Quadrature Amplitude Modulation Patents (Class 375/298)
  • Patent number: 8848830
    Abstract: A method for providing a first modulation scheme based on a second modulation scheme, the second modulation scheme including a first constellation point associated with a first bit pattern and a second constellation point associated with a second bit pattern. The method includes mapping the second bit pattern from the second constellation point to the first constellation point, wherein an energy associated with the second constellation point is greater than an energy associated with the first constellation point.
    Type: Grant
    Filed: November 17, 2011
    Date of Patent: September 30, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventor: Thorsten Clevorn
  • Patent number: 8848831
    Abstract: An apparatus comprises a direct digital synthesizer, a mixer having first and second input ports and an output port, and a numerically-controlled oscillator. The direct digital synthesizer has a first output coupled to the first input port of the mixer and a second output coupled to a control input of the numerically-controlled oscillator, and the numerically-controlled oscillator has an output coupled to the second input port of the mixer. The mixer provides a quadrature modulated signal at its output port, and the first and second outputs of the direct digital synthesizer control respective portions of the quadrature modulated signal. For example, the first and second outputs of the direct digital synthesizer may control respective amplitude and phase portions of the quadrature modulated signal.
    Type: Grant
    Filed: September 20, 2012
    Date of Patent: September 30, 2014
    Assignee: LSI Corporation
    Inventor: Roger A. Fratti
  • Patent number: 8842770
    Abstract: A method is for decoding a pulse signal modulated through a transmitted reference modulation scheme. The modulated pulse signal may include, repetitively, a reference pulse followed by an information pulse delayed with a delay. The method may include subtracting or adding from the modulated pulse signal, a version of the modulated pulse signal delayed with the delay for obtaining a processed signal, and performing a non-coherent detection on the processed signal.
    Type: Grant
    Filed: April 17, 2013
    Date of Patent: September 23, 2014
    Assignee: STMicroelectronics N.V.
    Inventors: Gian Mario Maggio, Chiara Cattaneo, Philippe Rouzet
  • Patent number: 8842761
    Abstract: Communication systems are described that use geometrically shaped constellations that have increased capacity compared to conventional constellations operating within a similar SNR band. In several embodiments, the geometrically shaped is optimized based upon a capacity measure such as parallel decoding capacity or joint capacity. In many embodiments, a capacity optimized geometrically shaped constellation can be used to replace a conventional constellation as part of a firmware upgrade to transmitters and receivers within a communication system. In a number of embodiments, the geometrically shaped constellation is optimized for an Additive White Gaussian Noise channel or a fading channel. In numerous embodiments, the communication uses adaptive rate encoding and the location of points within the geometrically shaped constellation changes as the code rate changes.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: September 23, 2014
    Assignee: Constellation Designs, Inc.
    Inventors: Maged F. Barsoum, Christopher R. Jones
  • Publication number: 20140269960
    Abstract: D-dimensional vectors that each have D real-valued symbols as elements are converted into D-dimensional rotated vectors that each have D real symbols as elements. The conversion is performed by multiplying each of the D-dimensional vectors by a D×D orthogonal matrix. A complex symbol sequence including NC=NS/2 complex symbols is generated from NS real symbols. The complex symbol sequence is generated such that the distance between any two of the D real symbols of each of the D-dimensional rotated vectors is NC/D complex symbols or NC/D?1 complex symbols, or such that the distance between any two of the D real symbols of each of the D-dimensional rotated vectors, except for part of the D-dimensional rotated vectors, is NC/D complex symbols or NC/D?1 complex symbols.
    Type: Application
    Filed: November 7, 2012
    Publication date: September 18, 2014
    Inventor: Mihail Petrov
  • Publication number: 20140269992
    Abstract: An apparatus and a method for operating a transmission end in a wireless communication system that supports Frequency and Quadrature-Amplitude Modulation (FQAM) are provided. The method includes dividing an information bit stream into a plurality of portions, encoding each of the plurality of portions using different encoding schemes, and generating an FQAM symbol by combining result values of the encoding of each of the plurality of portions, wherein the encoding schemes are different according to at least one of an encoding order, an encoding rate, an input size, and an encoding technique.
    Type: Application
    Filed: March 11, 2014
    Publication date: September 18, 2014
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Sung-Nam HONG, Min SAGONG, Chi-Woo LIM, Hyun-Kyu YU, Kyung-Whoon CHEUN
  • Patent number: 8837618
    Abstract: Information bits are encoded according to a low density parity check code with code rate 7/15 and a codeword length of 16200. The resulting codeword bits are bit-interleaved and the interleaved bits are demultiplexed into 8 sequences of bits. The 8 sequences of bits are permuted according to a predetermined permutation rule: v0=b2, v1=b6, v2=b0, v3=b1, v4=b4, v5=b5, v6=b3, v7=b7.
    Type: Grant
    Filed: June 14, 2012
    Date of Patent: September 16, 2014
    Assignee: Panasonic Corporation
    Inventor: Mihail Petrov
  • Patent number: 8830107
    Abstract: A frequency translating analog-to-digital converter for receiving an analog band-pass signal is described. The analog-to-digital converter comprises an adder/input block for receiving the analog band-pass signal and an analog band-pass feedback signal, thereby forming an analog band-pass error signal. The analog-to-digital converter has at least one analog mixer for mixing and down converting the analog band-pass error signal and thus generating a down-converted analog error signal and at least one quantization path for generating at least one digital signal.
    Type: Grant
    Filed: April 16, 2013
    Date of Patent: September 9, 2014
    Inventor: Udo Karthaus
  • 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: 8817936
    Abstract: A system for synchronizing IQ demodulators includes IQ demodulators, phase-controlling devices, a reference signal, a phase detector, and a control device. The phase-controlling devices are each associated with one of the IQ demodulators for outputting an output signal to its associated IQ demodulator having a phase controlled by the associated phase-controlling device. The phase detector is in communication with the output signals for determining whether the phase of any of the output signals is out-of-phase with a reference phase of the reference signal. The control-device is in communication with the phase-controlling devices programmed, internally or externally, to send a control signal to the associated phase-controlling device for any of the output signals which are out-of-phase with the reference phase of the reference signal so that the associated phase-controlling device synchronizes the phase of the output signal to being in-phase with the reference phase of the reference signal.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: August 26, 2014
    Assignee: The Boeing Company
    Inventor: David Charles Dominguez
  • Patent number: 8817911
    Abstract: Wireless communication wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. An encoding operation encodes and outputs transmitting data (bit string) and a bit converting operation converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’. A modulating operation modulates the bit string inputted from the bit converting operation by using a single modulation mapper and a plurality of data symbols are generated.
    Type: Grant
    Filed: November 4, 2013
    Date of Patent: August 26, 2014
    Assignee: Panasonic Intellectual Property Corporation of America
    Inventors: Kenichi Miyoshi, Hidetoshi Suzuki, Katsuhiko Hiramatsu, Christian Wengerter, Alexander Golitschek Edler von Elbwart
  • Patent number: 8817909
    Abstract: A polar modulator arrangement includes a first and a second node to receive a signal having a first and a second component corresponding to an amplitude component and a phase component. A frequency separation device separates the first component into a low-frequency portion and a high-frequency portion depending on a cut-off frequency. The high-frequency portion is nonlinearly filtered and combined with the low-frequency portion to a first processed component. A combination element generates a polar modulated radio frequency signal as a function of the first processed component and the second component.
    Type: Grant
    Filed: November 29, 2006
    Date of Patent: August 26, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Chitao Goe, Markku Renfors
  • Patent number: 8817910
    Abstract: Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. These are used to provide differing BER performances among bits sent from a transmitter to a receiver.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: August 26, 2014
    Assignee: Blackberry Limited
    Inventors: Shouxing Qu, Yan Xin, Johanna Lisa Dwyer, Paul Carpenter
  • Patent number: 8811533
    Abstract: A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: August 19, 2014
    Inventor: Earl W. McCune, Jr.
  • Patent number: 8811509
    Abstract: Forward error correction (FEC) m-bit symbol modulation. Any desired FEC, error correction code (ECC), and/or combination thereof generates coded bits for combination with either uncoded bits, separately generated coded bits, and/or combination thereof to generate a number of symbols that undergo mapping to a constellation whose respective constellation points have a mapping characterized by a maximum minimum intra-Euclidean distance between the respective constellation points thereby generating a sequence of discrete-valued modulation symbols. The sequence of discrete-valued modulation symbols may then undergo modulation of any of a number of different operations (e.g., digital to analog conversion [e.g., digital to analog converter (DAC)], scaling, frequency shifting, filtering, etc.) to generate a continuous time signal for transmission via a communication channel. Such a device operative to perform including such functionality, circuitry, capability, etc.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: August 19, 2014
    Assignee: Broadcom Corporation
    Inventors: Ba-Zhong Shen, Avi Kliger
  • Publication number: 20140226755
    Abstract: The present invention relates to a method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to a method of receiving a signal, which includes interleaving in an appropriate manner for a channel bonding system. The interleaving can allow decoding a user requested service at a random tuner window position.
    Type: Application
    Filed: April 9, 2014
    Publication date: August 14, 2014
    Applicant: LG Electronics Inc.
    Inventors: Woo Suk KO, Sang Chul MOON
  • Publication number: 20140226754
    Abstract: Disclosed is a method of transmitting dual digital signals through a single antenna. The method includes receiving, by a transmitter, a first data stream and a second data stream which use the same carrier frequency, modulating, by the transmitter, each of the first data stream and the second data stream, lowering, by the transmitter, a power level of the modulated second data stream, combining, by the transmitter, the modulated first data stream and the second data stream with the lowered power level, and transmitting, by the transmitter, the added first data stream and second data stream to a single antenna in the same channel.
    Type: Application
    Filed: October 28, 2013
    Publication date: August 14, 2014
    Applicant: GCT Semiconductor, Inc.
    Inventors: Eal Wan LEE, Dae Hong KIM, Jeong Min KIM
  • Patent number: 8804605
    Abstract: Systems and methods are disclosed for feeder link configurations to layered modulation. One feeder link system employs feeder link spot beam to antennas in distinct coverage areas to enable frequency reuse. Another system employs narrow beam width feeder link antenna to illuminate individual satellites also enabling frequency reuse. Yet another system uses layered modulation in the feeder link. Another feeder link system employs a higher order synchronous modulation for the satellite feeder link than is used in the layered modulation downlink signals.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: August 12, 2014
    Assignee: The DIRECTV Group, Inc.
    Inventors: Paul R. Anderson, Joseph Santoru, Ernest C. Chen
  • Patent number: 8804874
    Abstract: A polar transmitter includes a frequency modulating path, a clock divider and a digital processing block. The frequency modulating path is arranged for generating a frequency modulated clock in response to a frequency modulating signal. The clock divider is coupled to the frequency modulated clock, and arranged for generating a down-divided clock. The digital processing block is coupled to the down-divided clock, and arranged for generating the frequency modulating signal, wherein the frequency modulating signal is adjusted for frequency deviation of the frequency modulated clock. A method for polar transmission includes: generating a frequency modulated clock in response to a frequency modulating signal; dividing a frequency of said frequency modulated clock to generate a down-divided clock; and generating said frequency modulating signal according to said down-divided clock, wherein said frequency modulating signal is adjusted for frequency deviation of said frequency modulated clock.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: August 12, 2014
    Assignee: Mediatek Inc.
    Inventors: Chi-Hsueh Wang, Kai-Peng Kao, Robert Bogdan Staszewski
  • 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: 8798198
    Abstract: A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment for receiving an amplitude-modulated calibration signal from the electronic device. The calibration system may include calibration computing equipment for extracting pre-distortion coefficients from the amplitude-modulated calibration signal. The calibration computing equipment may be configured to detect a bulk phase drift in the amplitude-modulated calibration signal. The calibration computing equipment may be configured to remove the bulk phase drift from the amplitude-modulated calibration signal. The wireless communications circuitry may include a power amplifier that distorts a signal generated by the wireless communications circuitry. The wireless communications circuitry may include a pre-distortion compensator for countering the distortion.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: August 5, 2014
    Assignee: Apple Inc.
    Inventor: Gary Lang Do
  • Patent number: 8798200
    Abstract: The present invention provides a constellation mapping method, and the method includes: flipping a plurality of bits in each modulation symbol unit to be mapped in part of or all of modulation symbol units to be mapped of a bit sequence to be mapped; and mapping each flipped modulation symbol unit to be mapped as a modulation symbol in a constellation. By means of the present invention, the phenomenon that consecutive bits have the same reliability can be effectively avoided by changing unevenness of reliability distribution of the consecutive bits, and at the same time, the link performance can be improved.
    Type: Grant
    Filed: July 3, 2009
    Date of Patent: August 5, 2014
    Assignee: ZTE Corporation
    Inventors: Jin Xu, Jun Xu, Zhifeng Yuan, Qianzi Xu, Xianwei Gong, Bo Sun, Huiying Fang
  • Publication number: 20140211887
    Abstract: A method for supporting Time-Quadrature Amplitude Modulation (TQAM) in a wireless communication system includes generating a transmission symbol identified by a combination of a QAM symbol and a position of a time resource to which the QAM symbol is mapped, shifting at least one QAM symbol among QAM symbols contained in the transmission symbols with respect to a time axis, and readjusting a constellation point of the QAM symbol on the basis of a shifting quantity. A method for operating a receive end comprises receiving a reception symbol identified by a combination of a QAM symbol and a position of a time resource to which the QAM symbol is mapped, restoring at least one QAM symbol shifted in a transmit end for uniformizing of the time-axis distribution of QAM symbols contained in the reception symbols, generating decoding metrics for the reception symbol, and performing decoding the reception symbol using the decoding metric.
    Type: Application
    Filed: January 28, 2014
    Publication date: July 31, 2014
    Applicant: Samsung Electronics Co., Ltd
    Inventors: Min Sagong, Chi-Woo Lim, Sung-Nam Hong, Hyun-Kyu Yu, Kyung-Whoon Cheun
  • Patent number: 8792640
    Abstract: A digital data signal, such as a digital video signal, is intentionally pre-distorted before being sent over a network. In one embodiment, this pre-distortion may be performed in accordance with a pre-distortion pattern or algorithm which is shared with only intended receivers. The pre-distortion pattern may be used to vary the pre-distortion on a periodic basis, as frequently as on a symbol-by-symbol basis. The pre-distortion function may include distorting the phase and/or the amplitude of the digital signal's modulation.
    Type: Grant
    Filed: January 29, 2008
    Date of Patent: July 29, 2014
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventors: Kenichi Kawasaki, Robert Hardacker
  • Patent number: 8787477
    Abstract: Embodiments of the invention provide a methods for the assignment of codewords to the available constellation points to minimize the Hamming distance between adjacent codewords. An hexagonal constellation is modeled as a two-dimensional trellis with an horizontal axis varying across a plurality of constellation points and a vertical axis varying across a plurality of codewords [0, 1, . . . , N?1]. A best path through the trellis is found to select a single constellation point per each codeword where a codeword is to be assigned. A each state in the transition across the trellis diagram, a current score and the best path that leads to the state is stored in a memory. Each codeword is assigned to the selected constellation point. The hexagonal constellation is used for transmitting data in a communication system.
    Type: Grant
    Filed: September 18, 2013
    Date of Patent: July 22, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Mohamed Farouk Mansour, Srinath Hosur, JuneChul Roh
  • Patent number: 8781026
    Abstract: In one embodiment, a sequence of a plurality of pairs of in-phase (I) and quadrature (Q) modulated signal samples are applied to a radio frequency digital-to-analog converter (RFDAC) for upconversion. A phase of a local oscillator (LO) signal supplied to the RFDAC is selected according to a quadrant determined by signs of a given pair of I and Q modulated signal samples. The selected phase of the LO is supplied to the RFDAC for use in upconverting the sequence of I and Q modulated signal samples. In another embodiment, a current steering DAC is used for directly upconverting the I and Q modulated signal samples. A clock signal at four times the LO frequency is supplied to a counter and to the current steering DAC. One of the I and Q modulated signal samples and negative I and negative Q modulated signal samples is selected for supply to an input of the current steering DAC based on a count state of the counter.
    Type: Grant
    Filed: November 6, 2012
    Date of Patent: July 15, 2014
    Assignee: MStar Semiconductor, Inc.
    Inventors: Khurram Muhammad, Bernard Ginetti, Dennis Mahoney
  • Publication number: 20140192926
    Abstract: A general purpose hybrid includes a first input port in communication with a first dual vector generator, a second input port in communication with a second dual vector generator, a first active combiner receives a first signal from the first dual vector generator and a third signal from the second dual vector generator, where the first and second dual vector generators independently apply phase shifting and amplitude control to the first and third signals; a second active combiner receives a second signal from the first dual vector generator and a fourth signal from the second dual vector generator, where the first and second dual vector generators independently apply phase shifting and amplitude control to the second and fourth signals; a first output port provides a first composite signal from the first active combiner; and a second output port provides a second composite signal from the second active combiner.
    Type: Application
    Filed: February 8, 2014
    Publication date: July 10, 2014
    Applicant: VIASAT, INC.
    Inventors: DAVID R. SAUNDERS, DAVID W. CORMAN, KENNETH V. BUER, DEAN L. COOK
  • Patent number: 8774286
    Abstract: A receiving apparatus includes a buffer configured to store packets of a first packet sequence made up of packets extracted from one transport stream that are common to packets of another transport stream and packets of a second packet sequence made up of common packets, a read control section configured to read the packets of the first packet sequence and the second packet sequence stored in the buffer after the passing of a predetermined time after synchronization is established between the packets of the first packet sequence and the packets of the second packet sequence, thereby reconstructing one transport stream from the first packet sequence and the second packet sequence, and an output section configured to output the reconstructed transport stream.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: July 8, 2014
    Assignee: Sony Corporation
    Inventors: Takashi Yokokawa, Satoshi Okada
  • Publication number: 20140185704
    Abstract: An outdoor communication unit (ODU) for implementation within a dual channel microwave backhaul system, is provided. The ODU includes an radio frequency (RF) module, having digital capabilities, which is configured to utilize the digital capabilities to perform adaptive adjustments to correct errors in data in a digital domain, a conversion block configured to convert the data between an analog domain and the digital domain, and a processing module configured to adaptively adjust a characteristic of the data and a characteristic of a dual channel wireless link, and to facilitate a transmission of the data over the dual channel wireless link by performing mathematical manipulation techniques.
    Type: Application
    Filed: January 3, 2013
    Publication date: July 3, 2014
    Applicant: Broadcom Corporation
    Inventors: Kobi STURKOVICH, Igal Kushnir
  • Patent number: 8767882
    Abstract: A mobile wireless communications device may include an antenna, and a receiver coupled to the antenna and being configured to use a modulation having memory for a received message in a block structure. The block structure may include a pair of mini-probes and a body therebetween. The receiver may be configured to demodulate the received message by determining a corresponding set of received signal characteristic values based upon the pair of mini-probes, and determining a decode starting point in the body based upon the set of received signal characteristic values. The receiver may be configured to demodulate the received message by at least, from the decode starting point, decoding the body in a first time direction, and decoding the body in a second time direction based upon a result of the decoding in the first direction.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: July 1, 2014
    Assignee: Harris Corporation
    Inventors: Joseph B. Shaver, John Wesley Nieto, William N. Furman
  • Publication number: 20140177756
    Abstract: A method for transmitting a signal by a signal transmission apparatus in a communication system is provided. The method includes detecting a parameter related to a Quadrature Amplitude Modulation (QAM) scheme and a parameter related to a Frequency Shift Keying (FSK) scheme based on channel quality and an interference component, and modulating information bits using a modulation scheme based on the QAM scheme and the FSK scheme which uses the parameter related to the QAM scheme and the parameter related to the FSK scheme.
    Type: Application
    Filed: December 23, 2013
    Publication date: June 26, 2014
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Jeong-Ho PARK, Tae-Young KIM, Won-Il ROH, Min SAGONG, Ji-Yun SEOL, Hyun-Kyu YU, Kyung-Whoon CHEUN, Jae-Weon CHO, Sung-Nam HONG
  • Publication number: 20140177687
    Abstract: A modulation method and an apparatus with consideration of adaptive Hybrid Automatic Repeat reQuest (HARQ) in a wireless communication system are provided. The method of a transmission end supporting a hybrid modulation technique in which different types of modulation schemes are mixed, information of a channel state with a reception end is collected. A modulation order of a first type of a modulation scheme and a modulation order of a second type of a modulation scheme are determined. The modulation order of a first type of a modulation scheme and a modulation order of a second type of a modulation scheme form the hybrid modulation technique.
    Type: Application
    Filed: December 23, 2013
    Publication date: June 26, 2014
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Ji-Yun SEOL, Tae-Young KIM, Won-Il ROH, Jeong-Ho PARK, Min SAGONG, Hyun-Kyu YU, Kyung-Whoon CHEUN, Jae-Weon CHO, Sung-Nam HONG
  • Publication number: 20140169488
    Abstract: A method of signal generation includes selecting a subset of contiguous OFDM symbols from a set of contiguous OFDM symbols, selecting a subset of contiguous subcarriers from a set of subcarriers, and generating a preamble that occupies the subset of contiguous subcarriers in the subset of contiguous OFDM symbols. The preamble includes portions in respective OFDM symbols of the subset of contiguous OFDM symbols. In the time domain each preamble portion corresponds to a repeating sequence of samples when subcarriers outside of the subset of contiguous subcarriers are filtered out. Generating the preamble may include flipping the sign of one or more occurrences of the repeating sequence for a final preamble portion and may include placing modulation symbols on regularly spaced subcarriers in the subset of contiguous subcarriers and phase-shifting the modulation symbols for a respective preamble portion with respect to a previous preamble portion.
    Type: Application
    Filed: August 13, 2013
    Publication date: June 19, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Nicola Varanese, Muhammad Awais Amin, Christoph A. Joetten, Juan Montojo
  • Publication number: 20140169499
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using nDSQ format(s) over optical communication networks. In certain embodiments, the communication interface is used by various devices, such as spine switches and leaf switches, within a spine-leaf network architecture, which allows large amount of data to be shared among servers.
    Type: Application
    Filed: July 26, 2013
    Publication date: June 19, 2014
    Applicant: Inphi Corporation
    Inventors: Jamal RIANI, Sudeep BHOJA
  • Patent number: 8755447
    Abstract: A communications system, e.g., a wireless microphone, incorporates a quadrature modulator system to reduce power consumption with respect to traditional approaches and is general in nature to support any two-dimensional digital technique. The quadrature modulator system comprises different subsystems, including a digital-analog transformation circuit, a baseband filter, and a quadrature modulator. The digital-analog transformation circuit converts discrete time samples to a continuous time signal, and further includes an oversampling noise-shaping modulator such as a sigma-delta modulator. The baseband filter then removes out-of-band energy including sampling images and quantization noise. Some of the circuit components may comprise discrete devices that may result in a reduction of power consumption for the quadrature modulator system. Alternatively, some or all of the circuit components may be incorporated in a single electronic device.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: June 17, 2014
    Assignee: Shure Acquisition Holdings, Inc.
    Inventors: Michael Joseph Goodson, Thomas J. Kundmann, Jeffrey Arthur Meunier
  • Patent number: 8755263
    Abstract: The present invention relates to a device and method for optimal estimation of the distortion caused by the transmission medium by means of the sequential emission of pairs of quadrature complementary sequences, estimating the frequency spectrum of a transmission channel allows obtaining information of considerable interest to analyze its characteristics or correcting the distortion effects introduced in a communication system. This invention describes a new method for extracting said characteristics generating a transmission preamble using complementary sequences, which allows upon reception identifying the distortion caused in each of the I/Q phases of a quadrature modulation system on the transmitted symbols, canceling the phase distortion effects caused by the medium and reducing the equalization of the channel to a single equalizing baseband filter identical for both I2/Q2 phases.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: June 17, 2014
    Inventors: Vicente Diaz Fuente, Daniel Hernanz Chiloeches, Jesus Berian Mugica
  • Patent number: 8750407
    Abstract: A transmitter, channel coder, and method for coding and transmitting a sequence of symbols in a digital communication system utilizing soft pilot symbols. In one embodiment, the transmitter transmits a set of soft pilot symbols with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The transmitter shares the modulation type and location (time/frequency/code) of the soft pilot symbols with a receiver. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. In another embodiment, soft pilot symbols are inserted by low-level puncturing of channel encoded bits and replacing the punctured bits with known bit patterns.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: June 10, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Jung-Fu Cheng, Tracy Fulghum, Douglas Cairns
  • Patent number: 8750421
    Abstract: A communications transmitter includes a combination modulator and a baseband processor configured to generate amplitude, angle, in-phase and quadrature signals. The combination modulator is configured to modulate in the quadrature domain or the polar domain, depending on an output power level of the transmitter and/or the type of modulation scheme being used. When configured to modulate in the quadrature domain, the baseband processor is configured to generate time-varying in-phase and quadrature modulating signals and time-invariant amplitude and angle signals for the combination modulator. When configured to modulate in the polar domain, the baseband processor is configured to generate time-varying amplitude and angle modulating signals and time-invariant in-phase and quadrature signals for the combination modulator. In another embodiment of the invention, the communications transmitter is configurable to operate in three different operational modes: linear, envelope tracking and switch modes.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: June 10, 2014
    Inventor: Earl W. McCune, Jr.
  • Patent number: 8744014
    Abstract: A FFR (fractional frequency reuse)-based network MIMO (multiple-input multiple-output) transmission architecture in a cellular system that employs cell sectoring using directional antennas. Each cell is sectorized into three outer sectors using three directional antennas which transmit in three different directions using three different frequency subbands. The cell sectors are arranged based on a frequency partition scheme so that three sectors in three neighboring cells form a coordinated group for network MIMO transmission. A regular and a rearranged frequency partition are described. Further, a practical implementation of SON (self organizing network)-based three-cell FFR-based network MIMO for a wireless OFDM system is described.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: June 3, 2014
    Assignee: Mediatek Inc.
    Inventors: Chu-Jung Yeh, Li-Chun Wang, I-Kang Fu
  • Patent number: 8743976
    Abstract: Techniques, apparatuses and systems for providing communications based on time reversal of a channel impulse response of a pulse in a transmission channel between a transmitter and a receiver to enhance reception and detection of a pulse at the receiver against various effects that can adversely affect and complicate the reception and detection of the pulse at the receiver.
    Type: Grant
    Filed: September 3, 2010
    Date of Patent: June 3, 2014
    Assignee: Ziva Corporation
    Inventors: David F. Smith, Anis Husain
  • Patent number: 8744005
    Abstract: A method of generating modulation signals is disclosed including generally three steps. A plurality of modulation signals are generated, each of which is to be transmitted from a different one of a plurality of antennas in an identical frequency band, wherein each modulation signal includes a pilot symbol sequence including a plurality of pilot symbols used for demodulation. Each of the pilot symbol sequences is inserted at the same temporal point in each modulation signal, wherein the pilot symbol sequences are orthogonal to each other with zero mutual correlation among the plurality of modulation signals, each pilot symbol having a non-zero amplitude, the quantity of the plurality of pilot symbols in each sequence being greater than the quantity of the plurality of modulation signals to be transmitted. The plurality of modulation signals each including different transmission data and one of the pilot symbol sequences are output to the antennas.
    Type: Grant
    Filed: September 5, 2013
    Date of Patent: June 3, 2014
    Assignee: Panasonic Corporation
    Inventors: Yutaka Murakami, Masayuki Orihashi, Akihiko Matsuoka
  • Patent number: 8744003
    Abstract: A transmitter may comprise a symbol mapping circuit that is configurable to operate in at least two configurations, wherein a first of the configurations of the symbol mapping circuit uses a first symbol constellation and a second of the configurations of the symbol mapping circuit uses a second symbol constellation. The transmitter may also comprise a pulse shaping circuit that is configurable to operate in at least two configurations, wherein a first of the configurations of the pulse shaping circuit uses a first set of filter taps and a second of the configurations of the pulse shaping circuit uses a second set of filter taps. The first set of filter taps may correspond to a root raised cosine (RRC) filter and the second set of filter taps corresponds to a partial response filter.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: June 3, 2014
    Assignee: MagnaCom Ltd.
    Inventor: Amir Eliaz
  • Publication number: 20140140432
    Abstract: A method of compensating phase error of a received signal is disclosed. The signal comprises a symbol set comprising a plurality of symbols of a first type having an N-Quadrature Amplitude Modulation, N-QAM, signal configuration, where N is an integer larger than 4, and at least one symbol of a second type having an Amplitude and Phase-Shift Keying, A-PSK, signal configuration, wherein both the symbols of the first type and of the second type carries data and wherein the symbols of the second type also are arranged as pilot symbols for determination of phase rotation determination. A receiver and transmitter, as well as a communication system, employing the symbol set are disclosed.
    Type: Application
    Filed: July 8, 2011
    Publication date: May 22, 2014
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Dan Weinholt, Carmelo Decanis
  • Patent number: 8724738
    Abstract: Techniques for rotating and transmitting multidimensional constellations are disclosed. A method for rotating a multidimensional constellation may include constructing a first rotation matrix, constructing a second rotation matrix, applying orthogonality constraints to the first and second rotation matrices; selecting an optimizing rotation matrix from the first and second rotation matrices; and rotating the multidimensional constellation using the optimizing rotation matrix. Constructing the first rotation matrix and second rotation matrices may include constructing a first column that includes first matrix dements based on the number of axes in the multidimensional constellation, and additional columns that include permutations of the first matrix elements.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: May 13, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rabih Chrabieh, Ozgur Dural
  • Publication number: 20140126671
    Abstract: In one embodiment, a sequence of a plurality of pairs of in-phase (I) and quadrature (Q) modulated signal samples are applied to a radio frequency digital-to-analog converter (RFDAC) for upconversion. A phase of a local oscillator (LO) signal supplied to the RFDAC is selected according to a quadrant determined by signs of a given pair of I and Q modulated signal samples. The selected phase of the LO is supplied to the RFDAC for use in upconverting the sequence of I and Q modulated signal samples. In another embodiment, a current steering DAC is used for directly upconverting the I and Q modulated signal samples. A clock signal at four times the LO frequency is supplied to a counter and to the current steering DAC. One of the I and Q modulated signal samples and negative I and negative Q modulated signal samples is selected for supply to an input of the current steering DAC based on a count state of the counter.
    Type: Application
    Filed: November 6, 2012
    Publication date: May 8, 2014
    Applicant: MSTAR SEMICONDUCTOR, INC.
    Inventors: Khurram Muhammad, Bernard Ginetti, Dennis Mahoney
  • Publication number: 20140126672
    Abstract: Information bits are encoded according to a low density parity check code with code rate 7/15 and a codeword length of 16200. The resulting codeword bits are bit-interleaved and the interleaved bits are demultiplexed into 8 sequences of bits. The 8 sequences of bits are permuted according to a predetermined permutation rule: v0=b2, v1=b6, v2=b0, v3=b1, v4=b4, v5=b5, v6=b3, v7=b7.
    Type: Application
    Filed: June 14, 2012
    Publication date: May 8, 2014
    Inventor: Mihail Petrov
  • Patent number: 8718174
    Abstract: A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: July 31, 2012
    Date of Patent: May 6, 2014
    Assignee: NEC Laboratories America, Inc.
    Inventors: Narayan Prasad, Guosen Yue, Mohammad A. Khojastepour, Meilong Jiang, Sam Path Rangarajan
  • Patent number: 8718189
    Abstract: A digital television (DTV) system uses parallel concatenated coding (PCC), together with QAM constellations for modulating OFDM carriers. A first encoder responds to ONEs' complemented bits of randomized data to generate a first component of PCC. A second encoder responds to delayed bits of the randomized data to generate a second component of PCC. A constellation mapper generates QAM symbols responsive to successive time-slices of the first component of the PCC interleaved with successive time-slices of the second component of the PCC. An OFDM modulator generates a COFDM modulating signal responsive to the QAM symbols. In a receiver for the DTV system, the second component of the PCC and delayed first component of the PCC are iteratively decoded. Soft bits from the second component and delayed first component of the parallel concatenated coding are code-combined to supply soft randomized data used in that iterative decoding.
    Type: Grant
    Filed: June 11, 2012
    Date of Patent: May 6, 2014
    Inventor: Allen LeRoy Limberg
  • Patent number: 8718212
    Abstract: Embodiments of the present invention provide a rate matching method and apparatus. The method includes: receiving bit data of a first, a second, and a third input subblock, inserting dummy data into bit data in each subblock to respectively form even-numbered rows and odd-numbered rows of a matrix to be buffered for each subblock; inputting bit data of the even-numbered rows in the even-numbered row buffer and bit data of the odd-numbered rows in the odd-numbered row buffer of each subblock to a second buffer, and forming a matrix by using the bit data of the even-numbered rows and the bit data of the odd-numbered rows; controlling the second buffer to send data at the specified address; selecting data sent by the second buffer; and deleting the dummy data from the selected data to obtain valid output data.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: May 6, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventor: Xin Ma
  • Patent number: RE44927
    Abstract: A method is provided for specifying a transmission mode for each signal portion of a multi-carrier signal transmitted between a first and second device. The method includes defining an adaptive modulation and coding set divided into a plurality of subsets, each of the plurality of subsets including a plurality of transmission modes for transmitting a signal portion. The method further includes selecting a transmission mode subset from the plurality of subsets for transmission of the multi-carrier signal from a first to a second device, selecting a signal portion transmission mode for each signal portion from the plurality of transmission modes of the selected transmission mode subset, defining semantic bits that indicate the selected transmission mode subset, defining an indicator bit for each signal portion indicating the selected sub-carrier transmission mode, and transmitting the semantic bits and the indicator bit for each signal portion from a first to a second device.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: June 3, 2014
    Assignee: Nokia Corporation
    Inventors: Olav Tirkkonen, Paolo Priotti, Ulrico Celentano