Multi-receiver Or Interference Cancellation Patents (Class 375/148)
  • Publication number: 20140016679
    Abstract: An apparatus, system, and method, the method including receiving clock frequency parameter information for at least one clock source; receiving radio parameter information for at least one radio receiver; determining one or more spread spectrum clocking (SSC) profiles for the at least one clock source and the at least one radio receiver, each SSC profile to reduce radio frequency interference between the clock and radio receivers; and storing the SSC profiles.
    Type: Application
    Filed: December 30, 2011
    Publication date: January 16, 2014
    Inventors: William Dawson Kesling, Harry G. Skinner
  • Publication number: 20140016678
    Abstract: A communication device according to an embodiment of the present invention includes a communication antenna that receives a transmission signal where a spectrum spread signal subjected to a spectrum spread is modulated; an intermediate frequency converting unit that converts the transmission signal received by the communication antenna into an intermediate frequency signal having a predetermined frequency; an analog to digital converting unit that discretizes the intermediate frequency signal and outputs a discretization signal; a noise removing unit that detects a noise other than a normal thermal noise included in the discretization signal and removes the detected noise from the discretization signal; and a demodulating unit that demodulates the spectrum spread signal, based on the discretization signal that is output from the noise removing unit.
    Type: Application
    Filed: July 15, 2013
    Publication date: January 16, 2014
    Inventors: Katsuyuki TANAKA, Hideki Takahashi
  • Publication number: 20140016677
    Abstract: A method, an apparatus, and a computer program product for wireless communication are provided in connection with dynamic selection of a UE receiver. In one example, a communications device is equipped to obtain one or more channel impulse response (CIR) estimates, generate a delay spread metric value that characterizes a multipath delay spread of a channel based on the obtained one or more CIR estimates, and select a receiver option with a first power consumption value, for use by the UE, from a plurality receiver options with different optimal power consumption values, based on the generated delay spread metric value. In an aspect, a comparatively more complex receiver option may be selected when the channel is rich in multipath. In another aspect, a comparatively less complex receiver option may be selected when the channel exhibits flat fading.
    Type: Application
    Filed: March 12, 2013
    Publication date: January 16, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Aditya Dua, Lei Xiao
  • Publication number: 20140016680
    Abstract: A method and apparatus for multi-user detection is disclosed. A signal is received in a shared spectrum, and samples of the received signals are produced as a received vector. The received vector is segmented into vector segments. Each segment has a portion that overlaps with another segment and the overlapping portion includes at least one chip less than twice a channel impulse response length. For each vector segment, symbols are successively determined for communications by determining symbols for a communication in the communications, ordering the communications by received power and removing a contribution of the communication from the vector segment. The determining of symbols includes equalizing an input vector corresponding to a segment of the received vector using fast Fourier transform. The determined symbols are assembled into a data vector for each communication in the communications.
    Type: Application
    Filed: September 23, 2013
    Publication date: January 16, 2014
    Applicant: InterDigital Technology Corporation
    Inventor: Ariela Zeira
  • Patent number: 8630602
    Abstract: Techniques for generalized pilot interference cancellation in a communications receiver. In an exemplary embodiment, a residual pilot is cancelled from a post-traffic cancellation signal following initial first-pass pilot cancellation. Residual pilot cancellation is achieved by adding the first-pass cancelled pilot as earlier stored in memory back to the post-traffic cancellation signal, and pilot filtering the resulting signal to generate an improved pilot interference estimate. In an alternative exemplary embodiment, an arbitrary number of iterations may be applied to generate the pilot interference estimate by successively storing each generated pilot interference estimate in memory.
    Type: Grant
    Filed: June 15, 2009
    Date of Patent: January 14, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rashid Ahmed A. Attar, Yu-Cheun Jou, Peter J. Black, Jun Ma
  • Patent number: 8625656
    Abstract: Techniques for deriving channel estimates with different channel estimation filters are described. In one scheme, a filter selection metric is determined for a signal to be recovered, a channel estimation filter is selected based on the filter selection metric, and a channel estimate is derived with the selected channel estimation filter. In another scheme, a first channel estimate is derived with a first channel estimation filter having a first filter response, a first signal is recovered with the first channel estimate, and interference due to the first signal is estimated and removed. A second channel estimate is derived with a second channel estimation filter having a second filter response that is different from the first filter response.
    Type: Grant
    Filed: March 4, 2010
    Date of Patent: January 7, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Aleksandar Damnjanovic, Durga Prasad Malladi
  • Publication number: 20140003471
    Abstract: A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal.
    Type: Application
    Filed: June 3, 2013
    Publication date: January 2, 2014
    Inventors: GAGANDEEP SINGH LAMBA, TOMMY GUESS, MICHAEL MCCLOUD, ANAND P. NARAYAN
  • Publication number: 20140003470
    Abstract: In a user equipment, a unified receiver structure may be specified as both an equalizer and a multi-user detector. That is, the receiver may transfer between an equalizer and a multi-user detector within the same structure. A received signal may be estimated using the combined equalizer and multi-user detector unit.
    Type: Application
    Filed: October 31, 2012
    Publication date: January 2, 2014
    Inventor: Qiang Shen
  • Patent number: 8619836
    Abstract: Apparatus and method for providing correlation in a CDMA receiver. A Generic Correlation Coprocessor comprises one or more correlation blocks. Each correlation block comprises a correlation input buffer coupled to one or more correlators. The correlators are coupled to an interpolator input buffer and to a correlator output buffer. One or more interpolators are coupled to the interpolation input buffer and to the correlation output buffer. The correlators correlate the received signal with PN codes to produce a correlated signal. The correlated signal is stored in the correlator output buffer and/or the interpolation input buffer, and provided from the interpolation input buffer to the one or more interpolators. The one or more interpolators interpolate the correlated signal to produce an interpolated signal. The interpolated signal is stored in the correlator output buffer. Signals are provided from the correlator output buffer to other receiver processing systems.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: December 31, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Filip J. Moerman, Raphael Defosseux
  • Patent number: 8619920
    Abstract: A transmitter comprises a first spreading unit configured to multiply each of multiple data symbols with a first spreading code sequence of a first spreading factor; a compression and repetition unit configured to compress output signals of the first spreading unit in time domain and repeat the compressed signal L times (where L is a natural number greater than or equal to 2); a phase modulation unit configured to multiply the compressed and repeated signal with a user dependent phase and output a data block consisting of L sub-blocks; a second spreading unit configured to replicate the data block according to a second spreading factor and multiply each set of the replicated sub-blocks with a second spreading code sequence of the second spreading factor to produce a two-dimensionally spread signal; and a wireless transmission unit configured to transmit the two-dimensionally spread signal using a single-carrier transmission scheme.
    Type: Grant
    Filed: November 5, 2008
    Date of Patent: December 31, 2013
    Assignees: NTT DoCoMo, Inc., Agency for Science, Technology and Research
    Inventors: Hiroyuki Atarashi, Mamoru Sawahashi, Francois Po Shin Chin, Zhongding Lei, Xiaoming Peng, Ying-Chang Liang
  • Publication number: 20130343434
    Abstract: In an RF communication system, aspects for processing multipath clusters may comprise tracking a plurality of received clusters of signals and estimating a phase and amplitude of at least a portion of each of the plurality of received clusters of signals. Each of the plurality of received clusters of signals may be specified in time and an aggregate of received signal paths in a single cluster for a single base station may be processed. At least one cluster path processor may be assigned to process the plurality of received clusters of signals from each transmitting antenna at a single base station. At least one cluster path processor may be assigned to each of a plurality of base stations that are utilized for soft handoff.
    Type: Application
    Filed: March 21, 2013
    Publication date: December 26, 2013
    Applicant: Broadcom Corporation
    Inventor: Broadcom Corporation
  • Patent number: 8615030
    Abstract: Systems and methods for multi-user detection are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises a processing unit configured to process a plurality of received chips into a plurality of received symbols for a plurality of users. The apparatus further comprises a computation unit configured to compute a multi-user matrix relating a plurality of user symbols for the plurality of users to the plurality of received symbols and a detection unit configured to detect the plurality of user symbols for the plurality of users using the computed multi-user matrix and the plurality of received symbols.
    Type: Grant
    Filed: May 4, 2009
    Date of Patent: December 24, 2013
    Assignee: Qualcomm Incorporated
    Inventors: Farrokh Abrishamkar, Yingqun Yu, Michael McCloud, Divaydeep Sikri
  • Publication number: 20130336366
    Abstract: In an overlay, network-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect uplink radio signaling for use in TOA, TDOA and/or AoA positioning methods. In a UMTS, the dual nature of the uplink allows for identification of the correct uplink signal even in the presence of co-channel interference from other UMTS mobile devices.
    Type: Application
    Filed: June 19, 2012
    Publication date: December 19, 2013
    Applicant: TRUEPOSITION, INC.
    Inventor: Rashidus S. Mia
  • Patent number: 8611398
    Abstract: A MIMO receiver for processing N data streams received by N antennas for a direct-sequence spread-spectrum wireless communication system comprising a linear equalizer operating at the chip level for performing linear chip level Inter-Chip Interference and all Inter-Stream Interference cancellation of said N data streams, and generating N output chip level data streams; de-spreading blocks for separately de-spreading the N outputs of the linear equalizer; and a non linear detector for performing spatial equalization and multi-stream detection.
    Type: Grant
    Filed: September 16, 2010
    Date of Patent: December 17, 2013
    Assignees: St-Ericsson SA, St-Ericsson (France) SAS
    Inventors: Andrea Ancora, Fabrizio Tomatis
  • Patent number: 8611311
    Abstract: Methods and systems for estimating and canceling pilot interference in a wireless (e.g., CDMA) communication system. In one method, a received signal comprised of a number of signal instances, each including a pilot, is initially processed to provide data samples. Each signal instance's pilot interference may be estimated by despreading the data samples with a spreading sequence for the signal instance, channelizing the despread data to provide pilot symbols, filtering the pilot symbols to estimate the channel response of the signal instance, and multiplying the estimated channel response with the spreading sequence. The pilot interference estimates due to a plurality of interfering multipaths are accumulated to derive the total pilot interference, which is subtracted from the data samples to provide pilot-canceled data samples. These samples are then processed to derive demodulated data for each of at least one (desired) signal instance in the received signal.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: December 17, 2013
    Assignee: Qualcomm Incorporated
    Inventors: Alessandro Vanelli Coralli, Henry David Pfister, Jilei Hou, John Edward Smee, Roberto Padovani, Brian K Butler, Jeffrey A Levin, Thomas B Wilborn, Paul E Bender
  • Patent number: 8605844
    Abstract: A signal receiver is configured for receiving signals from multiple antennas, wherein the signal from one of the antennas is phase compensated relative to the signal from another of the antennas. The receiver comprises (i) an equalizer configured to equalize signals received from the antennas in accordance with a determined equalization vector and (ii) a processor for determining the equalization vector. The processor is configured to determine the equalization vector in dependence on (i) a first channel estimate for a first channel from one of the antennas to the receiver and (ii) a phase-adjusted version of a second channel estimate for a second channel from another of the antennas to the receiver.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: December 10, 2013
    Assignee: Cambridge Silicon Radio Limited
    Inventors: Andrew Papageorgiou, Jason Woodard
  • Patent number: 8605837
    Abstract: A method and apparatus to align data blocks in a data signal and a reference signal to increase cross-correlation between the data signal and the reference signal as compared to the unaligned data and reference signals and cancel interference in the data signal in the frequency-domain under changing conditions and in the presence of the data signal.
    Type: Grant
    Filed: October 10, 2008
    Date of Patent: December 10, 2013
    Assignee: Broadcom Corporation
    Inventors: Brian R. Wiese, Philip Desjardins, Jayasuryan Iyer
  • Patent number: 8605842
    Abstract: A method for noise rise estimation in a wireless communication system comprises measuring (210) of received total wideband power a plurality of times and computing (212) of an estimate of a noise floor measure based on at least a number of the measured received total wideband powers. The method further comprises performing (214) of an interference whitening based on one of GRAKE, GRAKE+ and chip equalizer for a first user and determining (216) of a user equivalent total wideband power as an available total wideband power after the interference whitening for the first user. The estimate of a noise floor measure is compensated (218) for the interference whitening into a user equivalent noise floor measure and a noise rise measure for the first user is calculated (220) based at least on the user equivalent total wideband power and the user equivalent noise floor measure.
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: December 10, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Karl Torbjörn Wigren
  • Patent number: 8605829
    Abstract: Teachings presented herein offer improved symbol block detection by including a decoder unit in a demodulation system. Utilizing a decoder unit in a demodulation system can significantly enhance symbol block detection because the decoder can produce bit likelihood values (soft bit values), and these bit likelihood values can be used to construct a set of candidate symbol values. Advantageously, this set of candidate symbol values is more likely to contain the actually transmitted symbol(s) than if the decoder unit was not used in the demodulation system.
    Type: Grant
    Filed: March 23, 2010
    Date of Patent: December 10, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Stephen Grant, Gregory E. Bottomley
  • Patent number: 8605771
    Abstract: A CDMA receiver computes an accurate estimate of the data to pilot power ratio. First, a biased estimate of the data to pilot power ratio is obtained from the data channel. A multiplicative correction factor is then computed from the pilot channel, and applied to the biased data to pilot power ratio estimate.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: December 10, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Douglas A. Cairns
  • Patent number: 8599972
    Abstract: A method and apparatus removes bias from an initial signal-to-interference ratio (SIR). In an exemplary embodiment, an initial SIR calculator in an SIR processor calculates the initial SIR based on the signal received by the wireless receiver, while an average SIR calculator in the SIR processor generates an average SIR. Using the average SIR, a bias remover removes the bias from the initial SIR.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: December 3, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Gregory Edward Bottomley, Carmela Cozzo
  • Patent number: 8599904
    Abstract: A receiver architecture for processing spread spectrum signals. The receiver has an RF front end to receive and down convert a broadcast signal to an intermediate frequency carrier. The IF signal is digitized and provided to a processor (which may be a software-driven DSP, an ASIC or other embodiment) for processing. A given IF carrier is removed and the signal is low pass filtered. The signal is provided to a number of channels, each, for example, correspond to a unique transmitter. On each channel the sample rate is reduced to a predetermined fixed rate with timing mismatch compensated. The Doppler frequency shift, as estimated for the channel, is removed succeedingly. A locally generated copy of the spreading code used by the transmitter is applied to the carrier and Doppler removed signal at the predetermined fixed sample rate. The de-spread signal is used to provide estimates of the Doppler shift and for subsequent sample selection.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: December 3, 2013
    Assignee: Analog Devices, Inc.
    Inventors: Wei An, Yosef Stein
  • Patent number: 8599905
    Abstract: A path searcher for use in a spread spectrum receiver, including a correlator for correlating a received signal in different time positions with a reference code to select for further processing time positions of the signals showing the strongest correlations, wherein the correlator is operable to obtain a correlation energy result for each time position in a set of possible time positions, a comparator for comparing the correlation energy results with each of a plurality of energy thresholds and a recorder for recording data indicating time positions for correlation energy results which are not less than the respective thresholds in different groups corresponding to the respective thresholds. Also described is a semiconductor device and a receiver incorporating the path searcher and a method of operation of the path searcher.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: December 3, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Dmitry Lachover, Amir Chass, Gideon Kutz
  • Patent number: 8601338
    Abstract: Modified error distance decoding. In certain communication systems, multiple signals (e.g., which may be viewed as being codewords, groups/sets of bits or symbols, etc.) can be commonly affected by such deleterious phenomenon as burst noise when traversing a communication channel (e.g., from a transmitter communication device to a receiver communication device). In such instances, a test error pattern may be identified which covers those affected bits (or symbols) among at least two respective signals (e.g., all of the respective signals or any subset thereof). Various respective test error patterns may be employed, each having a different respective weight, to the desired group of signals (e.g., codewords, groups/sets of bits or symbols, etc.). As such, more than one possible estimate of each respective signal may be generated. A variety of selection operations may be employed when more than one possible estimate exists (e.g., random selection, that estimate with minimum distance, etc.).
    Type: Grant
    Filed: November 26, 2010
    Date of Patent: December 3, 2013
    Assignee: Broadcom Corporation
    Inventor: Thomas J. Kolze
  • Patent number: 8599978
    Abstract: An interference elimination method provided herein includes: the ith transmitter of a group transmitters obtains an interference vector of each user, where: the interference vector of the kth user is Hkiwim; obtains at least L?N linear combinations for each user, wherein: the linear combination includes linear combinations of aligned interference vectors and linear combinations of N?Lk interference vectors, N is the number of receiving antennas of the user, and L is a sum of the signal flows of all users; the pre-coding vectors of all transmitters is obtained according to the linear combinations of all users; and the signals pre-coded using the pre-coding vectors are sent. Accordingly, a data transmitting apparatus is provided herein.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: December 3, 2013
    Assignee: Huawei Technologies Co., Ltd.
    Inventor: Sheng Liu
  • Patent number: 8594151
    Abstract: A user equipment and corresponding method detect a frequency division permanent common pilot and include a controller configured to use a sliding correlator with a frequency division phase-shift, an averaging unit configured to average a peak magnitude output of the sliding correlator over a predetermined number of sub-frames for each of possible reference pilot sequence and each sample shift of the sliding correlator, and a maximum peak storing unit configured to store first and second maximum peaks depending on corresponding ratios and a threshold. The user equipment and method thereof also include a pilot sequence index candidate storing unit configured to store a pilot sequence index candidate for each shift of the sliding correlator. The user equipment and method thereof include a selector configured to select the pilot sequence index candidate with a lowest peak ratio to shift the sliding correlator.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: November 26, 2013
    Assignee: Nokia Corporation
    Inventors: Gilles Charbit, Ãœlo Parts, Kaj Jansen
  • Patent number: 8594157
    Abstract: A method for removing selected signals from a received signal prior to decoding begins by receiving communication signals from a transmitter over a CDMA air interface. The received communication signals are input to a traffic signal cancellation system for canceling unwanted traffic signals, thereby producing an output (O). The received communication signals are input to a pilot signal cancellation system for removing a global pilot signal, thereby producing an output (Oadd). The output (Oadd) of the pilot signal cancellation system is subtracted from the output (O) of the traffic signal cancellation system to provide a cancellation system output.
    Type: Grant
    Filed: January 22, 2013
    Date of Patent: November 26, 2013
    Assignee: InterDigital Technology Corporation
    Inventors: Fatih M. Ozluturk, Nadir Sezgin
  • Patent number: 8593976
    Abstract: It is an object to provide a wireless base station and a terminal equipment capable of shortening the processing time by not requiring the detection of the spatial correlation coefficient, which is required in general technology, and simplifying the selection process for terminal equipments to be connected to each other in a wireless base station that performs spatial multiplexing transmission to a plurality of terminal equipments and a terminal equipment responding for spatial multiplexing transmission. A terminal equipment 12 includes an interference cancellation capability information data maintaining section 20 that maintains interference cancellation capability information data indicating the interference cancellation capability of the terminal equipment 12 and signals the interference cancellation capability information data to a wireless base station 1.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: November 26, 2013
    Assignee: Panasonic Corporation
    Inventors: Takaaki Kishigami, Shutai Okamura, Hidekuni Yomo, Yoshihito Kawai
  • Patent number: 8594156
    Abstract: A multi-carrier spread spectrum device using cyclic shift orthogonal keying includes: a modulation unit for receiving a first part of data bits and transforming the first part of data bits to a modulation symbol di by modulation; a cyclic-shift unit for receiving a base code c(0) and a second part of data bits, and performing a cyclic-shift to the base code c(0) in accordance with the second part of data bits to generate a CSOK symbol c(mi); and a multiplier for multiplying the modulation symbol di by the CSOK symbol c(mi) to generate a spread spectrum signal ci.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: November 26, 2013
    Assignee: Yuan Ze University
    Inventors: Jeng-Kuang Hwang, Yu-Lun Chiu
  • Patent number: 8588325
    Abstract: A communication system capable of achieving a high usage efficiency of frequencies without the need for cooperation of multiplexed users is disclosed. The communication system communicates over frequency channels set by dividing a frequency bandwidth assigned to the system and allows interference between channels by overlapping the adjacent frequency channels with each other in the frequency domain. A transmitting and receiving device, which transmits and receives a signal by allowing the interference between symbols at a waveform level for each channel to decrease the occupied bandwidth, is provided. The receiving device is provided with an Inter-Channel Interference (ICI) removal and Inter-Symbol Interference (ISI) compensation filter serving as either an ICI removal filter for removing the interference between channels or an ISI compensation filter for compensating the interference between symbols.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: November 19, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Anass Benjebbour, Takahiro Asai, Hitoshi Yoshino, Tatsuo Furuno, Tomoyuki Ooya
  • Publication number: 20130301686
    Abstract: A CDMA multi-code joint demodulation solution in which impairment suppression and channel matching operations are performed prior to despreading. Embodiments include a linear front end that performs chip-level suppression of signal components that are not included in a subsequent joint demodulation process. The pre-processing stage also carries out metric preparation and provides a vector decision statistic that is processed by a joint demodulation stage to extract per-code soft values for the symbols of interest in the received signal. Both code-specific and code-averaged versions of the linear processing are disclosed, as are several front-end configurations with equivalent performance, but different complexity trade-offs. These new approaches use a block formulation, requiring a set of input chip samples as an input, and perform all operations as matrix-vector multiplications, which is an approach amenable to efficient DSP or hardware implementation.
    Type: Application
    Filed: May 10, 2012
    Publication date: November 14, 2013
    Inventors: Andres Reial, Stephen Grant, Michael Samuel Bebawy, Yi-Pin Eric Wang
  • Publication number: 20130301687
    Abstract: Techniques are disclosed for processing a received spread spectrum signal containing multiple signals of interest and one or more interfering signals with known spreading codes. An example method begins with the generation of a despread signal vector for each signal of interest, for a given symbol time, using a corresponding group of correlators for each of the signals of interest. The method continues with the calculating of a covariance matrix for the given symbol time, the covariance matrix representing impairment correlations among the correlators from sources other than the signals of interest, as well as from inter-symbol interference in and among the signals of interest. The covariance matrix includes diagonal blocks that each represent impairment correlations among a single one of the groups of correlators; the diagonal blocks are calculated based on first terms that account in a code-specific manner for same-symbol-time interference from each of the interfering signals.
    Type: Application
    Filed: May 10, 2012
    Publication date: November 14, 2013
    Inventors: Stephen Grant, Michael Samuel Bebawy
  • Patent number: 8582691
    Abstract: A receiving apparatus for receiving a downlink signal in which pilot symbols are mapped discontinuously, includes: a unit configured to extract reference signals from the downlink signal that is Fourier transformed by a Fourier transform unit; a unit configured to generate a first signal having a first window size by arranging the extracted reference signals on the frequency axis and by performing inverse Fourier transform on the reference signals; a unit configured to divide the first signal into a plurality of signals to extract a signal included in a second window; a unit configured to generate a second signal that includes the signal included in the second window and that has a window size similar to the first window size; a Fourier transform unit configured to generate a third signal from the second signal; and a unit configured to calculate received power based on the third signal.
    Type: Grant
    Filed: September 4, 2009
    Date of Patent: November 12, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Mototsugu Suzuki, Tetsurou Imai, Koushirou Kitao, Yoshihiro Ishikawa
  • Patent number: 8582710
    Abstract: Embodiments allow for the use of the SS modulation technique (and thus for significant reduction of EMI due to clock transmission) in scenarios involving tight synchronization requirements between two devices. In particular, embodiments can be used in high-speed communication networks (e.g., high-speed Ethernet) where a clock signal embedded in the data stream at the transmitter and recovered from the data stream at the receiver is the only source for synchronization between the transmitter and the receiver (i.e., no other synchronization channel available). Embodiments are also especially useful in communication systems utilizing echo cancellers.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: November 12, 2013
    Assignee: Broadcom Corporation
    Inventors: Neven Pischl, Joseph Cordaro, Yongbum Kim
  • Patent number: 8582623
    Abstract: Searcher hardware is multiplexed to perform simultaneous searches in either an IS-95 CDMA mode or a GPS mode. In the IS-95 mode, the search hardware is time-multiplexed into a number of searcher time slices, each of which can generate a PN sequence to despread a data sequence. In the GPS mode, the search hardware is configured as a number of distinct GPS channels, each of which can generate a Gold code sequence for tracking a GPS signal from a particular GPS satellite. This configuration allows the searcher to perform multiple GPS signal searches simultaneously. Signal searching in both IS-95 and GPS modes is performed at significantly higher speeds compared to conventional searcher hardware. Moreover, the search hardware can be dynamically configured to operate in either the IS-95 or the GPS mode, eliminating the need for dedicated circuitry for each mode of operation.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: November 12, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Wang Paul Poon, Qiuzhen Zou
  • Patent number: 8582626
    Abstract: A method for receiving Acknowledgement/Negative acknowledgement (ACK/NACK) information in a mobile communication system includes receiving a first signal including first spread ACK/NACK information and second spread ACK/NACK information from a first antenna set of a transmitting end in an orthogonal frequency division multiplexing (OFDM) symbol; receiving a second signal including third spread ACK/NACK information and fourth spread ACK/NACK information from a second antenna set of the transmitting end in an OFDM symbol; and de-spreading at least the first and third spread ACK/NACK information or the second and fourth spread ACK/NACK information for identifying the ACK/NACK information.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: November 12, 2013
    Assignee: LG Electronics Inc.
    Inventors: Jung Hoon Lee, Ki Jun Kim, Dong Wook Roh, Daewon Lee, Joon Kui Ahn
  • Patent number: 8582624
    Abstract: A set of channelization codes to be monitored is divided into two groups. The first group includes those codes for which an associated symbol modulation and transmit-diversity scheme is known. In the second group are those codes that are characterized by an unknown symbol modulation or unknown transmit-diversity scheme. The quality of the transmission of each code is then evaluated, using a metric. The metric in turn is used to determine whether the code should be used in estimating the covariance matrix by correlating the RAKE data corresponding to the code (i.e., by computing a correlation matrix for the code) or by first subtracting the channel estimates from the channel samples before correlation (i.e., by computing a covariance matrix for the code). An impairment covariance matrix is computed from the covariance matrices and correlation matrices so computed.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: November 12, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (Publ)
    Inventors: Elias Jonsson, Yoshitaka Murata, Jaroslaw Niewczas, Amit Singh, Kazuyoshi Uesaka
  • Patent number: 8582625
    Abstract: A method for receiving at least one of a plurality of channels in a communication signal includes receiving a spread spectrum communication signal, demodulating the spread spectrum communication signal using a rake receiver and a pseudo-noise pilot signal for a selected channel, despreading the demodulated signal of a selected channel, performing a QPSK hard decision in association with a complex conjugate of the despread signal to produce a correction signal, and mixing the correction signal to a rake receiver output to remove relative phase error without an absolute phase reference, to produce a corrected signal.
    Type: Grant
    Filed: August 24, 2012
    Date of Patent: November 12, 2013
    Assignee: Interdigital Technology Corporation
    Inventors: Fatih M. Ozluturk, David K. Mesecher, Alexander M. Jacques
  • Patent number: 8576962
    Abstract: A method of and system for determining cross-polarization isolation is described. In one embodiment, a modulated signal is obtained from a communication link. The modulated signal includes a modulated co-polarized signal component and a modulated cross-polarized signal component. Cross-polarization isolation is determined using the modulated co-polarized signal component and the modulated cross-polarized signal component. The determined cross-polarization isolation can be used to adjust an antenna.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: November 5, 2013
    Assignee: Glowlink Communications Technology, Inc.
    Inventors: Michael L. Downey, Jeffrey C. Chu
  • Publication number: 20130287066
    Abstract: A receiver circuit provides improved noise estimation processing by at least partially removing receiver frequency error bias. An initial noise estimate is compensated using an error term based on the observed receiver frequency error, and the resulting compensated noise estimate can be used to improve other signal processing in the receiver. For example, the receiver may use compensated noise estimates to generate signal quality estimates, e.g., Signal-to-Interference (SIR) estimates, having improved accuracy. Additionally, or alternatively, the receiver may use the compensated noise estimates to generate RAKE combining weights having improved noise suppression characteristics. In an exemplary embodiment, the initial noise estimate is a noise correlation matrix generated from a received reference signal, e.g., pilot symbols, and the error term is an error matrix directly generated using the observed receiver frequency error and channel estimates taken from the reference signal.
    Type: Application
    Filed: June 26, 2013
    Publication date: October 31, 2013
    Inventor: Anders Wallén
  • Patent number: 8571088
    Abstract: The subject matter disclosed herein relates to suppressing the effects of multipath signals. For an example, a signal comprising at least one binary offset carrier (BOC) modulation signal is received. The BOC modulation signal is modulated with a pseudorandom noise sequence comprising a plurality of chips, wherein each of the chips has a set interval. The received signal is correlated with portions of the plurality of chips to provide a power signal and to remove at least a portion of a multipath component in the received signal from the power signal. The portions of the chips are less than the set interval.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: October 29, 2013
    Assignee: QUALCOMM Incorporated
    Inventor: Rayman Pon
  • Patent number: 8571090
    Abstract: In one embodiment, a method for demodulating and searching for a preamble signal containing a complex phasor signal is disclosed. The complex phasor is demodulated using a phasor-rotated fast transformer. A received signal is correlated with a spreading code to produce a correlated signal. The correlated signal is coherently accumulated to produce a coherently accumulated signal. A first phasor-rotated signal transformation is performed on a real component of the coherently accumulated signal, and a second phasor-rotated signal transformation is performed on an imaginary component of the coherently accumulated signal. Finally, the signal power of the transformed real and imaginary components of the coherently accumulated signal is determined.
    Type: Grant
    Filed: June 12, 2012
    Date of Patent: October 29, 2013
    Assignee: Agere Systems LLC
    Inventors: Eliahou Arviv, Daniel Briker, Gennady Zilberman
  • Patent number: 8571153
    Abstract: A method and apparatus for mitigating interference in a satellite signal receiver is described. The satellite signal receiver receives satellite signals from a plurality of satellites. In one example, a control signal is transmitted to the satellite signal receiver upon occurrence of data transmission from a wireless transceiver operating in proximity to the satellite signal receiver. Signal integration within the satellite signal receiver is gated in response to the control signal. In another example, one or more values of satellite signal samples are selected from a plurality of possible values. Signal integration within the satellite signal receiver is gated in response to a percentage of satellite signal samples taken over a predefined period exceeding a predefined threshold. In yet another example, a gain setting of an automatic gain control circuit within the satellite signal receiver is adjusted in response to detection of interference.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: October 29, 2013
    Assignee: Global Locate, Inc.
    Inventor: Charles Abraham
  • 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: 20130279547
    Abstract: Techniques are disclosed for determining which channelization codes are used for an interfering HS-PDSCH transmission without knowing whether a neighboring UE targeted by that transmission has had its 64QAM capability activated by higher layer signaling. The average amplitude is measured for each of several possible groups of channelization codes for each of one or more nearby UEs that might be the targets of interfering HS-PDSCH messages. Testing whether the amplitude is approximately the same across the codes in a possible combination of channelization codes yields a metric value that indicates whether that particular combination of codes is likely to be transmitted to a given UE. A second metric that detects the most likely modulation for possible groups of channelization codes is also calculated. The metrics are combined to determine which combination of channelization codes and modulation scheme is most likely being used for addressing the neighboring UE.
    Type: Application
    Filed: April 20, 2012
    Publication date: October 24, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON
    Inventors: Elias Jonsson, Kazuyoshi Uesaka
  • Publication number: 20130279546
    Abstract: A transmitter transmits an outbound message signal via the power distribution system. The transmitter includes a spreader for spreading the spectrum of the communications signal before transmitting the outbound message signal. A receiver despreads the spectrum of the received digitized signal and digitally demodulates the received despread signal to generate the message. The transmitted signal is orthogonal to a source of interference on the power distribution system.
    Type: Application
    Filed: November 30, 2011
    Publication date: October 24, 2013
    Applicant: ACLARA POWER-LINE SYSTEMS INC.
    Inventor: David W. Rieken
  • Patent number: 8565706
    Abstract: A RAKE receiver is adapted to receive input from at least a first and a second antenna (104a, 104b). The RAKE receiver comprises a despreading unit (303) adapted to allocate a number (Nf) of despreading fingers to a number of delay positions of a signal which is transmitted over a channel. The RAKE receiver further comprises a delay position selection unit (305) which estimates an antenna correlation (formula 1) between the at least first and second antenna (104a, 104b) and controls the despreading unit (303) according to a first strategy for allocating the number (Nf) of fingers if the antenna correlation (formula 1) is below a predetermined threshold, and according to a second strategy otherwise. The threshold (formula 2) is selected based on at least one of the following: number of available finger in the RAKE receiver (Nf), dispersion of the channel, range of direction of arrivals (??).
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: October 22, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Andres Reial
  • Patent number: 8565287
    Abstract: A wireless system may receive a plurality of multipath signals from a plurality of transmitters and allocate per-cell modules for generating an interference suppressed signal from the multipath signals. Data symbols may be sequentially processed in the received multipath signals utilizing the per-cell modules and subtracting the processed symbols from a residual buffer storing the received multipath signals. Desired information received from one or more of the transmitters may be recovered utilizing the interference suppressed signal. Timing of the data symbols may be correlated utilizing a cell chip combiner. The data symbols may be descrambled utilizing conjugated scrambling codes associated with one of the plurality of transmitters. Orthogonal variable spreading factor (OVSF) codes may be generated utilizing a Walsh transform on the data symbols. Power levels of the OVSF codes may be estimated and estimated signals may be generated based on the OVSF codes and the estimated power levels.
    Type: Grant
    Filed: October 8, 2009
    Date of Patent: October 22, 2013
    Assignee: Broadcom Corporation
    Inventors: Mark Hahm, Wei Luo, Bin Liu, Jun Wu, Severine Catreux-Erceg, Shuangquan Wang
  • Publication number: 20130272343
    Abstract: Methods and apparatuses for channel estimation are disclosed. The method includes: converting ?1's in a local Barker code to 0's; receiving a first preamble symbol output from a first Barker correlator and a second preamble symbol output from a second Barker correlator with a symbol determination module, the first preamble symbol being adjacent to the second preamble symbol; multiplying a result output from the symbol determination module with a correlation result output from the cyclic Barker correlator by using a multiplication module so as to obtain a channel estimation response; and receiving channel estimation responses with a time-domain channel data storage unit, and averaging them to obtain a noise-reduced channel estimation response. The channel estimation method and apparatus of the present invention can be achieved based on few hardware resources and low computation complexity.
    Type: Application
    Filed: August 28, 2012
    Publication date: October 17, 2013
    Inventor: Yun Zhang
  • Publication number: 20130266043
    Abstract: A method of detecting a transmission. The method comprises: measuring, from a first portion of a received spread-spectrum signal, a first code-phase of a spreading-code; measuring, from a second portion of the signal, a second code-phase of the spreading-code; comparing the first and second code-phases; and detecting whether the transmission is present according to the result of the comparison. Also disclosed are corresponding methods and apparatus for transmission and reception of signals.
    Type: Application
    Filed: December 21, 2011
    Publication date: October 10, 2013
    Applicant: enModus Limited
    Inventor: Philip Young