINS WITH VECTOR DECODING - A receiver chain is provided for use in wireless data communication including a plurality of receive antennas and a vector Barker decoder or a CCK decoder. The vector Barker decoder operates on the plurality of received signals, preferably processed through a plurality of channel matched filters. The weightings of the plurality of channels can be done using a slicer variance, a PLL variance or another method.01-07-2010
20090141836RECEPTION DEVICE - A reception device according to the present invention receives a transmission frame including a synchronization symbol string, having a synchronization symbol repeated multiple times, inserted before a data symbol string. The synchronization symbol is obtained by synthesizing a plurality of sub band symbols which are mutually orthogonal and having different carrier frequencies. The carrier frequencies of the sub band symbols are located at an equal predetermined frequency interval. The synchronization symbol includes a repeated synchronization pattern. The reception device detects a rough carrier frequency error from a phase difference of a synchronization pattern correlation value to correct the frequency, and then detects a residual frequency error from an inter-symbol phase difference of each sub band to correct the frequency. The reception device detects a sampling clock frequency error from an inter-sub band phase difference to correct the frequency. Thus, the demodulation error of the data symbol is reduced.06-04-2009
20100142658APPARATUS AND METHOD FOR REMOVING COMMON PHASE ERROR IN A DVB-T/H RECEIVER - A receiver is a Digital Video Broadcasting-Terrestrial/Handheld (DVB-T/H) receiver. The DVB-T/H receiver comprises a phase error corrector and a channel estimation and equalization element. The phase error corrector rotates a signal in accordance with an estimate of a phase error, e.g., CPE, which is determined as a function of channel state information (CSI) provided by the channel estimation and equalization element.06-10-2010
20110142182MATCHED FILTER CIRCUIT APPARATUS IN THE BASE BAND PROCESS SYSTEM OF THE TERMINAL DEVICE AND METHOD THEREOF - The present invention discloses a matched filtering circuit apparatus in the baseband processing system of the terminal device and method thereof. The circuit apparatus comprises a control unit for controlling the processing procedures of de-scrambling, de-spreading, de-rotating and maximal ratio combining data, the output ports of the control unit connects with a V vector buffer unit, a shift integral selection unit and a coherent integral unit for implementing the matched filtering and data buffer. Due to the application of entirely pipeline design structure, the processes of data buffer and matched filtering can be carried out simultaneously, thus shortening time consumption of the terminal hardware accelerator and effectively improving the operation efficiency of the mobile communication terminal hardware system.06-16-2011
20090052596DECODER AND DECODING METHOD - Provided are a decoding apparatus and method for a system supporting an Orthogonal Frequency Division Multiplexing (OFDM)/Orthogonal Frequency Division Multiple Access (OFDMA) scheme, the apparatus and method capable of simply performing decoding by a non-coherent method. The decoding method includes the steps or receiving quadrature phase shift keying (QPSK) modulated signal; performing subcarrier demodulation whereby correlation metrics are generated on the basis of the received signal; and performing decoding using a decoding metric derived from the correlation metrics. The correlation metrics are obtained by multiplying tile, bin or zone of received signal by sets of basis vectors. The decoding apparatus includes: a receiving buffer for buffering received QPSK modulated signal; a correlation metric generator for generating correlation metrics on the basis of the received signal buffered in the receiving buffer; and a decoding processor for performing decoding using a decoding metric derived from the correlation metrics.02-26-2009
20090252261System, Apparatus, and Method for Processing a Received Orthogonal Frequency Division Multiplexing Signal - A wireless communication system, an apparatus and a method for processing a received OFDM signal is provided. The wireless communication system comprises an interface and a processing apparatus. The interface is configured to receive a received OFDM signal. The processing apparatus comprises an estimation module and a calculation module. The estimation module is configured to estimate an auto-correlation matrix relating to the received OFDM signal, with the auto-correlation matrix comprising a plurality of elements. Then, the calculation module is configured to calculate an amplitude and a phase for each of the elements to determine the carrier frequency offset (CFO) and timing offset (TO) of the received OFDM signal according to the amplitudes and phases. By exploiting the auto-correlation matrix of the received OFDM signal, the CFO and TO can be derived efficiently.10-08-2009
20090252260METHOD FOR GENERATING A REFERENCE SIGNAL SEQUENCE USING GROUPING - Method for generating reference signal sequence using grouping is explained. In this method, base sequences are grouped such that each group contains at least one base sequence of each length, so UE(s) can use various length sequences as a reference signal. And in this method, inter cell interference caused by using various length sequence as a reference signal sequence can be minimized by grouping sequences having the high cross correlation relation.10-08-2009
20100014617METHOD AND APPARATUS FOR SINGULAR VALUE DECOMPOSITION OF A CHANNEL MATRIX - A method and apparatus for decomposing a channel matrix in a wireless communication system are disclosed. A channel matrix H is generated for channels between transmit antennas and receive antennas. A Hermitian matrix A=H01-21-2010
20100150283METHOD AND APPARATUS FOR DIGITAL SIGNAL RECEPTION - The present invention relates to a digital signal reception method and apparatus. Said digital signal receiver comprises a Common Phase Error removal unit for eliminating CPE contained in the received signal by using CSI corrected pilot sub-carriers; a channel estimation unit for estimating channel state information of the received signal after removing the CPE and feed the CSI to the CPE removal unit, and a means for generating the CSI corrected pilot sub-carriers by multiplying the CSI with 1 or −1 according to positive or negative sign of the local pilot sub-carriers only in response to continual pilots of the received signal. Said method comprises estimating the CSI of the received digital signal after removing CPE; and eliminating the CPE of the received signal by using the CSI corrected pilot sub-carriers, whereby a low complexity and high accuracy are achieved.06-17-2010
20100183103Method and apparatus for signal detection - In order to reduce the complexity of complex signal correlator and realize algorithm optimization, the present invention provides a method and an apparatus for implement complex signal correlation by means of shifter and adder instead of complex multiplier. In the method, the amplitude and radial angle of a corresponding received symbol is firstly adjusted based on a pre-stored local reference symbol. Then, the radial angle of the adjusted received signal is rotated based on a corresponding interchange indicator. Finally, all the processed received signals are combined to obtain a final complex correlation signal. With this method, the chip size and computing load can be greatly reduced.07-22-2010
20090116591SPECTRAL DECOMPOSITION OF LARGE SIGNALS IN A NARROW-RANGE SAMPLING SYSTEM - A sampling method that determines the deterministic and random components of a signal when the magnitude of the signal exceeds the range of the sampler.05-07-2009
20130216007WIRELESS COMMUNICATIONS DEVICE HAVING TEMPORARY CORRELATION MATRIX WITH TIME INVERSION AND RELATED METHODS - A wireless communications device may include a receiver configured to receive a continuous phase modulation (CPM) signal and a demodulator coupled downstream from the receiver. The demodulator may be configured to generate a CPM correlation matrix based upon an expected CPM signal, and generate a temporary correlation matrix. The temporary correlation matrix may include a first copy of the CPM correlation matrix inverted in time, and a second copy of the CPM correlation matrix.08-22-2013
20120140858FINE SYMBOL TIMING ESTIMATION - Systems and methods for fine symbol timing estimation are disclosed herein. In one embodiment, a wireless receiver includes a differential detector, a correlator, a coarse symbol timing estimator, and a fine symbol timing estimator. The differential detector is configured to detect phase differences in a received preamble signal modulated using differential phase shift keying. The correlator is configured to correlate symbol values output by the differential detector against a reference sequence. The coarse symbol timing estimator is configured to generate a coarse symbol timing estimate, and to generate a coarse timing sample symbol index value corresponding to the coarse symbol timing estimate. The fine symbol timing estimator is configured to generate a fine symbol timing estimate that is more accurate than the coarse symbol timing estimate based on the coarse timing sample symbol index value and correlation samples at index values preceding and succeeding the coarse timing sample index value.06-07-2012
20100208852Cascaded 4G, 3G, 2G and other systems - A Global Positioning System (GPS), a touch screen generated signal, a first Orthogonal Frequency Division Multiplexed (OFDM) signal, a first Code Division Multiple Access (CDMA) signal and a first Time Division Multiple Access (TDMA) signal is received by two or more antennas and is processed into processed GPS, touch screen, OFDM, CDMA and TDMA signal and is provided to a subscriber unit-interface circuitry. The processed CDMA signal is a cross-correlated in-phase and quadrature-phase baseband signal. One or more of the processed GPS, touch screen, first OFDM, first CDMA or first TDMA baseband signal is provided for cascade processing, modulation and transmission into a second OFDM, second CDMA or second TDMA signal, wherein the second signal is distinct from the first signal. The transmitter has two or more antennas for transmission and linearly and a non-linearly amplified amplifier for linear and for non-linear amplification of modulated signals.08-19-2010
20120033768NON-COHERENT DETECTION APPARATUS AND METHOD FOR IEEE 802.15.4 LR-WPAN BPSK RECEIVER - A non-coherent detection apparatus and method for an IEEE 02-09-2012
20090074117Pulse Radio Receiver - A pulse radio receiver not needing re-setting of the threshold for reception synchronization, judging the direction and amount of adjustment of the synchronization even if the signal strength varies, and having a shortened pull-in time of the synchronization position. The receiver comprises a detect (03-19-2009
20090323868Selection of a Received Sequence By Means of Metrics - A method of received data sequence assessment, the method comprising producing a correlation metric describing the fit to a received sequence of the most likely of a set of candidates for the received sequence and calculating an error metric indicative of discrepancies between the received sequence and its most likely candidate.12-31-2009
20110110470FRAME BOUNDARY DETECTION - A method of WLAN frame detection in a received signal, wherein the frame comprises first and second training sequences and the method comprises auto-correlating the signal with a delayed version of itself to establish a first frame boundary estimate based on behaviour of the autocorrelation result due to the inclusion of the first training sequence in the frame, cross-correlating the signal with a copy of the second training sequence at a range of time offsets in order to generate a first cross-correlation profile, classifying the first cross-correlation profile into one of a number of categories, establishing a second frame boundary estimate from the first cross-correlation profile in a manner dependent upon the category assigned to the first cross-correlation profile and determining a refined frame boundary estimate on the basis of a consideration of the first and second frame boundary estimates. Apparatus for performing the method is also described.05-12-2011
20130129022Method and Associated Apparatus of Communication Parameter Detection - A method of communication parameter detection for detecting a temporal length of a guard interval of cyclic messages in a communication is provided. The method includes: searching peaks of an autocorrelation signal in the communication signal, and providing a peak for each cyclic message; sorting a time difference between two consecutive peaks to one of bins of a histogram, and determining the temporal length of the guard interval according to a result of the histogram; while a peak is found, providing a signal average according to an average of the autocorrelation signal over an average calculating period, comparing whether a ratio of the peak to the signal average is greater than a threshold, and accordingly detecting whether the communication signal carries valid information.05-23-2013
20100296611DOWNLINK PREAMBLE PROCESSING TECHNIQUES FOR INITIAL ACQUISITION - An apparatus, system, method, and article for downlink (DL) preamble processing for initial acquisition are described. The apparatus may include an autocorrelator node to determine an autocorrelation response of samples and to detect a downlink preamble based on the autocorrelation response. The samples may include a periodic sequence having two or more periods. The apparatus may include a frequency domain matched filter processing node to perform downlink preamble recognition based on a maximum peak of a frequency domain matched filter response and on an index of the downlink preamble. Other embodiments are described and claimed.11-25-2010
20100303179SYNCHRONIZATION TIMING DETECTING APPARATUS, RECEIVING APPARATUS, AND SYNCHRONIZATION TIMING DETECTING METHOD - A synchronization timing detecting apparatus includes a correlation calculator configured to generate a first correlation value by calculating a cross-correlation between an input signal being sampled and a reference signal or an auto-correlation of the sampled input signal, an interpolation processor configured to generate a second correlation value interpolating a plurality of the first correlation values having a different combination of sampling points of the input signal, and a detector to detect a synchronization timing based on the first and the second correlation values.12-02-2010
20100310021METHOD FOR COMPUTING CORRELATION OF PN SEQUENCE AND CIRCUIT THEREOF - The present invention relates to a method for computing correlation of a PN sequence and a circuit thereof. A plurality of input values of an input sequence is summed up to give a first sum. A PN sequence comprising a plurality of first values and a plurality of second values, which correspond to the plurality of input values, are received. Summing up the plurality of input values corresponding to the plurality of first input values in the PN sequence gives a second sum. According to the first sum and the second sum, a correlation value is given. The present invention uses a simple method for computing correlation of a PN sequence. Hence, the operation efficiency is enhanced and the time to give the correlation of the PN sequence is shortened.12-09-2010
20110026649Technique for determining a frequency offset - A technique for determining a frequency offset between components of a communication network based on a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence is described. A method implementation of this technique comprises a provision of a set of correlation signals at different frequencies, with each correlation signal being indicative of a specific frequency offset hypothesis and comprising the CAZAC sequence. Once a synchronization signal comprising the CAZAC sequence is received, this synchronization signal is correlated with each of the correlation signals to obtain a correlation result for each frequency offset hypothesis. In a next step, at least one of the frequency offset hypotheses is selected based on a comparison of the correlation results. The frequency offset may then be determined based on the at least one selected frequency offset hypothesis.02-03-2011
20090323867Adaptive synchronization enhancement technique for serial modulated waveforms - Methods and apparatus for synchronization (SYNC) detection of a received serial offset quadrature pulse shaped waveform modulated by a symbol SYNC sequence are provided. The waveform is serially demodulated into a serial baseband signal and correlated in parallel with segments of the symbol SYNC sequence. Correlation strength estimates of each of the correlated output signals are computed and used to adjust a SYNC threshold level. The correlation strength estimates or the correlated output signals are combined and a peak is determined in the resulting signal. The peak in the resulting signal is compared to the SYNC threshold level to detect synchronization.12-31-2009
20090323869METHOD AND APPARATUS FOR SPACE DIVISION MULTIPLE ACCESS RECEIVER - Methods and systems consistent with this invention receive a plurality of transmitted signals in a receiver having a plurality of receive elements, wherein each transmitted signal has a different spatial location. Such methods and systems receive the plurality of transmitted signals at the plurality of receive elements to form a plurality of receive element signals, form a combined signal derived from the plurality of receive element signals, and detect each of the plurality of transmitted signals from the combined signal by its different spatial location. To achieve this, methods and systems consistent with this invention generate a plurality of arbitrary phase modulation signals, and phase modulate each of the plurality of receive element signals with a different one of the phase modulation signals to form a plurality of phase modulated signals. Such methods and systems then combine the plurality of phase modulated signals into a combined signal, generate expected signals, and cross-correlate the combined signal with the expected signals to form correlation signals. Such methods and systems then store the correlation signals in a correlation signal memory and analyze the correlation signals to extract information from the transmitted signals.12-31-2009
20110249777FRAME SYNCHRONIZATION APPARATUS AND METHOD BASED ON DIFFERENTIAL CORRELATION IN COMMUNICATION SYSTEM - A frame synchronization apparatus and method based on differential correlation in a communication system are provided. A correlation analysis is performed by using sync word in a prior search window and a posterior search window for obtaining a plurality of prior-window correlation values and a plurality of posterior-window correlation values, respectively. N maximum correlation values in the correlation values are selected, wherein indexes of the maximum correlation values are I10-13-2011
20120201335START-UP AUTOMATIC FREQUENCY CONTROL (AFC) METHOD AND APPARATUS - A method and apparatus for use in connection with wireless communication to adjust the frequency of an oscillator to synchronize with a received signal by correlating a synchronization code channel with training sequences to estimate relative offsets which are employed to estimate an error, which is then filtered. The filtered output preferably provides a voltage controlling a voltage controlled oscillator (VCO). The same technique may be employed to control a numeric controlled oscillator (NCO).08-09-2012
20110150148APPARATUS AND METHOD FOR DETECTING SIGNAL IN WIRELESS COMMUNICATION SYSTEM - The apparatus includes a radio frequency (RF) unit configured to arrange a plurality of symbols received through an antenna at a frequency domain, an analog to digital (AD) converter configured to converts the plurality of symbols arranged at the frequency domain to digital symbols, a fast Fourier transform (FFT) unit configured to transform the digital symbols through a fast Fourier transform scheme, a compensator configured to compensate a gain mismatch between an I-channel and a Q-channel of the transformed digital symbols, a mapping unit configured to the compensated digital symbols to a constellation diagram, and a detector configured to correlate the mapped symbols, extract correlation results, and detect a high throughput (HT) signal using the extracted correlation results.06-23-2011
20110249778METHOD AND APPARATUS FOR PACKET DETECTION VIA CROSS-CORRELATION IN THE PRESENCE OF FREQUENCY OFFSET - An apparatus and method for packet detection using cross-correlation in the presence of frequency offset. The method comprises: segmenting a received signal; and cross-correlating each segment with an expected signal. The apparatus comprises a slicer that segments a received signal; and a cross correlator that cross-correlates each segment with an expected signal.10-13-2011
20080253484METHOD AND APPARATUS FOR REFERENCE SIGNAL GENERATION IN WIRELESS COMMUNICATION SYSTEM - To provide a reference signal generation method and apparatus capable of obtaining many reference signal sequences having excellent properties. CAZAC sequences that satisfy the condition that the absolute value (|N−L|) of a difference between a sub-carrier number N in a resource block and a CAZAC sequence length L is not larger than a threshold value K are selected, and a sequence having a largest among greatest prime factors among the prime factors constituting the sequence length(s) is further selected from the initially selected sequences. Then, a reference signal sequence(s) is generated from a selected CAZAC sequence.10-16-2008
20100310022DATA PROCESSING APPARATUS AND METHOD - A receiver detects and recovers data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including a plurality of sub-carrier symbols formed in the frequency domain and transformed into the time domain for transmission, the time domain OFDM symbols including a guard interval. The guard interval of the OFDM symbols is one of a plurality of predetermined temporal lengths and the guard interval is formed by repeating time domain samples of the OFDM symbol from useful samples of the OFDM symbols for a period corresponding to the guard interval from the OFDM symbols. The receiver includes a correlator operable to correlate the time domain samples at a separation determined in accordance with the useful samples of the OFDM symbols and for each of a plurality of possible guard intervals combining the correlated samples for a period equal to the guard interval, for a plurality of consecutively received OFDM symbols, to form for each of the possible guard intervals a correlation output value, and a guard interval identifier arranged to receive the output from the correlator and to identify one of the guard intervals used for the received OFDM symbols from the correlation output value for each of the plurality of possible guard intervals. Accordingly in a system such as DVB-T2, where the guard interval is provided in signalling data communicated with the OFDM symbols, the guard interval can be detected without or before the signalling data is detected, thereby reducing a time for detecting the data conveyed by the OFDM symbols or the guard interval and/or improving an integrity with which the guard interval and therefore the data can be detected.12-09-2010
20080240308APPARATUS AND METHOD FOR ESTIMATING CHANNEL USING SLIDING WINDOWS IN A BROADBAND WIRELESS COMMUNICATION SYSTEM - An apparatus and a method for estimating a channel using sliding windows in a broadband wireless communication system are provided. The apparatus includes an estimator, a first calculator, a second calculator, and a third calculator. The estimator estimates a speed of travel. The first calculator calculates a time correlation values using the estimated speed. The second calculator calculates weight factors using the time correlation values. The third calculator calculates a channel estimation value by multiplying corresponding pilot symbols by the weight factors and equalizing the pilot symbols.10-02-2008
20100260294SYSTEM AND METHOD FOR TIME SYNCHRONIZATION OF OFDM-BASED COMMUNICATIONS - Systems and methods for time synchronization of orthogonal frequency-division multiplexing (OFDM)-based communications are disclosed. A cyclic prefix (CP) correlation-based timing synchronization method is disclosed for early path (e.g. first-received path) detection for OFDM-based communication. Systems and methods are disclosed for performing double peak value detection in an OFDM-based system for reliably detecting an early (e.g., first-received) path in a received OFDM symbol for use in timing synchronization. In the double peak value detection method, a first peak value detection is performed to detect the path with the largest power, and a second peak value detection is then performed to detect a desired early (e.g., first-received) path. A compensation linear curve is used to facilitate the second peak value detection.10-14-2010
20110150150DEVICE AND METHOD FOR DETECTING TIMING SYNCHRONIZATION - A timing synchronous detection device includes: a first autocorrelator that performs autocorrelation using a received signal and a first delay signal in which the received signal is delayed; a second autocorrelator that performs autocorrelation using the received signal and a second delay signal in which the received signal is delayed; an average-normalization device that obtains an average value of an output signal of the first autocorrelator and an output signal of the second autocorrelator; a comparator that compares the average value and a threshold value and that outputs, if the average value is larger than the threshold value, the average value; and a maximum value search device that searches for a maximum value of the average values that are output from the comparator.06-23-2011
20110150149APPARATUS AND METHOD FOR DETECTING PACKET END POINT IN WIRELESS COMMUNICATION SYSTEM - An apparatus for detecting a packet end point in a wireless communication system includes: a signal reception unit configured to receive a signal from an outside, convert the signal into a baseband signal, perform analog-digital conversion of the baseband signal, and perform a digital front end; a storage unit configured to store an output of the signal reception unit; a frequency offset estimation unit configured to estimate a frequency offset using the output of the storage unit; a frequency offset correction unit configured to compensate for a frequency error using the estimated frequency offset; an offset correlation unit configured to calculate correlation of the frequency offset and a cyclic prefix; an auto-correlation operation unit configured to calculate auto-correlation of the cyclic prefix; and a packet end detection unit configured to check a packet end point using the auto-correlation.06-23-2011
20110255641Receiver for Voice Services Over Adaptive Multi-User channels on One Slot - A receiver, in particular a VAMOS receiver, is provided. The receiver is adapted to split the complex-valued baseband signal into its real and imaginary parts. The two branch system thus created is modeled as a real-valued Multiple Input Multiple Output, MIMO, system. The receiver is further adapted to use correlations of the noise, both in time and between branches of a channel to suppress the noise for multi-users in the same channel. In accordance with one embodiment the receiver is adapted to take into account the known symmetries present in a symbol constellation when more than one user exists in the same channel. This is for example the case in adaptive symbol constellation such as an adaptive alpha-QPSK constellation. Using the receiver in accordance with the above can provide the same performance as a joint detection receiver in the presence of Gaussian white noise, while giving better interference suppression than either SAIC or joint detection in the presence of GMSK modulated interference.10-20-2011
20080205559TEMPLATE PULSE GENERATING CIRCUIT, COMMUNICATION DEVICE, AND COMMUNICATION METHOD - A template pulse generating circuit that generates a template pulse used for detection of a received pulse in pulse communication includes an output mode switching circuit for switching an output mode in accordance with a supplied control signal between a continuous output mode that continuously outputs the template pulses and an intermittent output mode that intermittently outputs the template pulses so that the template pulse is generated in either one of the continuous output mode and the intermittent output mode.08-28-2008
20110164708SYMBOL TIMING METHODS AND APPARATUSES USING THE SAME IN MULTI-CARRIER RECEIVING SYSTEMS - A symbol timing method for a multi-carrier system is provided, including: receiving an input symbol; executing a correlation operation by using a first summation window with a size smaller than a duplicated data to generate a first characteristic signal; determining a first search region according to a first predetermined threshold and the first characteristic signal and searching a local peak value in the first search region; locating a right edge point of the first characteristic signal according to a difference value and the local peak value; obtaining a coarse symbol timing position for a following input symbol according to a predetermined movement and the right edge point; and outputting the coarse symbol timing position to a signal transformation module, wherein signal transformation is executed by the signal transformation module according to the coarse symbol timing position.07-07-2011
20100284498Circuit for Detecting a Predetermined Symbol in a Digital Data Stream and Associated Method - A circuit for detecting a predetermined symbol of a digital data stream includes a frequency shifter, a correlator, a filter and a decision unit. The frequency shifter performs inverse-frequency shifting upon a first data to generate a first frequency-shifted data. The correlator calculates correlation upon the first frequency-shifted data and a second data to generate a correlated data. The filter, coupled to the correlator, filters and the correlated data to generate a filtered correlated data according to a time-domain windowing length. The decision unit, coupled to the filter, determines the predetermined symbol from the digital data stream according to the filtered correlated data.11-11-2010
20100329396Interference Detector and Method Thereof - An interference detector receives a data stream including predetermined symbols that include a first data and a second data, between which is a frequency offset. The interference detector includes a correlation apparatus that generates a first correlation result and a second correlation result according to the data stream; a power searching unit, coupled to the correlation apparatus, that generates a first maximum correlation result and a first neighboring power according to the first correlation result, and generates a second maximum correlation result and a second neighboring power according to the second correlation result; and a determining unit, coupled to the power searching unit, that generates a determination result according to the first maximum correlation result, the first neighboring power, the second maximum correlation result and the second neighboring power to indicate existence of interferences.12-30-2010
20080219386QUADRATURE IMBALANCE ESTIMATION USING UNBIASED TRAINING SEQUENCES - A system and method are provided for removing quadrature imbalance errors in received data. The method accepts an unbiased training sequence in a quadrature demodulation receiver. An unbiased training sequence has a uniform accumulated power evenly distributed in a complex plane, and includes predetermined reference signals (p) at frequency +f and predetermined mirror signals (p09-11-2008
20100111235METHOD OF DETERMINING AS TO WHETHER A RECEIVED SIGNAL INCLUDES AN INFORMATION SIGNAL - A method of determining as to whether a received signal includes an information signal is provided. The method provided includes determining a covariance matrix from a received signal and transforming the covariance matrix into a transformed covariance matrix, wherein the transformation is configured such that the transformed covariance matrix is a non-diagonal matrix in case the received signal includes the information signal, wherein the non-diagonal matrix includes non-zero non-diagonal matrix elements. The method provided further includes determining a first function using at least one of the non-zero non-diagonal matrix elements of the transformed covariance matrix, determining a second function using at least one matrix element of the transformed covariance matrix, wherein the second function is different from the first function, and determining as to whether a received signal includes an information signal based on a comparison of a value of the first function and a value of the second function.05-06-2010
20110096875Adaptive Digital Baseband Receiver - An adaptive digital baseband receiver is described in which operating parameters of the receiver, such as bit-widths and operating frequencies, are determined that achieve a target bit-error-ratio (BER) as a function of received signal-to-noise ratio (SNR) and interference levels in a wireless channel and enable the receiver to consume a minimum amount of power. Over consumption of power may be avoided due to a functional relationship between optimal resolution and input signal conditions. In exemplary embodiments, the adaptive digital receiver is provided that adjusts bit-widths and operating frequency at power efficient levels while meeting a target BER. Simulations can be used to determine a relation between bit-width, operating frequency, and input signal conditions, for example.04-28-2011
20100166121METHODS AND APPARATUS FOR RECEIVER HAVING FAST WALSH TRANSFORM - Methods and apparatus for correlating a receiving signal using a Fast Walsh Transform for efficient processing. In one embodiment, a Walsh encoded signal is received and then processing using a Fast Walsh Transform to generate outputs from which a largest one of the orthogonal sequences is selected.07-01-2010
20100166120Method and Apparatus for Correlating Two Data Sections - Watermarking of audio signals intends to manipulate the audio signal in a way that the changes in the audio content cannot be recognised by the human auditory system. The watermark data are decoded from the received watermarked audio signal by correlation with corresponding candidate reference sequences. One or more of the sync symbols are embedded twice in the watermark data frame in the encoder. Thereafter a circular correlation is calculated instead of a standard correlation.07-01-2010
20100158164APPARATUS AND METHOD FOR TIME SYNCHRONIZATION AND RECEPTION APPARATUS OF OFDM SYSTEM - An apparatus for time synchronization of an orthogonal frequency division multiplexing (OFDM) system oversamples a received signal using a master clock having a frequency at least four times higher than a minimum sampling frequency in a transmission apparatus, sets one of a plurality of oversampled signals to an on-time signal, and shifts each of the remaining oversampled signals by a predetermined time on the basis of the on-time signal. The apparatus for time synchronization calculates a correlation value by correlating each of the shifted signals and the on-time signal with a previously known signal, detects a maximum energy value among the calculated correlation values, and detects a start point of a frame by comparing the maximum energy value with a predetermined threshold value.06-24-2010
20100158163Velocity Estimation Algorithm for a Wireless System - A method for estimating the velocity of the Mobile Station (MS) in Orthogonal Frequency Divisional Multiplexing (OFDM)/Orthogonal Frequency Divisional Multiplexing Access (OFDMA) system is disclosed. First, the pilots in the preamble are received by MS and the pilots in a specified symbol of the specific zone are received by MS. An auto-correlation between the received pilots in preamble and the received pilots in the specified symbol of the specific zone is calculated. The auto-correlation is the calculated with frame by frame basis, and the average auto-correlation is calculated from number of frames. Once the average auto-correlation is obtained, the velocity of MS is estimated from predetermined function according to the obtained average auto-correction.06-24-2010
20100195774LEAST SQUARES CHANNEL IDENTIFICATION FOR OFDM SYSTEMS - An OFDM system generates a channel estimate in the time domain for use in either a frequency domain equalizer or in a time domain equalizer. Preferably channel estimation is accomplished in the time domain using a locally generated reference signal. The channel estimator generates an initial estimate from a cross correlation between the time domain reference signal and an input signal input to the receiver and generates at least one successive channel estimate. Preferably the successive channel estimate is determined by vector addition (or subtraction) to the initial channel estimate. The at least one successive channel estimate reduces the minimum mean square error of the estimate with respect to a received signal.08-05-2010
20110051863CHANNEL ESTIMATOR - The channel estimator includes a plurality of correlating sections configured to calculate a plurality of time correlation values between the signal and a plurality of known pattern signals having different code lengths, an analyzing section configured to output a control signal representing a selected period for extracting a preferable correlation output from the output from each of the plurality of correlating sections, and a delay profile generating section configured to output a delay profile obtained by adaptively selecting or combining parts of the outputs from the plurality of correlating sections based on the output from the analyzing section.03-03-2011
20110051862METHODS AND APPARATUS FOR OFDM SYMBOL SYNCHRONIZATION FOR IN-DOOR DIGITAL TV RECEPTION - A received signal comprises a continuous sequence of symbols φ03-03-2011
20100020905APPARATUS AND METHODS FOR COMPUTING CONSTANT AMPLITUDE ZERO AUTO-CORRELATION SEQUENCES - Apparatus and methods for calculating constant amplitude zero auto-correlation sequences are disclosed. One method includes calculating an argument of trigonometric functions used for calculating a constant amplitude zero auto-correlation sequence based at least on additive recursion of an input sequence root constant and without multiplication by a variable. A constant amplitude zero auto-correlation sequence is then computed using a CORDIC algorithm configured to calculate trigonometric functions used in determining the sequence without performing multiplication operations and based on the calculated argument. The disclosed methods and apparatus may be applied, in particular, to efficiently computing Zadoff-Chu sequences in preamble detection in particular physical random access channels in Long Term Evolution LTE communication systems. By allowing computation of such sequences, memory requirements can be reduced.01-28-2010
20090175391MATCHED FILTER AND RECEIVER - A matched filter and receiver is provided to delete the tap coefficients of a matched filter used in an OFDM receiver. In the matched filter and receiver, a transmitting signal is generated by using a symmetric series (Y) obtained from C[k]=exp [j*π*M/N*(k+0.5)̂2], where X=[0, C[N/2], C[N/2+1], . . . , C[N−1], 0, 0, . . . , 0, C[0], C[1], . . . , C[N/2−1]], and Y=inverse FFT (X) as a base symbol. The matched filter, which detects the signal, reduces the number of multipliers by using the coefficient symmetric property.07-09-2009
20100128822OFDM RECEIVING APPARATUS, OFDM RECEIVING METHOD, OFDM RECEIVING CIRCUIT, INTEGRATED CIRCUIT, AND PROGRAM - A synchronization section 05-27-2010
20090285337FREQUENCY DOMAIN ROOT CAZAC SEQUENCE GENERATOR - The present invention provides a method for implementation in a random access channel receiver. One embodiment of the method includes generating at least one frequency domain reference sequence by multiplying a generator function and a first frequency domain root CAZAC sequence. The frequency domain reference sequence(s) is generated in response to receiving a signal at the random access channel receiver. This embodiment of the method also includes correlating the received signal and the frequency domain reference sequence(s).11-19-2009
20110305304Signal Reception - A method of receiving a demodulated waveform according to a protocol in which the waveform represents a block of transmitted bits comprising a first group of bits and a second group of bits, the second group of bits being a function of the first group of bits, the method comprising: sampling the demodulated waveform to recover a first group of sample values corresponding to the first group of transmitted bits and a second group of sample values corresponding to the second group of transmitted bits; assigning bit values to reliable sample values of the first group of sample values; generating a set of candidates for a block of bits corresponding to the demodulated waveform, each candidate comprising a first group of candidate bits and a second group of candidate bits, the first group of candidate bits being generated using the assigned bit values and a combination of bit values unique to that candidate in the set of candidates, and the second group of candidate bits being generated by applying the said function to the first group of candidate bits; performing a correlation operation by determining a correlation between each candidate and the recovered first and second groups of sample values to form a correlation value associated with each candidate; and selecting the candidate associated with the correlation value that is indicative of the strongest degree of correlation between a candidate and the first and second groups of sample values to be the block of bits corresponding to the demodulated waveform.12-15-2011
20120039424Receiver and Method for the Reception of a Node by a Receiver in a Wireless Network - In one embodiment, a method includes receiving a radio frequency (RF) signal; synchronizing the received RF signal with a preamble to determine a time base; determining a first energy value of the received RF signal by averaging received signal strength indication (RSSI) values of the received RF signal over a first period of time; determining a second energy value of the received RF signal over a second period of time; determining a difference value between the first energy value and the second energy value; comparing the difference value with a predetermined energy threshold value; determining a quality value of the received RF signal; comparing the quality value of the received RF signal with a predetermined quality threshold value; and, if the difference value exceeds the predetermined energy threshold value or the quality value is below the predetermined quality threshold value, then erasing the time base.02-16-2012
20120099682DIVERSITY RECEPTION DEVICE - A diversity reception device includes a power combiner to combine electric powers of OFDM signals, each OFDM signal being received by a first antenna and second antenna, a switch to change connections between branched output-ports of the first and second antennas, in mid-stream of effective symbol periods, the effective symbol periods are assigned respectively in each of symbol periods of the OFDM signals, a receiver to demodulate the OFDM signals, a phase shifter to shift phases of the OFDM signals received by the second antenna, and an arithmetic and control processing circuit to calculate complex correlation coefficient between a guard interval, assigned in each of the symbol periods associated with the first antenna, and a copy-source interval, assigned in each of the symbol periods associated with the second antenna, and to determine rotation angle on the basis of the complex correlation coefficient.04-26-2012
20120099681RECEPTION APPARATUS, RECEPTION METHOD, AND PROGRAM - A reception apparatus is disclosed which includes: a detection section configured to detect the presence or absence of spectrum inversion in data transmitted by a multi-carrier transmission system based on whether a known signal can be decoded using that part of the transmitted data which has been transmitted by carriers used for transmitting the known signal; and a correction section configured to correct the data transmitted by the multi-carrier transmission system if the presence of spectrum inversion is detected.04-26-2012
20110090995SIMULTANEOUS CELL GROUP AND CYCLIC PREFIX DETECTION METHOD, APPARATUS AND SYSTEM - A method, and associated apparatus and system, for simultaneous cell group and cyclic prefix (CP) detection, having the steps of determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the S-SyS signal; and detecting the cell group and CP length by the correlation giving maximum energy.04-21-2011
20110317792TIMING SYNCHRONIZATION METHOD AND APPARATUS IN A WIRELESS COMMUNICATION SYSTEM - Provided are a timing synchronization method and apparatus in a wireless communication system that may synchronize timing based on channel energy having a low Signal to Noise Ratio (SNR) in a wideband (WB) system. The timing synchronization apparatus in the wireless communication system may capture optimal channel energy by performing a comparison using a timing estimation scheme based on a correlation peak.12-29-2011
20100303178Method and System for Down-Converting an Electromagnetic Signal, and Transforms for Same - Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.12-02-2010
20120045025DIVERSITY RECEPTION DEVICE AND DIVERSITY RECEPTION METHOD - A diversity reception device includes branches, a controller and a combining section. Each branch includes a correlation section that generates a correlation signal that represents a correlation between a received signal and a delayed signal or between the received signal and a reference signal, where the correlation signal level disregarding the received signal level, a time position detector that detects time positions at which the level of the correlation signal is at a peak, a demodulation section that demodulates the received signal, and a multiplication section that multiplies the demodulated signal with a weighting factor. The controller controls the weighting factor on the basis of the respective levels of the correlation signals at the detected time positions. The combining section combines, by adding, the respective demodulated signals of the branches subsequent to the demodulated signal of each branch being multiplied with the weighting factor.02-23-2012
20090185645Receiver Device, Error Detection Circuit, and Receiving Method - A receiver device which is small in scale of circuit configuration yet capable of detecting an error between symbol timing of a received signal and that generated therein and also restraining an error signal from varying due to variation in input level of the received signal. A delayer delays the received signal for one effective symbol period, a correlator calculates a correlation signal from the product of the received signal and the delayed signal, and an integrator calculates an integral value of the correlation signal. First and second accumulative adders accumulatively add up the integral values over respective predetermined periods before and after symbol start timing generated within the receiver device. An error signal generator generates an error signal by normalizing the difference between first and second sums obtained from the first and second accumulative adders, respectively, by means of the sum total of the first and second sums.07-23-2009
20120002763HALF BIT CORRELATOR COMBINING FOR DATA DEMODULATION - A method for demodulating a data signal according to one embodiment includes processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. A system for demodulating a data signal according to one embodiment includes a correlator module having logic for: processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. Additional systems and methods are also presented.01-05-2012
20120002762SINGLE OR DUAL COMPLEX SUBCARRIER DOWNCONVERSION - A method for subcarrier downconversion and data detection according to one embodiment includes determining whether to use an upper sideband frequency section of a complex downconverter output, a lower sideband frequency section of the complex downconverter output, or both sideband frequency sections of the complex downconverter output; and processing the output corresponding to the selected sideband frequency section or sections based on the determination, wherein the processing includes correlation and data detection. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented.01-05-2012
20120057664METHOD AND APPARATUS FOR SYMBOL TIMING RECOVERY - Methods and apparatus for symbol timing recovery are provided. Both a coarse symbol timing recovery method and apparatus, and a fine symbol timing recovery method and apparatus are described which can be used jointly for symbol recovery, for example in phase shift keying receivers. The coarse method involves the use of differential correlations and finding the time difference in peak values of the correlation results. The fine method involves interpolation of a received digital signal, followed by filtering and timing error detection. The error detection signal is further filtered and used to control the interpolator. The methods provide for robust symbol timing synchronization.03-08-2012
20120057663Terminal State Management in a Telecommunications Network - A signal transmitted in a radio telecommunications network is received (03-08-2012
20120057662BIT CHANGE DETERMINATION METHOD AND BIT CHANGE DETERMINATION DEVICE - A bit change determination method includes performing a correlation operation of a signal received from a satellite and a replica code, segmenting the signal using a bit transition timing of navigation message data and performing a first calculation to calculate the result of the correlation operation for a first period having N (N≧1) continuous unit periods with a bit period of navigation message data as a unit period, performing a second calculation to calculate the result of the correlation operation for a second period having M (M>1) continuous unit periods adjacent to the first period, and determining whether a bit value changes or not at a boundary between the first period and the second period using the first and second calculation results.03-08-2012
20110026648METHOD AND SYSTEM FOR INCREASING THE ACCURACY OF FREQUENCY OFFSET ESTIMATION IN MULTIPLE FREQUENCY HYPOTHESIS TESTING IN AN E-UTRA/LTE UE RECEIVER - A mobile device receives a radio frequency (RF) signal comprising a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS). The mobile device performs multiple frequency hypothesis (MFH) testing via multiple MFH branches. A PSS correlation process is performed for each MFH branch. Frequency offset for receiving data is estimated using resulting correlation data. A desired offset is placed in each MFH branch. A baseband signal is frequency offset per MFH branch according to the desired frequency offset before the PSS correlation process. A received PSS is detected based on a maximum PSS correlation over the entire set of MFH branches. A frequency offset is estimated for the MFH branch associated with the detected PSS by combining an associated residual frequency with a corresponding desired offset. The frequency offset estimate is used for baseband signal processing and/or adjusting a reference oscillator frequency at the mobile device.02-03-2011
20120114082MOBILE WIRELESS TERMINAL DEVICE AND BASE STATION SEARCH METHOD - According to one embodiment, a mobile wireless terminal device includes a receiver detecting a beacon and a communication module detecting a base station identification. The receiver comprises an accumulation module accumulating levels of a sampling received wireless signal to obtain a reception profile, a correlation module detecting a shift amount maximizing a correlation between a present reception profile and a past reception profile, a first detector detecting a beacon, when a difference between the detected shift amount and a default amount is larger than a predetermined amount, in accordance with a difference between a shifted profile by the default amount, and the present reception profile, and a second detector which detects a beacon, when the difference is not larger than the predetermined amount, in accordance with a difference between a shifted profile by the detected shift amount, and the present reception profile.05-10-2012
20120027135SYSTEM AND METHOD FOR SYNCHRONIZATION TRACKING IN AN IN-BAND MODEM - Processing the synchronization of an inband modem to detect sample slip conditions is disclosed. Decision logic reliably detects the sample slip condition while minimizing the number of false alarms.02-02-2012
20120027136SYSTEM ACCESS AND SYNCHRONIZATION METHODS FOR MIMO OFDM COMMUNICATIONS SYSTEMS AND PHYSICAL LAYER PACKET AND PREAMBLE DESIGN - A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.02-02-2012
20120250807SCHEMES FOR DETECTING GUARD INTERVALS IN OFDM SYSTEM - A receiver and method of detecting a guard interval estimate accurately by performing an Nth order polynomial based non-linear quantization on a pre-estimated guard interval in a received Orthogonal Frequency Division Multiplexing (OFDM) signal in a receiver is provided. The pre-estimated guard interval is obtained by performing normalized auto-correlation on the received OFDM signal. The method includes (i) performing a rounding operation on (a) one or more m10-04-2012
20120250806NON-PARAMETRIC UPLINK INTERFERENCE CANCELLATION - Aspects of an apparatus and method of wireless communication include detecting, by a base node, at least one path of a transmission corresponding to received samples from a user equipment. Further, the aspects include assigning a bank of correlators around the detected at least one path, and estimating a composite channel impulse response at an output of each correlator of the bank of correlators. Further, the aspects include refining noisy channel estimates, and reconstructing a received signal from the user equipment based on the refined noisy channel estimate of the composite channel impulse response. Additionally, the aspects include canceling the reconstructed received signal from the received samples10-04-2012
20120207253METHOD AND APPARATUS FOR PERFORMING CHANNEL ESTIMATION IN A WIRELESS COMMUNICATION SYSTEM - A method and apparatus for performing channel estimation in a wireless communication system, in which a channel estimate of each pilot tone included in adjacent first and second resource allocation blocks is calculated. Channel estimates of first pilot tones are detected, which have a predetermined subcarrier spacing or less from the second resource allocation block, channel estimates of second pilot tones are detected; and which have a predetermined subcarrier spacing or less from the first resource allocation block. The channel estimates of the first and second pilot tones are updated, and channel estimation is then performed using the updated channel estimates.08-16-2012
20120207254APPARATUS AND METHOD FOR MMSE CHANNEL ESTIMATION IN CONSIDERATION OF OFFSET COMPENSATION IN WIRELESS COMMUNICATION SYSTEM - A channel estimation method of a channel estimation apparatus in a wireless communication system is provided. The method includes predefining a plurality of weight tables about at least one of a speed and a Carrier to Interference-and-Noise Ratio (CINR) using a correlation value considering offset compensation; selecting a weight table to be used for channel estimation based on at least one of the estimated speed and the CINR, from the plurality of weight tables; and multiplying a pilot channel estimation value and the selected weight table, and performing data channel estimation.08-16-2012
20130170590Receiver Node and A Method Therein for Compensating Frequency Offset - According to embodiments herein an ambiguity problem when compensating for frequency offset may be solved by compensating a received reference symbol according to two different frequency offset hypotheses; the estimated frequency offset and the a mirrored version of the same. Then by comparing the compensated reference symbol of the different frequency hypotheses with a target reference symbol, which is known at the receiver node 07-04-2013
20100172448METHOD AND RECEIVER APPARATUS FOR DETERMINING A CORRELATION VALUE CONSIDERING FREQUENCY CORRECTION - A receiver apparatus for determining a correlation value of a predetermined repetitive chip sequence in a receive signal, the chip sequence having a chip sequence duration and a chip sequence duration cycle. The receiver apparatus has a receive unit for receiving the receive signal and a segmenter for providing receive signal segments from the receive signal, two receive signals representing the same chip sequence in different repetition cycles and having at least one repetition cycle time spacing.07-08-2010
20120121048MULTI-ANTENNA CHANNEL ESTIMATION METHOD BASED ON POLYPHASE DECOMPOSITION - A multi-antenna channel estimation method based on polyphase decomposition includes: receiving frequency domain received signals transformed using discrete fourier transformation (DFT) in pilot symbols; performing phase correction on the frequency domain received signals; performing polyphase decomposition on the frequency domain received signals which are corrected using phase correction and acquiring polyphase signals; performing interpolation on the polyphase signals and acquiring the estimation values of the multi-antenna channel parameters with various linear combinations on each frequency; acquiring decorrelation array based on the pilot structure of the transmission antenna and decorrelating the estimation values of the multi-antenna channel parameters with various linear combination on each frequency using the decorrelation array and acquiring channel parameters of the pilot symbols on each frequency; acquiring channel parameters of data symbols based on the channel parameters of the pilot symbols. With the present invention, the inversion problem in multi-antenna channel estimation is avoided with lower complexity, and results of the multi-antenna channel estimation method become more accurate since the DFT and filtering are performed in the interpolation after polyphase decomposition.05-17-2012
20100290569POST DFT/FFT TIME TRACKING ALGORITHM FOR OFDM RECEIVERS - A method for time synchronization tracking in an orthogonal frequency division multiplexing (OFDM) receiver is described, the method comprising the steps: obtaining a DFT output vector; determining a sample timing offset indication using reference symbols that are extracted from the DFT output vector; and adapting the OFDM symbol timing using said determined indication. In order to provide an improved post-DFT algorithm for estimating a time tracking error in OFDM receivers such as to allow an effective time tracking even in single frequency networks, and more particular to devise a time tracking algorithm for OFDM receivers that supports longer channel impulse responses without causing inter-symbol interference, said determining step comprises the steps of: (a) estimating (11-18-2010
20120128106RECEPTION CIRCUIT - A reception circuit is provided which can detect the beginning of data regardless of a preamble or a unique word contained or not in a received signal and regardless of coding systems for received signals. The reception circuit includes a correlation operation portion that performs a correlation operation to generate a correlation signal while sliding one symbol of reference signal in relation to a received signal. The reference signal goes to a high level during a first half symbol period and goes to a low level during a second half symbol period. The reception circuit further includes: a delay portion that outputs a delay signal by delaying the reference signal for a half symbol period in relation to the received signal; and a data beginning timing detection portion that detects a beginning peak timing for the correlation signal as a beginning timing of data contained in the delay signal.05-24-2012
20120163515DEFINING ADAPTIVE DETECTION THRESHOLDS - A wireless device (06-28-2012
20120163514PREAMBLE DETECTION AT LOW SIGNAL-TO-NOISE LEVELS - A preamble detector has a correlator outputting for every sample position of the preamble part of an incoming sampled signal stream a score and associated class value; and a multiple cluster unit receiving the class and score output values from the correlator, wherein a first cluster receives output values from the correlator and the following clusters are coupled in series such that each cluster receives output values from the correlator and a preceding cluster and wherein the output values of the correlator and a cluster are processed such that an n-th cluster of the multiple cluster unit, with n>1, accumulates the highest score values of n score values with matching class values.06-28-2012
20120213316PREAMBLE DETECTION WITH UNKNOWN CHANNEL - A system comprises a correlation module that correlates modulated signals with a plurality of preamble sequences and that generates correlation values. A control module selects a largest correlation value from said correlation values and detects one of said preamble sequences in said modulated signals upon determining that a magnitude of said largest correlation value is greater than or equal to a first predetermined threshold.08-23-2012
20120213315PROCESS FOR ESTIMATING THE CHANNEL IN A OFDM COMMUNICATION SYSTEM, AND RECEIVER FOR DOING THE SAME - MIMO receiver for processing N data streams received by N antennas for a direct-sequence (DS) spread-spectrum wireless communication system comprising: 08-23-2012
20120134454APPARATUS, AND ASSOCIATED METHOD, FOR FILTERING A RECEIVE SIGNAL BY ADAPTIVE OPERATION OF AN INPUT NOISE WHITENING FILTER - Apparatus, and an associated method, for the receive part of a receiving station, such as a mobile station or other transceiver of a cellular communication system. Selection is made of filter characteristics to be exhibited by an adaptive, input noise whitening filter. A noise estimator estimates a noise component of a noise sequence. An autocorrelation estimator estimates the noise-component autocorrelation. A determination is made as to whether the autocorrelation exceeds a threshold. If so, filter characteristics are selected to cause the input noise whitening filter to operate to inject whitening noise into the received sequence.05-31-2012
20090060099DEVICES FOR CARRIER RECOVERY AND RELATED METHODS - Devices for carrier recovery and related methods are provided. A receiving signal is provided to perform an interpolation filtering process and a frequency multiplication sampling process. The receiving signal is then processed with a dealing signal. The dealing signal is generated by shifting a PN code with a frequency offset.03-05-2009
20120177156CLOCK RECOVERY APPARATUS - The invention relates to a clock recovery apparatus being configured to recover clock information from an input signal. The clock recovery apparatus comprises Fourier transforming means (07-12-2012
20120177155APPARATUS AND METHOD FOR RECEIVING DATA IN COMMUNICATION SYSTEM - Disclosed is an apparatus for receiving data in a communication system, including a receiving unit configured to receive data through a multi-channel in a MIMO (multi-input multi-output) scheme; a calculating unit configured to calculate a receiving power distribution value in each antenna of a multi-antenna and in each channel of the multi-channel, correspondingly to the MIMO scheme, and to generate a receiving synchronization signal using the receiving power distribution value; and a synchronization unit configured to synchronize frames for the data receiving of the receiving unit using the receiving synchronization signal.07-12-2012
20100008453ANTENNA ARRAY PATTERN DISTORTION MITIGATION - At least one feature provides a way to perform point-to-multipoint transmissions using adaptive or directional antennas while reducing antenna pattern distortion. Generally, rather than transmitting the same waveform to two or more receivers, an information-bearing signal is transformed into different decorrelated waveforms and each decorrelated waveform is transmitted to a different receiver. In one implementation, an information-bearing signal is transformed into two decorrelated signals such that their crosscorrelation, or autocorrelation of the information-bearing signal, is zero or very small. Such decorrelation may be achieved by sending a first signal to a first receiver while sending a second signal, having a radio frequency spectrum that is the spectrally inverted version of the first signal, to a second receiver. In another implementation, a first signal is transmitted to a first receiver and is also transmitted to a second receiver with a time delay.01-14-2010
20100008452METHOD AND APPARATUS FOR ESTIMATING DOPPLER FREQUENCY IN A MOBILE TERMINAL - A method and apparatus for estimating a Doppler frequency in a mobile terminal are provided. The method includes calculating two autocorrelation values for intervals of at least one sample from a channel estimation tap with a maximum power, and estimating a maximum Doppler frequency using the two autocorrelation values. The two autocorrelation values are autocorrelation values for intervals of different numbers of samples.01-14-2010
20120328057METHOD AND APPARATUS FOR IMPLEMENTING SIGNAL QUALITY METRICS AND ANTENNA DIVERSITY SWITCHING CONTROL - A method for detecting the digital quality of a radio signal includes: receiving a radio signal including a digital portion modulated by a series of symbols each including a plurality of samples; computing correlation points between endpoint samples in cyclic prefix regions of adjacent symbols; and using the correlation points to produce a digital signal quality metric. Receivers that implement the method are also provided.12-27-2012
20090213969Wireless Communication Device, Equalizer, Computer-Readable Medium Storing Program for Obtaining Weight Coefficients in the Equalizer, and Process for Obtaining Weight Coefficients in the Equalizer - In an equalizer arranged in a wireless communication device: information on correlation in one or more first wireless signals is generated; a channel vector is generated on the basis of the one or more first wireless signals; an extended correlation matrix which contains a correlation matrix indicating the information on correlation and is extended so as to become a circulant matrix is generated; an extended channel vector is generated by extending the channel vector so that the extended channel vector contains elements of the channel vector and has rows the number of which is identical to the number of rows of the extended correlation matrix; and weight coefficients are calculated as a solution, in the frequency domain, of an equation expressed by the extended correlation matrix and the extended channel vector, where the solution is obtained by solving the equation.08-27-2009
20120230453CHANNEL ESTIMATION AND SYMBOL BOUNDARY DETECTION METHOD - A channel estimation method for use with a received signal by a receiver is disclosed. The received signal comprises multiple data bursts which are transmitted to the receiver via multiple path channels, with each of the data bursts having a plurality of preamble symbols which are decoded. The channel estimation method includes the following steps: firstly, at least one correlation pattern is generated according to the decoded preamble symbols. Then, a cross correlation of the correlation pattern with the received signal is performed to yield at least one correlation result of channel impulse response (CIR). Wherein, the symbol boundary of the received signal is decided according to the correlation result.09-13-2012
20100027723TIME SYNCHRONIZATION METHOD AND FREQUENCY OFFSET ESTIMATION METHOD USING THE SAME IN OFDM NETWORK - Provided are a time synchronization method and a frequency offset estimation method using the same in an OFDM system. The time synchronization method using a preamble transmitted from a transmitter to a receiver in the OFDM communication network includes the steps of: a) calculating a moving sum of a first sequence and a second sequence obtained by a product of neighboring elements in a received signal when the received signal containing a preamble is received from the transmitter; b) estimating a location of the received signal corresponding to the moving sum having a maximum value; and c) acquiring a time synchronization with respect to the received signal, based on the estimated location, wherein the first sequence is obtained from a product of neighboring elements in the preamble and a correlation value obtained by correlating another sequence with the first sequence is smaller than a predetermined value.02-04-2010
20080298515Method and Apparatus for Implementing a Digital Signal Quality Metric - A method for detecting a digital radio signal includes the steps of receiving the digital radio signal including a series of symbols, developing a correlation waveform having a peak that corresponds to a symbol boundary, normalizing the correlation waveform, and calculating a peak value of the normalized correlation waveform, wherein the peak value represents the quality of the received digital radio signal. A receiver that performs the method is also provided.12-04-2008
20110002423METHOD AND DEVICE FOR PROCESSING DATA AND COMMUNICATION SYSTEM COMPRISING SUCH DEVICE - A method and a device are provided for data processing. The data contains symbols and a control parameter is determined based on a correlation property of the symbols of the data. In this manner signal recovery is achieved that is robust against any kind of distortion and is fast enough to track time varying clocking disturbances. Further, a communication system is provided containing such a device.01-06-2011
20110002422Apparatus for Detecting Digital Video Signal Parameters and Method Thereof - A method for detecting digital video signal parameters detects an integer carrier frequency offset (ICFO), a pilot pattern and a carrier mode of a signal received by an Orthogonal Frequency-Division Multiplexing (OFDM) communication system. The method includes receiving a first OFDM symbol comprising a plurality of first frequency-domain sub-carriers and a second OFDM symbol comprising a plurality of second frequency-domain sub-carriers; generating a plurality of sub-carrier correlation results according to the first frequency-domain sub-carrier and the second frequency-domain sub-carrier; and determining a maximum sub-carrier correlation result from the plurality of sub-carrier correlation results; and outputting an ICFO, a pilot pattern and a carrier mode corresponding to the maximum sub-carrier correlation result.01-06-2011
20110038444RECEIVING APPARATUS AND RECEIVING METHOD - Disclosed herein is a receiving apparatus including a first correlation value computation section, an operation section, a second correlation value computation section, a decoding section, and a determination section.02-17-2011
20100226463SYNCHRONIZATION STRUCTURE AND METHOD FOR A RECEIVING APPARATUS OF A COMMUNICATION SYSTEM - The present invention relates to a synchronization structure for a receiving apparatus for receiving signals in a communication system, in which the signals are transmitted in frames, each frame comprising a synchronization part with synchronization sequences, wherein at least one of the synchronization sequences as a different phase than the other synchronization sequences, comprising correlation means adapted to perform a correlation on the synchronization part, peak detection means adapted to detect candidate correlation peaks and the correlation result, and correlation peak detection means adapted to detect a correlation peak among said candidate correlation peaks on the basis of a confidence value and phase information.09-09-2010
20120087448SYSTEM AND METHOD FOR ACQUISITION OF SIGNALS - A system for processing a received signal having at least one code applied thereto, the received signal having a frequency, the system comprising: first correlator circuitry arranged to correlate the received signal with a first code to provide an output; second correlator circuitry arranged to correlate the received signal with a second code to provide an output, wherein the first code and the second code are different; and processor for processing together the outputs of the first and second correlator circuitry to cancel the frequency.04-12-2012
20120087447APPARATUS AND METHOD FOR ESTIMATING HIGH SPEED FREQUENCY OFFSET IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method estimate a high speed frequency offset in a wireless communication system. The apparatus includes a correlator, an accumulator, a phase calculator, and a frequency offset coupler. The correlator performs a first correlation and a second correlation based on a first reference signal and a second reference signal. The accumulator accumulates results of the correlations. The phase calculator calculates a first phase and a second phase from the accumulated first correlation value and the accumulated second correlation value. The frequency offset coupler determines whether a frequency offset deviates from a frequency offset estimate range based on a difference between the first phase and the second phase, and compensates the frequency offset according to the determination result. The apparatus can estimate a frequency offset within an error allowable range under an environment where a terminal moves at high speed.04-12-2012
20120281792METHOD AND SYSTEM FOR GENERATING TIMED EVENTS IN A RADIO FRAME IN AN E-UTRA/LTE UE RECEIVER - A mobile device coupled to a common system clock receives a signal comprising a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS) in a radio frame. Sample counts are generated for timed events based on corresponding operating bandwidths. The timed events are detected at modulo sample counts of the generated sample counts according to corresponding operating bandwidths. PSS symbol timing determined via the PSS synchronization is aligned to the generated sample counts based on corresponding operating bandwidth. The generated sample counts are bit-shifted relative to the aligned PSS symbol timing for other timed events based on corresponding operating bandwidths. The one or more timed events are determined via performing modulo counting after the bit-shifting. Timing operations are performed at the determined timed events and the determined one or more timed events are refined, accordingly.11-08-2012
20100202574SPECTRUM SENSING FOR OFDM SIGNALS BY UTILIZING PILOT TONES - An apparatus comprises a downconverter for providing a signal that may be a received orthogonal frequency division multiplexed (OFDM) symbols from a selected channel, each OFDM symbol comprising N subcarriers at least some of which are pilot subcarriers; and a processor that (a) correlates the received OFDM symbols for providing at least one correlated value, (b) generates a metric value as a function of the at least one correlated value and (b) compares the metric value to a threshold value for detecting if an incumbent signal is present.08-12-2010
20130022157DIGITAL FRONT-END CIRCUIT AND METHOD FOR USING THE SAME - A digital front-end circuit is disclosed. In one aspect, the circuit includes a filtering block for filtering received data. The filtering block has a first filter branch for filtering the received data in a first frequency band and a second filter branch for filtering the received data in a selected second frequency band. The second filter branch is in parallel with the first filter branch, is programmable and includes a block for resampling the received data. The front-end circuit also includes a circuit for performing synchronization and spectrum sensing on the received data, which is in connection with the output of the filtering block. The front-end circuit also includes a controller block for controlling the filtering block and the synchronization circuit.01-24-2013
20130022158CHANNEL ESTIMATION METHOD AND SYSTEM FOR INTER-CARRIER INTERFERENCE-LIMITED WIRELESS COMMUNICATION NETWORK - A method and system for wireless communication channel estimation. A frequency offset hypothesis is determined. An interchannel interference (“ICI”) matrix based on the frequency offset hypothesis is generated. Pilot channel estimates based on the ICI matrix are obtained. A correlation error of the pilot channel estimates to the frequency offset hypothesis is calculated. The correlation error is compared with a predetermined correlation error value. The frequency offset hypothesis is updated and the aforementioned steps are iteratively repeated if the correlation error is greater than the predetermined correlation error value. The pilot channel estimates are used to estimate the wireless communication channel.01-24-2013
20120243645DIGITAL RECEIVER FOR REACTIVE RADIO - A digital receiver is disclosed. In one aspect, the receiver includes a receiving module for receiving packetized data. The receive may further include a first processing module for packet detection having a first programmable processor. The receiver may further include a second processing module for demodulation and packet decoding having a second programmable processor. The receiver may further include a first digital receive controller having a third processor arranged for being notified of detection of data by the first processing module and for activating the second processing module.09-27-2012
20080247494Wireless Receiver For Sorting Packets - A wireless receiver that sorts packets including a packet detector, multiple correlators, and multiple packet processors. Each correlator correlates a received signal according to packet type. Each packet processor processes the received signal according to packet type. A signal power detector may be provided to initially qualify the received signal as containing a packet, and the correlators determine whether a packet is present. The correlators may be configured for sequential or simultaneous correlation. For the simultaneous correlator configuration, a correlation monitor is provided to monitor correlation results to determine if the received signal contains a packet, and if so, to determine packet type. A low SNR packet detector may be provided which correlates the received signal to detect weak packet signals. The signal power detector may be omitted, where the correlators simultaneously monitor the received signal while a correlation monitor continuously monitors correlation results for packet detection.10-09-2008
20100086085Method and system for estimating the speed of a mobile device in a network - A method for estimating the speed of a mobile device in a network is provided that includes selecting a correlation length from a plurality of possible correlation lengths. A correlation result is generated based on the selected correlation length. A speed estimate is generated for the mobile device based on the correlation result.04-08-2010
20130170589Filter Offset Compensation - Problems arising from a pre-emphasis filter, particularly an infinite-impulse-response filter, in a signal modulator are solved by detecting sequences of the same bit or symbol in a modulation signal and compensating the corresponding d.c. offset in the signal generated by the pre-emphasis filter without real-time feedback. The amount of offset compensation can be defined during design of the modulator or adjusted or calibrated during production. It is not necessary to change the transfer function of the pre-emphasis filter, but only to correct the d.c. offset of the filter output signal.07-04-2013
20130177110Mid-Packet Clear Channel Assessment - A mid-packet detection technique is provided that detects a packet with periodic repetitions of a fixed duration at a point in time of the packet other than a start-of-packet pattern, e.g., a preamble, associated with the packet. The process performs packet detection without detecting a preamble and does not require carrier frequency recovery, timing recovery (synchronization) or channel estimation. In one embodiment, a doubly differential matched filter autocorrelation of the received signal is computed and used as a metric for packet detection when the preamble is not observed or to complement preamble detection. The metric is compared to a threshold to indicate detection of a packet.07-11-2013
20130177109SIGNAL DETECTOR, SIGNAL DETECTION METHOD, AND COMMUNICATION TERMINAL APPARATUS - There is provided a signal detector which includes a correlation emphasis unit configured to generate correlation emphasis signals corresponding to the respective fixed intervals, an autocorrelation matrix generation unit configured to generate an autocorrelation matrix, a noise power estimation unit configured to estimate noise power in the correlation emphasis signals, a noise power matrix generation unit configured to generate, a noise power matrix having noise power components, a noise removal unit configured to remove an influence of noise from the autocorrelation matrix, an eigenvalue calculation unit configured to calculate an eigenvalue of the autocorrelation matrix from which the influence of noise has been removed by the noise removal unit, and a signal judgment unit configured to determine whether a signal transmitted from an external apparatus is included in the received signals.07-11-2013
20130142292METHOD AND APPARATUS FOR ESTIMATING FREQUENCY - A method and apparatus for use in connection with wireless communication to adjust the frequency of an oscillator to synchronize with a received signal by correlating a synchronization code channel with training sequences to estimate relative offsets which are employed to estimate an error, which is then filtered. The filtered output preferably provides a voltage controlling a voltage controlled oscillator (VCO). The same technique may be employed to control a numeric controlled oscillator (NCO).06-06-2013
20130136216RECEPTION DEVICE - There are provided a correlation calculation unit that takes a cross-correlation between a signal from which a DC component of an analog baseband signal is removed, and to which a known fixed DC offset is added, and a known signal, an inter-correlation peak phase difference detection unit that estimates a carrier frequency offset from a peak of the calculated correlation vector, and a residual DC offset estimation unit that estimates a residual DC offset component from a mean value of the sidelobe of the calculated correlation vector.05-30-2013
20130094620ESTIMATION OF A MULTIPATH SIGNAL IN A WIRELESS COMMUNICATION SYSTEM - Described herein is a method and system for estimating a time-varying multipath communication channel. The system comprises a receiver for receiving a signal comprising a data packet transmitted over the multipath communication channel. The system also comprises a frequency-domain channel estimator that generates a frequency-domain channel estimate based on the received signal. The system further comprises a time-domain channel modeller that receives the frequency-domain channel estimate and generates an estimate of parameters in a time-domain model of the multipath communication channel. The model characterises the multipath communication channel as a delay line with a plurality of taps, each tap having tap parameters defining a delay, a Doppler and a gain for the tap. The tap parameters are constant over the data packet.04-18-2013
20130142290Method and Apparatus for Modulation and Coding Scheme Adaption in a MIMO System - Method and apparatus for decoding a transmitted signal by a receiver in a MIMO system into a first estimate component for estimating a first signal, a first interference component indicating interference resulting from a correlation relationship among a set of signals to be transmitted, and a first noise component. A base station generates the transmitted signal from the set of signals through a coding process, the coding process defining a correlation relationship amongst the set of signals. The correlation information about the correlation relationship is transmitted to the receiver directly or by a dedicated reference symbol. The decoding is performed by determining a linear receiver filter for the first signal in accordance with the correlation information, and de-correlating the first signal and interferences.06-06-2013
20130142291Synchronization Signals Detection - A wireless device correlates received signals with predetermined synchronization signals to produce correlation values. The wireless device identifies a first synchronization signal as a synchronization signal transmitted by a first base station. The wireless device subtracts a processed first synchronization signal from received signals to generate an updated received signal and correlates the updated received signal with a second plurality of predetermined synchronization signals to produce correlation values. The wireless device identifies a second synchronization signal as a synchronization signal transmitted by a second base station based on correlation values.06-06-2013
20110249776METHOD FOR DETERMINING AS TO WHETHER A RECEIVED SIGNAL INCLUDES A DATA SIGNAL - A method of determining as to whether a received signal includes a data signal is provided. The method provided includes determining a first value based on a cyclic auto-correlation of the received signal and determining a second value based on the cyclic auto-correlation of the received signal. The method provided further includes determining as to whether a received signal includes a data signal based on a comparison of the first value and the second value.10-13-2011
20130148765COARSE TIMING ACQUISITION - A coarse timing acquisition technique includes generating a sequence detection indicator. The sequence detection indicator indicates detection of a sequence of repeated symbols in a received signal. The sequence detection indicator is based on a first energy threshold and a normalized moving sum of an autocorrelation signal. The autocorrelation signal is based on the received signal.06-13-2013
20130148766SIGNAL DETECTION DEVICE AND SIGNAL DETECTION METHOD - In this signal detection device (06-13-2013
20120275551Correlation Computation Method, Device and System - An aspect of the invention is a signal processing method for correlation computation between received signal samples, code replica and carrier replica. The method is characterized in that the method comprises steps of: mapping (11-01-2012
20120275550METHOD FOR DETECTING S-SCH IN CELL SEARCHING AND RECEIVER USING THE SAME - Disclosed is a method for detecting S-SCH in cell searching including: detecting an m0 value corresponding to an even index in a secondary synchronization channel (S-SCH) signal having an even index; determining an m1 group defined by the m0 value; detecting an m1 value using correlation detection relation within the m1 group; and detecting a group ID using the m0 value and the m1 value.11-01-2012
20100316171DATA PROCESSING APPARATUS AND METHOD, RECEIVING APPARATUS AND METHOD, SYNCHRONOUS DETECTION APPARATUS AND METHOD, AND COMPUTER PROGRAM - A data processing apparatus includes a first correlation operation unit which performs a mutual correlation operation of a first input series and a second input series, a threshold value operation unit which calculates a threshold value based on the first input series, a first comparison unit which compares a first mutual correlation value with the threshold value, a search window setting unit which sets a search window for detecting the second input series to the first input series on the basis of the comparison result, a hard decision unit which performs binarization of the first input series, a second correlation operation unit which performs a mutual correlation operation of a first input hard decision value, and a detection position determining unit which searches for a maximum value of the mutual correlation value within the search window and determines the detection time of the maximum value.12-16-2010
20120281791FREQUENCY CORRECTION CIRCUIT, RADIO RECEIVING APPARATUS, AND FREQUENCY CORRECTION METHOD - A radio receiving apparatus according to the present invention receives a preamble signal through one frequency band and also detects a periodic symbol timing in a receiving period of a part of a symbol that composes the preamble signal. A frequency correction circuit includes a generating unit, a detecting unit, and a correction unit. The generating unit generates a detection window of a predetermined time width including each of a first and a second symbol timing that are previously determined among the periodic symbol timings in the receiving period of a remaining symbol that composes the preamble signal. The detecting unit sequentially receives a correlation value between the preamble signal and a reference signal and detects a maximum value from the correlation value input during a period when the detection window is opened. The correction unit corrects a frequency deviation of the one frequency band based on the maximum value.11-08-2012
20130188758JOINT SOURCE CHANNEL DECODING USING PARAMETER DOMAIN CORRELATION - Methods, systems, and apparatuses are provided for performing joint source channel decoding in a manner that exploits parameter domain correlation. Redundancy in speech coding and packet field parameters is exploited to generate conditional probabilities that a decoder utilizes to perform joint source channel decoding. The conditional probabilities are based upon correlations of parameters of a current frame with parameters of the same or other frames or historical parameter data. Parameter domain correlation provides significant channel decoding improvement over prior bit domain solutions. Also provided are methods, systems, and apparatuses for utilizing received statistics of monitored data bits from which conditional probabilities are generated to perform channel decoding. The techniques described may be implemented at the decoder side and thus do not interfere with transmission standards.07-25-2013
20120020440METHOD AND DEVICE FOR DETERMINING SMOOTH WINDOW LENGTH IN CHANNEL ESTIMATION - A method and a device for determining a smooth window length in channel estimation is provided. The method includes: obtaining autocorrelation values of pilot signals, where the autocorrelation values include first autocorrelation values and second autocorrelation values, at least two first autocorrelation values exist, and at least one second autocorrelation value exists; determining a speed range according to symbols of the first autocorrelation values or the symbols of the first autocorrelation values and a ratio value between the second autocorrelation value and one of the first autocorrelation values; and determining the smooth window length according to the speed range. Through the method provided in embodiments of the present invention, the problems caused by a fixed smooth window length may be avoided, and this improves system performance.01-26-2012
20120020439RECEIVER WITH CHANNEL ESTIMATION CIRCUITRY - The invention concerns receive circuitry for demodulating an input signal received from a transmission channel, the receive circuitry including a frequency interpolation filter arranged to provide channel estimations (Ĥn) of the entire channel, the frequency interpolation filter having at least one filter receiving the pilot frequency channel estimations and performing filtering based on a plurality (Q) of the pilot channel estimations at a time; and a memory arranged to store the filter coefficients for the at least one filter, the coefficients being based on a frequency-domain autocorrelation of a model of the transmission channel, the model representing the time distribution of the channel power of the transmission channel determined independently of the pilot frequency channel estimations, wherein said model is based on a χ01-26-2012
20130195229MULTIPLE CORRELATORS FOR COMMUNICATION DEVICE DETECTION - A receiver unit of a communication device can employ multiple correlators for decoding the access address of a packet received from another communication device. A dynamically determined primary frequency offset is applied to a phase difference signal that is determined from an RF signal that comprises the packet. For each of a plurality of access address decoding chains of the receiver unit, a secondary frequency offset associated with the access address decoding chain is applied to the phase difference signal, the phase difference signal is correlated with a predetermined access address of the communication device, and a resultant correlation output is compared against a correlation threshold. One of the access address decoding chains that generated the correlation output that is greater than the correlation threshold is selected and the packet is demodulated based, at least in part, on the phase difference signal corresponding to the selected access address decoding chain.08-01-2013
20130202068WIDEBAND DETECTION OF NARROWBAND TRIGGER SIGNALS - A mechanism can be implemented for reducing the power consumption of a wireless radio device in establishing a wireless connection by utilizing a wideband signal to detect a narrowband trigger signal at a potential narrowband trigger frequency. The wireless radio device may operate a wideband receiver to receive an RF signal. Being aware of the potential narrowband trigger frequencies, the wideband receiver may utilize the received RF signal to detect the presence of a narrowband trigger signal at one of the potential narrowband trigger frequencies.08-08-2013
20130202069Frequency Offset Compensation for Multi-carrier Communication Systems - The present disclosure provides a frequency offset compensation technique for use by a multi-carrier receiver. Compared with legacy receiver designs, the technique introduces a new function which correlates various frequency offsets of the different carriers involved in multi-carrier signal transmission and reception. This new function can be coupled with an Automatic Frequency Control (AFC) function which can then utilize the correlation information provided by the new function to achieve significantly better frequency error/offset estimation when the carriers are correlated. As a method aspect, the frequency offset compensation technique comprises the steps of receiving signals modulated on a plurality of carrier frequencies, deriving a frequency offset for each carrier frequency to thereby provide a plurality of frequency offsets corresponding to the plurality of carrier frequencies; correlating these plurality of frequency offsets; and controlling compensation of the frequency offsets based on a result of the correlation.08-08-2013
20130094619SYSTEMS AND METHODS FOR PACKET DETECTION - Systems, methods, and devices for detecting packets in signals are described herein. The apparatus comprises a receiver configured to receive a signal comprising a plurality of samples. The apparatus comprises circuitry. The circuitry is configured to apply a match filter to the plurality of samples to produce a plurality of blocks of samples, each block comprising a number of samples. The circuitry is configured to correlate a subset of the samples of a first block with a subset of the samples of a second block to produce an output. The circuitry is configured to compare the output to a threshold value to determine whether the signal comprises a data packet.04-18-2013
20120082271DETECTING DIGITAL RADIO SIGNALS - In one embodiment, a receiver front end circuit can receive and process multiple radio frequency (RF) signals and output downconverted signals corresponding to these signals. In turn, multiple signal processors can be coupled to this front end. Specifically, a first signal processor can receive and process the downconverted signals to output a first signal obtained from content of a first RF signal, and a second signal processor can receive and process the downconverted signals to output a second signal obtained from content of a second RF signal. In addition, the apparatus may include a detection circuit coupled to the receiver front end circuit to detect presence of at least the second signal and enable the second signal processor responsive to the detected presence.04-05-2012
20120093267Method for Unifying Secondary Synchronization Signal Detection and Frame Timing Synchronization - A method for joint secondary synchronization signal detection and frame timing synchronization includes: (1) generating local secondary synchronization sequences SSC04-19-2012

Patent applications in class Correlative or matched filter