Amplitude Modulation Patents (Class 375/320)
  • Patent number: 10237114
    Abstract: A transmitter device comprises a first predistortion circuit and a second predistortion circuit having at least one correction stage provided with a correction path for determining a correction term. The correction term for each source signal is a function of a corresponding symbol of a predefined constellation for each source signal and of the output of a model having a circuit to emulate modulation means and the second predistortion circuit, a circuit to emulate a non-linear transmission link over which a predistorted version of an aggregate pulse-shaped signal is to be transmitted for amplitude levels before saturation of an AM/AM characteristic of the transmission link occurs and to emulate the non-linear transmission link for amplitude levels beyond saturation of the AM/AM characteristic, and a circuit to emulate demodulation means.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: March 19, 2019
    Assignee: NEWTEC CY
    Inventors: Dieter Duyck, Olivier De Deken
  • Patent number: 10193685
    Abstract: A reception circuit includes a determination circuit including comparator circuits configured to determinate a level of a received signal and a logic circuit configured to generate a digital signal based on outputs of the comparator circuits. The determination circuit is configured to determinate by a first number of the comparator circuits when the received signal is a first signal which is a multi-valued signal and determinate by a second number of the comparator circuits, the second number being smaller than the first number, when the received signal is a second signal. The logic circuit is configured to operate as a decoder which decodes outputs of the comparator circuits and generates the digital signal when the received signal is the first signal, and operates as a selector which selects an output of the comparator circuit for generating the digital signal when the received signal is the second signal.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: January 29, 2019
    Assignee: SOCIONEXT INC.
    Inventor: Masahiro Kudo
  • Patent number: 9860035
    Abstract: A method of an RFC chip for a station, the RFC chip including a WLAN communication module to decode a DL MU-MIMO wireless signal, the method including: determining an FS layer column based on a product of a channel matrix of the station and an estimate of a steering matrix of the station; ordering columns of a sub-matrix of an effective channel matrix of the station to determine one or more SS layer columns from the sub-matrix, the sub-matrix being determined by removing, from the effective channel matrix, a column corresponding to the determined FS layer column; configuring a modified effective channel matrix based on the determined FS layer column and the ordered columns of the sub-matrix, the determined FS layer column being determined as an FS layer column of the modified effective channel matrix; and determining a symbol of the station based on the modified effective channel matrix.
    Type: Grant
    Filed: May 25, 2016
    Date of Patent: January 2, 2018
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Ji Hun Koo
  • Patent number: 9621883
    Abstract: The invention relates to a method and apparatus for evaluating a network and for predicting network performance for a higher order modulation by analyzing network signals modulated using a lower order modulation format. A margin index may be generated for the current or projected modulation formats based on displacement vectors for received symbols to indicate a margin remaining before a codeword error occurs to alert the network operator of potential performance issues before actual codeword errors occur.
    Type: Grant
    Filed: May 15, 2015
    Date of Patent: April 11, 2017
    Assignee: VIAVI SOLUTIONS INC.
    Inventors: Jim Walsh, Ching-Chang Liao
  • Patent number: 9571168
    Abstract: A data transceiver device for near field communication is provided which includes a matching and filtering circuit connected between an antenna and a transceiver and configured to conduct filtering and impedance matching for a reception signal and a transmission signal. The matching and filtering circuit includes a variable attenuator of which the impedance varies with a frequency so that an attenuation ratio of the reception data is smaller than that of the reception carrier signal.
    Type: Grant
    Filed: July 10, 2015
    Date of Patent: February 14, 2017
    Assignee: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Byeongtaek Moon, Jinwoo Kim, Junho Kim
  • Patent number: 9252712
    Abstract: Described herein is a fixed-point piece-wise linear (FP PWL) approximation technique for computations of nonlinear functions. The technique results in circuit designs having relatively few and simple arithmetic operations, short arithmetic operands and small-sized look-up tables and the circuits resultant there from can be efficiently pipelined to run at multi-GSamples/s throughputs. In one exemplary embodiment, the FP PWL approximation technique was used in the design of an energy-efficient high-throughput and high-precision signal component separator (SCS) for use with in an asymmetric-multilevel-outphasing (AMO) power amplifier. The FP PWL approximation technique is appropriate for use in any application requiring high-throughput, area and power constrained hardware implementations of nonlinear functions.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: February 2, 2016
    Assignee: Massachusetts Institute of Technology
    Inventors: Yan Li, Zhipeng Li, Yehuda Avniel, Alexandre Megretski, Vladimir Marko Stojanovic
  • Patent number: 9036738
    Abstract: A receiving device including: a demodulation circuit configured to generate first likelihood data of reception symbols based on a transmission format of the reception symbols, the transmission format being selected from transmission formats and including a modulation scheme applied to the reception symbols, the modulation scheme being one of amplitude modulation schemes, a processor configured to estimate a scale ratio of an implementation scale to a theoretical scale, the implementation scale being a scale of the first likelihood data, the theoretical scale being a scale of second likelihood data of the reception symbols, the second likelihood data being defined by a theory and not depending on an implementation of the receiving device, and to generate the second likelihood data based on the first likelihood data and the scale ratio, and a decoding circuit configured to decode the second likelihood data based on the transmission format.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: May 19, 2015
    Assignee: FUJITSU LIMITED
    Inventor: Shunji Miyazaki
  • Patent number: 9036742
    Abstract: A demapping scheme, having a low computational cost, suitable for any transmission in which only exhaustive demapping can guarantee good performance. The scheme, proposed in this document, can be used in any transmission based on no differential modulation. For example the proposed scheme can be directly applied to a transmission on flat fading AWGN channels or to a transmission on frequency selective channels after equalization or on each sub-carrier of an OFDM System. The proposed solution can be applied for the demapping of any communication system. The proposed scheme can be used for rotated and un-rotated constellation.
    Type: Grant
    Filed: March 15, 2012
    Date of Patent: May 19, 2015
    Assignee: ALi Europe Sarl
    Inventors: Matteo Butussi, Stefano Tomasin
  • Patent number: 9031168
    Abstract: A method for optimizing a constellation for M-ary amplitude phase shift keying (M-APSK) that provides signal modulation for transmitting a series of digital bits in an analog signal by a transmitter to be received by a receiver over a communications channel. The method includes identifying symbol-wise mutual information of a transmitted constellation, where the symbol-wise mutual information includes a conditional probability density function. The method identifies an unconstrained capacity that defines an ultimate performance limit of the constellation, and minimizes a difference between a rate of the symbol-wise mutual information and a rate of the unconstrained capacity to determine the number of rings, the number of symbols in each ring and the ring ratio in the constellation.
    Type: Grant
    Filed: April 21, 2014
    Date of Patent: May 12, 2015
    Assignee: Northrop Grumman Systems Corporation
    Inventor: Daniel N. Liu
  • Publication number: 20150124907
    Abstract: Described herein is a fixed-point piece-wise linear (FP PWL) approximation technique for computations of nonlinear functions. The technique results in circuit designs having relatively few and simple arithmetic operations, short arithmetic operands and small-sized look-up tables and the circuits resultant there from can be efficiently pipelined to run at multi-GSamples/s throughputs. In one exemplary embodiment, the FP PWL approximation technique was used in the design of an energy-efficient high-throughput and high-precision signal component separator (SCS) for use with in an asymmetric-multilevel-outphasing (AMO) power amplifier. The FP PWL approximation technique is appropriate for use in any application requiring high-throughput, area and power constrained hardware implementations of nonlinear functions.
    Type: Application
    Filed: May 5, 2013
    Publication date: May 7, 2015
    Applicant: Massachusetts Institute of Technology
    Inventors: Yan Li, Zhipeng Li, Yehuda Avniel, Alexandre Megretski, Vladimir Marko Stojanovic
  • Patent number: 9025430
    Abstract: A system, method and node for modulation and coding scheme adjustment for a Long Term Evolution (LTE) shared Data Channel. The method determines an actual number of orthogonal frequency division multiplexing (OFDM) symbols, NOS utilized for the shared Data Channel. A modulation order for transmission of data on the shared Data Channel is increased when the actual number of OFDM symbols NOS is less than 11 and decreased when NOS is more than 11. A modulation and coding scheme field (IMCS) of a downlink control information of the shared Data Channel may also be determined. If 0?IMCS+11?NOS?28, the modulation order is modified by utilizing a factor of (IMCS+11?NOS) in a standardized modulation scheme. If it is determined that IMCS+11?NOS<0, the modulation order is set to Quadrature Phase Shift Keying (QPSK). If it is determined that IMCS+11?NOS>28, the modulation order is set to 64 Quadtrative Amplitude Modulation (64QAM).
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: May 5, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Jung-Fu Cheng, Yang Hu
  • Publication number: 20150117866
    Abstract: Modulation and demodulation of digital signals comprising symbols representing four or more bits uses a constellation map in which initial two bits of the modulated data identify a quadrant of the constellation map and the remaining bits of the modulated data identify a symbol within the quadrant corresponding to the four or more data bits. In some systems, the constellation map is made up from each successive two bits of the input data bits successively identifying a quadrant within a quadrant until a group of bits is uniquely mapped to a single symbol.
    Type: Application
    Filed: October 29, 2014
    Publication date: April 30, 2015
    Inventors: Hung-Chang Chien, Zhensheng Jia, Jianjun Yu
  • Patent number: 9013277
    Abstract: In a method of allocating digital data (55a, 55b) coming from transponders, a reader (1) receives a first signal (13) that comprises a first signal component (7) coming from a first transponder (2) and a second signal component (8) coming from a second transponder (3). The digital data (55a) coming from the first transponder (2) are encoded in the first signal component (7) and digital data (55b) coming from the second transponder (3) are encoded in the second signal component (8). Second and third signals (10, 11) are generated by subjecting the first signal (13) to an in-phase and to an in-quadrature demodulation. The digital data (55a, 55b) of the first and second transponders (2, 3) are encoded in the second and third signals (10, 11). Clusters (51-54) of the digital data (55 a, 55b) associated with a constellation diagram, which is related to the second and third signals (10, 11), are allocated to the first and second transponder (2, 3).
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: April 21, 2015
    Assignee: NXP B.V.
    Inventor: Ulrich Muehlmann
  • Patent number: 9014289
    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: Grant
    Filed: October 28, 2013
    Date of Patent: April 21, 2015
    Assignee: GCT Semiconductor, Inc.
    Inventors: Eal Wan Lee, Dae Hong Kim, Jeong Min Kim
  • Patent number: 9014253
    Abstract: A method, apparatus, and computer program for detecting sequences of digitally modulated symbols transmitted by multiple sources are provided. A real-domain representation that separately treats in-phase and quadrature components of a received vector, channel gains, and a transmitted vector transmitted by the multiple sources is determined. The real-domain representation is processed to obtain a triangular matrix. In addition, at least one of the following is performed: (i) hard decision detection of a transmitted sequence and demapping of corresponding bits based on a reduced complexity search of a number of transmit sequences, and (ii) generation of bit soft-output values based on the reduced complexity search of the number of transmit sequences. The reduced complexity search is based on the triangular matrix.
    Type: Grant
    Filed: January 7, 2013
    Date of Patent: April 21, 2015
    Assignees: STMicroelectronics, S.r.l., The Regents of the University of California
    Inventors: Massimiliano Siti, Michael P. Fitz
  • Publication number: 20150103956
    Abstract: A high order modulation method, a demapping method, and a corresponding device are provided. With the high order modulation method, important bits is distinguished, and the important bits are divided into important bits for distinguishing large regions and important bits for distinguishing small regions according to the difficulty of judgment areas. Therefore, the judgment accuracy rate of a demodulator is further improved.
    Type: Application
    Filed: December 19, 2014
    Publication date: April 16, 2015
    Inventors: Yanxing Zeng, Guangjian Wang, Kunpeng Liu
  • Patent number: 9008229
    Abstract: A device for obtaining a RCC signal and related methods are described herein improves the reliability of the RCC signal reception and demodulation. In one aspect, a device configured to obtain a RCC signal includes: a receiving circuit to receive an analog AM RCC signal and to process said analog AM RCC signal to generate a digital AM RCC signal; and a demodulation circuit in connection with said receiving circuit, to demodulate said digital AM RCC signal to generate the RCC signal. In another aspect, a method for obtaining a RCC signal includes: processing a received analog AM RCC signal to generate a digital AM RCC signal; and demodulating said digital AM RCC signal to generate said RCC signal. Since the digital processing method is more reliable than the analog processing method, the reliability of RCC signal reception and demodulation are improved.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: April 14, 2015
    Assignee: Beijing KT Micro, Ltd.
    Inventor: Zhen Li
  • Patent number: 9008230
    Abstract: In one embodiment, an apparatus is provided that includes a first circuit configured and arranged to provide a modulated carrier signal in response to a signal provided from the antenna. The modulated carrier signal conveys data using peaks or amplitudes of the carrier signal. A second circuit is configured to rectify the modulated carrier signal and integrate the rectified signal in response to a first clock signal. A third circuit is coupled to an output of the second circuit and is configured to sample the integrated signal values and provide therefrom a sample-based approximation of the modulated carrier signal.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: April 14, 2015
    Assignee: NXP B.V.
    Inventors: Remco C. VandeBeek, Massimo Ciacci, Ghiath Al-kadi
  • Publication number: 20150098514
    Abstract: A technique for generating a bit log-likelihood ratio (LLR) in a communication system includes generating a demodulated signal based on a received symbol and a reference symbol. An input for a bit LLR generator is generated based on the demodulated signal and a normalization value that is based on the received symbol or the reference symbol. A bit LLR is generated for the received symbol, using the bit LLR generator, based on the input.
    Type: Application
    Filed: October 8, 2013
    Publication date: April 9, 2015
    Inventor: Raja V. Tamma
  • Publication number: 20150098528
    Abstract: A device (101) for data-reception using amplitude modulation, comprises a coil (121) having a coil terminal (123) and being adapted to receive an amplitude modulated electromagnetic wave (116), whereupon an amplitude modulated signal (Vb) is induced in the coil (121) and provided at the coil terminal (123), the amplitude modulated signal (Vb) comprising a positive voltage portion (325, 427) and a negative voltage portion (324,428); and an adjustment circuit (125, 300,400) connected via an input terminal (129, 302,403) to the coil terminal (123), wherein the adjustment circuit is adapted: to adjust the amplitude modulated signal such as to reduce the positive voltage portion (325,427) by a constant amount (?) and to provide the adjusted amplitude modulated signal (129, 323,425) at an output terminal (131,317,427) of the adjustment circuit (125, 300,400).
    Type: Application
    Filed: August 28, 2014
    Publication date: April 9, 2015
    Inventors: Juergen Nowottnick, Juergen Lemke
  • Patent number: 9001949
    Abstract: A method in a QAM receiver (100) for performing timing recovery. The QAM receiver (100) is configured to receive a sequence of symbols. Each symbol is represented by a respective IQ pair comprising a respective inphase component I and a respective quadrature component Q. The QAM receiver (100) samples the respective I component and the respective Q component with a relative timing offset between the sampling of the respective I component and the respective Q component. The QAM receiver (100) establishes a first value associated to a quality of the I component samples, and a second value associated to a quality of the Q component samples, and compares the first value and second value to determine if the sampling timing should be advanced or delayed to improve the sample quality. The QAM receiver (100) adjusts subsequent sampling by advancing or delaying a sampling timing based on the comparison.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: April 7, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Christer Svensson
  • Patent number: 8995583
    Abstract: A technique for decoding a signal in a communication network is provided. A method implementation of the technique comprises the steps of receiving a signal; identifying a position in the signal; initializing a Viterbi state metric; and decoding the encoded signal by means of a wrap-around Viterbi algorithm. The received signal comprises information, wherein the signal is encoded by a tail-biting convolutional code. The identified position relates to a known portion of the information. The initialized Viterbi state metric is consistent with the known portion of the information. The decoding uses the initial Viterbi state metric, wherein the decoding starts at a decoding step following the identified position.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: March 31, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Stefan Mueller-Weinfurtner, Matthias Kamuf
  • Patent number: 8989314
    Abstract: A computer-readable medium stores instructions causing one or more processors to demodulate a received signal including a plurality of user signals. Respective user data in each of at least some of the plurality of user signals is encoded with a respective finite state machine encoder having a respective number of states Si, wherein i=1, 2, . . . , N, N being the number of users, and wherein at least a first user signal and a second user signal are encoded independently of each other. The instructions cause the processor(s) to calculate distances between transmit symbols in the received signal and an expected joint symbol value, and jointly decode, with a finite state machine decoder, user data in the demodulated received signal, including at least first user data corresponding to the first user signal, based on the calculated distances. The finite state machine decoder has S1*S2* . . . *SN states.
    Type: Grant
    Filed: March 17, 2014
    Date of Patent: March 24, 2015
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Jihwan P. Choi
  • Patent number: 8988260
    Abstract: A continuous-time delta-sigma digital-to-analog converter (DAC) includes a first delta-sigma modulator configured to quantize a most significant bit or bits of a digital input signal and produce a first quantization error signal, and a second multi-stage delta-sigma modulator configured to quantize less significant bits of the digital input signal. A first DAC is coupled to an output of the first delta-sigma modulator, and a second DAC is coupled to an output of the second noise-shaping filter. The second DAC has a greater resolution than the first DAC. A low pass output filter is coupled to a sum of an output of the first DAC and an output of the second DAC.
    Type: Grant
    Filed: October 26, 2012
    Date of Patent: March 24, 2015
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Martin Kinyua
  • Patent number: 8989317
    Abstract: An efficient decoding of vector signaling codes is obtained using a circuit that ranks received signal levels, designates ranked values as representing particular code elements, and translates those particular code elements into a decoded result. An optimized ranking circuit combines analog crossbar switching of signal values with comparators that provide digital results. These elements may be repetitively tiled into processing arrays capable of larger ranking operations, or iteratively applied to selected portions of the data set under control of a sequencer or controller.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: March 24, 2015
    Assignee: Kandou Labs, S.A.
    Inventors: Brian Holden, Amin Shokrollahi
  • Patent number: 8989244
    Abstract: A receiver is provided that receives signals from a device under test (DUT) for one or more modes of operation. For each mode, the system detects beacon transmission signals from the DUT, and counts the number of beacons for a period of time. If the count is not consistent with an expected count, e.g. a stored value, the system may preferably provide an output to indicate that there is a problem with the DUT. If the count is consistent with the expected count, the system may preferably perform further testing for other modes of operation. If the count output of the DUT is consistent with expected counts over each of the operation modes, the system may provide an indication that the DUT has passed the beacon tests.
    Type: Grant
    Filed: December 10, 2012
    Date of Patent: March 24, 2015
    Assignee: NETGEAR, Inc.
    Inventors: Joseph Amalan Arul Emmanuel, Jonathan M. Hummel, Shahrokh M. Zardoshti
  • Publication number: 20150078486
    Abstract: Disclosed are a code modulation method and apparatus for high order modulation. The method comprises: converting information that needs to be transmitted into a bit data stream, and demultiplexing the bit data stream into more than one channel of bit data stream; performing first-type coding on at least one channel of bit data stream in the more than one channel of stream, to obtain first output data; performing second-type coding on at least one channel of the remaining channels of bit data stream on which the first-type coding is not performed, to obtain second output data; and performing quadrature amplitude modulation on the first output data, to generate a modulation symbol for output. Compared with the prior art, the correctness rate of demodulation in the technical solution is improved significantly, achieving higher transmission efficiency.
    Type: Application
    Filed: November 24, 2014
    Publication date: March 19, 2015
    Inventors: Guangjian Wang, Yanxing Zeng, Kunpeng Liu
  • Patent number: 8981970
    Abstract: A binary allocation in a hierarchical coding/decoding comprising a coding/decoding of a digital signal enhancement layer. The signal comprises a succession of L samples, each sample being represented by a mantissa and an exponent. The method comprises the allocation of a predetermined number Nb of enhancement bits to a part at least of the L samples of highest exponent values. In particular, the method comprises the steps: a) enumerating the exponents of the L samples each having a given value, b) calculating at least one aggregate of enumerations of exponents by decreasing values of exponent until the predetermined number Nb is approximated from above, for c) determining a threshold value of largest exponent iexp0 of sample for which no more enhancement bit is available, and allocating the Nb enhancement bits, according to chosen rules, to the samples whose exponent is greater than the aforesaid threshold value iexpo.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: March 17, 2015
    Assignee: Orange
    Inventor: Claude Lamblin
  • Patent number: 8976846
    Abstract: A wireless transmission system includes a wireless HDMI transmitter and a wireless HDMI receiver. The wireless HDMI transmitter includes a carrier oscillator provided for each channel of an HDMI transmission path to output a carrier signal in a millimeter band, an OOK modulator provided for each carrier oscillator to perform on-off keying modulation on a carrier signal outputted by its corresponding carrier oscillator, and an input circuit provided for each channel of the HDMI transmission path to input a digital signal outputted by a source device to the OOK modulator. Radio signals have different planes of polarization from their adjacent channels.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: March 10, 2015
    Assignees: Silicon Library Inc., Hitachi Chemical Co., Ltd., Hiroshima University
    Inventors: Junzoh Shimizu, Minoru Fujishima, Masahiko Ohta, Toshio Takada
  • Patent number: 8971453
    Abstract: A digital receiver includes a radio frequency analog front end, a digital processing unit, a plurality of cascaded amplifier stages configured to receive output of the radio frequency analog front end, a first analog to digital converter configured to convert an analog signal output from the plurality of cascaded amplifier stages into a digital signal output to the digital processing unit, a first received signal strength indicator unit configured to receive outputs of each of the plurality of cascaded amplifier stages and output signal to the digital processing unit, a second received signal strength indicator unit configured to receive output of at least one amplifier stage in the plurality of cascaded amplifier stages, and a received signal strength indicator detection unit configured to activate and to deactivate digital units according to a comparison of output from the second received signal strength indicator unit to a predetermined threshold.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: March 3, 2015
    Assignee: Uniband Electronic Corp.
    Inventors: Yiping Fan, Chun-Yuan Lin, Sheng-Chia Huang, Chun-Chin Chen
  • Patent number: 8964818
    Abstract: A short reach communication system includes a plurality of communication SERDES that communicate data over a short reach channel medium such as a backplane connection (e.g., PCB trace) between, for example, chips located on a common PCB. A multi-level modulated data signal is generated to transmit/receive data over the short reach channel medium. Multi-level modulated data signals, such as four-level PAM, reduce the data signal rate therefore reducing insertion loss, power, complexity of the circuits and required chip real estate.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: February 24, 2015
    Assignee: Broadcom Corporation
    Inventors: Lorenzo Longo, Vivek Telang
  • Publication number: 20150049844
    Abstract: A method and transmitter and receiver for determining and transmitting or receiving a non-uniform QAM signal comprises selecting a signal to noise ratio for a channel and forward error corrector and then determining positions of constellation points that maximise a measure of channel capacity at the selected signal to noise ratio. The position of one constellation point and another constellation point within the constellation are constrained to be equal to one another prior to determining the positions of the constellation points. In doing so, a so called condensed QAM constellation arrangement may be derived having fewer than conventional number of constellation points for a given QAM scheme. The condensed QAM arrangement has improved performance at certain signal to noise ratios.
    Type: Application
    Filed: February 6, 2013
    Publication date: February 19, 2015
    Applicant: British Broadcasting Corporation
    Inventor: Jonathan Stott
  • Patent number: 8942634
    Abstract: Aspects of a method and system for interference suppression using information from non-listened base stations are provided. A wireless communication device may be operable to receive a raw signal comprising one or more desired signals from one or more serving base transceiver stations (BTSs) and comprising one or more undesired signals from one or more non-listened BTSs. The wireless communication device may be operable to generate first estimate signals that estimate the one or more undesired signals as transmitted by the one or more non-listened BTSs, generate an interference suppressed version of the raw signal based on the first estimate signals, and recover the one or more desired signals from the interference suppressed version of the raw signal. The non-listened BTSs may comprise one or more BTSs that are not serving the wireless communication device and are not involved in a hand off of the wireless communication device.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: January 27, 2015
    Assignee: Broadcom Corporation
    Inventors: Mark Hahm, Wei Luo
  • Publication number: 20150023452
    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: October 9, 2014
    Publication date: January 22, 2015
    Inventors: Jamal RIANI, Sudeep BHOJA
  • Patent number: 8934578
    Abstract: A method of demodulating a plurality of multiplexed modulation signals is provided, including: i) inputting the plurality of multiplexed modulation signals, each of which being outputted from a plurality of outputs of a communication partner, wherein each modulation signal in the multiplexed modulation signals includes a pilot symbol sequence consisting of a plurality of pilot symbols used for demodulation, ii) estimating respective channels of the multiplexed modulation signals based on one or more of the pilot symbol sequences; and iii) demodulating each modulation signal in the plurality of multiplexed modulation signals based on the channel estimation. Each of the pilot symbol sequences is inserted at a same temporal point in each modulation signal among the multiplexed modulation signals. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the modulation signals in the multiplexed modulation signals, and each pilot symbol has a non-zero amplitude.
    Type: Grant
    Filed: April 18, 2014
    Date of Patent: January 13, 2015
    Assignee: Wi-Fi One, LLC
    Inventors: Yutaka Murakami, Masayuki Orihashi, Akihiko Matsuoka
  • Publication number: 20150003564
    Abstract: A transmitter apparatus wherein a simple structure is used to successfully suppress the degradation of error rate performance that otherwise would be caused by fading or the like. There are included encoding parts that encode transport data; a mapping part that performs such a mapping that encoded data sequentially formed by the encoding parts are not successively included in the same symbol, thereby forming data symbols; and a symbol interleaver that interleaves the data symbols. In this way, a low computational complexity can be used to perform an interleaving process equivalent to a bit interleaving process to effectively improve the reception quality at a receiving end.
    Type: Application
    Filed: September 16, 2014
    Publication date: January 1, 2015
    Inventors: Yutaka MURAKAMI, Shutai Okamura, Kiyotaka Kobayashi, Masayuki Orihashi, Kazuaki Takahashi
  • Patent number: 8923444
    Abstract: A receiver for decoding a communication signal is disclosed. The receiver includes an input port and a filter. The input port receives the communication signal from a communication medium. The communication signal comprises a sequence of symbols. Each symbol of the symbol sequence is an analog pulse that has a leading edge of exponential shape. The exponential shape has an exponential growth parameter value that has been selected from values ?0 and ?1, which are distinct positive values. For each symbol of the symbol sequence, the exponential growth parameter value for the leading edge of the symbol has been selected based on a corresponding bit from a stream of information bits. The filter receives the communication signal from the input port and filters the communication signal to obtain an output signal. The transfer function of the filter has one or more zeros at ?0.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: December 30, 2014
    Assignee: Board of Regents, The University of Texas System
    Inventor: Robert H. Flake
  • Publication number: 20140376418
    Abstract: Embodiments of this invention describe a method to reduce the effective inter carrier spacing between the sub-carriers of wireless, wired or optical transmissions and thereby increase the spectral efficiency of the communication system. Signal transmitted from multiple transmit chains are shifted in frequency at the transmitter. At the receiver a plurality of receive chains is used, the received signals are similarly shifted in frequency and used to reduce the inter carrier interference. Embodiments also describe a method for Full Duplex communication where the transmitters transmit using different frequency shifts. The receiver receives the transmitted signal and an echo of it's transmission. As the received transmission is shifted in frequency from it's transmission, it can cancel out the echo and receive the intended signal.
    Type: Application
    Filed: June 25, 2013
    Publication date: December 25, 2014
    Inventor: Raja BANERJEA
  • Publication number: 20140376666
    Abstract: A receiver stage for receiving a receive signal comprises M receiving paths, each receiving path comprises a signal processor and K comparators. The signal processors of the M receiving paths are configured to generate, for each of the M receiving paths, an amplified version of the receive signal, such that an amplification gain of the respective receiving path increases from a first of the M receiving paths to a last of the M receiving paths. For each of the M receiving paths the K comparators of the respective receiving paths are configured to compare the amplified receive signal of the respective receiving path with a respective threshold value. For each of the M receiving paths the threshold value increases from a first of the K comparators to the last of the K comparators.
    Type: Application
    Filed: September 4, 2014
    Publication date: December 25, 2014
    Inventors: Frank OEHLER, Markus EPPEL, Heinrich MILOSIU
  • Publication number: 20140369445
    Abstract: A decision circuit includes: a first decision block to distinguish a first bit of bits using an amplitude of an analog signal as a discrimination point, the analog signal being an amplitude shift keyed signal; a superposition block to acquire an absolute value of a difference of the analog signal in respect to an amplitude center value of the analog signal by superposing divided analog signals; an inversion block to control inverting of the signal based on a first distinction result of the first decision block; a second decision block to distinguish a second bit of the bits based on an amplitude of an output signal from the inversion block and the discrimination point; and an output buffer to output the first distinction result and a second distinction result of the second decision block in synchronization with a clock.
    Type: Application
    Filed: March 19, 2014
    Publication date: December 18, 2014
    Applicant: FUJITSU LIMITED
    Inventors: Takashi Shimizu, Jun Matsui, Tsuyoshi Yamamoto
  • Patent number: 8908778
    Abstract: A rail-to-rail comparator including a first comparison unit connected to a first terminal and configured to compare differential input signals to differential reference voltages; a second comparison unit connected to a second terminal and configured to compare the differential input signals to the differential reference voltages; and an output unit configured to be driven in response to a clock signal and to generate a complementary output signal according to comparison results of the first and second comparison units.
    Type: Grant
    Filed: August 21, 2012
    Date of Patent: December 9, 2014
    Assignee: SK Hynix Inc.
    Inventors: Jin Il Chung, Jun Hyun Chun, Jin Wook Burm, Dae Ho Yun
  • Patent number: 8908799
    Abstract: Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. Different bit positions mapped to such symbols are assigned to different receivers, with the result that there are different BER performances among bits sent from a transmitter to the different receivers. Bits for multiple receivers are mapped to a UASK constellation or a UQAM constellation without using superposition.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: December 9, 2014
    Assignee: Blackberry Limited
    Inventors: Shouxing Qu, Yan Xin, Johanna Lisa Dwyer
  • Patent number: 8908781
    Abstract: A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted 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 receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. 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.
    Type: Grant
    Filed: February 23, 2012
    Date of Patent: December 9, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Douglas Cairns, Elias Jonsson
  • Publication number: 20140348267
    Abstract: A low latency transmitter and receiver for an OFDM system are disclosed. The low latency transmitter includes an FFT module and a baseband modulator. The FFT module computes IDFT of PSK constellation data symbols or QAM constellation data symbols. The baseband modulator performs complex modulation of the IDFT samples by multiplying these samples with 1 and ?1 alternatively in time domain. The low latency receiver includes a baseband demodulator and another FFT module. The baseband demodulator performs complex demodulation of the received samples of OFDM symbols by multiplying the samples of OFDM symbols with 1 and ?1 alternatively in time domain thereby obtaining baseband demodulated symbols. The FFT module of the receiver computes DFT of samples of the baseband demodulated symbols to obtain samples of the OFDM demodulated symbols.
    Type: Application
    Filed: May 22, 2013
    Publication date: November 27, 2014
    Applicant: Uurmi Systems Private Limited
    Inventor: Nanda Kishore Chavali
  • Publication number: 20140348268
    Abstract: A method is provided for modulating a real data stream grouped into blocks of nb.M real data, where M is the number of carriers and nb is an integer greater than or equal to 2. The method includes, for a block of real data: a first modulation by a first modulator of the first M/2 data, delivering a first set of modulated carriers; a second modulation by a second modulator of the following (nb?1).M data, delivering a second set of (nb?1).M modulated carriers; a third modulation by a third modulator of the last M/2 data, delivering a third set of modulated carriers; and a superposition of the first, second and third sets, forming a block of OFDM/OQAM symbols of length nb.M/2, the first set being superposed with the start of the second set and the third set being superposed with the end of the second set.
    Type: Application
    Filed: January 9, 2013
    Publication date: November 27, 2014
    Inventors: Pierre Siohan, Youssef Dandach
  • Patent number: 8891686
    Abstract: Methods for detecting and/or indicating the presence of valid data and threshold setting and data detection circuitry are disclosed. The threshold setting and data detection circuitry and related methods may be useful for fast and accurate reception of optical signals. The detection circuit generally comprises (i) a first circuit configured to regulate or control a DC offset of a differential input signal, and (ii) a second circuit coupled to the first circuit, the second circuit configured to indicate the presence of a data signal at the differential input signal when a voltage difference between true and complementary nodes of the differential input signal is above a predetermined threshold.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: November 18, 2014
    Assignee: Source Photonics, Inc.
    Inventors: Mohammad Azadeh, Near Margalit
  • Patent number: 8874050
    Abstract: A circuit and method for a saturation correction of a power amplifier (PA) is provided in order to maintain a desirable switching spectrum. The circuit includes a closed loop system that is responsive to a dynamic PA control signal known as VRAMP. The method samples a detector voltage that represents the output of the PA at the maximum voltage level of VRAMP. The sampled detector voltage is then reduced by a predetermined amount and applied as a fixed voltage PA control signal in the place of VRAMP. As a result, the closed loop system responds to the fixed voltage PA control signal to bring the PA out of saturation before VRAMP can begin a voltage decrease. Once the VRAMP voltage decreases, VRAMP is reapplied as a dynamic PA control signal in place of the fixed voltage control signal.
    Type: Grant
    Filed: May 5, 2010
    Date of Patent: October 28, 2014
    Assignee: RF Micro Devices, Inc.
    Inventors: Alexander Wayne Hietala, Jeffery Peter Ortiz, Timothy Keith Coffman
  • Publication number: 20140307832
    Abstract: One or more embodiments provides method for transmitting a signal by a transmitting apparatus in wireless a communication system supporting a modulation scheme based on a quadrature amplitude modulation (QAM) scheme and a frequency shift keying (FSK) scheme. The method includes determining at least one first bit which will be mapped to at least one QAM symbol and at least one second bit which will be mapped to at least one FSK symbol among bits included in an encoded input bit stream; and generating a modulation symbol by mapping the at least one first bit to the at least one QAM symbol and mapping the at least one second bit to the at least one FSK symbol based on a Hamming distance of the at least one second bit.
    Type: Application
    Filed: April 15, 2014
    Publication date: October 16, 2014
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Min Sagong, Won-Il Roh, Jeong-Ho Park, Ji-Yun Seol, Hyun-Kyu Yu, Chi-Woo Lim, Kyung-Whoon Cheun, Jae-Weon Cho, Sung-Nam Hong
  • Publication number: 20140301505
    Abstract: A receiving device including: a demodulation circuit configured to generate first likelihood data of reception symbols based on a transmission format of the reception symbols, the transmission format being selected from transmission formats and including a modulation scheme applied to the reception symbols, the modulation scheme being one of amplitude modulation schemes, a processor configured to estimate a scale ratio of an implementation scale to a theoretical scale, the implementation scale being a scale of the first likelihood data, the theoretical scale being a scale of second likelihood data of the reception symbols, the second likelihood data being defined by a theory and not depending on an implementation of the receiving device, and to generate the second likelihood data based on the first likelihood data and the scale ratio, and a decoding circuit configured to decode the second likelihood data based on the transmission format.
    Type: Application
    Filed: March 26, 2014
    Publication date: October 9, 2014
    Applicant: FUJITSU LIMITED
    Inventor: Shunji MIYAZAKI
  • Patent number: 8855236
    Abstract: A transmitter using quadrature modulation includes a rectangular to polar converter for converting data symbols into a polar form, where each polar symbol has a magnitude signal and an angle signal. Digital phase modulation circuitry includes an all digital PLL circuit for generating a phase modulated RF carrier signal responsive to the angle signal frequency control word (FCW) and a carrier frequency FCW. A digitally controlled amplifier for amplifying the phase modulated signal is controlled by a digital amplitude control circuitry for controlling the gain of the digitally controlled amplifier responsive to the magnitude signal.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: October 7, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Robert B. Staszewski, Sameh Rezeq, Dirk Leipold