Having Correlation-type Receiver Patents (Class 375/142)
  • Patent number: 8576963
    Abstract: A non-coherent detection apparatus includes, inter alia, a correlation unit, a frequency offset estimator, and a signal detector. The correlation unit obtains a differential phase signal by multiplying a complex conjugate value of a delay signal obtained by delaying a received signal by (N+1) chips by the received signal, sums-up resultant values obtained by multiplying each component of the differential phase signal by each component of a correlation sequence and outputs a correlation signal. The frequency offset estimator estimates a frequency offset based on a value obtained by accumulatively summing-up the correlation signals corresponding to preamble portions of the received signal. The signal detector detects an original signal from the received signal based on a size of a real-number part of a resultant value obtained by multiplying the frequency offset estimated by the frequency offset estimator by the correlation signal corresponding to a PHY payload portion of the received signal.
    Type: Grant
    Filed: April 13, 2010
    Date of Patent: November 5, 2013
    Assignee: Chung-Ang University Industry-Academy Cooperation Foundation
    Inventors: Tae-Gyu Chang, Hyeon-Jin Jeon, Tanee Demeechai
  • Patent number: 8571087
    Abstract: A baseband processing module according to the present invention includes a multi-path scanner module. The multi-path scanner module is operable to receive timing and scrambling code information regarding an expected multi-path signal component of a WCDMA signal. Then, the multi-path scanner module is operable to identify a plurality of multi-path signal components of the WCDMA signal by descrambling, despreading and correlating a known symbol pattern of/with a baseband RX signal within a search window. The multi-path scanner module is operable to determine timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window and to pass this information to a coupled rake receiver combiner module.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: October 29, 2013
    Assignee: Broadcom Corporation
    Inventors: Mark David Hahm, Baoguo Yang
  • Publication number: 20130279541
    Abstract: A method and apparatus for performing frequency analysis of sub-epoch correlations to estimate an unknown frequency of a received signal is provided. The method includes forming a sequence of correlation values from a plurality of correlations performed over a period less than a repeating period of a code, and analyzing the sequence of correlation values to estimate the frequency that is used to receive a signal comprising the code.
    Type: Application
    Filed: June 24, 2013
    Publication date: October 24, 2013
    Inventors: Jason GOLDBERG, Charles Abraham, Emre Tapucu
  • Patent number: 8565288
    Abstract: A method for performing delay locked looping upon a received signal which reduces the asymmetry of auto-correlation function resulting from sampling is provided. The received signal is a spread spectrum code signal, and the method includes: generating a plurality of replica spread spectrum code signals according to an estimated code phase delay and phase spacing, the replica spread spectrum code signals having phases respectively different from the phase of the received signal; calculating a spread spectrum code error statistics signal according to the replica spread spectrum code signals and the received signal; and adjusting the estimated code phase delay according to the spread spectrum code error statistics signal and a phase difference between a sampled point of at least one replica spread spectrum code signal and a corresponding signal transition point.
    Type: Grant
    Filed: March 6, 2011
    Date of Patent: October 22, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventors: Kai-Di Wu, Kun-Sui Hou
  • Patent number: 8553746
    Abstract: The number of users and data capacity of wireless systems are increased by employing apparatus and method for increasing the number of spreading codes available in the system by providing a mechanism to reuse the already allocated spreading code or use the codes that may correlate to those already being used within the same sector/cell. This, in return, provides capacity improvement proportional to the number of added base station (BS) antennas for each cell. An antenna null steering technique for code allocation maintains the cross correlation properties of the codes only for the desired user and to obtain a gain in capacity improvement.
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: October 8, 2013
    Assignee: Interdigital Technology Corporation
    Inventors: Nadar Bolourchi, Leonid Kazakevich, Rui Yang
  • Patent number: 8548107
    Abstract: A method for detecting multi-user signals including conducting a first energy burst detection detecting a first plurality of user signals as a first energy burst, attempting to decode a user signal from the first plurality of signals within the first energy burst, cancelling out a first user signal from the first energy burst if the first user signal is successfully decoded from the first energy burst, determining a second user signal to be discarded if the second user signal is not successfully decoded from the first energy burst, conducting a second energy burst detection detecting a second plurality of signals as a second burst, and iteratively cancelling out the first user signal successfully decoded from the first energy burst from the second energy burst, wherein the second energy burst detection is conducted when all user signals within the first energy burst are either cancelled out or determined to be discarded.
    Type: Grant
    Filed: January 25, 2010
    Date of Patent: October 1, 2013
    Assignee: Comtech Mobile Datacom Corporation
    Inventors: Richard Candell, Paul Ebert, John Fossaceca, Greg Handermann, Mark Holland, Lajuana Johnson, Bruce L. McKinley, Bo Wang, Ralph Eugene Crenshaw
  • Patent number: 8537878
    Abstract: A method for communicating comprises generating at least one spreading code from a preferred Golay generator and/or a preferred generalized Golay generator. The preferred generalized Golay generator may comprise a plurality of preferred Golay generators. The outputs of the preferred Golay generator are logic 0 and 1. Each stage of the preferred Golay generator may comprise a single basic storage unit, such as a Flip-Flop. Generalized Golay codes comprise pseudo-complementary sequences having code lengths that differ from Golay complementary sequences and are characterized by low autocorrelation sidelobes relative to the autocorrelation peak.
    Type: Grant
    Filed: April 26, 2009
    Date of Patent: September 17, 2013
    Assignee: Adeptence, LLC
    Inventor: Ismail Lakkis
  • Patent number: 8537940
    Abstract: A wireless communication system includes: a frequency down-converting circuit for receiving a wireless signal and for performing frequency down-conversion on the wireless signal to output a frequency down-converted signal; a first training circuit for performing frequency comparison between the frequency down-converted signal and a plurality of candidate carrier signals having different frequencies so as to determine a plurality of selected carrier signals from the candidate carrier signals; a second training circuit for performing phase comparison between the frequency down-converted signal and phases of a pseudo-noise sequence at each of the selected carrier signals so as to determine a matching phase and a matching carrier; and a demodulator for demodulating the frequency down-converted signal according to the matching carrier and the matching phase so as to generate a demodulated signal.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: September 17, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventor: Kun-Sui Hou
  • Patent number: 8532233
    Abstract: A user terminal transmits a preamble signal generated using a Zadoff-Chu sequence. A correlation processing unit calculates autocorrelation of a received preamble signal. A preamble detection unit detects a side peak position of the autocorrelation of the preamble signal and calculates the main correlation value representing correlation at the main peak position and the side correlation value representing correlation at the side peak position. A frequency offset estimation unit estimates frequency offset that has occurred in the wireless transmission path according to the main correlation value and the side correlation value.
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: September 10, 2013
    Assignee: Fujitsu Limited
    Inventor: Tsuyoshi Shimomura
  • Patent number: 8532159
    Abstract: A transmitter has a portion that sets a parameter about the transmitter itself based on a parameter made to correspond to a condition for selecting a receiver with which the transmitter communicate with, a portion that generates a spread code based on the set parameter, and a sending portion that spreads transmit-data to form a spread signal by the generated spread code, and that sends the spread signal. The receiver has a portion that receives the signal transmitted by the transmitter, a portion that sets a parameter about the receiver itself based on the parameter made to correspond to the condition, a portion that generates a despread code based on the set parameter, a portion that performs a correlation computation of the received signal and the generated despread code, and a portion that selects a transmitter with which the receiver communicates, based on a result of the correlation computation.
    Type: Grant
    Filed: August 28, 2008
    Date of Patent: September 10, 2013
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kazunori Kagawa, Norimasa Kobori, Yukinori Fujita
  • Patent number: 8526540
    Abstract: A method and device is provided for detecting data symbols in a received radio signal. Each data symbol is allocated transmit-side a symbol value-specific PN sequence of successive PN chips in the chip clock, and the allocated PN sequences are offset QPSK modulated. The method for incoherent detection includes converting the received radio signal into a complex baseband signal sampled in the chip clock, generating a demodulated signal by differential demodulation of the complex baseband signal, calculating correlation results by correlating the demodulated signal with the derived sequences, and deriving the values of the data symbols by evaluating the correlation results. Each derived sequence is assigned to a PN sequence allocable transmit-side and includes derived chips, whose values correspond to a logic linking of particular PN chips of the PN sequence allocable transmit-side that is assigned the derived sequence. The invention relates furthermore to a corresponding receiving unit.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: September 3, 2013
    Assignee: Atmel Corporation
    Inventors: Frank Poegel, Eric Sachse, Michael Schmidt
  • Patent number: 8520719
    Abstract: Methods and apparatuses are provided for implementing a multiple-mode correlator within a receiver. The multiple-mode correlator may include at least one pre-multiplier portion and a plurality of correlation portions that selectively process multiply result signals from the pre-multiplier portion.
    Type: Grant
    Filed: May 25, 2010
    Date of Patent: August 27, 2013
    Assignee: QUALCOMM Incorporated
    Inventor: Paul A. Conflitti
  • Patent number: 8520717
    Abstract: Radiolocalization receiver having a plurality of correlation taps, and including a module of cross-correlation detection in which spurious correlation terms are detected by statistical analysis of the frequencies of the candidate peaks. The system can restrict further integration to those taps whose frequency is outside the cross-interference signal, or trigger new acquisition of different space vehicles, upon detection of a cross-interference situation.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: August 27, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Joel Brenner, Angelo Genghi
  • Patent number: 8514117
    Abstract: A method and corresponding apparatus are provided. In operation, an analog signal is integrated with an integrator to generate an integrated analog signal. The integrated analog signal is compared, in synchronization with a first clock signal and a second clock signal, to a reference voltage with a plurality of comparators to generate a comparator output signal. A feedback current is then generated, in synchronization with the second clock signal, from the comparator output signal. The feedback current is fed back to at least one of the comparators, and the comparator output signal is latched in synchronization with the first clock signal to generate a latched output signal. This latched output signal is converted to a feedback analog signal, and a difference between the analog signal and the feedback analog signal is determined.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: August 20, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Venkatesh Srinivasan, Patrick Satarzadeh, Victoria W. Limetkai, Baher Haroun, Marco Corsi
  • Patent number: 8515435
    Abstract: An adaptive transmission scheme provides multiple levels of adaptation. At a first level, a selection is made between a limited feedback or limited feedback scheme and a rich feedback scheme. At a second level of adaptation, a diversity mode is selected. Additional levels of adaptation could be employed.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: August 20, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Leonid Krasny, Karl Molnar, Jung-Fu Thomas Cheng, Stephen Grant, Yi-Pin Eric Wang
  • Patent number: 8503504
    Abstract: This method for estimating a carrier-frequency offset in a telecommunication signals receiver comprises the following steps: computation of the partial correlations relating to several successive portions of a reference binary sequence, each partial correlation being computed between a portion of a signal received by the receiver at said carrier frequency, this signal comprising said reference binary sequence, and a predetermined portion of said reference binary sequence stored and/or generated by the receiver, in several possible relative positions between the received signal and the predetermined portion, and determination of the carrier-frequency offset from the computed partial correlations. It also comprises a step of selecting a synchronization position and the determination step comprises the estimation of a phase shift between computed partial correlations at the selected synchronization position.
    Type: Grant
    Filed: February 22, 2010
    Date of Patent: August 6, 2013
    Assignee: Comissariat á l'Energie Atomique
    Inventor: François Dehmas
  • Patent number: 8503594
    Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: August 6, 2013
    Assignee: Broadcom Corporation
    Inventors: Tommy Yu, Amy Gayle Hundhausen
  • Patent number: 8503505
    Abstract: An apparatus and a method for transmitting/receiving data generate main service data of broadcasting data, generate additional data of the broadcasting data, transform the additional data into a parallel type, generate pseudo-random noise sequences as a spreading code of the additional data, select polarities of the pseudo-random noise sequences using any one additional data bits in the additional data in the transformed parallel type, map the remaining additional data bits excluding the one additional data bit from the additional data in the transformed parallel type to a single sequence, multiply a single sequence to which the remaining additional data bits are mapped by pseudo-noise sequences of which the polarities are selected, control mean power of the additional data multiplied by the sequences, couple the additional data of which the mean power is controlled with the main service data, and then, transmit the broadcasting data.
    Type: Grant
    Filed: May 11, 2011
    Date of Patent: August 6, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jeongchang Kim, Sung-Ik Park, Heung-Mook Kim
  • Patent number: 8498325
    Abstract: The teachings presented herein improve the processing of individual signals of interest included in a received composite signal by computing combining weights and/or signal quality estimates for each signal of interest, e.g., for linear equalization, based on either shared or non-shared correlation estimates. As a non-limiting advantage, the use of shared correlation estimates reduces computational loading as compared to the processing load that would be needed for computing non-shared correlation estimates for all signals of interest. As a further non-limiting advantage, the conditional use of shared and non-shared correlation estimates provides for the use of non-shared correlation estimates where signal characteristic(s) of one or more of the signals of interest warrant such usage, e.g., for one or more high-rate signals of interest.
    Type: Grant
    Filed: January 18, 2008
    Date of Patent: July 30, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Gregory E. Bottomley, Yi-Pin Eric Wang
  • Patent number: 8488693
    Abstract: A method used in a wireless communication apparatus based on reference signals is provided. The method may include obtaining a plurality of pilot rules and obtaining radio channel information of a radio channel between the wireless communication apparatus and another wireless communication apparatus. The wireless communication apparatus may be in an area including at least one cell and using one or more data streams. Further, the method may include selecting applicable pilot rules from the plurality of pilot rules based on the radio channel information, creating at least one pilot structure to be used in the radio channel; and using the created at least one pilot structure to transmit data over the radio channel.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: July 16, 2013
    Assignee: Industrial Technology Research Institute
    Inventors: Chung-Lien Ho, Ren-Jr Chen, Yan-Xiu Zheng
  • Patent number: 8488649
    Abstract: A code converting apparatus is designed to estimate the incoming time and the like of a signal modulated by a spreading sequence composed of m elements in a set A having n kinds of symbols as elements accurately. A symbol sequence memory section 102 stores a converted sequence of symbols obtained by concatenating consecutive 2d symbols at the center of each sequence pattern pi composed of 4d elements in the set A. The converted sequence of symbols is structured so that d symbol immediately preceding the 2d symbols and d symbol immediately following the 2d symbols are identical to d symbol immediately preceding corresponding 2d symbols and d symbol immediately following the corresponding 2d symbols of a corresponding sequence pattern. A symbol sequence specifying section 103 specifies a matching sequence pattern for every consecutive 2d symbols in a symbol sequence obtained by assigning a symbol to the signal in a coding cycle of the spreading sequence.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: July 16, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takafumi Nagano, Takashi Iwamoto
  • Patent number: 8477866
    Abstract: The method includes performing a wired back-to-back test by forming M wired paths connecting one of the N transmission antennas with the M reception antennas through M cables, separating ith digital data corresponding to an ith receiver wired path from the plurality of digital data stored in the receiver wherein i is a natural number greater than 1 and smaller than M, extracting a time delay by decimating the separated ith digital data and performing sliding correlation on the decimated data, and extracting attenuation and phase characteristics of the ith receiver wired path by extracting samples after the time delay among the decimated samples.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: July 2, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung-Jun Lee, Kwang-Chun Lee, Hyun-Kyu Chung
  • Patent number: 8472504
    Abstract: A method for optimizing an acquisition phase of a spread-spectrum signal by a mobile receiver includes searching for a trend path having the maximum energy for different frequency assumptions and among all the positive trend paths of frequencies between initial and final instants marking the beginning and the end of a coherent signal integration.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: June 25, 2013
    Assignees: Thales, Centre National d'Etudes Spatiales
    Inventors: Damien Kubrak, Michel Monnerat, Lionel Ries, Géraldine Artaud
  • Patent number: 8472503
    Abstract: A method and apparatus for performing frequency analysis of sub-epoch correlations to estimate an unknown frequency of a received signal is provided. The method includes forming a sequence of correlation values from a plurality of correlations performed over a period less than a repeating period of a code, and analyzing the sequence of correlation values to estimate the frequency that is used to receive a signal comprising the code.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: June 25, 2013
    Assignee: Global Locate, Inc.
    Inventors: Jason Goldberg, Charles Abraham, Emre Tapucu
  • Patent number: 8472571
    Abstract: 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.
    Type: Grant
    Filed: July 23, 2012
    Date of Patent: June 25, 2013
    Assignee: Broadcom Corporation
    Inventor: Prasanna Desai
  • Patent number: 8467462
    Abstract: To suppress effects produced on other terminals as much as possible, while obtaining the advantage of soft-combining. A multicarrier receiving apparatus that receives a packet comprised of at least a propagation path estimation symbol and a scrambled information symbol to demodulate, and has propagation path estimating sections 3-a and 3-b that respectively estimate propagation paths of radio signals transmitted from a plurality of transmission antennas, scramble multiplying sections 5-a and 5-b that respectively perform the same scrambling on propagation path estimation values output from the propagation path estimating sections 3-a and 3-b as scrambling provided in the information symbol on the transmission antennas sides, an adding section 3-c that adds scrambled propagation path estimation values, and a propagation path compensating section 7 that performs propagation path compensation of the information symbol included in the received packet using a signal output from the adding section 3-c.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: June 18, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuhiro Hamaguchi, Minoru Kubota, Shimpei To, Shoichi Shitara, Kimihiko Imamura
  • Patent number: 8467347
    Abstract: Incoming signals that are sparse in the code-correlation domain, such as CDMA signal (GPS signals being a specific example of such signals) are processed by sampling the incoming signal at irregular time intervals at an average rate that is significantly lower than the Nyquist rate; which in the case of GPS signals is the chip rate of a pseudorandom code sequence that is embedded in the signal. The sampled signal is processed with locally generated signals that are also sampled the same irregular time intervals.
    Type: Grant
    Filed: October 27, 2010
    Date of Patent: June 18, 2013
    Inventors: Xingxin Gao, David P Varodayan
  • Patent number: 8462829
    Abstract: A method of wireless communication in a lossy environment entails generating a direct sequence spread spectrum (DSSS) code string that includes a pseudo-noise (PN) sequence followed by instances of shifted PN sequences, where the shifted PN sequences are produced in response to the content of the message. The PN sequence includes a plurality of chips arranged in a first order, and each of the shifted PN sequences includes the plurality of chips arranged in another order. A beacon signal modulated by the DSSS code string is transmitted from a transceiver and received at a receiver within the communication system. Correlation peaks are formed at the receiver, where each correlation peak is associated with one of the PN sequences or one of the shifted PN sequences. Shift values are determined from the correlation peaks and the shift values are decoded to produce the message at the receiver.
    Type: Grant
    Filed: November 3, 2011
    Date of Patent: June 11, 2013
    Assignee: Sandia Research Corporation
    Inventors: Steven M. Shope, Vigneswaran Rajagopalan
  • Patent number: 8463196
    Abstract: A method of decoding in a wireless receiver, a wireless transmission from a predefined user, the method comprising: receiving a wireless transmission signal (r(m)); determining a one or more interfering spreading codes (si(m)) contributing to the received wireless transmission signal (r(m)); estimating a one or more interferer symbols ({circumflex over (b)}i(m)) from the received wireless transmission signal (r(m)) and the or each interfering spreading codes (si(m)); calculating a one or more scaling factors (Pi(m)) at which the or each of the interferer symbols ({circumflex over (b)}i(m)) was originally transmitted; simulating an interference signal i(m) in the received wireless transmission signal (r(m)); removing the simulated interference signal i(m) from the received wireless transmission signal (r(m)) to produce a processed wireless signal (o(m)); and estimating a one or more symbols {circumflex over (b)}(m) transmitted by the predefined user in the processed wireless signal (o(m)).
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: June 11, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Belkacem Mouhouche
  • Patent number: 8457255
    Abstract: A method of improving sensitivity in the demodulation of a received signal by a receiver over an arbitrary measurement time epoch, said method comprising the steps of correlating said received signal with a local replica of pseudo noise code in a coherent fashion creating a correlation signal and utilizing a Viterbi phase state keying trellis demodulation with a variable resolution of phase states over 0 to 360° to demodulate the radio frequency phase trajectory of said correlation signal throughout the measurement time epoch for improving sensitivity in the demodulation of a received signal.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: June 4, 2013
    Assignee: Research In Motion Limited
    Inventor: Jorgen S. Nielsen
  • Publication number: 20130136155
    Abstract: Sub-microsecond time transfer in a GPS/GNSS receiver using a weak GPS/GNSS signal is provided. The digitized complex baseband signal and the generated PN code are cross-correlated for each code period so as to output a complex correlation value at each code epoch of the generated PN code, where a sequence of the output correlation values form a data stream representing the navigation message. Bit synchronization generates bit sync pulses at bit boundaries. The location of a target segment having a known sequence at a known bit location in the navigation message is detected by searching through a plurality of subframes and accumulating search results for the plurality of subframes. Transmission time of the target segment is determined from the detected location of the target segment, with a certain time ambiguity. Accurate local time is determined by solving the time ambiguity using approximate time obtained from an external source.
    Type: Application
    Filed: January 22, 2013
    Publication date: May 30, 2013
    Applicant: MAGELLAN SYSTEMS JAPAN, INC.
    Inventor: Magellan Systems Japan, Inc.
  • Patent number: 8451958
    Abstract: 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.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: May 28, 2013
    Assignee: Juniper Networks, Inc.
    Inventors: Joseph Boutros, Emmanuel Lemois
  • Patent number: 8451946
    Abstract: A method is for decoding a pulse signal modulated through a transmitted reference modulation scheme. The modulated pulse signal may include, repetitively, a reference pulse followed by an information pulse delayed with a delay. The method may include subtracting or adding from the modulated pulse signal, a version of the modulated pulse signal delayed with the delay for obtaining a processed signal, and performing a non-coherent detection on the processed signal.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: May 28, 2013
    Assignee: STMicroelectronics N.V.
    Inventors: Gian Mario Maggio, Chiara Cattaneo, Philippe Rouzet
  • Patent number: 8447005
    Abstract: Methods and apparatus for have frequency offset estimation and cell search in radio communication systems take into account the time-frequency correlation properties of reference and synchronization signals in such systems. This reduces the probability of misdetection of the physical layer cell ID and frequency offset by accounting for time-frequency ambiguities and evaluating correlation signal peaks in the frequency domain, saving signal processing time and making initial cell search considerably faster. Also, lower-grade and hence cheaper oscillators can be used without causing problems in the user's experience with a receiver, such as a cellular telephone.
    Type: Grant
    Filed: November 5, 2009
    Date of Patent: May 21, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Joakim Axmon, Bengt Lindoff
  • Patent number: 8442132
    Abstract: A multi-carrier linear equalization receiver, e.g., a RAKE receiver or chip equalization receiver, is described herein. The multi-carrier receiver distributes processing delays among a plurality of received carriers based on a comparison between the signal-to-interference ratios (SIRs) determined for each carrier. The receiver initially allocates a minimum number of processing delays to each carrier. In one embodiment, any remaining additional processing delays are distributed evenly between the carriers when a comparison between the largest and smallest SIR is less than or equal to a threshold. In another embodiment, the remaining additional processing delays are distributed to favor the carrier(s) with the strongest SIR(s) when the comparison between the largest and smallest SIR exceeds the threshold.
    Type: Grant
    Filed: June 3, 2009
    Date of Patent: May 14, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Elias Jonsson, Oskar Drugge
  • Publication number: 20130114643
    Abstract: A method of wireless communication in a lossy environment entails generating a direct sequence spread spectrum (DSSS) code string that includes a pseudo-noise (PN) sequence followed by instances of shifted PN sequences, where the shifted PN sequences are produced in response to the content of the message. The PN sequence includes a plurality of chips arranged in a first order, and each of the shifted PN sequences includes the plurality of chips arranged in another order. A beacon signal modulated by the DSSS code string is transmitted from a transceiver and received at a receiver within the communication system. Correlation peaks are formed at the receiver, where each correlation peak is associated with one of the PN sequences or one of the shifted PN sequences. Shift values are determined from the correlation peaks and the shift values are decoded to produce the message at the receiver.
    Type: Application
    Filed: November 3, 2011
    Publication date: May 9, 2013
    Applicant: SANDIA RESEARCH CORPORATION
    Inventors: Steven M. Shope, Vigneswaran Rajagopalan
  • Patent number: 8437435
    Abstract: 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 (110) received signal samples into a range of unsigned integers; separating (120) bits of the mapped N-bit sample sequences into N sequences of bits; performing at least one exclusive or (XOR) operation between a sequence of bits and the code; counting (140) number of bits having value 1 in the result of the exclusive or (XOR); remapping (150) the sum back into numeric range of the received signal samples; multiplying the remapped sum by carrier replica; and accumulating (170) the product of multiplication for an interval of at least a code epoch.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: May 7, 2013
    Assignee: Fastrax Ltd.
    Inventor: Timo Jokitalo
  • Patent number: 8428107
    Abstract: A method for estimating an unknown spreading code in a received signal by using a set of genetic algorithms. The method comprises: selecting at least one seed of the unknown spreading code for initialization purposes, wherein the unknown spreading code comprises a plurality of chips, and performing a breeding process of the unknown spreading code by executing a breeding algorithm.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: April 23, 2013
    Assignee: Trimble Navigation Ltd.
    Inventors: Gregory C. Best, Bruce D. Riter, Bruce Edward Peetz
  • Patent number: 8428106
    Abstract: The technology comprises method(s) and apparatus for operating a telecommunications system. In its basic form the method comprises providing plural channelization codes for potential use by an uplink receiver; using unused channelization codes of the plural codes to generate an estimate of an impairment covariance matrix; and using the estimate of the impairment covariance matrix to form a processing parameter. For example, the processing parameter can be one or more weight values which, in turn, are can be used for generating a combined output signal.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: April 23, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Douglas A. Cairns, Yi-Pin Eric Wang, HÃ¥kan Bjorkegen
  • Patent number: 8422603
    Abstract: 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.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: April 16, 2013
    Assignee: Sony Corporation
    Inventors: Katsumi Takaoka, Doan Tien Dung
  • Patent number: 8411726
    Abstract: A method and apparatus for selecting a signal processing resolution. A received signal is processed using a first resolution. When a multipath condition is detected, the signal is processed using a second resolution.
    Type: Grant
    Filed: December 28, 2009
    Date of Patent: April 2, 2013
    Assignee: Global Locate, Inc.
    Inventors: Charles Abraham, Donald L. Fuchs
  • Patent number: 8411729
    Abstract: In a WCDMA network, a communication system may include a baseband processor that enables determination of a primary synchronization position and a plurality of scrambling codes based on received configuration information from at least one base station. The baseband processor may also determine a slot boundary in at least one signal received from the at least one base station based on the determined primary synchronization position. The baseband processor may concurrently apply segments of the plurality of scrambling codes to the received at least one signal. The segments of the plurality of scrambling codes are generated from a plurality of time shifted versions of one of the plurality of scrambling codes. The system may also include a multipath detector that enables unscrambling of the received at least one signal based on the determined slot boundary and at least a portion of the one or more scrambling codes.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: April 2, 2013
    Assignee: Broadcom Corporation
    Inventors: Mark Kent, Francis Swarts, Uri Landau
  • Patent number: 8406277
    Abstract: Radiolocalization receiver for a satellite radiolocalization system like GPs, Galileo or the like, including a staged correlation and accumulation unit, in which the correlation data is biased in order to be to always non-negative. Thanks to this feature, the accumulated data grow monotonically during the accumulation. Overflow rate of a first correlation stage (100, 150-153) is scaled down respect to the rate of the input data. Thus the higher correlation stages (200, 154-158) can be used in multiplex. The bit-flip rate in memories is very low, with an effective reduction of dynamic power consumption. The logic structure of the accumulator is also simplified by the invention, thus further savings in silicon space and power are possible.
    Type: Grant
    Filed: December 8, 2006
    Date of Patent: March 26, 2013
    Assignee: QUALCOMM Incorporated
    Inventor: Phil Young
  • Patent number: 8406353
    Abstract: Signal sequence detection techniques are provided to enable a wireless communication device to detect presence of a sequence, such as a preamble sequence, in the presence of other transmission that would otherwise interference with the ability of the device to detect the sequence. At the wireless communication device, energy in a frequency band is received and a receive signal is generated from the received energy. The receive signal is divided into windows of a predetermined time duration. A running auto-correlation of the receive signal is computed to produce an auto-correlation sequence for a sequence to be detected in the receive signal. Data representing a mask is generated for a window based on the receive signal. The mask is applied to the auto-correlation sequence to filter out portions of the auto-correlation sequence that are outside of the mask. A position of sequence, e.g.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: March 26, 2013
    Assignee: Cisco Technology, Inc.
    Inventors: Yanxin Na, Hang Jin
  • Patent number: 8401055
    Abstract: Apparatus for recovering symbols from control and data channels corresponding to a plurality of users is described. Samples corresponding to control channel signals from multiple users are processed on a time shared basis with various control channel processing elements being reused multiple times to processes the samples and recover signals, e.g., symbols, corresponding to the plurality of users. While the control channel processing elements are used on a time shared basis, a separate data channel processing chain or module maybe provided for each of the plurality of users. In some embodiments the order of despreading and filtering is reversed for the control and data channel signal processing.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: March 19, 2013
    Assignee: Spidercloud Wireless Inc.
    Inventors: Colin Campbell, Oliver Charlesworth, Peter Worters
  • Patent number: 8396097
    Abstract: In one exemplary embodiment of the invention, a device includes: a first frequency search engine configured to receive input values and determine a frequency of a signal to be within a first frequency band; a second delay component configured to store at least a portion of the plurality of input values; and a second frequency search engine configured to determine the frequency of the signal to be within a second band that is a subset of the first band. The first frequency search engine includes: a shift register configured to store bits of the input values; a combining circuit configured to combine bits of the plurality of input values; a first delay component configured to serially store a plurality of accumulator values; and a feedback circuit configured to add a function of the first delay component output to a next accumulator value to obtain a modified next accumulator value.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: March 12, 2013
    Assignee: L-3 Communications Corp
    Inventors: Thomas R. Giallorenzi, Johnny M. Harris, Matthew A. Lake, Samuel C. Kingston, Myren Iverson
  • Patent number: 8391334
    Abstract: Systems and methods for improving the reliability of a hub-spoke communications system use a first antenna and a second antenna at the hub terminal. Spread spectrum transmission from the hub terminal uses the first antenna, and the second antenna is enabled when blockage between the first antenna and any one of the spoke terminals is present. The first antenna and the second antenna have substantially orthogonal polarizations. The spread spectrum transmissions from the first antenna and second antenna have different pseudonoise code timing so that the received transmissions are offset by at least one chip interval from each other.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: March 5, 2013
    Assignee: L-3 Communications Corp
    Inventors: Vaughn L. Mower, Merle L. Keller, Roger Baker
  • Patent number: 8391340
    Abstract: A low-cost GPS/GNSS receiver receives a satellite signal at an RF frequency (fRF). The GPS/GNSS receiver includes a front end section for receiving the satellite signal and generating a digital complex signal having a first bandwidth, the received satellite signal being converted into a complex signal before digitizing, a signal capturing section for searching for and acquiring the satellite signal, the signal capturing section including a capture memory, a baseband processor for tracking the acquired satellite signal, and a signal splitter coupled to the front end section. The signal splitter splits the digital complex signal into two bandwidths, by generating a narrowband digital complex signal having a second bandwidth substantially smaller than the first bandwidth. The signal splitter provides the narrowband digital signal to the capture memory and the wider first bandwidth digital complex signal to the baseband processor.
    Type: Grant
    Filed: September 15, 2008
    Date of Patent: March 5, 2013
    Assignee: Magellan Systems Japan, Inc.
    Inventor: Lawrence R. Weill
  • Patent number: 8391336
    Abstract: To generate a pulse for ranging, a kernel is convolved with a spreading sequence. The spreading sequence is parametrized by one or more ordered (length, sparsity) pairs, such that the first sparsity differs from the bit length of the kernel and/or a subsequent sparsity differs from the product of the immediately preceding length and the immediately preceding sparsity. Alternatively, a kernel is convolved with an ordered plurality of spreading sequences, all but the first of which may be non-binary. The pulse is launched towards a target. The reflection from the target is transformed to a received reflection, compressed by deconvolution of the spreading sequence, and post-processed to provide a range to the target and/or a direction of arrival from the target.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: March 5, 2013
    Assignee: A.P.M. Automation Solutions Ltd
    Inventor: Alex Chiskis
  • Patent number: 8391337
    Abstract: Wireless communication receiver with hybrid equalizer and RAKE receiver. The receiver compares performance of the system for RAKE only and RAKE in combination with equalizer estimates. The receiver enables or disables the equalizer accordingly.
    Type: Grant
    Filed: March 22, 2009
    Date of Patent: March 5, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Peter J. Black, Michael A. Howard