Equalizers Patents (Class 375/229)
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Publication number: 20140321523Abstract: Disclosed is a transmitter for a communication system. The transmitter comprises a sidelobe suppression module configured to apply a suppression matrix to an input vector comprising symbols to be transmitted by the transmitter; a modulation module configured to modulate the precoded vector to a time-domain symbol using a plurality of subcarriers, each symbol in the precoded vector having a corresponding subcarrier; and a digital-to-analog conversion module configured to convert the time-domain symbol to an analog waveform for transmission. The suppression matrix is constructed such that emissions at one or more predetermined suppression distances lying outside a frequency band defined by the subcarriers are set to zero according to a predetermined emission model.Type: ApplicationFiled: July 7, 2014Publication date: October 30, 2014Inventors: Jian Zhang, Xiaojing Huang, Yingjie Jay Guo
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Patent number: 8873614Abstract: A system including a storage medium, a demodulator, and a decoder. The demodulator is configured to receive an input signal from the storage medium and demodulate the input signal. The decoder is configured to estimate data stored in the storage medium by decoding the demodulated input signal to provide an output signal. The decoder includes a filter and first and second processors. The filter is configured to generate a first equalized signal based on the output signal. The first processor is configured to, based on the first equalized signal and a first Viterbi algorithm, generate a first estimate of the data and an estimate of noise. The second processor is configured to generate a second estimate of the data based on the first estimate of the data, the estimate of the noise, and a second Viterbi algorithm. The output signal includes the second estimate of the data.Type: GrantFiled: November 25, 2013Date of Patent: October 28, 2014Assignee: Marvell International Ltd.Inventors: Hongwei Song, Zining Wu, Shaohua Yang
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Patent number: 8873613Abstract: A detection process for a receiver of a wireless communication system based on Multiple-In-Multiple-Out antennas, the process involving: —a preprocessing which only depends on the channel H, said preprocessing involving: —A QRD decomposition (61) for the purpose of decomposing said channel H into two Q and R matrices, with QHQ=I and R being upper triangular; —a lattice reduction (62) for the purpose of generating (formula AA, formula BB) and a permutation matrix T; —a loading phase (63, 64, 65) comprising a linear LRA-Minimum-Mean-Square-Error equalization applied on said symbols y in accordance with the result of said lattice reduction for the purpose of generating a value (formula CC).Type: GrantFiled: November 29, 2011Date of Patent: October 28, 2014Assignee: St-Ericsson SAInventor: Sebastien Aubert
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Patent number: 8873612Abstract: One or more embodiments describe a decision feedback equalizer with multiple cores for highly spectrally efficient communications. An equalization circuit in a receiver may include a decision feedback equalizer circuit having a first plurality of tap coefficients that are determined based on a cost function that receives as input an error signal that is an inter-symbol-correlated (ISC) signal. The decision feedback equalizer circuit may further include a second plurality of tap coefficients that are determined based on a filter with an ISC response. The cost function may determine the mean square of the error signal. The cost function is constrained or unconstrained. The error signal may represents error caused by a channel. In some embodiments, the ISC signal may be a partial response signal, and the filter with an ISC response may be a partial response filter.Type: GrantFiled: January 31, 2013Date of Patent: October 28, 2014Assignee: MagnaCom Ltd.Inventor: Amir Eliaz
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Patent number: 8873974Abstract: An embodiment of the invention is a technique to equalize received samples. A coefficient generator generates filter coefficients using an error vector and input samples. A filter stage generates equalized samples from input samples using the filter coefficients. The received samples are provided by a receiver front end in an optical transmission channel carrying transmitted symbols. Other embodiments are also described.Type: GrantFiled: May 7, 2013Date of Patent: October 28, 2014Assignee: Fundación TarpuyInventors: Mario Rafael Hueda, Diego Ernesto Crivelli, Hugo Santiago Carrer
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Patent number: 8867597Abstract: The present invention discloses a clock dejitter method comprising: a data sending adapter module inputting data with a system clock and using a sending clock to send data; a clock dejitter module associating the system clock with the sending clock of the data sending adapter module using; and the clock dejitter module tracking variations in the system clock and a data enable signal reflecting data sending state by referring to the system clock, and dynamically generating the sending clock varying with the data sending state. The present invention also discloses a clock dejitter apparatus and a data transmission system. The present invention greatly improves the free scheduling processing ability of services and reduces the bit error rate of data transmission while increasing efficiency of large capacity data switch transmission by dynamically adjusting the sending clock.Type: GrantFiled: June 22, 2010Date of Patent: October 21, 2014Assignee: ZTE CorporationInventor: Xiaoyi Wei
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Patent number: 8867598Abstract: An equalizer is disclosed, and associated operational method. The equalizer has a configuration that balances performance and complexity by obtaining samples that are strongly correlated with future and past transmitted bits, and are weakly correlated with future and past bit transitions, and is useful for timing recovery circuits. Samples are only obtained or collected at time intervals more than one sample period away from the reference sample. Samples are shifted by a delay value less than the sample period, and are obtained at a sample period of one unit interval. A means to adjust the sampling point delay is also disclosed. In an implementation, samples that are within the sample period away from the reference sample are obtained and used for implementing a timing shift, not for equalization of the timing recovery signal. Embodiments are also disclosed for optimizing performance for data recovery.Type: GrantFiled: August 14, 2012Date of Patent: October 21, 2014Assignee: PMC-Sierra US, Inc.Inventor: Mathieu Gagnon
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Patent number: 8868736Abstract: A method of estimating a level of severity of a network fault is provided. Performance parameters are monitored on upstream and downstream links to terminal network elements on a network to detect potential network faults. An alarm is raised with respect to a potential network fault automatically if at least one of the performance parameters as monitored crosses a preset threshold. After an alarm is raised, a level of severity is assigned to the alarm based on pre and post forward error correction (FEC) bit error rates (BER). In addition, the total number of terminal network elements that are impacted by the network fault is estimated and, when multiple alarms are raised of an equal level of severity, a higher priority is placed upon an alarm that affects service to a greatest number of terminal network elements.Type: GrantFiled: April 27, 2012Date of Patent: October 21, 2014Assignee: Motorola Mobility LLCInventors: David B. Bowler, Brian M. Basile, Clarke V. Greene, Xiang He
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Patent number: 8867599Abstract: Transmissions from mid-bus test equipment to a first device and from a second device to the mid-bus test equipment are equalized. Equalization instructions are passed from the first device through the mid-bus test equipment to the second device. The mid-bus test equipment changes the quality of transmissions sent to the first device in order to steer the first device to produce equalization instructions that will produce optimized transmissions from the mid-bus test equipment to the first device and from the second device to the mid-bus test equipment.Type: GrantFiled: February 11, 2013Date of Patent: October 21, 2014Assignee: SerialTek, LLCInventors: Dale T Smith, Eric J Lanning
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Patent number: 8866508Abstract: A system and method is disclosed for adaptively adjusting a driving strength of a signal between a first and second chip in a 3D architecture/stack. This may be used to adaptively calibrate a chip in a 3D architecture/stack. The system may include a transmission circuit on one chip and a receiver circuit on another chip. Alternatively, the system may include a transmission and receiver circuit on just one chip.Type: GrantFiled: January 20, 2012Date of Patent: October 21, 2014Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.Inventors: Ying-Yu Hsu, Ruey-Bin Sheen, Chih-Hsien Chang
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Patent number: 8867601Abstract: A receiver is provided that can receive a first signal transmitted on a first carrier and a second signal transmitted on a second carrier. The receiver includes a channel estimation portion, a multicarrier nonlinear equalizer, a first log likelihood computing portion and a second log likelihood computing portion. The channel estimation portion can output a first estimation. The multicarrier nonlinear equalizer can output a first equalized signal and a second equalized signal. The first log likelihood ratio computing portion can output a first log likelihood ratio signal based on the first equalized signal. The second log likelihood ratio computing portion can output a second log likelihood ratio signal based on the second equalized signal. The multicarrier nonlinear equalizer can further output a third equalized signal and a fourth equalized signal. The third equalized signal is based on the first signal, the second signal and the first estimation.Type: GrantFiled: June 12, 2013Date of Patent: October 21, 2014Assignee: Hughes Network Systems, LLCInventor: Bassel Beidas
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Patent number: 8862957Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for data processing systems with symbol selective scaling interacting with parity forcing.Type: GrantFiled: July 27, 2012Date of Patent: October 14, 2014Assignee: LSI CorporationInventors: Weijun Tan, Shaohua Yang, Kelly K. Fitzpatrick, Xuebin Wu, Fan Zhang
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Patent number: 8861643Abstract: A signal transmitting device and a method for transmitting via a signal transmitting device is disclosed. In one embodiment the transmitting device comprises a first resonant circuit with a resonant circuit inductance and a resonant circuit capacitance and a second resonant circuit with a resonant circuit inductance and a resonant circuit capacitance, a coupling element which couples the first resonant circuit to the second resonant circuit, a first excitation circuit, coupled to the first resonant circuit, and at least one further excitation circuit coupled to the second resonant circuit.Type: GrantFiled: May 14, 2013Date of Patent: October 14, 2014Assignee: Infineon Technologies AGInventor: Martin Feldtkeller
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Patent number: 8861580Abstract: Methods and apparatus are provided for determining one or more channel compensation parameters based on data eye monitoring. According to one aspect of the invention, a method is provided for evaluating the quality of a data eye associated with a signal. The received signal is sampled for a plurality of different phases, for example, using at least two latches, and the samples are evaluated to identify when the signal crosses a predefined amplitude value, such as a zero crossing. It is determined whether the points of predefined amplitude crossing satisfy one or more predefined criteria. One or more parameters of one or more channel compensation techniques can optionally be adjusted based on a result of the determining step. One or more parameters of an adjacent transmitter can also be adjusted to reduce near end cross talk based on a result of the determining step.Type: GrantFiled: May 16, 2006Date of Patent: October 14, 2014Assignee: Agere Systems LLCInventors: Christopher J. Abel, Mohammad S. Mobin, Gregory W. Sheets, Lane A. Smith
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Patent number: 8861575Abstract: 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: GrantFiled: November 15, 2012Date of Patent: October 14, 2014Assignee: AT&T Intellectual Property I, LPInventor: Arunabha Ghosh
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Patent number: 8861583Abstract: One embodiment relates to an equalizer circuit for a data link. The equalizer circuit including a continuous-time linear equalizer, a first circuit loop, and a second circuit loop. The continuous-time linear equalizer receives a received signal and outputs an equalized signal. The first circuit loop determines a first average signal amplitude. The first average signal amplitude may be an average signal amplitude of the equalized signal. The second circuit loop a second average signal amplitude. The second average signal amplitude may be an average signal amplitude of a high-frequency portion of the equalized signal. Other embodiments and features are also disclosed.Type: GrantFiled: December 14, 2012Date of Patent: October 14, 2014Assignee: Altera CorporationInventor: Wing Liu
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Patent number: 8860477Abstract: A receiver circuit includes a data interpolator to interpolate an input data signal and generate an interpolation data signal, a data determination unit to determine a data determination result of the interpolation data signal, a clock recovery unit to detect phase information based on a data determination result and output an interpolation code determining an interpolation rate to the data interpolator based on the detected phase information, a first interpolator to interpolate the input data signal and generate an interpolation data signal for an eye pattern monitor, a first determination unit for the eye pattern monitor to compare the interpolation data signal with a reference voltage, a match determination unit to determine whether the data determination result of the data determination unit matches a comparison result of the first determination unit, and an eye pattern regenerator to generate an eye pattern based on the phase information and a determination result.Type: GrantFiled: November 12, 2013Date of Patent: October 14, 2014Assignee: Fujitsu LimitedInventor: Takushi Hashida
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Patent number: 8862951Abstract: A circuit includes a summation circuit for receiving an input data signal and a feedback signal including a previous data bit. The summation circuit is configured to output a conditioned input data signal to a clock and data recovery circuit. A first flip-flop is coupled to an output of the summation circuit and is configured to receive a first set of bits of the conditioned input data signal and a first clock signal having a frequency that is less than a frequency at which the input data signal is received by the first summation circuit. A second flip-flop is coupled to the output of the summation circuit and is configured to receive a second set of bits of the conditioned input data signal and a second clock signal having a frequency that is less than the frequency at which the input data signal is received by the first summation circuit.Type: GrantFiled: June 21, 2012Date of Patent: October 14, 2014Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.Inventors: Ming-Chieh Huang, Chan-Hong Chern, Tao Wen Chung, Yuwen Swei, Chih-Chang Lin, Tsung-Ching Huang
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Patent number: 8861667Abstract: A signal receiving circuit having an equalizer calibration function. The signal receiving circuit includes a sampling circuit, output driver and clock signal generator. The sampling circuit captures samples of a data signal in response to a sampling clock signal. The output driver outputs an equalizing signal to an input of the sampling circuit in response to a first clock signal. The clock signal generator adjusts a phase of the first clock signal to achieve phase alignment between transitions of the equalizing signal and transitions of the data signal.Type: GrantFiled: July 12, 2002Date of Patent: October 14, 2014Assignee: Rambus Inc.Inventors: Jared L. Zerbe, Vladimir M. Stojanovic, Fred F. Chen
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Patent number: 8855237Abstract: A digital broadcasting transmission/reception system having improved receiving performance and signal processing method thereof. A digital broadcasting transmitter according to the present invention includes a data pre-processor which processed robust data and generates robust data packet of predetermined format, a TS stream generator which combines robust data packet with a normal data packet to generate a TS stream of a predetermined format, a randomizer which randomizes the TS stream output from the TS stream generator, a convolution encoder which performs convolution encoding with respect to the robust data of the data output from the randomizer, and a RS encoder which performs RS encoding with respect to the data output from the convolution g encoder. Accordingly, digital broadcasting receiving performance can be improved in a poor multipath channel, while maintaining compatibility with existing transmission/reception system.Type: GrantFiled: October 30, 2008Date of Patent: October 7, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Eui-jun Park, Yong-deok Chang
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Patent number: 8855177Abstract: Embodiments of the present disclosure generally pertain to systems and methods for reducing RF interference in communication systems. A communication system in accordance with an exemplary embodiment of the present disclosure comprises an element management system (EMS) communicating through a network with a plurality of network access devices. The EMS is configured to manage at least one network access device such that the device refrains from communicating data or reduces a data rate within a frequency range of a nearby interferer during time periods when interfering activity of the interferer is increased. Accordingly, the effects of RF interference for signals communicated by the device is reduced and degradation of service is prevented to an extent.Type: GrantFiled: November 19, 2010Date of Patent: October 7, 2014Assignee: ADTRAN, Inc.Inventors: Arlynn Wayne Wilson, Kent E. Darzi, Philip David Williams
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Patent number: 8855255Abstract: Systems and methods are provided for performing the required phase calculation in a telecommunications system in order to optimize system performance more quickly and with reduced complexity as compared to prior approaches to solving this problem. In accordance with the preferred exemplary embodiment of the present invention, the phase delay of the precursor equalizer (EQ) is calculated off-line and as a result it is not necessary to fill the precursor EQ delay line with the indicated number of symbols as in the previous approach. Additionally, because the precursor EQ is fractionally spaced, both sine and cosine values of the 4kHz tone's initial phase can be achieved simultaneously. As a result, only 36 quick timing sequence (QTS) symbols are needed in order to perform the required estimation.Type: GrantFiled: March 29, 2002Date of Patent: October 7, 2014Assignee: U.S. Robotics Corp.Inventors: Qing Chen, Qian Cheng
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Patent number: 8855238Abstract: A digital broadcasting transmission/reception system having improved receiving performance and signal processing method thereof. A digital broadcasting transmitter according to the present invention includes a data pre-processor which processed robust data and generates robust data packet of predetermined format, a TS stream generator which combines robust data packet with a normal data packet to generate a TS stream of a predetermined format, a randomizer which randomizes the TS stream output from the TS stream generator, a convolution encoder which performs convolution encoding with respect to the robust data of the data output from the randomizer, and a RS encoder which performs RS encoding with respect to the data output from the convolution g encoder. Accordingly, digital broadcasting receiving performance can be improved in a poor multipath channel, while maintaining compatibility with existing transmission/reception system.Type: GrantFiled: October 30, 2008Date of Patent: October 7, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Eui-jun Park, Yong-deok Chang
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Patent number: 8855239Abstract: A digital broadcasting transmission/reception system having improved receiving performance and signal processing method thereof. A digital broadcasting transmitter according to the present invention includes a data pre-processor which processed robust data and generates robust data packet of predetermined format, a TS stream generator which combines robust data packet with a normal data packet to generate a TS stream of a predetermined format, a randomizer which randomizes the TS stream output from the TS stream generator, a convolution encoder which performs convolution encoding with respect to the robust data of the data output from the randomizer, and a RS encoder which performs RS encoding with respect to the data output from the convolution g encoder. Accordingly, digital broadcasting receiving performance can be improved in a poor multipath channel, while maintaining compatibility with existing transmission/reception system.Type: GrantFiled: October 30, 2008Date of Patent: October 7, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Eui-jun Park, Yong-deok Chang
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Patent number: 8855183Abstract: A method of wireless communication with improved performance employs an equalizer receiver with multiple receive antennas. Equalizer taps for linear filters of the equalizer receiver are generated by determining a conditioned covariance matrix of a first data path and a second data path based on a first gain (g0) of this first data path and a second gain (g1) of the second data path. The equalizer taps of the first data path and the second data path are determined based on the conditioned covariance matrix. The first data path and the second data path are then equalized using the equalizer taps. An equalized signal is generated by combining the equalized first data path with the equalized second data path.Type: GrantFiled: August 16, 2011Date of Patent: October 7, 2014Assignee: Qualcomm IncorporatedInventors: Aditya Dua, Lei Xiao, Je Woo Kim, Feng Lu
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Patent number: 8848832Abstract: A digital broadcasting transmission/reception system having improved receiving performance and signal processing method thereof. A digital broadcasting transmitter according to the present invention includes a data pre-processor which processed robust data and generates robust data packet of predetermined format, a TS stream generator which combines robust data packet with a normal data packet to generate a TS stream of a predetermined format, a randomizer which randomizes the TS stream output from the TS stream generator, a convolution encoder which performs convolution encoding with respect to the robust data of the data output from the randomizer, and a RS encoder which performs RS encoding with respect to the data output from the convolution g encoder. Accordingly, digital broadcasting receiving performance can be improved in a poor multipath channel, while maintaining compatibility with existing transmission/reception system.Type: GrantFiled: October 30, 2008Date of Patent: September 30, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Eui-jun Park, Yong-deok Chang
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Patent number: 8848837Abstract: A method for carrier frequency tracking of a received signal having a burst structure includes dividing each burst into a number of segments. The carrier frequency offset of a first segment within a burst is measured to obtain a first segment carrier frequency offset measurement value. The carrier frequency offset of a second segment within the burst is corrected by a second segment carrier frequency offset correction value based on the first segment carrier frequency offset measurement value.Type: GrantFiled: October 19, 2006Date of Patent: September 30, 2014Assignee: Intel Mobile Communications GmbHInventors: Burkhard Becker, Stefan Fechtel
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Patent number: 8848826Abstract: A method for adaptively driving data transmission and a communication device using the same are provided. The proposed method includes following procedures. Detection result is generated after detecting a receiving signal on a receiving path of the communication device. Driving parameter is generated according to the detection result. Finally, a transmitting signal on a transmitting path is adjusted according to the driving parameter.Type: GrantFiled: May 14, 2012Date of Patent: September 30, 2014Assignee: ASMedia Technology Inc.Inventors: Shu-Yu Lin, Sheng-Chung Wu
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Patent number: 8842722Abstract: Equalization techniques are provided for high-speed data communications and, more specifically, DFE (decision feedback equalizer) circuits and methods are provided which implement a high-order continuous time filter in a DFE feedback path to emulate structured elements of a channel response.Type: GrantFiled: August 22, 2012Date of Patent: September 23, 2014Assignee: International Business Machines CorporationInventors: Timothy O. Dickson, Rui Yan Matthew Loh
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Patent number: 8842767Abstract: Methods and systems to substantially eliminate effects of EMI burst noise in an Ethernet system are provided herein. The method includes the step of computing and storing filter coefficients configured to adapt to a range of EMI frequencies. The method further comprises the step of receiving a signal and detecting EMI and frequency of the EMI in the received signal. The method further comprises selecting filter coefficients corresponding to the determined frequency of the detected EMI and adjusting a frequency response of one or more filters using the selected filter coefficients so as to substantially eliminate effects of the EMI in the received signal. The method further includes the step of sending filter coefficients to a link partner corresponding to the frequency of the detected EMI.Type: GrantFiled: April 30, 2010Date of Patent: September 23, 2014Assignee: Broadcom CorporationInventors: Tooraj Esmailian, Scott Powell, Chung Ming Tu, KuoRuey Han, Kadir Dinc, German Feyh
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Patent number: 8842778Abstract: A receiver may be dynamically configurable, during run-time, into a plurality of modes of operation. In a first mode of operation the receiver may demodulate received signals having relative low inter-symbol correlation using a near zero ISI filter and symbol slicing. In a second mode of operation the receiver may demodulate received signals having relatively high inter-symbol correlation using an input filter configured to achieve a desired total partial response and a sequence estimation algorithm.Type: GrantFiled: January 31, 2013Date of Patent: September 23, 2014Assignee: MagnaCom Ltd.Inventor: Amir Eliaz
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Publication number: 20140269860Abstract: Systems and methods for improving data communication over less than perfect power lines or transmission lines are described. The systems and methods allow for pushing out electrically any null within a frequency range of interest and/or for lossless transmission by providing impedance matching between communication devices and the transmission line. This is achieved by implementing line equalizing modules within the transceivers, at the transmitter side and/or the receiver side, or by plugging, as a stand-alone module, into an electrical outlet within a building. The line equalizing module includes multiple inductor-capacitor cells coupled in cascade where multiple switches allow for selective and concurrent connection between the inductor-capacitor cells. In another embodiment, the line equalizing module includes variable inductor-capacitor cells. The line equalizing module provides a variable propagation delay that allows for stretching electrically the transmission line.Type: ApplicationFiled: March 14, 2014Publication date: September 18, 2014Applicant: Dockon AGInventors: Forrest Brown, Alexandre Dupuy, Patrick Rada
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Patent number: 8837571Abstract: One embodiment relates to a receiver with both decision feedback equalization and on-die instrumentation. A clock data recovery loop obtains a recovered clock signal from an input signal, and a first sampler, which is triggered by the recovered clock signal, generates a recovered data signal from the input signal. A phase interpolator receives the recovered clock signal and generates a phase-interpolated clock signal. A second sampler is triggered by the recovered clock signal in a decision feedback equalization mode and by the phase-interpolated clock signal in an on-die instrumentation mode. Other embodiments and features are also disclosed.Type: GrantFiled: August 2, 2013Date of Patent: September 16, 2014Assignee: Altera CorporationInventors: Yanjing Ke, Thungoc M Tran, Weiqi Ding, Jie Shen, Xiong Liu, Sangeeta Raman, Peng Li
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Patent number: 8837572Abstract: A receiver and a method for equalizing signals, the method includes: receiving input signals; sampling the input signals to provide oversampled samples; processing the oversampled samples to provide symbol spaced samples and to provide fractionally spaced samples that represent the oversampled samples; calculating taps of a fractionally spaced equalizer based on the symbol spaced samples; feeding the taps to the fractionally spaced equalizer; and filtering the fractionally spaced samples by the fractionally spaced equalizer to provide equalized samples.Type: GrantFiled: November 26, 2009Date of Patent: September 16, 2014Assignee: Freescale Semiconductor, Inc.Inventors: Weizhong Chen, Noam Zach, Gideon Kutz
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Patent number: 8831083Abstract: Provided are a transmission channel estimating device, a transmission channel estimating method, and a receiving apparatus. A transversal filter unit generates an estimated reception signal on the basis of a stored known signal sequence and tap coefficients, generates an error signal on the basis of a difference between a reception signal and the estimated reception signal, generates updated tap coefficients on the basis of the known signal sequence, the tap coefficients and the error signal, designates an effective section formed by a predetermined number of taps out of a plurality of taps in the transversal filter unit 2, and designates a first section and a second section set so as to include a center tap, wherein the generation of the estimated reception signal and the updated tap coefficients is performed by generating an estimated reception signal and updated tap coefficients for the first section and generating an estimated reception signal and updated tap coefficients for the second section.Type: GrantFiled: November 30, 2011Date of Patent: September 9, 2014Assignee: Mitsubishi Electric CorporationInventors: Ryuichiro Kono, Jun Ido
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Patent number: 8830919Abstract: A time tracking method is provided for channel estimation of a mobile communication receiver and a related channel estimation apparatus is provided. The channel estimation apparatus includes a channel estimation control unit for analyzing and outputting a delay profile of a multipath channel by using a channel estimation value of each multi-tap, a tracking mode control unit for calculating a distance between an earliest tap and a preset margin tap by using the delay profile analysis results, and for generating and outputting a hopping tracking control signal for tracking a position of the earliest tap to a position of the margin tap at a time when the determined distance is greater than a preset hopping threshold value, and a hopping tracking mode execution unit for receiving the hopping tracking control signal and for shifting the position of the earliest tap to the position of the margin tap at a time.Type: GrantFiled: June 3, 2010Date of Patent: September 9, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Jae Hong Lee, Young Min Ki
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Patent number: 8831142Abstract: Described embodiments include a receiver for a serial-deserializer or the like. The receiver has adaptive offset voltage compensation capability. The offset voltage is canceled by a controller in a feedback loop to generate a compensation signal depending on a data decision error signal or by timing signals used for clock recovery.Type: GrantFiled: December 18, 2012Date of Patent: September 9, 2014Assignee: LSI CorporationInventors: Shiva Prasad Kotagiri, Pervez M. Aziz, Amaresh V. Malipatil
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Patent number: 8831082Abstract: Various embodiments described herein are directed to methods and systems for blind mode adaptive equalizer system to recover complex valued data symbols from the signal transmitted over time-varying dispersive diversity wireless channels. For example, various embodiments may utilize an architecture comprised of a bank of estimation units, a normalizing gain estimator, a DSP unit and a feedback shift register providing the equalizer feedback state vector. The estimation unit may be further comprised of a multiplicity of adaptive algorithms providing various filtered estimates of the data symbol to the DSP unit or providing the joint estimate of the transmitted data symbol.Type: GrantFiled: February 7, 2013Date of Patent: September 9, 2014Inventor: Rajendra Kumar
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Publication number: 20140247861Abstract: Fractional symbol based phase noise mitigation, including methods and systems to determine phase noise trajectory, or indication of phase noise, for each of multiple fractional portions of a frequency domain symbol, and modify the symbol based on the phase noise trajectories of the subsets. Multiple correction hypotheses may be generated for each fractional portion of the symbol based on pre-defined phase noise hypotheses. The correction hypotheses may include frequency domain correction hypotheses. The correction hypotheses for a subset may be evaluated to select one of the phase noise hypotheses as the trajectory for the subset. The evaluation may include applying each correction hypothesis to a corresponding equalized frequency domain symbol to generate corresponding symbol hypotheses, computing a signal quality for each symbol hypothesis, and comparing the signal qualities. Signal qualities may be determined as error vector magnitudes, and may be based on all or a subset of corresponding symbol tones.Type: ApplicationFiled: December 27, 2011Publication date: September 4, 2014Applicant: INTEL CORPORATIONInventors: Amir Rubin, Assaf Gurevitz, Gil Paryanti
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Patent number: 8824538Abstract: Methods and systems adaptively equalizing an analog information signal, the method including sampling the analog information signal to provide analog samples including post-transition samples and steady-state samples, and equalizing the analog samples to produce equalized analog samples. The equalizing includes determining a difference between an average post-transition amplitude associated with at least one of the post-transition samples and an average steady-state amplitude associated with at least one of the steady-state samples, and adjusting an equalization coefficient to adjust the difference between the average post-transition amplitude and the average steady-state amplitude.Type: GrantFiled: May 16, 2013Date of Patent: September 2, 2014Assignee: Broadcom CorporationInventors: Aaron Buchwald, Xicheng Jiang, Hui Wang, Howard A. Baumer, Avanindra Madisetti
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Patent number: 8824540Abstract: Equalization techniques are provided for high-speed data communications and, more specifically, DFE (decision feedback equalizer) circuits and methods are provided which implement a high-order continuous time filter in a DFE feedback path to emulate structured elements of a channel response.Type: GrantFiled: August 22, 2012Date of Patent: September 2, 2014Assignee: International Business Machines CorporationInventors: Timothy O. Dickson, Rui Yan Matthew Loh
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Patent number: 8824539Abstract: An OFDM receiver for processing an OFDM received signal to perform OFDM reception in presence of Doppler effects is provided. The receiver has at least two parallel processing chains, each processing chain has a time domain windowing for processing an OFDM block. The processing consisting of the multiplication, element by element of the OFDM block, by a set of predetermined coefficients. The receiver also has a DFT block (such as FFT) for demodulating said windowed OFDM symbol into the frequency domain equivalent wherein the windowings of the at least two parallel processing chains have complementary profiles so as to avoid any loss of information throughout the OFDM sample. The invention also provides a process to be used in an OFDM receiver.Type: GrantFiled: March 11, 2010Date of Patent: September 2, 2014Assignee: ST Ericsson SAInventors: Ancora Andrea, Giuseppe Montalbano
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Patent number: 8824537Abstract: A method, receiver and program for equalizing digital samples of a radio signal received over a wireless communications channel. The method comprises: receiving digital samples of the radio signal; calculating equalizer coefficients in the frequency domain; transforming the equalizer coefficients from the frequency domain to the time domain; and equalizing the digital samples in the time domain using the transformed time domain equalizer coefficients.Type: GrantFiled: January 27, 2011Date of Patent: September 2, 2014Assignee: ICERA Inc.Inventors: Steve Allpress, Carlo Luschi, Simon Nicholas Walker
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Publication number: 20140241409Abstract: An apparatus, method, computer readable medium, and system are provided to generate a symbol placement associated with a transmission scheme by transforming a retrieved set of equalization coefficients. Symbols included in the symbol placement may be analyzed and quantified in terms of their distance from a decision boundary. Symbols may be synthesized on an iterative basis in order to obtain visibility into the underlying performance of the transmission scheme over time. If equalization is unable to reduce a signal impairment below a threshold value within a predetermined amount of time, then a determination may be made that a non-linear distortion source is present in a network or communication system. Signals received from a plurality of user terminals may be compared with one another in order to determine a probable location or cause of the non-linear distortion.Type: ApplicationFiled: February 24, 2014Publication date: August 28, 2014Applicant: COMCAST CABLE COMMUNICATIONS, LLCInventors: Lawrence D. Wolcott, Phillip F. Chang
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Patent number: 8817863Abstract: The disclosed embodiments relate to the design of a linear equalizer that supports low-power, high-speed data transfers. In some embodiments, this linear equalizer contains a passive network that provides selective frequency peaking in a frequency range associated with a falling edge of a frequency response of the channel. It also includes a level shifter coupled between the channel and the passive network, wherein the level shifter is an active component that provides amplification and/or level-shifting. Moreover, the linear equalizer is designed so that power from the level shifter facilitates the selective frequency peaking of the passive network.Type: GrantFiled: January 25, 2012Date of Patent: August 26, 2014Assignee: Rambus Inc.Inventors: Kambiz Kaviani, Jason Chia-Jen Wei, Farshid Aryanfar
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Patent number: 8817866Abstract: A data equalizing circuit includes an equalizer configured to output data according to a control code; and a detection unit configured to divide the data into N number of calculation periods, count data transition frequencies for the N calculation periods, calculate dispersion values of the data transition frequencies for the N calculation periods, and output the control code corresponding to a largest dispersion value, in response to a counting interruption signal and a counting completion signal, wherein n is equal to or greater than 2, N is greater than n, and the data is divided to n number of unit intervals (UI), and wherein a phase shift of each of the calculation periods with respect to its corresponding UI is different from a phase shift of any of the other calculation periods with respect to its corresponding UI.Type: GrantFiled: February 28, 2012Date of Patent: August 26, 2014Assignee: SK Hynix Inc.Inventors: Chun Seok Jeong, Jae Jin Lee, Chang Sik Yoo, Jang Woo Lee, Seok Joon Kang
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Patent number: 8817865Abstract: Linear distortion and interference estimation using decision feedback equalizer coefficients. Processing of different respective groups of equalizer coefficients may be made to determine the residual frequency response of an equalizer and/or device in which the equalizer is implemented. Such an equalizer may be implemented within any of a number of respective communication devices including those operative within satellite, wireless, wired, fiber-optic, and/or mobile communication systems. A first group of equalizer coefficients corresponds to certain filtering characteristics of the equalizer and/or device in which the equalizer is implemented. The equalizer is implemented to process a signal to generate a second group of equalizer coefficients.Type: GrantFiled: February 28, 2012Date of Patent: August 26, 2014Assignee: Broadcom CorporationInventors: Bruce J. Currivan, Thomas J. Kolze, Roger Fish, Victor T. Hou
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Patent number: 8817862Abstract: An equalizer and a related equalizing method for equalizing signal reflection caused by a stub at a transmitting end are provided. The equalizer includes a summing device and a delay device. The summing device is utilized for adding a feedback delay signal to the input signal to generate the equalized signal. The delay device is coupled to the summing device, and utilized for delaying the equalized signal to generate the feedback delay signal. Wherein the delay device has a variable delay time and the variable delay time is a non-integer multiple of a bit time of the input signal.Type: GrantFiled: March 16, 2011Date of Patent: August 26, 2014Assignee: Realtek Semiconductor Corp.Inventors: Chao-Cheng Lee, Tzu-Chien Tzeng
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Publication number: 20140233625Abstract: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors based on the same transmitted vector. The receiver linearizes each received signal vector using one or more zero-forcing, MMSE, or other suitable linear equalizers. The components of the equalized signal vectors may be combined using maximum-ratio combining to form the components of a combined equalized signal vector. The components of the combined equalized signal vector may then be decoded individually using a linear decoder.Type: ApplicationFiled: April 24, 2014Publication date: August 21, 2014Applicant: Marvell World Trade Ltd.Inventors: Jungwon Lee, Woong Jun Jang, Hui-Ling Lou
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Patent number: 8811464Abstract: Apparatuses, methods, and other embodiments associated with adaptively determining equalizer setting for 10GBASE-KR transmitter are described. According to one embodiment, an apparatus for tuning an equalizer configured to undo the effects of a channel connecting a transmitter communicating to a receiver via a backplane includes a tuning logic configured to adaptively determine equalizer settings for the equalizer. The tuning logic includes a symmetric search logic configured to determine a desired boost setting for the equalizer, and an asymmetric search logic configured to determine a desired phase response for the equalizer.Type: GrantFiled: December 27, 2010Date of Patent: August 19, 2014Assignee: Marvell International Ltd.Inventors: Jagadish Venkataraman, Jamal Riani, Pui Shan Wong