Fourier Transform Patents (Class 370/210)
  • Patent number: 8831117
    Abstract: Method and apparatus for signal processing to minimize the peak to average power ratio of an Orthogonal Frequency Division Multiplexing (“OFDM”) or Orthogonal Frequency Division Multiple Access (“OFDMA”) signal with bounded error vector magnitude for an integrated circuit are described. An Active Constellation Extension (“ACE”) iteration, using a constellation points adjustment module, is performed. Symbols outside of a bounded region after the ACE iteration are identified. The bounded region is determined responsive to an error vector magnitude target. The symbols identified are translated to the bounded region.
    Type: Grant
    Filed: April 27, 2009
    Date of Patent: September 9, 2014
    Assignee: Xilinx, Inc.
    Inventors: Raghavendar M. Rao, Christopher H. Dick
  • Patent number: 8831124
    Abstract: A transmitter may comprise a symbol mapper circuit and operate in at least two modes. In a first mode, the number of symbols output by the mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter may be greater than the number of data-carrying subcarriers used to transmit the OFDM symbol. In a second mode, the number of symbols output by said mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter is less than or equal to the number of data-carrying subcarriers used to transmit said OFDM symbol. The symbols output by the symbol mapper circuit may be N-QAM symbols. While the circuitry operates in the first mode, the symbols output by the mapper may be converted to physical subcarrier values via filtering and decimation prior to being input to an IFFT circuit.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: September 9, 2014
    Assignee: MagnaCom Ltd.
    Inventors: Amir Eliaz, Ilan Reuven
  • Patent number: 8831122
    Abstract: Methods of transmitting a plurality of communications signals over a plurality of discontiguous bandwidth segments in a frequency band include defining a plurality (NFFT) of orthogonal subcarriers across the frequency band, defining a plurality (N) of available physical subcarriers from among the orthogonal subcarriers. The available physical subcarriers are distributed among, the plurality of discontiguous bandwidth segments. The methods further include spreading the data symbols for each user and combining the spread data symbols to provide composite data signals. The composite data signals are converted to parallel input signals and interleaved. The interleaved signals are assigned to the N available physical subcarriers. Related transmitters, receivers and communications systems are also disclosed.
    Type: Grant
    Filed: June 24, 2013
    Date of Patent: September 9, 2014
    Assignee: ATC Technologies, LLC
    Inventor: Dunmin Zheng
  • Patent number: 8830931
    Abstract: The present invention relates to a method in which a user equipment transmits a plurality of sounding reference signals to a base station in a wireless communication system. More particularly, the method comprises the steps of: generating a plurality of sounding reference signals on the basis of repetition factors (RPFs) corresponding to the number of transmitting antennas; multiplexing the plurality of sounding reference signals to a frequency domain in the same OFDM symbol or SC-FDMA symbol on the basis of a transmitting antenna index; and transmitting the multiplexed sounding reference signals to the base station using a plurality of transmitting antennas.
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: September 9, 2014
    Assignee: LG Electronics Inc.
    Inventors: Jae Hoon Chung, Yeong Hyeon Kwon, Min Seok Noh, Moon Il Lee
  • Patent number: 8824271
    Abstract: The present invention relates to an orthogonal frequency-division multiplexing receiver, and more particular to an orthogonal frequency-division multiplexing receiver including an FFT/IFFT operating core and a scheduler. In order to simultaneously share the FFT/IFFT operating core, the scheduler manages input/output timings of FFT/IFFT operations and control signals. The FFT/IFFT operating core supports decimation-in-time (DIT) and decimation-in-frequency (DIF) FFT/IFFT operations at the same time.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: September 2, 2014
    Assignee: FCI Inc.
    Inventors: Young-Il Chun, Chang-Ik Hwang, Jae-Jun Ban
  • Patent number: 8824269
    Abstract: Aspects of a method and system for a reference signal (RS) timing loop for OFDM symbol synchronization and tracking may include tracking symbol timing in an Orthogonal Frequency Division Multiplexing (OFDM) signal based on at least a reference symbol set. A receiver timing may be adjusted based on at least the symbol timing. The symbol timing may be tracked by generating an output signal as a function of a guard time ?tg in a phase discrimination feedback loop. The reference symbol (RS) set may be generated in an RS extraction module or circuit, from at least a fast Fourier transform of the received OFDM signal. The receiver timing may be coarsely adjusted and then finely adjusted. The coarse receiver timing adjustment may be based on processing at least a primary synchronization signal and a secondary synchronization signal.
    Type: Grant
    Filed: June 18, 2013
    Date of Patent: September 2, 2014
    Assignee: Broadcom Corporation
    Inventor: Mark Kent
  • Patent number: 8824267
    Abstract: A transmission method and apparatus that combines the benefits of DFT precoding and transmit diversity coding for PUCCH transmission. In one aspect, the invention provides an improved transmit diversity coding method and apparatus for DFTS-OFDM PUCCH with minimal impact on multiplexing capacity. In one embodiment, the improved transmit diversity method and apparatus has the feature of employing frequency-domain separation for the payload signals.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: September 2, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Jung-Fu Cheng, Robert Baldemair, Dirk Gerstenberger, Daniel Larsson
  • Patent number: 8824272
    Abstract: An improved method for resolving interference between co-channel users is disclosed. A peak in a spectrum generated by a MUSIC algorithm is determined for a signal of interest (“SOI”) using a noise subspace. Also, an estimated carrier frequency offset (“CFO”) is determined for the SOI based on the determined peak in the spectrum.
    Type: Grant
    Filed: October 9, 2012
    Date of Patent: September 2, 2014
    Assignee: The Aerospace Corporation
    Inventor: Seema Sud
  • Patent number: 8824580
    Abstract: Methods and systems are disclosed for transmitting data over a desired frequency tone in the presence of an interference that has an unknown magnitude that is substantially constant. In general, data symbols are transmitted in a null space of the desired frequency tone. The null space of the desired frequency tone is orthogonal to the desired frequency tone. As such, the data symbols transmitted in the null space of the desired frequency tone are not interfered with by the interference at the desired frequency tone regardless of the magnitude of the interference. The data symbols transmitted in the null space of the desired frequency tone can then be recovered by a receiver without estimation of or compensation for the interference at the desired frequency tone.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: September 2, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Dennis Hui
  • Patent number: 8817692
    Abstract: A method and apparatus for allocating backhaul resources to a relay in a wireless communication system, particularly a method and apparatus for processing a downlink signal at a relay in a wireless communication system are discussed. The method in one embodiment includes receiving resource allocation information indicating a resource block set from a Base Station (BS) through higher layer signaling, receiving a downlink subframe, starting from a predetermined Orthogonal Frequency Division Multiplexing (OFDM) symbol, from the BS, monitoring the resource block set in the downlink subframe to receive a physical control channel, and performing an operation according to the received physical control channel.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: August 26, 2014
    Assignee: LG Electronics Inc.
    Inventors: Hak Seong Kim, Han Byul Seo, Ki Jun Kim, Dong Youn Seo
  • Patent number: 8817898
    Abstract: A method and apparatus for filtering a received Orthogonal Frequency Division Multiplexed (ODFM) signal to reduce noise. The ODFM signal includes a plurality of symbols n in the time direction, each symbol including a plurality of sub-carriers k in the frequency direction, each a-th sub-carrier of each symbol being transmitted as a pilot sub-carrier with known amplitude and phase, and each symbol having its pilot sub-carriers spaced by b sub-carriers relative to the adjacent symbol. An m-tap filter is utilized for producing a filtered version of a selected pilot sub-carrier to be used in subsequent interpolation, by inputting into respective taps of the m-tap filter, m pilot sub-carriers surrounding the selected pilot sub-carrier. The m pilot sub-carriers each satisfy a relationship between n and k, wherein the relationship defines a diagonal line in the n-k plane.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: August 26, 2014
    Assignee: Imagination Technologies, Limited
    Inventors: Adrian John Anderson, Paul Damon Murrin
  • Patent number: 8817900
    Abstract: A system and method are provided for frequency domain peak power reduction on a plurality of orthogonal frequency divisional multiplexing (OFDM) signals in a communications system, wherein frequency domain processing of at least one OFDM signal carrier is iteratively performed to reduce peak power transmissions. OFDM signal carriers can include both in-band sub-carrier signals, and guard-band sub-carrier signals. Each iteration of peak power reduction takes as an input the frequency domain representation of the signal from the previous iteration that has been altered with respect to an error signal also represented in the frequency domain, determines an error signal (in the frequency domain), and subtracts this from the input to produce a further peak power reduced frequency domain signal. If there are no peaks above the configured peak power reduction threshold, then the signal passes through the FPPR iterations with no change.
    Type: Grant
    Filed: April 10, 2012
    Date of Patent: August 26, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Neil McGowan, Marthinus Willem Da Silveira
  • Patent number: 8817906
    Abstract: A modulator 11 modulates an input signal in a predetermined modulation manner to generate a primary modulation signal. The serial-parallel converter 12 applies a serial-parallel conversion to a predetermined number of complex numbers and the primary modulation signal, and assigns the converted complex numbers and primary modulation signal to subcarriers to generate a subcarrier modulation signal. An IFFT calculator 13 applies an IFFT to the subcarrier modulation signal. A decomposer 14 decomposes a calculation result into real-part data and imaginary-part data. A real-part calculator 151 subtracts the average value of the maximum value and minimum value of elements of the real-part data from each element of the real-part data. An imaginary-part calculator 152 carries out a similar calculation on the imaginary-part data. A combiner 16 combines the calculated real-part data and imaginary-part data to generate a baseband signal. A transmitter 17 transmits a transmission signal generated from the baseband signal.
    Type: Grant
    Filed: May 14, 2013
    Date of Patent: August 26, 2014
    Assignee: Icom Incorporated
    Inventor: Nobuyoshi Nishikawa
  • Patent number: 8811503
    Abstract: A method and system for generating a space frequency block code relay signal includes a signal detection unit which detects a received signal by receiving a first and second source signals transmitted from a first and second source nodes, a relay signal generation unit which generates a relay signal cooperating with the first and second source signals using a space frequency block code (SFBC) scheme based on the received signal, and a signal transmitter which transmits the relay signal to a destination node.
    Type: Grant
    Filed: February 18, 2008
    Date of Patent: August 19, 2014
    Assignees: Samsung Electronics Co., Ltd., Postech Academy-Industry Foundation
    Inventors: Young-Doo Kim, Eung Sun Kim, Chang Yong Shin, Gi Hong Im, Jong Bu Lim, Tae-Won Yune
  • Patent number: 8804480
    Abstract: Systems and methods for reducing the latency and for increasing throughput for MoCA devices that are connected via a coax network are provided. One method according to the invention includes, in a network having a plurality of network modules, each of the plurality of network modules being connected to a coax backbone, communicating over the coax backbone between the plurality of network modules. The method further includes a requesting the use of short burst messages. The method further includes responding to the requesting by constructing a short burst message with a single channel equalization section and reducing the number of bits per hertz in the transmission constellation. The resulting messages can be received with an acceptable error rate while making more efficient use of the MoCA network.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: August 12, 2014
    Assignee: Broadcom Corporation
    Inventors: Avraham Kliger, Philippe Klein, Yitshak Ohana
  • Patent number: 8804481
    Abstract: A method and an apparatus of transmitting scheduling request (SR) in a wireless communication system are provided. The method includes configuring a physical uplink control channel (PUCCH) for a SR in a subframe, the subframe comprising a plurality of single carrier-frequency division multiple access (SC-FDMA) symbols, wherein one SC-FDMA symbol on the PUCCH is punctured and transmitting the SR on the PUCCH in the subframe.
    Type: Grant
    Filed: June 24, 2013
    Date of Patent: August 12, 2014
    Assignee: LG Electronics Inc.
    Inventors: Hak-seong Kim, Young Woo Yun, Dae Won Lee, Joon Kui Ahn, Bong Hoe Kim, Ki Jun KIm
  • Patent number: 8804479
    Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least two signalling patterns adjacent to each other in the frequency direction and at least one data pattern. Frame forming means arranges signalling data and pilot signals in each of said at least two signalling patterns in a frame and arrange data on frequency carriers of said at least one data pattern in a frame. Scrambling means scrambles the signalling data by use of a unique scrambling sequence. Transforming means transforms said signalling patterns and said data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal. Transmitting means transmits said time domain transmission signal.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: August 12, 2014
    Assignee: Sony Corporation
    Inventors: Lothar Stadelmeier, Dietmar Schill, Joerg Robert
  • Patent number: 8804478
    Abstract: The present invention relates to a data transceiving method in a communication system based on a plurality of carriers, and more particularly, to a method of designing a sequence in a communication system using orthogonal subcarriers. The present invention includes the steps of generating a time-domain sequence with a specific length in a time domain, generating a frequency-domain sequence by performing a DFT or FFT operation on the time-domain sequence according to a length of the generated sequence, including a DC subcarrier and a guard subcarrier in the frequency-domain sequence, and performing an IDFT or IFFT operation on the frequency-domain sequence including the DC subcarrier and the guard subcarrier.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: August 12, 2014
    Assignee: LG Electronics Inc.
    Inventors: Seung Hee Han, Min Seok Noh, Yeong Hyeon Kwon, Hyun Hwa Park, Hyun Woo Lee, Dong Cheol Kim
  • Patent number: 8798182
    Abstract: A precoding method and apparatus are disclosed. The corresponding method includes: constructing a Lagrange function according to a precoding matrix, transmit power, a receive filter matrix and a weighting matrix, and obtaining a Lagrange multiplier by using the Lagrange function; updating the precoding matrix according to the Lagrange multiplier to obtain an iterative precoding matrix and an iterative receive filter matrix; obtaining an iterative Lagrange multiplier according to the iterative precoding matrix, the transmit power, the iterative receive filter matrix and the weighting matrix, and repeating the above steps in an iterative manner of updating the iterative precoding matrix according to the iterative Lagrange multiplier till the iterative precoding matrix converges to a threshold; and precoding information to be transmitted according to the iterative precoding matrix converging to the threshold.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: August 5, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Hui Shen, Bin Li, Yi Luo, Hufei Zhu
  • Patent number: 8798180
    Abstract: Systems and methods are provided for transmitting time domain signals over a network. A prime factor inverse Fourier transform module is configured to receive a frequency domain symbol comprising n samples and convert the frequency domain symbol into a time domain signal. The prime factor inverse Fourier transform module includes a prime factor module that is configured to perform an inverse Fourier transform on the frequency domain symbol to reduce the number of samples of the frequency domain symbol by a factor of p, where p is a prime number, and where p is a factor of n. The prime factor inverse Fourier transform module further includes a reduced inverse Fourier transform module that is configured to convert the reduced number of samples to a time domain signal for transmission over the network.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: August 5, 2014
    Assignee: Marvell International Ltd.
    Inventor: Hidayat Lioe
  • Patent number: 8797837
    Abstract: Systems and methods for multiplexing signals are disclosed. In one embodiment, the method comprises receiving a first signal having at least a real component, receiving a second signal having at least a real component, generating an in-phase signal based, at least in part, on the first signal, the in-phase signal being real in a first domain, generating a quadrature signal based, at least in part, on the second signal, the quadrature signal being imaginary in the first domain, adding the in-phase signal and the quadrature signal to generate a multiplexed signal, and transmitting the multiplexed signal.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: August 5, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Xiaochen Li, Chiu Ngo
  • Patent number: 8792426
    Abstract: Systems and methodologies are described that facilitate improved resource management in a wireless communication system. As described herein, supergroups can be formed from groups of Physical Hybrid Automatic Repeat Request Channels (PHICHs) such that respective PHICH supergroups are multiplexed onto respective non-overlapping resource element subsets, thereby improving resource usage efficiency for the extended cyclic prefix case and limited numbers of transmit antennas. In one example described herein, even-indexed PHICH groups are mapped to a selected subset of resource elements in a group while odd-indexed PHICH groups are mapped to the remaining resource elements in the group. This mapping can be performed by modifying orthogonal sequences associated with the PHICH groups and/or by performing resource mapping in different manners for respective PHICH supergroups.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: July 29, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Juan Montojo, Tao Luo, Xiaoxia Zhang
  • Patent number: 8792324
    Abstract: The present invention relates to digital data communication and provides an efficient method for generating multi-dimensional constellations for digital data modulation with a high degree of modulation diversity, a method for transmitting and receiving data on the basis of such constellations, and a corresponding apparatus. This is achieved by considering only multi-dimensional rotation matrices with all elements on the diagonal having the same first absolute value and all other elements having the same non-zero second absolute value. In this manner, multi-dimensional rotation matrices can be generated having only a single independent parameter and a structure that is as regular as possible. The independent parameter can be configured in order to minimize the error probability for various constellation sizes.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: July 29, 2014
    Assignee: Panasonic Corporation
    Inventors: Mihail Petrov, Tomohiro Kimura
  • Patent number: 8792325
    Abstract: A system includes a mapping device. The mapping device groups encoded bits of OFDM symbols into first groups. For each of the first groups, the mapping device maps adjacent bits onto non-adjacent subcarriers of multiple subcarriers and in an alternating manner onto bits of a signal constellation such that: every other one of the adjacent bits are mapped to first bits on the signal constellation; and bits other than the every other one of the adjacent bits are mapped to second bits on the signal constellation. Each of the first groups has a corresponding complex number. The mapping device: groups predetermined numbers of the first groups into second groups, where each of the second groups corresponds to one of the OFDM symbols; and maps each of the second groups to one of the multiple subcarriers such that the multiple subcarriers are modulated based on the complex numbers.
    Type: Grant
    Filed: July 15, 2013
    Date of Patent: July 29, 2014
    Assignee: Marvell International Ltd.
    Inventor: Ravi Narasimhan
  • Patent number: 8792322
    Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least two signalling patterns adjacent to each other in the frequency direction and at least two data patterns, the transmitting apparatus including signalling mapping means to map signalling data on frequency carriers of each of the at least two signalling patterns in a frame, each signalling pattern having the same length, data mapping means to map data on frequency carriers of the at least two data patterns in a frame, transforming means to transform the signalling patterns and the data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal, and transmitting means to transmit the transmission signal. A corresponding transmitting method and a frame pattern for a multi carrier system are also provided.
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: July 29, 2014
    Assignee: Sony Corporation
    Inventors: Lothar Stadelmeier, Samuel Asangbeng Atungsiri, Martin Lovell, Tamotsu Ikeda
  • Patent number: 8787486
    Abstract: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. For each received signal vector, the receiver evaluates a decoding metric using each possible value of the transmitted signal vector to produce a set of distances. The receiver then combines distances from across the received signal vectors to produce a combined distance associated with each possible value of the transmitted signal vector. Using the combined distances, the receiver may choose among the possible values of the transmit signal vector to determine the actual transmit signal vector.
    Type: Grant
    Filed: January 29, 2014
    Date of Patent: July 22, 2014
    Assignee: Marvell World Trade Ltd.
    Inventors: Jungwon Lee, Woong Jun Jang
  • Patent number: 8787143
    Abstract: A system and method for hybrid FDM (frequency division multiplexing)-CDM (code division multiplexing) structure for single carrier control channels is provided. The hybrid FDM-CDM structure maximizes frequency diversity over the entire available bandwidth such that orthogonality between signals from users in a given cell is maintained. Thus, users in the given cell can transmit over a non-contiguous set of tones. Furthermore, the hybrid FDM-CDM structure maintains orthogonality of a pilot of users in different cells based on a despreading operation in the time domain.
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: July 22, 2014
    Assignee: QUALCOMM Incorporated
    Inventor: Durga Prasad Malladi
  • Patent number: 8787146
    Abstract: A discontinuous change in a transmission timing in a time domain, which is caused by a transmission timing adjustment processing of an OFDMA uplink or the like, brings about a discontinuous rotation of a signal phase in a frequency domain, resulting in reduced communication quality. A wireless communication system of the present invention allows the signal phase of the frequency domain in a receiving station to be continuous before and after the timing adjustment processings by controlling a signal sequence in a transmission signal after conversion in the time domain in synchronization with the timing adjustment processing.
    Type: Grant
    Filed: February 16, 2009
    Date of Patent: July 22, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Tamaki, Mikio Kuwahara, Kenzaburo Fujishima, Pinai Linwong, Katsuhiko Tsunehara
  • Patent number: 8787923
    Abstract: A management device of a stopping or moving base station includes: an information acquisition unit that acquires first information about wireless environment from a neighboring base station and that acquires second information about the wireless environment by connecting to a backbone network; a position estimating unit that estimates a position of the neighboring base station based on the first information; and an operation condition selection unit that selects radio resources based on at least one of the first information and the second information.
    Type: Grant
    Filed: April 29, 2010
    Date of Patent: July 22, 2014
    Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research Institute
    Inventors: Sung Cheol Chang, Won-Ik Kim, Sung Kyung Kim, Hyun-Jae Kim, Chul Sik Yoon, Jee Hwan Ahn
  • Patent number: 8787861
    Abstract: In some implementations, an apparatus includes an echo canceller that generates an echo interference compensation signal that compensates for an echo interference signal in a communication signal, a crosstalk canceller that generates a crosstalk interference compensation signal that compensates for a crosstalk interference signal in the communication signal, and a combiner that generates a combined interference compensation signal based on the echo interference compensation signal and the crosstalk interference compensation signal.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: July 22, 2014
    Assignee: Marvell International Ltd.
    Inventors: Xiaopeng Chen, Runsheng He
  • Patent number: 8787140
    Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least one signalling pattern and one or more data patterns, the transmitting apparatus including frame forming means for arranging signalling data in the at least one signalling pattern in a frame, and for arranging data and at least one pilot signal in the one or more data patterns in a frame, whereby the length of each of the one or more data patterns in the frequency direction is equal to or a multiple of a minimum data pattern length, transforming means for transforming the at least one signalling pattern the one or more data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal, and transmitting means for transmitting the time domain transmission signal.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: July 22, 2014
    Assignee: Sony Corporation
    Inventors: Lothar Stadelmeier, Dietmar Schill, Joerg Robert
  • Patent number: 8781036
    Abstract: A system including an input module, a first gain module, a second gain module, and a preamble estimation module. The input module is configured to receive an input signal from a station. The input signal includes (i) a first preamble sequence, and (ii) subcarriers. The first gain module is configured to, based on the input signal, generate first channel gain values. Each of the first channel gain values is for a respective one of the subcarriers. A second gain module is configured to, based on the first channel gain values, generate second channel gain values. A preamble estimation module is configured to estimate the first preamble sequence based on (i) the first channel gain values, and (ii) the second channel gain values.
    Type: Grant
    Filed: November 27, 2012
    Date of Patent: July 15, 2014
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Hui-Ling Lou
  • Patent number: 8780942
    Abstract: A detection section (8) of a communication device (1) includes a correlation calculation section for calculating correlation between a known TCCH symbol pattern and a demodulated complex symbol pattern received by a reception section (20) in each of a last symbol period in one sub-slot and subsequent one symbol period and a reception state acquisition section for obtaining, based on a result of the calculation in the correlation calculation section, a delay amount of a timing of receiving the signal from a communication partner device.
    Type: Grant
    Filed: June 9, 2010
    Date of Patent: July 15, 2014
    Assignee: KYOCERA Corporation
    Inventor: Shinsuke Moriai
  • Patent number: 8773966
    Abstract: A receiver of a wireless communication device, the receiver including a fast Fourier transform module, a first power measuring module, and a gain control module. The fast Fourier transform module is configured to convert a signal from a time domain to a frequency domain. The signal includes a plurality of reference signals. The reference signals have a predetermined power. The first power measuring module is configured to generate a first power measurement of the signal in the frequency domain based on the plurality of reference signals. The gain control module is configured to adjust a gain of the receiver based on the first power measurement.
    Type: Grant
    Filed: May 5, 2011
    Date of Patent: July 8, 2014
    Assignee: Marvell International Ltd.
    Inventors: Vladan Petrovic, Manyuan Shen, Qing Zhao, Leilie Song
  • Patent number: 8773973
    Abstract: A receiving apparatus includes a first transform unit configured to perform orthogonal transform on a time-domain input signal and perform saturation when an overflow occurs to transform the input signal into a plurality of frequency-domain signals, a second transform unit configured to perform orthogonal transform on the time-domain input signal while restricting the number of bits during orthogonal transform and continue operations while not performing saturation when at least one of the operations overflows and leaving the operation overflowing to transform the input signal into a plurality of frequency-domain signals, and a bit restricting control unit configured to control the number of bits during orthogonal transform by the second transform unit based on output signals of the first transform unit.
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: July 8, 2014
    Assignee: Fujitsu Limited
    Inventor: Tsuyoshi Hasegawa
  • Patent number: 8773974
    Abstract: Methods and systems are provided that enable an OFDM transmitter to be used for transmitting conventional OFDM or a form of transformed OFDM. A technique is provided for transforming a coded and modulated sequence of samples prior to an IFFT that enables the transformed sequence of samples to be transmitted using conventional OFDM or transformed OFDM. The selection of a transform function for transforming the coded and modulated sequence of samples may be based on optimizing the transform function for particular operating conditions between the transmitter and receiver. In some embodiments of the invention OFDM and time transformed OFDM are multiplexed in time and/or frequency in a transmission frame. In some embodiments of the invention a pilot pattern is provided in which the pilot are sent using OFDM and data is sent using OFDM and/or transformed OFDM.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: July 8, 2014
    Assignee: Apple Inc.
    Inventors: Jianglei Ma, Wen Tong, Ming Jia, Hua Xu, Peiying Zhu, Hang Zhang
  • Patent number: 8767524
    Abstract: Methods and systems for communications that generate a plurality of spatial streams, wherein each of the spatial streams comprises a data packet with a training sequence; and multiply at least a portion of the training sequence in each of the spatial streams with a different spreading sequence. Methods and systems that receive a plurality of spatial streams, wherein each of the spatial streams comprises a data packet with a training sequence; multiply at least a portion of the training sequence in each of the spatial streams with a different spreading sequence; and decode the plurality of spatial streams based on the different spreading sequences.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: July 1, 2014
    Assignee: QUALCOMM Incorporated
    Inventor: Didier Johannes Richard Van Nee
  • Patent number: 8761678
    Abstract: A radio transmitting apparatus includes a storage unit configured to store a plurality of weight sequence sets, which are each assigned to a plurality of transmission blocks sectioned by time axes and frequency axes, by associating the plurality of weight sequence sets with the plurality of transmission blocks, a first selecting unit configured to select one transmission block from the plurality of transmission blocks, a second selecting unit configured to select one weight sequence from one weight sequence set assigned to the one transmission block signal, a converting unit configured to convert a data signal by using the one weight sequence to generate a converted signal, and a transmitting unit configured to transmit the converted signal by using the one transmission block.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: June 24, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Akita, Noritaka Deguchi, Ren Sakata, Koichiro Ban
  • Patent number: 8761283
    Abstract: A method of reporting channel state information (CSI) with reduced feedback overhead in a MIMO-OFDM system is provided. A receiver first estimates CSI of a multiple-input multiple-output (MIMO) channel based on a sounding signal transmitted from a transmitter. The CSI comprises L channel response matrices, and each matrix corresponds to an OFDM tone in the MIMO channel. Each channel response matrix is then decomposed into a first CSI component and a second CSI component. The receiver selects a first subset of the first CSI component based on a first tone group size and a second subset of the second CSI component based on a second tone group size. Finally, the receiver transmits the selected subsets of the first and the second CSI components to the transmitter. The reduced feedback does not have significant loss in the information content of CSI because of the coherent bandwidth in typical OFDM systems.
    Type: Grant
    Filed: October 7, 2011
    Date of Patent: June 24, 2014
    Assignee: Mediatek Singapore Pte. Ltd.
    Inventor: Vishakan Ponnampalam
  • Patent number: 8755476
    Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for antenna switching diversity comprising: identifying the start of an OFDM symbol period; switching from an original antenna to an alternative antenna; calculating a signal quality metric associated with the original antenna and the alternative antenna; and selecting either the original antenna or the alternative antenna for demodulation of a current OFDM symbol based on the calculated signal quality metric. In one aspect, the antenna switching diversity is based on either symbol rate switching or block rate switching, and a selection of one or the other is made.
    Type: Grant
    Filed: January 28, 2010
    Date of Patent: June 17, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Linbo Li, Ashok Mantravadi
  • Patent number: 8755264
    Abstract: Messages transmitted between a receiver and a transmitter are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: June 17, 2014
    Assignee: Intel Corporation
    Inventors: Marcos C. Tzannes, Dongjun Lee, Todor Cooklev, Colin Lanzl
  • Patent number: 8755453
    Abstract: In one embodiment, a transmitter includes a binary sequence generator unit configured to provide a sequence of reference signal bits, wherein the sequence is an inseparable function of a cell identification parameter, a cyclic prefix mode corresponding to the transmitter and one or more time indices of the sequence. The transmitter also include a mapping unit that transforms the sequence of reference signal bits into a complex reference signal, and a transmit unit configured to transmit the complex reference signal. In another embodiment, a receiver includes a receive unit configured to receive a complex reference signal and a reference signal decoder unit configured to detect a sequence of reference signal bits from the complex reference signal, wherein the sequence is an inseparable function of a cell identification parameter, a cyclic prefix mode corresponding to a transmitter and one or more time indices of the sequence.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: June 17, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Anand G. Dabak, Tarkesh Pande, Eko N. Onggosanusi
  • Publication number: 20140160917
    Abstract: There are provided a method of generating a ranging signal of a wireless terminal and a device for generating a ranging signal of a wireless communication system that can generate the ranging signal using one IFFT engine independently from a mode of the ranging signal transmitted in uplink in a wireless communication system in which a frequency interval of subcarriers used to generate an initial ranging signal and a frequency interval of subcarriers using periodic ranging are different. In this way, it is possible to decrease complexity of hardware and design of the wireless terminal, and decrease power consumption of the wireless terminal through hardware simplification.
    Type: Application
    Filed: October 8, 2013
    Publication date: June 12, 2014
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Kyung-Yeol SOHN, Seung-Jae BAHNG, Youn-Ok PARK
  • Patent number: 8750091
    Abstract: Apparatus and methods for updating symbol information in a communication device with hardware such as a microcontroller are disclosed. The disclosed apparatus and methods employ waiting for the beginning of a symbol in a sample stream at a predetermined time. One or more programmed instructions are read at the beginning of the symbol, and then symbol information is updated based on the one or more programmable instructions and setting a time for a beginning of a next symbol. The programmed instructions consist of instruction code words that are executed by a dedicated microcontroller or similar hardware, which affords flexibility for updating symbol information, particularly for multimode communication devices operable across multiple communication technologies.
    Type: Grant
    Filed: March 23, 2009
    Date of Patent: June 10, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Sundeep Rangan, Atul Maharshi, Frank Lane, Ozge Koymen
  • Patent number: 8750089
    Abstract: A method and system for iterative discrete Fourier transform (DFT) based channel estimation using minimum mean square error (MMSE) techniques are presented. Aspects of the method and system include a procedure for computing channel estimates in both the time domain and frequency domain (or mixed domain) using an iterative DFT method based on MMSE techniques. One aspect of the method and system may achieve low computational complexity and produce more accurate channel estimate values in low signal to noise ratio (SNR) regimes in comparison to conventional DFT-based channel estimation methods, which utilize least squares (LS) techniques. The method and system disclosed herein may be practiced in connection with a wide range of orthogonal frequency division multiplexing (OFDM) based systems, for example wireless local area networks (WLAN, for example IEEE 802.11 WLAN systems), and LTE systems.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: June 10, 2014
    Assignee: Broadcom Corporation
    Inventors: Sirikiat Ariyavisitakul, Jun Zheng
  • Patent number: 8743717
    Abstract: A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: June 3, 2014
    Assignee: Adaptix, Inc.
    Inventors: Xiaodong Li, Hui Liu, Wenzhong Zhang, Kemin Li
  • Patent number: 8743714
    Abstract: A mobile communications system having a first base station and one or more second base stations is disclosed, wherein the first base station includes a first generator which generates a first known signal for use in common between the first base station and the second base station and a second known signal use specific to each of the first base station and the second base station, and a radio transmitter which wirelessly transmits, to a subordinate terminal apparatus, the first known signal and the second known signal which are generated by the first generator.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: June 3, 2014
    Assignee: NTT Docomo, Inc.
    Inventors: Yoshihisa Kishiyama, Motohiro Tanno, Mamoru Sawahashi
  • Patent number: 8744016
    Abstract: A receiving apparatus includes a symbol timing detection unit, a Fourier transform unit, a first symbol timing correction unit, and an interpolation synthesis unit. The symbol timing detection unit is configured to detect a Fourier transform start position from a received transmitting signal of a symbol unit, the Fourier transform unit is configured to perform a Fourier transform using the detected Fourier transform start position. The first symbol timing correction unit is configured to calculate and correct an amount of change between the Fourier transform start position of a reference symbol and the detected Fourier transform start position, and the interpolation synthesis unit is configured to perform an interpolation synthesis of a plurality of delay profiles corresponding to a plurality of symbols including the reference symbol and a symbol in which the amount of change is corrected.
    Type: Grant
    Filed: April 9, 2012
    Date of Patent: June 3, 2014
    Assignees: Fujitsu Limited, Fujitsu Semiconductor Limited
    Inventors: Hiroaki Takagi, Naoto Adachi, Masataka Umeda
  • Patent number: 8743674
    Abstract: A cancellation system is disclosed for processing incoming and outgoing signals in a transform domain to create a cancellation signal for reducing or removing unwanted interference. Data is ordered based on Good-Thomas indexing into a two dimensional array in a buffer. The two dimensional array may have lr rows and lw columns. From the buffer, the columns of data undergo a Winograd small transform. The rows of data undergo a Cooley-Tukey operation to complete the transform operation into the frequency domain. Multipliers scale the transformed data to generate a cancellation signal in the frequency domain. Inverse (Cooley-Tukey) and Winograd transforms perform inverse processing on the cancellation signal to return the cancellation signal or data to the time domain. Re-ordering the data and combination of the cancellation signal or data with incoming or outgoing signals achieve interference cancellation.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: June 3, 2014
    Assignee: Marvell International Ltd.
    Inventors: Gavin D. Parnaby, George A. Zimmerman, Chris Pagnanelli, William W. Jones
  • Patent number: 8738020
    Abstract: A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: May 27, 2014
    Assignee: Adaptix, Inc.
    Inventors: Xiaodong Li, Hui Liu, Wenzhong Zhang, Kemin Li