Equalizers Patents (Class 375/229)
  • Patent number: 8803553
    Abstract: A differential transmission circuit comprises a sending unit that generates a pair of differential signals from an input signal, and sends the differential signals; a receiver that receives the differential signals sent by the sending unit; and a transmission path that transmits the differential signals from the sending unit to the receiver, wherein the sending unit has a selector that selects one of the input signal and a signal obtained by inverting a polarity of the input signal, and generates the differential signals from the signal selected by the selector.
    Type: Grant
    Filed: October 15, 2012
    Date of Patent: August 12, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Onuki, Hideyuki Rengakuji
  • Patent number: 8804794
    Abstract: Embodiments of methods, apparatuses and systems for transceiver processing are disclosed. One method includes a transceiver receiving a data stream from a link partner transceiver. A link parameter of a link between the transceiver and the link partner transceiver is determined. Allocation of transceiver processing between high-latency processing and low-latency processing is based at least in part on the link parameter.
    Type: Grant
    Filed: December 4, 2010
    Date of Patent: August 12, 2014
    Assignee: Aquantia Corporation
    Inventors: Moshe Malkin, Jose Tellado, Frank McCarthy
  • Patent number: 8804804
    Abstract: A system for estimating clock frequency offset and sampling clock offset in a communication system is provided. A receiver is configured to receive a communication signal having been transmitted from a transmitter via a communication channel. The receiver has a signal processor, wherein the signal processor is configured to generate an estimate of a carrier frequency offset and an estimate of a sampling clock offset from the received communication signal by: extracting a vector of pilot symbols from the received signal; performing equalization on the pilot symbols; performing clock frequency offset and sampling clock offset compensation on the pilot symbols; generating the estimate of a carrier frequency offset by estimating a common phase rotation using a first Taylor series approximation; and generating the estimate of the sampling clock offset by estimating phase differences between pairs of pilot symbols using a second Taylor series approximation.
    Type: Grant
    Filed: March 28, 2013
    Date of Patent: August 12, 2014
    Assignee: Antcor S.A.
    Inventor: Ioannis Sarris
  • Patent number: 8804879
    Abstract: A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver.
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: August 12, 2014
    Assignee: MagnaCom Ltd.
    Inventors: Amir Eliaz, Ilan Reuven, Gal Pitarasho
  • Publication number: 20140218172
    Abstract: Systems and methods for decoding data transmitted by RFID tags are disclosed. One embodiment of the invention includes an analyzer and equalizer configured to filter an input signal, an estimation block configured to obtain a baseband representation of the modulated data signal by mixing the filtered input signal with the carrier wave, and a coherent detector configured to perform phase and timing recovery on the modulated data signal in the presence of noise and to determine a sequence of data symbols.
    Type: Application
    Filed: October 7, 2013
    Publication date: August 7, 2014
    Applicant: Mojix, Inc.
    Inventor: Ramin Sadr
  • Patent number: 8798129
    Abstract: A BIIR system includes a first delay line for receiving at least one input data sample and generating delayed input samples as a function of the input data sample. The BIIR system further includes a second delay line including multiple delay elements connected in series for generating delayed output samples. An input of one of the delay elements receives at least one output data sample of the BIIR system. A summation element in the BIIR system generates the output data sample of the BIIR system as a function of an addition of at least first and second signals and a subtraction of at least a third signal. The third signal includes a first delayed output sample generated by the second delay line multiplied by a first prescribed value. The first delayed output sample and the output data sample are temporally nonadjacent to one another.
    Type: Grant
    Filed: January 4, 2012
    Date of Patent: August 5, 2014
    Assignee: LSI Corporation
    Inventors: Alexander Rabinovitch, Leonid Dubrovin
  • Patent number: 8798126
    Abstract: During a calibration process, a data input signal is sampled using each of plural receiver equalization setting. For each of the receiver equalization settings, a respective offset-data error-rate is measured. Based on the offset-data error-rate measurements, an equalizer setting is selected for use during normal non-calibration operation of the receiver.
    Type: Grant
    Filed: October 31, 2011
    Date of Patent: August 5, 2014
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Dacheng Zhou, Daniel Alan Berkram, Peter David Maroni
  • Patent number: 8792587
    Abstract: A multi-transport stream (TS) generating apparatus and method, and digital broadcasting transmission and reception apparatuses and method are provided. The multi-TS generating apparatus includes an adaptor to generate an adaptation field in some packets of a normal stream; an interleaver to interleave the normal stream; a turbo processor to turbo-code a plurality of turbo streams; a stuffer to generate a multi-TS by stuffing the plurality of the turbo streams into the adaptation field; and a deinterleaver to deinterleave the multi-TS. Accordingly, the plurality of the turbo streams can be transmitted far more easily.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: July 29, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-pil Yu
  • Patent number: 8792544
    Abstract: An equalization device is arranged for equalizing a received signal, wherein the received signal may include a primary signal and at least one interference signal. The equalization device may include a transformation module, a serial-to-parallel converter, and an equalization module, wherein the transformation module may include a predictive decision feed-back equalizer, a first feed-back filter and an adder. The transformation module is arranged for generating a transformation signal according to the primary signal and the at least one interference signal of the received signal, wherein the transformation signal includes a transformed primary signal and at least one transformed interference signal. The serial-to-parallel converter is arranged for respectively converting the transformed primary signal and the transformed interference signal into a plurality of transformation signal sequences.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: July 29, 2014
    Assignee: Realtek Semiconductor Corp.
    Inventor: Yi-Lin Li
  • Patent number: 8792543
    Abstract: An impulse noise mitigation circuit (INMC) may set a cut-off frequency of each of two high pass filters to bound a frequency bandwidth of a desired signal, wherein a first of the two filters allows frequencies higher than the frequency bandwidth of the desired signal, and a second of the two filters allows frequencies lower than the frequency bandwidth of the desired signal. The INMC may compute and store a mean magnitude separately for a first signal response of the first filter and a second signal response of the second filter. The INMC may select the first filter for impulse noise mitigation when the mean magnitude of the second filter is greater than the mean magnitude of the first filter. The INMC may select the second filter for impulse noise mitigation when the mean magnitude of the first filter is greater than the second filter.
    Type: Grant
    Filed: July 15, 2013
    Date of Patent: July 29, 2014
    Assignee: MaxLinear, Inc.
    Inventors: Andy Lo, Sugbong Kang
  • Publication number: 20140204990
    Abstract: Described herein is apparatus and system for switching equalization. The apparatus comprises a sampler to sample an input signal; and an attenuator, coupled to the sampler, with a hysteresis associated with the input signal, the hysteresis of the attenuator is configurable to cancel hysteresis of a communication channel coupled to the attenuator.
    Type: Application
    Filed: March 16, 2012
    Publication date: July 24, 2014
    Inventors: Sanquan Song, Jian J.X. Xu, Larry R. Tate
  • Patent number: 8787437
    Abstract: An adaptive equalizer and an adaptive equalizing method are provided. The adaptive equalizer includes an adaptive equalizing unit, for adaptively equalizing an inputted signal to output the equalized signal; a coefficient updating unit, for updating a coefficient of a filter of the adaptive equalizing unit; a switching unit, connected between the coefficient updating unit and the adaptive equalizing unit and a monitoring device, for controlling on or off of the switching unit in accordance with the fact that a down sampling phase of the inputted signal or a down sampling phase of the equalized signal is within a predetermined range. When the switching unit is on, the coefficient updating unit is capable of updating the coefficient of the adaptive equalizing unit, and when the switching unit is off, the coefficient updating unit is incapable of updating the coefficient of the adaptive equalizing unit.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: July 22, 2014
    Assignee: Fujitsu Limited
    Inventors: Ling Liu, Zhenning Tao, Takahito Tanimura
  • Patent number: 8787510
    Abstract: A method, a mobile system, and a user device for determining a delay spread are disclosed. A memory 306 may store a compound test value based on a multiburst history. The multiburst history may be a set of power delay profile decisions. A processor 304 may create a short power delay profile channel estimate and a long power delay profile channel estimate. The processor 304 may select a chosen power delay profile channel estimate based on the compound test value.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: July 22, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Sandeep Krishnamurthy, Colin Frank, Kenneth Stewart
  • Patent number: 8787438
    Abstract: A technique for a reconditioning equalizer filter for non-constant envelope signals is described. The input to a transmitter chain is modified by a reconditioning equalizer filter, prior to being applied to the transmitter. The reconditioning equalizer filter modifies and smoothens the amplitude of the signal. The modified and smoothened signal has its peaks reduced which results in lower Crest Factor. The input to the reconditioning equalizer filter could be a baseband, intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal, it needs to be down-converted to baseband before being applied to the reconditioning equalizer filter. The reconditioning equalizer filter could be performed in a digital or analog domain.
    Type: Grant
    Filed: December 23, 2013
    Date of Patent: July 22, 2014
    Assignee: Altera Corporation
    Inventor: Kiomars Anvari
  • Patent number: 8787500
    Abstract: A multi-transport stream (TS) generating apparatus and method, and digital broadcasting transmission and reception apparatuses and method are provided. The multi-TS generating apparatus includes an adaptor to generate an adaptation field in some packets of a normal stream; an interleaver to interleave the normal stream; a turbo processor to turbo-code a plurality of turbo streams; a stuffer to generate a multi-TS by stuffing the plurality of the turbo streams into the adaptation field; and a deinterleaver to deinterleave the multi-TS. Accordingly, the plurality of the turbo streams can be transmitted far more easily.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: July 22, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-pil Yu
  • Patent number: 8767812
    Abstract: Various systems and methods are described for performing fractionally spaced time domain equalization (TEQ). One embodiment is a method implemented in a communication system for training a fractionally spaced time domain equalizer (TEQ). The method comprises performing an initialization phase, averaging a received signal in the system to reduce effects of noise in a channel, determining a channel estimate, and aligning an ideal reference signal with the received signal. The method further comprises updating a target response filter according to a non-integer multiple of a base sampling rate, determining an adaptation error based on useful information both inside and outside a Nyquist band of the TEQ, and updating the TEQ according to the adaptation error.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: July 1, 2014
    Assignee: Ikanos Communications, Inc.
    Inventors: Lin Lin Li, Amitkumar Mahadevan
  • Patent number: 8767849
    Abstract: A wireless receiver is constructed to equalize a time-domain received signal, detect a plurality of symbols of the equalized time-domain received signal, and perform interference cancellation on the time-domain received signal. The interference cancellation can be performed using a partial result produced by an IDFT, and may use only neighboring symbols in a detected plurality of symbols. The resulting wireless receiver can be constructed to operate efficiently under a plurality of wireless standards.
    Type: Grant
    Filed: February 24, 2012
    Date of Patent: July 1, 2014
    Assignee: Futurewei Technologies, Inc.
    Inventors: Bei Yin, Kiarash Amiri, Joseph R. Cavallaro, Yuanbin Guo
  • Patent number: 8767883
    Abstract: The present invention is directed to a recoverable Ethernet receiver. A joint decision feedback equalizer (DFE) and Trellis decoder is configured to decode a receiving signal to result in a received symbol, and configured to generate a check-idle value which is used to indicate an idle mode. A physical coding sublayer (PCS) block is configured to generate a seed value and a polarity characterization according to the received symbol, with the joint DFE and Trellis decoder generating the check-idle value according to the seed value and the polarity characterization.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: July 1, 2014
    Assignee: Himax Media Solutions, Inc.
    Inventor: Tien-Ju Tsai
  • Patent number: 8767880
    Abstract: A method includes receiving a signal including first data precoded on the basis of a first codebook entry of a codebook, wherein the codebook includes at least one further codebook entry, averaging a set of matrices to obtain a mean matrix wherein each matrix of the set of matrices is determined on the basis of a respective other codebook entry of the at least one further codebook entry and determining a covariance matrix on the basis of the mean matrix.
    Type: Grant
    Filed: July 27, 2012
    Date of Patent: July 1, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Rajarajan Balraj, Tobias Scholand, Biljana Badic
  • Patent number: 8767811
    Abstract: An apparatus having a transmitter is disclosed. The transmitter generally has a filter coupled to a communication channel. The transmitter may be configured to adjust the filter using information based on an estimate of one or more characteristics of the communication channel.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: July 1, 2014
    Assignee: LSI Corporation
    Inventor: Lizhi Zhong
  • Patent number: 8761237
    Abstract: A variable gain amplifier (VGA) useful in a receiver that recovers transmitted digital signals. A first amplifier in the VGA has a first gain, an input coupled to an input of the VGA, and an output coupled to a load. A second amplifier in the VGA has a second gain, an input coupled to the input of the VGA, and an output coupled to the load. In a first mode of operation, the first gain is substantially zero and the second gain ranges between a maximum gain and a fraction of the maximum gain. In a second mode of operation the first gain is substantially the maximum gain and the second gain ranges between the maximum gain and the fraction of the maximum gain, and an algebraic sum of the first gain and second gain is no greater than the maximum gain to reduce non-linear distortion at low VGA gain.
    Type: Grant
    Filed: November 3, 2011
    Date of Patent: June 24, 2014
    Assignee: LSI Corporation
    Inventors: Pervez M. Aziz, Hiroshi Kimura
  • Patent number: 8761310
    Abstract: A receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a staggered quadrature amplitude modulator for providing an staggered quadrature amplitude modulated (SQAM) signal from a received signal; an equalizer and a data-aided symbol timing recovery (STR) loop. The equalizer operates outside of the data-aided symbol timing recover loop.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: June 24, 2014
    Assignee: Thomson Licensing
    Inventor: Maxim Belotserkovsky
  • Publication number: 20140169433
    Abstract: A method which includes receiving a first modulated signal from a first user device, the first modulated signal being generated based upon a time-frequency transformation of first user data. The method further includes receiving a second modulated signal from a second user device, the second modulated signal being generated based upon a time-frequency transformation of second user data. The first modulated signal and the second modulated signal are then processed.
    Type: Application
    Filed: June 25, 2013
    Publication date: June 19, 2014
    Applicant: COHERE TECHNOLOGIES, INC.
    Inventors: Ronny Hadani, Salim Shlomo Rakib
  • Patent number: 8755428
    Abstract: Circuits and methods are provided for efficient feed-forward equalization when sample-and-hold circuitry is employed to generate n time-delayed versions of an input data signal to be equalized. To equalize the input data signal, m data signals are input to m feed-forward equalization (FFE) taps of a current-integrating summer circuit, wherein each of the m data signals corresponds to one of the n time-delayed versions of the input data signal. A capacitance is precharged to a precharge level during a reset period of the current-integrating summer circuit. An output current is generated by each of the m FFE taps during an integration period of the current-integrating summer circuit, wherein the output currents from the m FFE taps collectively charge or discharge the capacitance during the integration period. A gating control signal is applied to an FFE tap during the integration period to disable the FFE tap during a portion of the integration period in which the data signal input to the FFE tap is invalid.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: June 17, 2014
    Assignee: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Daniel J. Friedman, Zeynep Toprak Deniz
  • Patent number: 8755427
    Abstract: A folding adaptive equalizer is provided. The equalizer comprises an equalizer core and an automatic gain control loop. The equalizing transfer function of the equalizer core is modulated by one or more gain control signals generated by the automatic gain control loop and by a folding signal generated by the automatic gain control loop. When the folding signal is inactive, an increase in the gain control signals produces an increase in the high-frequency, high-bandwidth gain of the transfer function of the equalizer core. When the folding signal is active, further gain can be applied by decreasing the gain control signals, which produces a frequency-shift in the transfer function of the equalizer core toward lower bandwidth and an increase in the high-frequency, low-bandwidth gain of the transfer function of the equalizer core.
    Type: Grant
    Filed: January 3, 2013
    Date of Patent: June 17, 2014
    Assignee: Semtech Canada Corporation
    Inventors: Hossein Shakiba, Mansour Shashaani
  • Publication number: 20140161169
    Abstract: A link adaptive orthogonal frequency-division multiplexed (OFDM) ultrasonic physical layer is provided that is capable of high data rate communication through metallic structures. The use of an adaptive OFDM subcarrier-based modulation technique mitigates the effects of severe frequency selective fading of the through-metal communication link and improves spectral efficiency by exploiting the slow-varying nature of the channel. To address the potential ill effects of peak-to-average power ratio (PAPR) and to make more efficient use of the power amplifiers in the system, the invention modifies and implements a symbol rotation and inversion-based PAPR reduction algorithm in the adaptive OFDM framework. This joint adaptive physical layer is capable of increasing data rates by roughly 220% in comparison to conventional narrowband techniques at average transmit powers of roughly 7 mW while constrained to a desired BER.
    Type: Application
    Filed: May 25, 2012
    Publication date: June 12, 2014
    Inventors: Richard Primerano, Kevin Wanuga, Magdalena Bielinski, Kapil R. Dandekar, Moshe Kam, Guillermo A. Sosa
  • Patent number: 8750363
    Abstract: Systems and techniques for equalization of a response of a receiver. In one embodiment, a response of a device to a known signal is measured to generate a measured signal. A processor is operated to apply an initial weighting to the measured signal and the known signal. The processor is operated to iteratively perform the operations of constructing an equalizer based on the weighted signals, testing the performance of the equalizer on the measured signal, and adjusting weighting applied to the measured signal and the known signal, until the performance of the equalizer on the measured signal meets a predetermined criterion.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: June 10, 2014
    Assignee: Broadcom Corporation
    Inventor: Markus Nentwig
  • Patent number: 8750361
    Abstract: A device and method is provided for iterative inter-cell interference cancellation and channel equalization in the mobile communication system. A downlink receiver of a mobile communication system according to the present invention includes a channel estimator for estimating channel impulse response of a selected cell from channel signals of respective cells; an equalizer for equalizing the channel impulse response output by the channel estimator using an equalization coefficient; a despreader for generating a symbol observation value per code channel by despreading the output of the equalizer with a code of the selected cell; and a cell interference estimator for estimating a symbol signal power and noise power of a data code channel from the symbol observation value and generates the estimated MMSE as a chip level regeneration sample.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: June 10, 2014
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Chae Man Lim, Ho Il Kim, Young Min Ki
  • Patent number: 8750366
    Abstract: An equalization device (500) includes a sample hold unit (501) that samples and holds an input signal, a multiplication unit (503) that multiplies the output signal of the sample hold unit (501) by a coefficient, a sample hold unit (502) that samples and holds the input signal at a timing delayed from the sample hold timing of the sample hold unit (501) by one symbol length, a multiplication unit (504) that multiplies the output signal of the sample hold unit (502) by a coefficient, and an addition unit (505) that adds the output signal of the multiplication unit (503) and the output signal of the multiplication unit (504) to output a sum signal.
    Type: Grant
    Filed: September 1, 2010
    Date of Patent: June 10, 2014
    Assignee: NEC Corporation
    Inventor: Hideyuki Hasegawa
  • Patent number: 8750432
    Abstract: In one aspect, the present disclosure provides an advantageous generalization of a SLIC receiver structure, by allowing multiple solutions to survive at any one or more of the serial stages included in the SLIC receiver. Where any given stage produces multiple solutions, the next stage of the SLIC receiver processes those multiple input solutions to produce multiple output solutions. Consequently, the contemplated SLIC receiver effectively builds a tree structure with as many levels as there are stages in the SLIC receiver. Such operations allow the SLIC receiver to form two or more solution threads spanning the stages, and to make an improved overall demodulation decision for a received symbol vector by selecting the best solution thread. Further, the additional complexity of allowing multiple survivor solutions at one or more SLIC stages is controlled in one or more embodiments, using survivor pruning for example.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: June 10, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Ali Khayrallah, Michael Samuel Bebawy
  • Patent number: 8750422
    Abstract: A multi-transport stream (TS) generating apparatus and method, and digital broadcasting transmission and reception apparatuses and method are provided. The multi-TS generating apparatus includes an adaptor to generate an adaptation field in some packets of a normal stream; an interleaver to interleave the normal stream; a turbo processor to turbo-code a plurality of turbo streams; a stuffer to generate a multi-TS by stuffing the plurality of the turbo streams into the adaptation field; and a deinterleaver to deinterleave the multi-TS. Accordingly, the plurality of the turbo streams can be transmitted far more easily.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: June 10, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-pil Yu
  • Patent number: 8750362
    Abstract: A method, apparatus and computer program product are configured to provide calibration accuracy in an analog filter. In this regard, a method is provided that includes estimating a cutoff frequency for an analog filter. The method further includes causing a filter tuning word to be modified based on the estimated cutoff frequency for the analog filter. The method also includes determining a residual cutoff frequency mismatch for the analog filter. The method also includes causing an equalizer configuration to be selected for a digital filter based on the determined residual cutoff frequency mismatch.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: June 10, 2014
    Assignee: Broadcom Corporation
    Inventors: Markus Nentwig, Aarno Parssinen
  • Patent number: 8750360
    Abstract: A mobile device comprises multiple receive antennas to receive spatially independent multipath signals from multiple transmit antennas located on a single base station. The mobile device concurrently generates a RAKE-based equivalent single path signal (RAKE ESPS) and an equalizer-based equivalent single path signal (equalizer ESPS) for the multipath signals received via each receive antenna. The generated RAKE ESPS or the generated equalizer ESPS is selected for channel decoding. Reference signal components are extracted from the multipath signals received to determine noise components, which is used to determine signal quality information of the generated RAKE ESPS and the generated equalizer ESPS. A final ESPS is selected from the generated RAKE ESPS and the generated equalizer ESPS based on the corresponding determined signal quality information. The selected final ESPS is diversity processed by combining signal components over the transmit/receive antennas.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: June 10, 2014
    Assignee: Broadcom Corporation
    Inventors: Mark Kent, Vinko Erceg
  • Publication number: 20140153630
    Abstract: The system may include a plurality of communication connections. A number of transmitters may transmit a signal to a number of receivers, the respective transmitter is adapted to convey transmit signal power to more than one receiver in the number of receivers. A process may adapt the allocation of power of a transmission to the receivers for signal transmission to more than one receiver.
    Type: Application
    Filed: June 11, 2013
    Publication date: June 5, 2014
    Inventors: Rainer Strobel, Lilia Smaoui, Vladimir Oksman
  • Patent number: 8743943
    Abstract: Equalization circuitry for receiving a digital data signal includes both feed-forward equalizer (“FFE”) circuitry and decision-feedback equalizer (“DFE”) circuitry. The FFE circuitry may be used to give the DFE circuitry a signal that is at least minimally adequate for proper start-up of the DFE circuitry. Thereafter, more of the burden of the equalization task may be shifted from the FFE circuitry to the DFE circuitry.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: June 3, 2014
    Assignee: Altera Corporation
    Inventors: Sergey Yuryevich Shumarayev, Wilson Wong, Rakesh Patel
  • Patent number: 8743939
    Abstract: A nonlinear echo compensator comprises a mapping circuit that includes a weighting circuit that generates a weighted signal based on a current symbol and a prior symbol and a function generating circuit that selects one of N functions based on the weighted signal, where N is an integer greater than one. The mapping circuit generates a driving signal based on the selected one of the N functions and the weighted signal. A canceling circuit generates a nonlinear echo compensation signal based on the driving signal.
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: June 3, 2014
    Assignee: Marvell International Ltd.
    Inventors: Xiaopeng Chen, Runsheng He, Shuran Wei
  • Patent number: 8744008
    Abstract: A multi-transport stream (TS) generating apparatus and method, and digital broadcasting transmission and reception apparatuses and method are provided. The multi-TS generating apparatus includes an adaptor to generate an adaptation field in some packets of a normal stream; an interleaver to interleave the normal stream; a turbo processor to turbo-code a plurality of turbo streams; a stuffer to generate a multi-TS by stuffing the plurality of the turbo streams into the adaptation field; and a deinterleaver to deinterleave the multi-TS. Accordingly, the plurality of the turbo streams can be transmitted far more easily.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: June 3, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-pil Yu
  • Patent number: 8743946
    Abstract: A communication receiver including a time domain receive filter to provide a filtered output, the filtered output including colored noise. The receiver also includes a frequency domain, fractionally-spaced equalizer (FSE) unit to receive the filtered output from the receive filter. The FSE unit determines a separate weighting factor for each subcarrier, and the weighting factor is determined based on a noise variance of the subcarrier.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: June 3, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: June Chul Roh
  • Patent number: 8744007
    Abstract: A multi-transport stream (TS) generating apparatus and method, and digital broadcasting transmission and reception apparatuses and method are provided. The multi-TS generating apparatus includes an adaptor to generate an adaptation field in some packets of a normal stream; an interleaver to interleave the normal stream; a turbo processor to turbo-code a plurality of turbo streams; a stuffer to generate a multi-TS by stuffing the plurality of the turbo streams into the adaptation field; and a deinterleaver to deinterleave the multi-TS. Accordingly, the plurality of the turbo streams can be transmitted far more easily.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: June 3, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-pil Yu
  • Patent number: 8743945
    Abstract: Described embodiments receive a signal by a set of fixed taps and a set of floating taps of a receiver, each tap corresponding to a detected symbol. Each of the floating taps is stored in a corresponding shift register to account for process, operating voltage and temperature (PVT) variations of the receiver without calibration of delay elements. Multiplexing logic selects (i) corresponding floating taps for equalization by coupling selected floating taps to the outputs of the fixed taps, and (ii) different phases of each possible floating tap position. The multiplexing logic prunes and/or amalgamates the phases of each possible floating tap position and selects floating taps based on a magnitude of each phase. A combiner adjusts each output value of the fixed taps and the selected floating taps by a corresponding tap-weight, combines the adjusted values into an output signal and subtracts the output signal from the input signal.
    Type: Grant
    Filed: July 3, 2012
    Date of Patent: June 3, 2014
    Assignee: LSI Corporation
    Inventors: Pervez M. Aziz, Hiroshi Kimura, Amaresh V. Malipatil, Hairong Gao
  • Patent number: 8737460
    Abstract: An equalizer configured to receive a data signal from a channel. The detector is coupled to the equalizer, and a calibration unit is coupled with the equalizer and the detector. The calibration unit is configured to jointly calibrate the equalizer and the detector using a metric subject to an entropy-preserving equalizer constraint.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: May 27, 2014
    Assignee: Seagate Technology, LLC
    Inventors: Raman Venkataranmani, William Michael Radich
  • Patent number: 8737458
    Abstract: Circuitry for use in a receiver may comprise: a front-end circuit operable to receive an orthogonal frequency division multiplexing (OFDM) symbol on a first number of physical subcarriers. The circuitry may comprise a decoding circuit operable to decode the OFDM symbol using an inter-carrier interference (ICI) model, the decoding resulting in a determination of a sequence of symbols, comprising a second number of symbols, that most-likely correspond to the received OFDM symbol, where the second number is greater than the first number. The sequence of symbols may comprise N-QAM symbols, N being an integer. The ISCI model may be based, at least in part, on non-linearity experienced by the OFDM symbol during transmission by a transmitter, propagation over a channel, and/or reception by the receiver. The ISCI model may be based, at least in part, on phase-noise introduced to the OFDM symbol during transmission by a transmitter, propagation over a channel, and/or reception by the receiver.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: May 27, 2014
    Assignee: MagnaCom Ltd.
    Inventors: Amir Eliaz, Ilan Reuven
  • Patent number: 8738074
    Abstract: A mobile communications radio receiver for multiple radio network operation includes an RF unit for generating a first down-converted signal from a radio signal received from a first radio network and a second down-converted signal from a radio signal received from a second radio network. Further, the receiver includes a first receiving unit including a user data channel demodulator configured to demodulate a dedicated user data physical channel and a control channel demodulator configured to demodulate a common control data channel of the first radio network based on the first down-converted signal. Still further, the receiver includes a second receiving unit including a pilot channel demodulator configured to demodulate a pilot channel of the second radio network based on the second down-converted signal. A first data connection is configured to couple control data contained in the second down-converted signal to the control channel demodulator of the first receiving unit.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: May 27, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Thorsten Clevorn, Herbert Dawid, Bertram Gunzelmann
  • Patent number: 8737499
    Abstract: An interference cancellation receiver for a pre-coded orthogonal frequency division multiplexed (OFDM) based system combines temporal interference cancellation within the OFDM framework. Multi-path equalization and inter-symbol interference (ISI) cancellation are performed on a time domain channel estimate of a received signal. An output from the multi-path equalization is transformed to the frequency domain. Inter-channel interference (ICI) is performed in the frequency domain on an equalized signal from the multi-path equalization after transforming the equalized signal from the time domain to the frequency domain.
    Type: Grant
    Filed: May 22, 2012
    Date of Patent: May 27, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Divaydeep Sikri, Farrokh Abrishamkar, Bahadir Canpolat
  • Publication number: 20140140384
    Abstract: A method for reducing a number of bits for representing a value is disclosed. A first value represented with a first number of bits is transformed to a second value represented with a second number of bits, wherein the first number of bits is greater than the second number of bits. The transformed second value is scaled by a scale factor to a third value. Transforming includes selecting a target window with a width of a third number of bits, wherein the third number of bits is smaller than the first number of bits. Transforming further includes saturating the first value to a most significant bit (MSB) within the selected target window and extracting bits within the selected target window from the saturated value.
    Type: Application
    Filed: November 6, 2013
    Publication date: May 22, 2014
    Applicant: SK hynix memory solutions inc.
    Inventors: Yu Kou, Lingqi Zeng
  • Patent number: 8731115
    Abstract: The present inventions are related to systems and methods for pre-equalizer noise suppression in a data processing system. As an example, a data processing system is discussed that includes: a sample averaging circuit, a selector circuit, an equalizer circuit, and a mark detector circuit. The sample averaging circuit is operable to average corresponding data samples from at least a first read of a codeword and a second read of the codeword to yield an averaged output based at least in part on a framing signal. The selector circuit is operable to select one of the averaged output and the first read of the codeword as a selected output. The equalizer circuit is operable to equalize the selected output to yield an equalized output, and the mark detector circuit is operable to identify a location mark in the equalized output to yield the framing signal.
    Type: Grant
    Filed: March 8, 2012
    Date of Patent: May 20, 2014
    Assignee: LSI Corporation
    Inventors: Shaohua Yang, Jin Lu
  • Publication number: 20140133540
    Abstract: A system may comprise circuitry that includes a sequence estimation circuit and a non-linearity modeling circuit. The circuitry may be operable to receive a single-carrier signal that was generated by passage of symbols through a partial response filter and through a non-linear circuit. The circuitry may be operable to generate estimated values of the symbols using the sequence estimation circuit and using the non-linearity modeling circuit. An output of the non-linearity modeling circuit may be equal to a corresponding input of the non-linearity modeling circuit modified according to a non-linear model that approximates the non-linearity of the non-linear circuit through which the received signal passed.
    Type: Application
    Filed: November 8, 2013
    Publication date: May 15, 2014
    Applicant: MAGNACOM LTD.
    Inventor: Amir Eliaz
  • Patent number: 8724690
    Abstract: The present invention is directed to a decision feedback equalizer that implements a multipath delay calculator to determine the delay between a line-of-sight component of a received data signal and a reflection of the line-of-sight component. The determined delay is used to control when decisions are used within the decision feedback equalizer so that the appropriate decisions are delayed until the reflection is received. In this way, the reflection can be substantially removed from the data signal using decisions that were generated when the line-of-sight component was received. Because the correction window is limited to the time when the reflection is received, the number of taps required to perform equalization is greatly reduced resulting in a decision feedback equalizer with less circuitry or logic.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: May 13, 2014
    Assignee: L-3 Communications Corp.
    Inventors: Teren G. Jameson, Zachary C. Bagley, Scott C. Smedley
  • Patent number: 8724689
    Abstract: Narrowband ingress estimation and characterization using equalizer taps. A equalizer including a feed forward equalizer (FFE) and a decision feedback equalizer (DFE) is implemented to process an input signal thereby generating an output signal. Analysis of the frequency response of the equalizer including the FFE and the DFE of the equalizer allows for the determination of whether or not narrowband ingress exists within the signal received by the equalizer. For example, analysis of the signal output from the equalizer provides for determination of the overall frequency response of the equalizer. In addition, analysis of the respective equalizer coefficients within one or both of the FFE and the DFE of the equalizer may be used to determine the overall frequency response of the equalizer. Narrowband ingress may be identified when the combination of the FFE (having a notch therein) and the DFE provides for an overall flat frequency response.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: May 13, 2014
    Assignee: Broadcom Corporation
    Inventors: Bruce J. Currivan, Thomas J. Kolze, Roger Fish, Victor T. Hou
  • Patent number: 8724746
    Abstract: A system and method for signaling and detecting in wireless communications systems are provided. A method for processing information includes operating in a first phase, operating in a second phase, and processing the detected information. The first phase includes iteratively inverting a first filtering operation on received signals, and the second phase includes iteratively inverting a second filtering operation on received signals with consideration given to a first estimation error of symbols of the first user and a second estimation error of symbols of the second user.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: May 13, 2014
    Assignee: FutureWei Technologies, Inc.
    Inventors: Christian Schlegel, Carmela Cozzo