Training Period Or Initial Set Up Patents (Class 375/231)
  • Patent number: 8472510
    Abstract: A receiver includes a discrete Fourier transform unit, a frequency-domain equalizer, an inverse discrete Fourier transform unit, a time-domain equalizer and an output circuit. The discrete Fourier transform unit is utilized for performing a discrete Fourier transform operation upon a received signal to generate a frequency-domain signal. The frequency-domain equalizer is utilized for equalizing the frequency-domain signal to generate an equalized frequency-domain signal. The inverse discrete Fourier transform unit is utilized for performing an inverse discrete Fourier transform operation upon the equalized frequency-domain signal to generate a first equalized time-domain signal. The time-domain equalizer is utilized for equalizing the received signal to generate a second equalized time-domain signal. The output circuit is utilized for generating a third equalized time-domain signal according to the first equalized time-domain signal and the second equalized time-domain signal.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: June 25, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventor: Yi-Lin Li
  • Publication number: 20130156086
    Abstract: Methods and apparatus are provided for detecting and decoding adaptive equalization training frames (having a frame marker comprised of a string of binary ones and binary zeroes). Training frames are detected by shifting the received data; inserting at least one binary value at one end of the shifted received data to generate a modified version of the received data; applying a logic function to the received data and the modified version of the received data that identifies when corresponding bit positions have different values; and detecting the frame marker when an output of the logic function has a first binary value in an approximate middle of a string of a second binary value. The training frames are decoded using a distance between the approximate center of the frame marker and a predefined binary value in an output of the logic function.
    Type: Application
    Filed: February 14, 2013
    Publication date: June 20, 2013
    Applicant: Agere Systems LLC
    Inventor: Agere Systems LLC
  • Patent number: 8457186
    Abstract: In the example embodiments, test signals sent from a transmitting system are received at a receiving system. The receiving system generates a determination signal indicating, in one embodiment, whether received signals have a desired relationship with respect to a clock signal at the receiving system. Timing of the clock signal or timing for transmitting signals may be adjusted based on the determination. In another embodiment, the receiving system generates a determination signal indicating whether the pulse width of a lone pulse signal equals a desired time interval. Equalization or pre-emphasis is controlled based on the determination signal.
    Type: Grant
    Filed: May 24, 2012
    Date of Patent: June 4, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Young-chan Jang
  • Patent number: 8451884
    Abstract: An offset calibration method is provided. Two input terminals of an equalizer are switched to a common voltage at a first time point, wherein the equalizer generates a first equalized signal and a second equalized signal according to the common voltage. It is determined whether a first offset voltage is present in the equalizer according to the first and second equalized signals generated from the common voltage. If the first offset voltage is determined to be present in the equalizer, a first compensation voltage is provided to the equalizer.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: May 28, 2013
    Assignee: Mediatek Inc.
    Inventors: Chien-Ming Chen, Chih-Chien Huang, Shang-Yi Lin
  • Patent number: 8446936
    Abstract: Disclosed is a co-channel feedback signal cancelling regenerative repeater of the Advanced Television Systems Committee (ATSC) that extracts a predetermined reference value of feedback signal to be able to cancel the feedback signal among received signals, including: a signal receiving unit; a signal demodulating unit that converts frequency of a received signal and demodulates it into a baseband signal; an interference equalizing unit that corrects characteristics of the demodulated signal and cancels feedback signal; a channel equalizing unit that compensates for channel distortion of an original signal from which the feedback signal is cancelled; a modulating unit that modulates the channel distortion-compensated original signal and converts it into an analog signal; and a signal transmitting unit that converts the frequency of the modulated signal, controls and amplifies its gain, and transmits a regenerative transmission signal.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: May 21, 2013
    Assignees: Darbs Co., Ltd., Korean Broadcasting System
    Inventors: Yong-Soek Kim, Sang-Gee Kang, Young-Woo Suh
  • Publication number: 20130121392
    Abstract: An OFDM communication system performs time domain channel estimation responsive to received symbols before the symbols are processed by a fast Fourier transform. The communication system generates virtual pilots from actual pilots to improve the stability and quality of channel estimation. The system generates a reference signal from the actual and virtual pilots and correlates the resulting reference signal with a signal responsive to the received symbol to generate an initial channel impulse response (CIR) and to determine statistics about the channel. In some circumstances, the resulting reference signal is correlated with a modified symbol in which the actual and virtual pilot locations are emphasized and the data locations are deemphasized. Time domain channel estimation iteratively improves on the initial CIR. The system determines channel estimates for data only symbols through averaging such as interpolation.
    Type: Application
    Filed: March 9, 2012
    Publication date: May 16, 2013
    Inventors: Steven C. Thompson, Fernando López deVictoria
  • Patent number: 8442102
    Abstract: A chip equalization apparatus and method for selecting cluster signals from broadcast signals being continuously received in multi-path channels for extracting a plurality of cluster signals from among the received broadcast signals and using a plurality of chip equalizers each having a tap coefficient update part for updating the tap coefficients of the selected cluster signals when the equalization outputs are combined to compensate the broadcast signals and provide low power consumption and efficient equalization for use in a satellite broadcasting receiving system.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: May 14, 2013
    Assignee: SK Telecom Co., Ltd.
    Inventors: Goon Seop Lee, Sung Hoon Lee, Jong Tae Ihm, Jae Hwang Yu, Dong Hahk Lee, Ku Ik Chung, Jin Hee Han
  • Patent number: 8437436
    Abstract: An apparatus and method for channel estimation decrease overhead and hardware complexity while supporting both Wiener-type channel estimation and Finite Impulse Response (FIR) filtering/Infinite Impulse Response (IIR) filtering in a wireless communication system. The apparatus includes a storage unit for storing coefficient sets for a plurality of channel estimation types. A controller selects one of the plurality of channel estimation types according to at least one of a type of a pilot signal and a reliability value of a channel parameter. An N-tap filter, including N multipliers and (N?1) adders, determines channel estimation values of data tones by using the coefficient sets for the selected channel estimation type.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: May 7, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jeong-Soon Park, Kyung-Min Kim, Jong-Han Lim, Sung-Soo Kim, In-Hyoung Kim, Jin Park
  • Patent number: 8437387
    Abstract: An apparatus is disclosed to compensate for non-linear effects resulting from the transmitter, the receiver, and/or the communication channel in a communication system. A receiver of the communication system contains an image cancellation module that compensates for images generated during the modulation and/or demodulation process. The image cancellation module includes a fine carrier correction loop to correct for frequency offsets between the transmitter and receiver. The image cancellation module includes a coarse acquisition mode and a decision directed mode. The decision directed mode allows for a larger signal-to-noise ratio for the receiver when compared against the coarse acquisition mode.
    Type: Grant
    Filed: April 4, 2012
    Date of Patent: May 7, 2013
    Assignee: Broadcom Corporation
    Inventors: Bruce J. Currivan, Loke Kun Tan, Thomas Joseph Kolze, Hanli Zou, Lin He
  • Patent number: 8433973
    Abstract: A digital receiving system, and a method of processing data are disclosed. The digital receiving system includes a receiving unit, a known sequence detector, and a channel equalizer. The receiving unit receives a broadcast signal including mobile service data and main service data. The known sequence detector detects known data linearly inserted in a data group. The channel equalizer performs channel-equalizing on the received mobile service data using the detected known data.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: April 30, 2013
    Assignee: LG Electronics Inc.
    Inventors: In Hwan Choi, Kook Yeon Kwak, Byoung Gill Kim, Jin Woo Kim, Hyoung Gon Lee, Won Gyu Song, Chul Kyu Mun
  • Patent number: 8432959
    Abstract: Methods and apparatus are provided for equalizing a received signal. A received signal is equalized by updating one or more equalization parameters; and discarding the updated equalization parameters if one or more predefined qualifier conditions are detected during the equalizing step. The received signal can optionally be equalized using the updated equalization parameters if the predefined qualifier conditions are not detected during the equalizing step. The updated equalization parameters can optionally be stored if the one or more predefined qualifier conditions are not detected during the equalizing step.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: April 30, 2013
    Assignee: Agere Systems LLC
    Inventors: Pervez M. Aziz, Mohammad S. Mobin, Gregory W Sheets, Lane A. Smith, Paul H. Tracy
  • Patent number: 8428111
    Abstract: Various embodiments are disclosed relating to crosstalk emission management. In an example embodiment, an amplitude of a main tap of a transmit equalizer may be determined to limit crosstalk emitted from a local channel to one or more other channels to be less than a threshold. A ratio of an amplitude of at least one secondary tap of the transmit equalizer to the amplitude of the main tap may be determined to provide equalization to the local channel.
    Type: Grant
    Filed: May 1, 2007
    Date of Patent: April 23, 2013
    Assignee: Broadcom Corporation
    Inventors: Magesh Valliappan, Howard Baumer, Anthony Brewster, Vivek Telang
  • Publication number: 20130094557
    Abstract: Methods and apparatus for calibration of interface operation of a display device. In one exemplary embodiment of the invention, an embedded DisplayPort (eDP) source element (such as a graphics processing unit (GPU)) configures itself to support the minimum requirements necessary to support a sink element (such as a screen display). Unlike prior art solutions, minimum sink requirements are identified during a calibration process, and the source is configured accordingly. By tailoring the source to the specific requirements of the sink, the device can initialize faster, consume less power, etc. Moreover, in another aspect of the present invention, if a device does not initialize to an expected configuration based on prior calibration settings, the device can be flagged as having faulty or failing components.
    Type: Application
    Filed: October 14, 2011
    Publication date: April 18, 2013
    Inventor: Colin Whitby-Strevens
  • Patent number: 8416842
    Abstract: A channel estimation method and apparatus using a self-tracking algorithm is provided for improving channel estimation accuracy. The channel estimation apparatus of a mobile terminal includes a receiver for converting a received radio signal into a baseband signal, a match filter for converting the baseband signal into a digital signal including at least two samples, a channel estimator for buffering the samples, for analyzing multipath signals to predict a maximum power position and multipath energy, and for estimating a channel by selecting a multi-tap at the maximum power position through a slew control, an equalization controller for calculating an equalization tap gain using the multi-tap selected by the channel estimator, and an equalizer for compensating for distortion in the samples output by the channel estimator using the equalization tap gain calculated by the equalization controller.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: April 9, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young Min Ki, Jae Hong Lee, Hun Kee Kim, Kyung Seung Ahn, Seong Wook Song, Min Sung Hur
  • Patent number: 8416677
    Abstract: Messages transmitted between a receiver and a transmitter are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: April 9, 2013
    Assignee: Intel Corporation
    Inventors: Marcos C. Tzannes, Dongjun Lee, Todor Cooklev, Colin Lanzl
  • Patent number: 8416896
    Abstract: Aspects of a method and system for channel estimation in a MIMO communication system with multiple RF chains for WCDMA/HSDPA may comprise receiving a plurality of communication signals from a plurality of transmit antennas. A plurality of vectors of baseband combined channel estimates may be generated based on phase rotation of the received plurality of communication signals. A matrix of processed baseband combined channel estimates may be generated based on the generated plurality of vectors of baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated based on the generated plurality of vectors of baseband combined channel estimates. An amplitude and a phase of at least a portion of the received plurality of communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: April 9, 2013
    Assignee: Broadcom Corporation
    Inventors: Mark Kent, Vinko Erceg, Uri M Landau, Peter van Rooyen
  • Patent number: 8411733
    Abstract: In an RF signal transmission network such as the reverse channels of a coaxial cable network, there is provided at least one adaptive equalizer for pre- or post-filtering inter-symbol interference in the transmitted signals, the adaptive equalizer having a series of coefficients for which values are required. In order to improve the transmission efficiency the preamble used in these channels is shortened by coarsely estimating the channel using a short “unique word’ placed at the beginning of the equalizer training sequence. The coarse channel estimate is crudely inverted to produce a set of equalizer coefficients which partially equalize the channel. By initializing the adaptive equalizer with these approximate coefficients, it is possible to reduce the length of the training sequence needed for the equalizer to converge.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: April 2, 2013
    Assignee: Vecima Networks Inc
    Inventors: Brian Berscheid, Zohreh Andalibi, Eric Salt
  • Patent number: 8411808
    Abstract: There is provided an information processing device, including a preamble detection portion, a sync detection portion, a storage portion, a storage control portion, a delay time imparting portion, a bias computation portion, a half sampling portion, an adaptive equalization portion an equalization performance determination portion that compares equalization errors for each one of the sync portion candidates for which the training equalization has been performed by the adaptive equalization portion, and that sets the candidate position with the least error, and a binary determination portion that decodes the Manchester code into NRZ code by subjecting to binary determination the received signal that has been adaptively equalized by the adaptive equalization portion. The storage control portion reads the received signal from the storage portion based on information about the candidate position with the least error that has been set by the equalization performance determination portion.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: April 2, 2013
    Assignee: Sony Corporation
    Inventor: Hirotaka Muramatsu
  • Patent number: 8406356
    Abstract: Embodiments of the invention comprise a continuous-time equalizer for reducing ISI in data received from a communication channel, and methods and circuitry for tuning or calibrating that equalizer. Selected coefficients for a transfer function of the equalizer circuit are fixed, while other coefficients are tuned by an adaptive algorithm. The adaptive algorithm minimizes errors associated with the tunable coefficients based on one or more training signals sent by the transmitter and received by the equalizer circuit at the receiver. The training signals allow for a variety of error terms to be calculated, from which the tunable coefficients are updated so as to iteratively minimize the error terms and simultaneously tune the equalizer to more accurately compensate for the degrading effects of the channel.
    Type: Grant
    Filed: June 6, 2007
    Date of Patent: March 26, 2013
    Assignee: Micron Technology, Inc.
    Inventor: Timothy M. Hollis
  • Publication number: 20130070833
    Abstract: A communication system is provided that includes a composite transfer module that receives an input signal and performs one or more selective operations defined by a first transfer function on the input signal. The composite transfer module outputs a first signal. A joint detection module receives the first signal and performs joint detection on the first signal. The joint detection module utilizes channel estimation information of the first transfer function so as to allow the joint detection module to perform joint detection with an oversampling rate of 2× or higher.
    Type: Application
    Filed: September 18, 2011
    Publication date: March 21, 2013
    Inventors: Aiguo Yan, Yonggang Hao, Marko Kocic
  • Publication number: 20130064280
    Abstract: Provided are a digital broadcast transmitter, a digital broadcast receiver, a stream-processing method for the digital broadcasting transmitter, and a stream-processing method for the digital broadcast receiver. The stream-processing method for the digital broadcasting transmitter includes: configuring a stream in which slots including a plurality of blocks are continuously disposed; and encoding and interleaving the stream to be output as a transport stream, wherein the configuring the stream includes, if slots of a block extension mode 00 are continuously placed, connecting known data placed in predetermined locations of adjacent slots to each other in order to generate a long training sequence.
    Type: Application
    Filed: May 13, 2011
    Publication date: March 14, 2013
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jin-hee Jeong, Jung-jin Kim, Yong-Sik Kwon
  • Patent number: 8396110
    Abstract: In one embodiment, a receiver circuit is provided. The receiver circuit includes a low-power equalization circuit having a first linear equalization circuit coupled to receive serial data. The receiver circuit includes a low-noise equalization circuit having a second linear equalization circuit coupled to receive the serial data, and a non-linear equalization circuit coupled to an output of the second linear equalization circuit. The receiver circuit includes a control circuit configured to enable the low-power equalization circuit and disable the low-noise equalization circuit in response to a first state of a control signal. The control circuit is configured to disable the low-power equalization circuit and enable the low-noise equalization circuit in response to a second state of the control signal.
    Type: Grant
    Filed: December 3, 2010
    Date of Patent: March 12, 2013
    Assignee: Xilinx, Inc.
    Inventor: Cheng-Hsiang Hsieh
  • Patent number: 8391431
    Abstract: Apparatus, and an associated method, for the receive part of a receiving station, such as a mobile station or other transceiver of a cellular communication system. Selection is made of filter characteristics to be exhibited by an adaptive, input noise whitening filter. A noise estimator estimates a noise component of a noise sequence. An autocorrelation estimator estimates the noise-component autocorrelation. A determination is made as to whether the autocorrelation exceeds a threshold. If so, filter characteristics are selected to cause the input noise whitening filter to operate to inject whitening noise into the received sequence.
    Type: Grant
    Filed: February 8, 2012
    Date of Patent: March 5, 2013
    Assignee: Research In Motion Limited
    Inventors: Huan Wu, Sean Simmons
  • Patent number: 8384569
    Abstract: A stochastic signal generation circuit includes a signal output circuit and a signal processing circuit connected with the signal output circuit. The signal output circuit includes two matching semiconductor components, wherein the signal output circuit detects a slight mismatch between the two matching semiconductor components, converts the detected slight mismatch into a corresponding electric signal, amplifies the electric signal, and outputs an analog voltage signal. The signal processing circuit converts the analog voltage signal into a stochastic digital signal. Also, a method for generating a stochastic signal is provided. The present invention decreases the cost of the integrated circuit, and better ensures the information security of the electronic products.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: February 26, 2013
    Assignee: IPGoal Microelectronics (SiChuan) Co., Ltd
    Inventor: Guojun Zhu
  • Patent number: 8379710
    Abstract: Techniques are described to adaptively adjust the equalizer settings of each transmitter in a transmitter-receiver pair. The transmitter-receiver pair can be used at least with implementations that comply with 40GBASE-CR4 or 100GBASE-CR10. For implementations that comply with 40GBASE-CR4, equalizer settings of four transmitters may be independently established.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: February 19, 2013
    Assignee: Intel Corporation
    Inventors: Amir Mezer, Adee Ran
  • Patent number: 8379743
    Abstract: A method of compensating interference of received symbols in a MIMO OFDM receiver employs MMSE equalization and LLR scaling, and a MIMO OFDM receiver includes a linear MMSE equalizer. The method provides a low-complexity, numerically robust method for compensating interference of received symbols and provides a low-cost, robust digital baseband receiver for MIMO-OFDM, achieved by merging linear MMSE equalization and scaling of the corresponding equalized symbols into a single algorithm that, for the 2×M MIMO case, completely avoids computationally extensive matrix inversion and allows for significant simplification of symbol detection as compared to separate equalization and scaling.
    Type: Grant
    Filed: September 3, 2010
    Date of Patent: February 19, 2013
    Assignee: Blue Wonder Communications GmbH
    Inventor: Andreas Bury
  • Patent number: 8374231
    Abstract: An equalization simulator with training sequence detection uses an oscilloscope to acquire digital samples of an analog waveform signal from a serial data link to produce a digitized waveform record. The equalization simulator has training sequence detection receiving the digitized waveform record and generates a training sequence, an equalization adapter receiving the digitized waveform record and the training sequence and generating equalizer taps, and an equalizer receiving the equalizer taps and the digitized waveform record and generating an equalized digitized waveform record.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: February 12, 2013
    Assignee: Tektronix, Inc.
    Inventor: Kan Tan
  • Patent number: 8358684
    Abstract: A demodulation circuit including: a first error calculation section configured to calculate a first error in accordance with a blind method; a second error calculation section configured to calculate a second error in accordance with a DD method; an update section configured to update filter coefficients for first and second filters based on the first or second error, the first filter filtering an input signal to generate a first signal, the second filter filtering a signal representing a hard decision value for a post-equalization signal to generate a second signal; a control section configured to, in the case where the update section is updating the filter coefficients based on the second error, controlling the filter coefficients to be updated based on the first error, when the degree of the second error has exceeded a first threshold; and a generation section configured to generate the post-equalization signal based on the first and second signals.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: January 22, 2013
    Assignee: Sony Corporation
    Inventor: Katsumi Takaoka
  • Patent number: 8355451
    Abstract: A method of processing a digital broadcast signal includes Reed-Solomon (RS) encoding enhanced service data for each column of at least one RS frame payload and adding a Cyclic Redundancy Check (CRC) checksum byte at a right end of each row of the at least one RS frame payload to build at least one RS frame and forming data groups including the enhanced service data in the built RS frame and a plurality of known data sequences. Forming the data groups includes mapping the RS encoded enhanced service data into each of the data groups and inserting a place holder for a non-systematic RS parity into each of the data groups. The method further includes deinterleaving data in each of the data groups including the enhanced service data and the place holder and multiplexing the enhanced service data in each of the formed data groups with main service data.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: January 15, 2013
    Assignee: LG Electronics Inc.
    Inventors: Byoung Gill Kim, In Hwan Choi, Kyung Won Kang, Kook Yeon Kwak, Woo Chan Kim
  • Patent number: 8355431
    Abstract: A Decision Feedback Equalizer (DFE) capable of preventing incremental increases of a jitter of a recovered clock and reduction of a voltage margin of decided data due to delay of feedback data. The DFE includes a combiner for combining received data with feedback data and outputting the combined data as equalization data, a decision circuit for deciding recovery data by receiving the equalization data, a feedback loop for supplying the recovery data to the combiner as feedback data and a clock recovery circuit for removing a delay data component from the equalization data through the feedback loop, recovering a clock with respect to the other equalization data except the delay data component and supplying the recovered clock for decision operation of the decision circuit.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: January 15, 2013
    Assignee: Hynix Semiconductor, Inc.
    Inventor: Ki-Hyuk Lee
  • Publication number: 20130010854
    Abstract: A transmitter includes an equalizer for conditioning a data signal in response to a first and a second equalizer setting. The first and second equalizer settings are both associated with a selected point on a two-dimensional search grid. The search grid includes a first equalizer setting and a second equalizer setting for each point on the search grid. The transmitter transmits a data signal across a first channel medium using settings associated with a selected point on the search grid. A receiver analyzes the received signal from the transmitter to determine a signal quality metric. The search grid is used to select settings from neighboring points to produce signals that are evaluated to produce signal quality metrics. The results of the evaluations are used to efficiently search the search grid for optimum equalizer settings for the transmitter.
    Type: Application
    Filed: July 8, 2011
    Publication date: January 10, 2013
    Inventors: David Christopher Sawey, Jian Chang
  • Publication number: 20130003816
    Abstract: Techniques for performing channel and noise estimation for a MIMO transmission sent from multiple transmit antennas to multiple receive antennas are described. Samples are obtained from the receive antennas. For a first scheme, channel estimates are derived by correlating the samples with at least one pilot sequence, and signal, noise and interference statistics are also estimated based on the samples. For a second scheme, total received energy as well as signal and interference energy are estimated based on the samples. Noise is then estimated based on the estimated total received energy and the estimated signal and interference energy. For a third scheme, signal and on-time interference statistics are estimated based on the samples. Noise and multipath interference statistics are also estimated based on the samples. Signal, noise and interference statistics are then estimated based on the estimated signal and on-time interference statistics and the estimated noise and multipath interference statistics.
    Type: Application
    Filed: September 10, 2012
    Publication date: January 3, 2013
    Applicant: Qualcomm Incorporated
    Inventor: Byoung-Hoon Kim
  • Patent number: 8345733
    Abstract: A system and apparatus are disclosed for a method and apparatus for equalizing signals. An apparatus that incorporates teachings of the present disclosure may include, for example, an equalizer (100) having a channel estimation calculator (102) for calculating a time domain channel estimation from a baseband signal, an FFT processor (104) for translating the time domain channel estimation to a frequency domain channel estimation, a tap weight calculator (106) for calculating a frequency domain tap weight according to the frequency domain channel estimation, an inverse FFT processor (108) for translating the frequency domain tap weight calculation to a time domain tap weight calculation, and a filter (110) for equalizing the baseband signal according to the time domain tap weight calculation.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: January 1, 2013
    Assignee: AT&T Intellectual Property I, LP
    Inventor: Arunabha Ghosh
  • Patent number: 8347339
    Abstract: A system and method for wirelessly transmitting audiovisual information. Training information may be stored in a memory. A plurality of packets may be generated, including the training information. The plurality of packets may also include audiovisual information. The plurality of packets may include first information identifying a first training pattern of a plurality of possible training patterns. The first training pattern may specify one or more locations of the training information in the plurality of packets. The first information may be usable by a receiver to determine the first training pattern of the plurality of possible training patterns. The plurality of packets may be transmitted in a wireless manner.
    Type: Grant
    Filed: May 30, 2009
    Date of Patent: January 1, 2013
    Assignee: Coherent Logix, Incorporated
    Inventors: Kevin A. Shelby, Peter J. Nysen, Michael B. Doerr
  • Patent number: 8340170
    Abstract: A receiver for receiving a data signal having a channel profile may include an equalizer, to which the data signal is feedable, the equalizer having a plurality of filters and a switching device coupled to the filters, a selection device, which is disposed such that it determines a first number and a second number in dependence on the channel profile, and the switching device is disposed such that it connects a number of linear filters corresponding to the first number to form a first overall filter and connects a number of linear filters corresponding to the second number to form a second overall filter.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: December 25, 2012
    Assignee: Intel Mobile Communications GmbH
    Inventors: Herbert Dawid, Matthias Hillebrand, Steffen Paul, Lothar Winkler, Manfred Zimmermann
  • Patent number: 8330535
    Abstract: An equalizer includes an oversampling logic unit, a direct current setting unit, and an alternating current setting unit. The oversampling logic unit oversamples data from a channel to generate a plurality of direct current terms and a plurality of alternating current terms according to an oversampling clock, and outputting a plurality of direct current terms corresponding to an output clock and a plurality of alternating current terms corresponding to the output clock according to the output clock. The direct current setting unit adjusts a direct current setting of the equalizer according to a plurality of direct current terms inputted by the oversampling logic unit within a first predetermined time. And the alternating current setting unit adjusts an alternating current setting of the equalizer according to a plurality of alternating current terms inputted by the oversampling logic unit within the first predetermined time.
    Type: Grant
    Filed: March 20, 2011
    Date of Patent: December 11, 2012
    Assignee: Etron Technology, Inc.
    Inventors: Kuo-Cyuan Kuo, Yu-Chiun Lin, Ming-Kia Chen
  • Patent number: 8332681
    Abstract: In a first embodiment of the present invention, a method for operating a device having a device reference clock, in a system including a host with a host reference clock is provided, the method comprising: beginning a link negotiation stage between the device and the host using the device reference clock; during the link negotiation stage, sampling data received from the host to determine a frequency offset of the host reference clock; applying the frequency offset to the device reference clock to create a corrected device reference clock; and completing the link negotiation stage using the corrected device reference clock. This completing may include either continuing the original link negotiation stage or restarting it.
    Type: Grant
    Filed: May 1, 2012
    Date of Patent: December 11, 2012
    Assignee: PLX Technology, Inc.
    Inventor: Philip David Rose
  • Patent number: 8325851
    Abstract: A method for compensating signal distortion in an emitting payload including determining a compensation transfer function and introducing it within the aggregate response of the payload; choosing an initial tentative compensation transfer function and introducing it within the aggregate response of the payload; acquiring an output signal of the emitting payload; based on the acquired output signal and on a reference signal, corresponding to an expected undistorted output signal, performing an estimation of a residual distortion transfer function of emitting payload; and based on the estimation of the residual distortion transfer function, computing an updated tentative compensation transfer function and introducing it within the aggregate response of the payload. The estimation can be a black-box estimating and the reference signal can be generated on-purpose, and not measured from within the emitting payload.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: December 4, 2012
    Assignee: Agence Spatiale Europeene
    Inventor: Dirk Hannes
  • Patent number: 8325846
    Abstract: A data transmission method in a multiple antenna system is provided. The method includes: defining a codebook including at least one precoding matrix composed of a plurality of rows and columns, wherein the codebook is at least one of a first type in which all elements of the precoding matrix are non-zero elements, a second type in which any one column of the precoding matrix includes non-zero element and the remaining columns include at least one zero element, and a third type in which all columns of the precoding matrix include at least one zero element; precoding an input symbol by using the defined codebook; and transmitting the precoded symbol.
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: December 4, 2012
    Assignee: LG Electronics Inc.
    Inventors: Hyun Soo Ko, Ja Ho Koo, Jae Hoon Chung, Moon Il Lee
  • Patent number: 8320475
    Abstract: A system for measuring inter-carrier interference (ICI) in an OFDM system includes a test symbol generator coupled to a transmitter of the OFDM system to generate an N*N orthogonal matrix having N*N test symbols, and to send the test symbols in a test symbol stream via the transmitter to a receiver of the OFDM system. The N*N test symbols are arranged by the test symbol generator into an N*N orthogonal matrix before being sent to the receiver. The system also includes an ICI measuring module coupled to the receiver to detect the N*N test symbols received in the receiver and to arrange the test symbols as a receiving matrix in the same way as the orthogonal matrix in the transmitter. The ICI measuring module outputs the receiving matrix as an ICI matrix of the OFDM system, wherein an element on the kth row, lth column of the ICI matrix represents interference from the lth sub-carrier on the kth sub-carrier, wherein k?l.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: November 27, 2012
    Assignee: Agilent Technologies, Inc.
    Inventors: Danxun Shen, Hong Wei Kong, Xu Zhao
  • Patent number: 8306100
    Abstract: A test circuit capable of reducing the number of data I/O pins of a tester at a read operation includes a data masking control unit for masking a part of output data in response to an activation of one of an upper data masking signal to control a group of upper data pins and a lower data masking signal to control a group of lower data pins when a test mode signal is activated at a read operation.
    Type: Grant
    Filed: July 22, 2008
    Date of Patent: November 6, 2012
    Assignee: SK hynix Inc.
    Inventor: Kwang-Su Lee
  • Patent number: 8306150
    Abstract: Systems and methods for identifying a transmission channel response and a feedback channel response from a plurality of composite system responses are disclosed. A plurality of shifted feedback signals are created by shifting a feedback signal frequency by a plurality of first offset values and/or by shifting a transmission signal frequency by a plurality of second offset values. The feedback signals are compared to an input signal to identify the transmission channel response and/or a feedback channel response. A control signal is generated for a pre-distortion circuit to modify the input signal by an inverse of the transmission channel response. The composite system response is measured at a plurality of operating frequencies and at the plurality of offset values. The measurements are stored in a matrix and singular value decomposition is applied to the matrix of measurements to calculate the transmission channel response and feedback channel response.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: November 6, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Fernando A. Mujica, Carson A. Wick, Lei Ding, Milind Borkar, Roland Sperlich
  • Patent number: 8300685
    Abstract: Embodiments include a decision feedback equalizer (DFE) that includes a first comparator configured to receive as inputs a soft value and a first threshold, a second comparator configured to receive as inputs the soft value and a second threshold, a selector configured to select an output of either the first comparator or the second comparator as a DFE output based on one or more previous bits output by the selector; an error calculator configured to determine an error for the first comparator and the second comparator, and a threshold adjuster configured to adjust the first threshold and the second threshold, the first threshold and the second threshold each being a non-linear combination of one or more previous outputs of the selector.
    Type: Grant
    Filed: August 27, 2007
    Date of Patent: October 30, 2012
    Assignee: Broadcom Corporation
    Inventors: Chung-Jue Chen, Vasudevan Parthasarthy, Sudeep Bhoja
  • Patent number: 8300684
    Abstract: In described embodiments, filter parameters for a filter applied to a signal in, for example, a Serializer/De-serializer (SerDes) receiver and/or transmitter are generated based on real-time monitoring of a data eye. The real-time eye monitor monitors data eye characteristics of the signal present in a data path, the data path applying the filter to the signal. The eye monitor generates eye statistics from the monitored data eye characteristics and an adaptive controller generates a set of parameters for the filter of the data path for statistical calibration of the data eye, wherein the eye monitor continuously monitors the data eye and the adaptive controller continuously generates the set of parameters based on the eye statistics.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: October 30, 2012
    Assignee: LSI Corporation
    Inventors: Mohammad Mobin, Ye Liu, Kenneth Paist, Mark Trafford
  • Patent number: 8295339
    Abstract: An inter-carrier interference (ICI) mitigating equalizer includes a channel estimator, a channel calculator, an ICI estimator, a subtracter, and an equalizer. The channel estimator estimates a channel response from a received signal, and the channel calculator calculates a basic component of a channel response and fluctuating components of the channel response from the estimated channel response. The ICI estimator multiplies the fluctuating components of the channel response by a received signal in a frequency domain, filters the multiplication results according to filter coefficients, and estimates an ICI component included in the received signal based on the filtering results. The subtracter subtracts the ICI component from the received signal in the frequency domain. The equalizer equalizes an output signal of the subtracter based on the basic component of the channel response.
    Type: Grant
    Filed: August 18, 2008
    Date of Patent: October 23, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Guanghui Liu
  • Patent number: 8295341
    Abstract: An example Cognitive Radio (CR) described herein may include equalization and Automatic Modulation Classification (AMC). The equalization may employ digital filter techniques with an adjustable length or order. The output of the equalization may be provided to the AMC, where the AMC may be adapted to identify various characteristics about the RF environment and also to identify probabilities of classification associated with the performance of the AMC itself. The CR device may be configured to adjust the equalization using feedback from the AMC to enhance performance of each other.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: October 23, 2012
    Inventors: Tamal Bose, Barathram Ramkumar
  • Patent number: 8290033
    Abstract: A system is described for performing combined equalization. The system comprises a time domain equalizer (TEQ) configured to receive a signal and shorten a CIR (channel impulse response) of the received signal, a Fast Fourier Transform (FFT) module for demodulating the received signal, and an equalization block for reducing inter-carrier interference (ICI) and inter-symbol interference (ISI). The equalization block comprises at least one of: a feed forward equalizer and a feed back equalizer. The system further comprises a slicer circuit configured to generate a hard-limited decision for a symbol corresponding to the received signal.
    Type: Grant
    Filed: January 9, 2009
    Date of Patent: October 16, 2012
    Assignee: Ikanos Communications, Inc.
    Inventors: Rahul Garg, Kunal Lal, Devesh Chauhan, Patrick Duvaut
  • Publication number: 20120257667
    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: Application
    Filed: April 8, 2011
    Publication date: October 11, 2012
    Inventor: Markus Nentwig
  • Patent number: 8284828
    Abstract: Instability resulting from non-linear impairments is detected and an equalizer of an end device is reset. An equalization instability threshold is retrieved from a data storage device. An equalization parameter for the end device is monitored and, if the equalization parameter exceeds the equalization instability threshold, the equalizer is reset.
    Type: Grant
    Filed: November 11, 2009
    Date of Patent: October 9, 2012
    Assignee: General Instrument Corporation
    Inventors: Michael J. Cooper, John L. Moran
  • Patent number: 8270524
    Abstract: In a communication system, a postcoder is coupled between first and second portions of each of a plurality of receivers. The postcoder is configured to receive an adaptive index representation of a scaled signal associated with the first portion of a first one of the receivers, and to process the adaptive index representation using an adjusted postcoder coefficient to generate a postcompensation signal. The postcompensation signal is supplied by the postcoder to the second portion of a second one of the receivers for use in postcompensation of at least one signal received by the second receiver.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: September 18, 2012
    Assignee: Alcatel Lucent
    Inventor: Adriaan J. De Lind Van Wijngaarden