Adaptive Patents (Class 375/232)
-
Patent number: 9020024Abstract: A rate-adaptive equalizer automatically initializes its tap coefficients to values. During an initialization process, a linear search algorithm is performed that sweeps the tap coefficients through different combinations of tap coefficients while assessing information about an eye associated with an input signal received over a communications channel. When the eye information indicates that the eye is open, the current tap coefficients are selected as the initial tap coefficients to be used at the beginning of the main adaptation algorithm.Type: GrantFiled: October 31, 2013Date of Patent: April 28, 2015Assignee: Avego Technologies General IP (Singapore) Pte. Ltd.Inventors: Faouzi Chaahoub, Georgios Asmanis, Sriramkumar Sundararaman, Samir Aboulhouda
-
Patent number: 9020025Abstract: A transceiver including an equalizer and a control circuit. The equalizer receives an input signal and first coefficients. The equalizer includes taps that, based on the first coefficients, filter the input signal to generate an output signal. The taps include a precursor tap, a unity tap and postcursor taps. The control circuit selects the first coefficients such that a sum of the first coefficients is equal to a predetermined value. The first coefficients include a precursor coefficient, a second coefficient, and post cursor coefficients corresponding respectively to the precursor tap, the unity tap, and the postcursor taps. The control circuit: maintains the second coefficient at a fixed value; based on the second coefficient, selects the precursor coefficient and the postcursor coefficients; and while maintaining the second coefficient at the fixed value and while the equalizer is receiving the input signal, adjusts the precursor coefficient or one of the postcursor coefficients.Type: GrantFiled: June 10, 2014Date of Patent: April 28, 2015Assignee: Marvell International Ltd.Inventor: Runsheng He
-
Publication number: 20150110165Abstract: A method of adjusting a post-cursor tap weight in a transmitter FIR filter in a high-speed digital data transmission system. A receiver, over a forward channel, receives a signal from the transmitter and equalizes the received signal using an adaptive analog equalizer coupled to the forward channel and a decision feedback equalizer (DFE) coupled to the analog equalizer. A gain coefficient used to adjust the peaking by the analog equalizer is adapted using an error signal generated by the DFE. The post-cursor tap weight of the transmitter filter is adjusted up or down based on a comparison of the gain coefficient to a set. of limits. The post-cursor tap weight is transmitted to the transmitter over a reverse channel and then equalizers in the receiver readapt. Alternatively, eye opening data and a DFE tap coefficient are used to determine whether the post-cursor tap weight is adjusted up or down.Type: ApplicationFiled: November 6, 2013Publication date: April 23, 2015Applicant: LSI CorporationInventors: Rajesh Ramadoss, Mohammad S. Mobin, Thomas F. Gibbons
-
Patent number: 9014254Abstract: Testing a Decision Feedback Equalizer (‘DFE’), the DFE including a summing amplifier operatively coupled to a plurality of latches and an input signal line for receiving a data signal, including: preventing a differential data signal from being received by the summing amplifier; and iteratively for each tap to be tested: setting a tap coefficient for each tap to zero; setting an output of the plurality of latches to a predetermined value; setting a tap coefficient for the tap to be tested to a full scale value; and determining whether a resultant output signal from the DFE matches a predetermined expected output signal.Type: GrantFiled: June 19, 2013Date of Patent: April 21, 2015Assignee: International Business Machines CorporationInventors: Eugene R. Atwood, Matthew B. Baecher, Minhan Chen, Hayden C. Cranford, Jr., William R. Kelly, Todd M. Rasmus
-
Patent number: 9014250Abstract: A channel in a multiple carrier communication system is equalized by computing a desired spectral response, shortening the impulse response of the channel so that a significant part of an energy of the impulse response is confined to a region that is shorter than a target length and filtering the signal based on the desired spectral response. A multiple carrier communication system may include a primary impulse shortening filter that receives an output signal of an analog to digital converter and accepts coefficients. A secondary impulse shortening filter may receive the output signal of the analog to digital converter, output an output signal, and pass coefficients to the primary impulse shortening filter. A reference signal generator may output a reference signal. A comparator may compare the output signal and the reference signal and output a resulting error signal. An adaptive processor may compute coefficients for the secondary impulse shortening filter based on the error signal.Type: GrantFiled: December 28, 2012Date of Patent: April 21, 2015Assignee: Tellabs Operations, Inc.Inventors: Gopal Harikumar, Daniel J. Marchok, Kenneth J. Rudofski
-
Patent number: 9014251Abstract: For digital data transmitted using a vector signaling encoding, a rank-order equalizer cancels various channel noise such as inter-symbol interference. Further, rank-order units may be cascaded to achieve improved equalization over successive sample vector signals in a rank-order equalizer. Multiple rank-order equalizers further operate in parallel in a feed forward mode or in series in a feedback mode to provide a continuous vector signaling stream equalization.Type: GrantFiled: June 5, 2014Date of Patent: April 21, 2015Assignee: Kandou Labs, S.A.Inventors: Harm Cronie, Klaas Hofstra, Amin Shokrollahi
-
Patent number: 9008167Abstract: Logic may comprise a single phase tracking implementation for all bandwidths of operation and the logic may adaptively change pre-defined and stored track parameters if the receiving packet is 1 MHz bandwidth. Logic may detect a packet and long training fields before performing a 1 MHz classification. Logic may auto-detect 1 MHz bandwidth transmissions by a property of the long training field sequences. Logic may auto-detect 1 MHz bandwidth transmissions by detecting a Binary Phase Shift Keying (BPSK) modulated first signal field symbol rather than the Quadrature Binary Phase Shift Keying (QBPSK) associated with the 2 MHz or greater bandwidth transmissions. Logic may perform an algorithm to determine an estimated phase correction value for a given orthogonal frequency division multiplexing symbol and several embodiments integrate this value with an intercept multiplier that may be 0.2 for 1 MHz transmissions and, e.g., 0.5 for 2 MHz or greater bandwidth communication.Type: GrantFiled: December 29, 2012Date of Patent: April 14, 2015Assignee: Intel CorporationInventors: Shahrnaz Azizi, Eldad Perahia, Thomas J. Kenney
-
Patent number: 9008168Abstract: A method of equalizing signals from a plurality of balanced transmission line cables having different lengths includes providing a first cable having a first length and a second cable having a second length, the first cable coupled to a variable resistor. A first signal is transmitted along the first cable to the variable resistor such that the first signal is attenuated to assume a first frequency domain characteristic. A second signal is transmitted along the second cable such that the second signal is attenuated to assume a second frequency domain characteristic. A voltage of the first signal is divided in the variable resistor such that the first signal assumes substantially the second frequency domain characteristic. The first signal having the second frequency domain characteristic is outputted.Type: GrantFiled: November 21, 2013Date of Patent: April 14, 2015Assignee: Magenta Research LimitedInventors: Chris Miller, Keith Mortensen
-
Patent number: 9008196Abstract: A computer system includes a processor, and the processor includes at least one interface for communicating with an electronic component. Each of the at least one interface has a set of interface settings. The computer system further includes a memory containing machine executable instructions. Execution of the instructions causes the processor to: monitor communications traffic on the at least one interface; store, eye distribution data acquired during the monitoring of the communications traffic in a database; compare the eye distribution data to a set of predetermined criteria; and generate a set of updated interface settings if the eye distribution does not satisfy the set of predetermined criteria.Type: GrantFiled: April 26, 2012Date of Patent: April 14, 2015Assignee: International Business Machines CorporationInventors: Frank W. Angelotti, Michael D. Campbell, Kenneth L. Christian, Martin Eckert, Hubert Harrer, Rohan Jones, Neil A. Malek, Gary A. Peterson, Andrew A. Turner, Dermot Weldon
-
Patent number: 9001943Abstract: Systems and methods are provided for adjusting gain of a receiver. Adaptation circuitry is operable to identify, based on a matrix representation of a receiver's output generated from horizontal and vertical sweeps of the receiver's output, an eye opening of the receiver's output. The adaptation circuitry is also operable to determine whether a size of the eye opening needs to be changed. When it is determined that the size of the eye opening needs to be changed, the adaptation circuitry is operable to generate a digital signal to change a gain setting of the receiver. When the signal at the receiver's output is under-equalized, the AC gain of the receiver is increased. When the signal at the receiver's output is over-equalized, the AC gain of the receiver is decreased.Type: GrantFiled: August 23, 2013Date of Patent: April 7, 2015Assignee: Altera CorporationInventors: Tim Tri Hoang, Nam V. Nguyen
-
Publication number: 20150092831Abstract: The present invention provides an equalization method and an equalizer for received signals in a microwave MIMO system. By performing vertical spatial filtering on and combining internal sub-signals for n received signals, an initial sliced signal corresponding to a received signal currently to be decoded is obtained; (n?1) ICI signals are generated based on (n?1) initial sliced signals corresponding to other (n?1) received signals; after the (n?1) ICI signals are eliminated from the n received signals, vertical spatial filtering is performed and internal sub-signals are combined to obtain a final sliced signal.Type: ApplicationFiled: December 10, 2014Publication date: April 2, 2015Inventor: Rui Lv
-
Publication number: 20150092829Abstract: A device for passive equalization and slew-rate control of a signal includes a first branch that includes a first driver coupled in series with an equalization capacitor, and a second branch that includes a second driver coupled in series with a resistor. The second branch may be coupled in parallel to the first branch, and the first branch may be configurable to enable one of passive equalization or slew-rate control of the signal based on a mode control signal.Type: ApplicationFiled: November 5, 2013Publication date: April 2, 2015Applicant: Broadcom CorporationInventors: Tamer ALI, Hassan Maarefi, Mahmoud Reza Ahmadi, Afshin Momtaz
-
Publication number: 20150092828Abstract: A system and method consistent with the present disclosure includes determining a jitter tolerance of a particular lane of a communication link corresponding to each of a plurality of equalization coefficients. Further, determining a particular equalization coefficient of the plurality of equalization coefficients that provides a maximum jitter tolerance. Next, using the particular equalization coefficient for the particular lane of the communication link during operation based on determining the particular equalization coefficient which provides the maximum jitter tolerance.Type: ApplicationFiled: September 27, 2013Publication date: April 2, 2015Inventors: Nathaniel L. Desimone, Theodore Z. Schoenborn, Earl Wight, Duane Heller, Maria F. Pineda
-
Publication number: 20150092830Abstract: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiplexing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. The present invention is based on the method of piecewise pre-equalized lookup table based predistortion, which is a cascade of a lookup table predistortion and piecewise pre-equalizers.Type: ApplicationFiled: September 8, 2014Publication date: April 2, 2015Inventors: Wan-Jong Kim, Kyoung Joon Cho, Jong Heon Kim, Shawn Patrick Stapleton
-
Patent number: 8995519Abstract: Generating updated coefficients for an adaptive equalizer involves generating phase tracking information using asynchronous detection strategy (ADS) based on resolved data, and equalized signals, and estimating a phase corrected error based on the equalized signals, the phase tracking information and the resolved data. An inhibit signal is generated to inhibit updating of the equalization coefficients, the inhibit signal representing a likelihood of the phase corrected error being accurate, determined according to the phase corrected error, and the equalized signals. The equalization coefficients for the equalizer are adapted based on the received signals, and on the phase corrected error, and the adapting is inhibited according to the inhibit signal. Compared to conventional ADS, the new combination with the inhibit signal can enable improved convergence of coefficient adaptation. This is particularly useful for coherent receivers for optical systems.Type: GrantFiled: October 15, 2010Date of Patent: March 31, 2015Assignee: Telefonaktiebolaget L M Ericsson (Publ)Inventors: Tommaso Foggi, Giulio Colavolpe
-
Patent number: 8995518Abstract: Apparatus and methods mitigate a problem of equalizing communications signals that have been distorted by severe non-linearities such as clipping or harsh compression. For example, severe non-linearity occurs when signal compression or signal clipping occurs at rates above 20% of the data transmission interval. Severe non-linearities may significantly reduce system performance. Disclosed techniques selectively apply DSP equalization based on the detection of non-linearity for a present sample or one or more samples prior to the present sample. These techniques can be implemented in relatively low-cost high-speed SerDes designs to improve eye openings and reduce sensitivity to InterSymbol Interference (ISI) and to improve bit error rate (BER).Type: GrantFiled: April 22, 2013Date of Patent: March 31, 2015Assignee: PMC-Sierra, Inc.Inventors: Ognjen Katic, Paul V. Yee, William D. Warner
-
Patent number: 8995520Abstract: In particular embodiments, a method includes receiving as an input signal a phase-distorted signal or a transmitted-data signal, the phase-distorted signal having been distorted from a phase-equalized signal by transmission across a communication channel, the transmitted-data signal comprising transmitted data; generating a non-derivative version of the input signal by applying a delay operator in a continuous-time domain to the input signal; generating a derivative version of the input signal by applying a derivative operator in a continuous-time domain to the input signal; generating a first product signal by multiplying the non-derivative version of the input signal by a first coefficient, the first coefficient being a positive number; generating a second product signal by multiplying the derivative version of the input signal by a second coefficient, the second coefficient being a negative number; and generating an output signal by summing the first and second product signals.Type: GrantFiled: February 14, 2011Date of Patent: March 31, 2015Assignee: Fujitsu LimitedInventor: Yasuo Hidaka
-
Patent number: 8995932Abstract: Systems and methods for suppressing transmitter noise in a receive band of a co-located receiver that are suitable for wideband applications are disclosed. In one embodiment, an analog radio frequency transmit signal output by a transmitter includes a desired signal in a transmit band of the transmitter and transmitter noise in a receive band of a main receiver. A secondary receiver obtains a secondary receiver input signal that is representative of at least the transmitter noise in the receive band of the main receiver and outputs a digital feedforward signal. A digital feedforward transmit noise cancellation subsystem generates a digital transmitter noise cancellation signal that is representative of the transmitter noise in the receive band based on the digital feedforward signal and subtracts the digital transmitter noise cancellation signal from a digital receive signal output by the main receiver to thereby provide a compensated digital receive signal.Type: GrantFiled: January 4, 2013Date of Patent: March 31, 2015Assignee: Telefonaktiebolaget L M Ericsson (publ)Inventor: Mark Wyville
-
Publication number: 20150085912Abstract: Provided are an adaptive equalizer for adaptively controlling an equalization coefficient until two comparators outputs a same value, after generating a sensitivity difference between signals at a front end of each comparator for performing sampling, and a method of controlling the adaptive equalizer.Type: ApplicationFiled: September 25, 2014Publication date: March 26, 2015Inventors: Seongho CHO, Wangsoo KIM, Jinsung YOUN, Wooyoung CHOI, Hojung KIM, Moonseung YANG
-
Publication number: 20150085913Abstract: A data receiving circuit that can accurately obtain a data signal corresponding to information data from a high speed high density transmitted signal, and a semiconductor device including the data receiving circuit. The amplitude of a first differential signal corresponding to a level difference between a pair of received differential signals, generated in a first differential stage, is amplified and binalized to obtain a received data signal. A second differential signal corresponding to the level difference between the received differential signals, and a third differential signal which is a phase-inverted signal of the second differential signal are generated in a second differential stage provided separately, and a current corresponding to the second differential signal and a current corresponding to the third differential signal are discharged into the respective ones of the pair of transmission lines, thereby suppressing the amplitudes of the received differential signals.Type: ApplicationFiled: December 4, 2014Publication date: March 26, 2015Applicant: LAPIS SEMICONDUCTOR CO., LTD.Inventors: Hideaki HASEGAWA, Kouji TAKEDA
-
Publication number: 20150085910Abstract: There is provided a reception device including a reception unit configured to receive an OFDM (Orthogonal Frequency Division Multiplexing) signal, an acquisition unit configured to acquire a transmission parameter concerning the OFDM signal contained in the OFDM signal, and a selection unit configured to select a demodulation mode of the OFDM signal in accordance with the acquired transmission parameter.Type: ApplicationFiled: May 22, 2013Publication date: March 26, 2015Inventors: Takashi Yokokawa, Hiroyuki Kamata, Hidetoshi Kawauchi, Yuken Goto, Kenichi Kobayashi
-
Publication number: 20150085911Abstract: This disclosure provides a method for equalizing the transmission spectrum of a wireless communication transmitter. The method includes: providing a plurality of single-frequency signals; respectively inputting the plurality of single-frequency signals into the transmitter, wherein each single-frequency signal has a predetermined frequency and all the predetermined frequencies are different from each other; loopbacking the plurality of single-frequency signals to an analog to digital converter so as to generate a plurality of digital loopback signals; calculating a frequency response of the transmitter at base band circuit according to the plurality of digital loopback signals; and equalizing the transmission spectrum of the transmitter according to the frequency response of the transmitter.Type: ApplicationFiled: September 24, 2014Publication date: March 26, 2015Inventor: CHING-CHIA CHENG
-
Patent number: 8989252Abstract: Systems and methods for power efficient iterative equalization on a channel are provided. An iterative decoder decodes received data from a channel detector using a decoding process. The decoder computes a decision metric based on the decoded data and adjusts the number of iterations of the decoding process based on the decision metric. The adjustment occurs prior to a reliability criterion for the decoded data being satisfied. The decoder may pass control back to the channel detector if the adjusted number of iterations has occurred or if the reliability criterion is satisfied. Adjusting the number of iterations of the decoding process may include increasing the number of iterations from a predetermined number of iterations. The decision metric may be based on syndrome weight or hard decisions. The decision metric may be chosen to reduce average power consumption of the detector, the decoder, or circuitry including the detector and the decoder.Type: GrantFiled: January 19, 2012Date of Patent: March 24, 2015Assignee: Marvell International Ltd.Inventors: Nedeljko Varnica, Gregory Burd
-
Patent number: 8989587Abstract: Methods, algorithms, architectures, circuits, and/or systems for determining the status of parameters associated with optical transceiver operation are disclosed. The method can include (a) accessing and/or monitoring parametric data for each of a plurality of parameters that are related to operation of the optical transceiver; (b) storing the parametric data in one or more memories; (c) comparing the parametric data for each of the plurality of parameters against at least one of a corresponding plurality of predetermined thresholds; and (d) generating one or more states indicating whether the parametric data for a unique one of the parameters has crossed one or more of the corresponding plurality of predetermined thresholds. The invention also relates to an optical triplexer, comprising the described optical transceiver.Type: GrantFiled: January 11, 2012Date of Patent: March 24, 2015Assignee: Source Photonics, Inc.Inventors: Todd Rope, Mark Heimbuch
-
Patent number: 8989250Abstract: Methods and circuits for equalizing a linear response in an observation path of a digital pre-distorter. A method comprises generating observed signals in an observation path based on observing a transmit signal; down-converting the observed signals into intermediate frequencies using different LO frequencies; calculating a ratio using the intermediate frequencies; and equalizing the linear response of the observation path on the observed signals using the ratio. An apparatus comprises a directional coupler for observing a transmit signal and generating observed signals; a down-converter for converting the observed signals into intermediate frequencies using different LO frequencies; and an adaptive estimator for calculating a ratio using the intermediate frequencies and using the ratio to equalize a linear response from the observation path on the observed signals.Type: GrantFiled: March 15, 2013Date of Patent: March 24, 2015Assignee: PMC-Sierra US, Inc.Inventors: William D. Warner, Andrew S. Wright, Bartholomeus T. W. Klijsen, Derek J. W. Ho
-
Patent number: 8989602Abstract: A digital coherent optical receiver includes a processor that is operative to separate electric signals obtained by converting an optical signal into a horizontal signal component and a vertical signal component; to generate a histogram of the horizontal signal component and the vertical signal component as outputs of the equalizing filter; and to determine a presence/absence of local convergence based on distribution of the histogram of the horizontal signal component and the histogram of the vertical signal component.Type: GrantFiled: October 27, 2011Date of Patent: March 24, 2015Assignee: Fujitsu LimitedInventors: Kosuke Komaki, Osamu Takeuchi
-
Patent number: 8989588Abstract: An optical transceiver includes an optical IC coupled to a processor IC. For transmit, the optical IC can be understood as a transmitter IC including a laser device or array. For receive, the optical IC can be understood as a receiver IC including a photodetector/photodiode device or array. For a transmitter IC, the processor IC includes a driver for a laser of the transmitter IC. The driver includes an equalizer that applies high frequency gain to a signal transmitted with the laser device. For a receiver IC, the processor IC includes a front end circuit to interface with a photodetector of the receiver IC. The front end circuit includes an equalizer that applies high frequency gain to a signal received by the receiver IC. The driver can be configurable to receive a laser having either orientation: ground termination or supply termination.Type: GrantFiled: January 22, 2013Date of Patent: March 24, 2015Assignee: Intel CorporationInventors: Gil Afriat, Lior Horwitz, Dror Lazar, Assaf Issachar, Alexander Pogrebinsky, Adee O. Ran, Ehud Shoor, Roi Bar, Rushdy A. Saba
-
Patent number: 8989253Abstract: A technique for a reconditioning equalizer filter for non-constant envelope signals is described. The input to a transmitter chain is modified by a reconditioning equalizer filter, prior to being applied to the transmitter. The reconditioning equalizer filter modifies and smoothens the amplitude of the signal. The modified and smoothened signal has its peaks reduced which results in lower Crest Factor. The input to the reconditioning equalizer filter could be a baseband, intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal, it needs to be down-converted to baseband before being applied to the reconditioning equalizer filter. The reconditioning equalizer filter could be performed in a digital or analog domain.Type: GrantFiled: June 17, 2014Date of Patent: March 24, 2015Assignee: Altera CorporationInventor: Kiomars Anvari
-
Patent number: 8989729Abstract: Embodiments of the claimed subject matter provide a method for supporting network monitoring of user equipment events. Some embodiments of the method include receiving, at a home subscriber server (HSS) in a public land mobile network (PLMN), a request to monitor one or more events associated with one or more users. The request is used to configure, activate, or deactivate delivery of reports from one or more entities in the PLMN to a monitor collection entity in response to the event(s). Some embodiments of the method also include configuring one or more profiles in the HSS associated with the user(s) based on the request and providing the request to monitor the event(s) associated with the user(s) to one or more serving nodes for user equipment associated with the user(s).Type: GrantFiled: November 9, 2012Date of Patent: March 24, 2015Assignee: Alcatel LucentInventors: Deborah L. Barclay, Bruno Landais, Laurent Thiebaut
-
Publication number: 20150078429Abstract: A communication device, such as a smart phone, includes logic to determine a noise power estimate. In an example, a frequency domain calculation may be used to determine noise components within the noise power estimate. Further, a product of a channel estimate and equalizer effect may be used in the determination of the levels noise components, such as, inter-symbol interference power and neighbor cell interference power.Type: ApplicationFiled: September 23, 2013Publication date: March 19, 2015Applicant: Broadcom CorporationInventors: Hou-Shin Chen, Fu-Hsuan Chiu
-
Patent number: 8982939Abstract: Described herein is an apparatus, method and system corresponding to relate to a low power digital phase interpolator (PI). The apparatus comprises: a digital mixer unit to generate phase signals from a series of input signals, the phase signals having phases which are digitally controlled; a poly-phase filter, coupled to the digital mixer unit, to generate a filtered signal by reducing phase error in the phase signals; and an output buffer, coupled to the poly-phase filter, to generate an output signal by buffering the filtered signal. The low power digital PI consumes less power compared to traditional current-mode PIs operating on the same power supply levels because the digital PI is independent of any bias circuit which are needed for current mode PIs.Type: GrantFiled: December 21, 2011Date of Patent: March 17, 2015Assignee: Intel CorporationInventor: Hongjiang Song
-
Patent number: 8983000Abstract: A receiver circuit includes a unit configured to determine filter coefficients based on a sampling time error of a received signal and a phase error of the received signal, as well as a filter configured to filter a signal, which is based on the received signal, based on the filter coefficients.Type: GrantFiled: October 18, 2012Date of Patent: March 17, 2015Assignee: Intel Mobile Communications GmbHInventors: Andreas Senst, Manfred Zimmermann, Clemens Buchacher, Peter Noest
-
Patent number: 8982940Abstract: The present disclosure relates to the field of network communication, and specifically discloses an adaptive equalization method, including: obtaining a first filtered signal according to a first filter coefficient; deciding the first filtered signal based on an original constellation map to obtain a first decision signal, and deciding the first filtered signal based on a level (n?1) constellation map to obtain a level (n?1) pseudo decision signal; if average energy of the level (n?1) error signal is less than a level (n?1) threshold, switching the level (n?1) constellation map to a level n constellation map; obtaining a second filter coefficient according to the update magnitude; obtaining a second filtered signal according to the second filter coefficient; and deciding the second filtered signal based on the original constellation map to obtain a second decision signal. Embodiments of the present disclosure also disclose an adaptive equalizer.Type: GrantFiled: April 23, 2013Date of Patent: March 17, 2015Assignee: Huawei Technologies Co., Ltd.Inventor: Rui Lv
-
Patent number: 8984038Abstract: Aspects of a method and system for unconstrained frequency domain adaptive filtering include one or more circuits that are operable to select one or more time domain coefficients in a current filter partition. A value may be computed for each of the selected one or more time domain coefficients based on a corresponding plurality of frequency domain coefficients. The corresponding plurality of frequency domain coefficients may be adjusted based on the computed values. A subsequent plurality of frequency domain coefficients in a subsequent filter partition may be adjusted based on the computed values. Input signals may be processed in the current filter partition based on the adjusted corresponding plurality of frequency domain coefficients. A time-adjusted version of the input signals may be processed in a subsequent filter partition based on the adjusted subsequent plurality of frequency domain coefficients.Type: GrantFiled: November 22, 2013Date of Patent: March 17, 2015Assignee: Broadcom CorporationInventors: Kuoruey (Ray) Han, Peiqing Wang, Linghsiao Wang, Kishore Kota, Arash Farhoodfar
-
Patent number: 8976855Abstract: An exemplary receiver equalizer includes a first decision feedback equalizer (DFE) sampler coupled to a summer, the first DFE to latch an equalized output of the summer. The first branch includes a second DFE sampler coupled to the first DFE sampler, the second DFE to latch an output of the first DFE sampler. The first branch includes a third DFE sampler coupled to the second DFE sampler, the third DFE to latch an output of the second DFE sampler. The summer coupled to the first, second, and third DFE samplers of the first branch, the summer to integrate the output of said DFE samplers, the received signal, and equalized outputs from one or more other branches, wherein the integrating occurs over a plurality of unit intervals (UIs).Type: GrantFiled: March 14, 2013Date of Patent: March 10, 2015Assignee: Intel CorporationInventors: Mingming Xu, Stefano Giacconi
-
Patent number: 8976854Abstract: A reconfigurable P-way parallel N-tap feed forward equalizer includes an adaptive filter configured to generate a series of coefficients (taps) and an input register for storing input symbols. A variable cursor position defined by a parameter corresponding to a position in the input register selects a set of pre-cursor and post-cursor taps for dynamic ISI correction of a like set of pre-cursor and post-cursor symbols. Multiplier banks generate partial result symbols by applying the taps to the set of input symbols, and a set of combiners or adder banks generate equalized output symbols from the partial result symbols. Two multiplexers adjust input symbols and coefficients according to the parameter, and a controller allows selection of an optimal parameter, and thus an optimal variable cursor position. The coefficient corresponding to the parameter may additionally be preset to save storage space.Type: GrantFiled: February 28, 2014Date of Patent: March 10, 2015Assignee: LSI CorporationInventors: Adam B. Healey, Tomasz Prokop, Volodymyr Shvydun, Chaitanya Palusa
-
Patent number: 8976853Abstract: A receiver may receive a signal that was generated by passage of symbols through a non-linear circuit. An equalizer of the receiver may equalize the received signal based on a first non-linearity compensated, inter-symbol correlated (ISC) feedback signal to generate an equalized signal. The receiver may correct a phase error of the equalized signal to generate a phase-corrected equalized signal. The phase correction may be based on a second, non-linearity compensated, inter-symbol correlated (ISC) feedback signal.Type: GrantFiled: October 14, 2013Date of Patent: March 10, 2015Assignee: MagnaCom Ltd.Inventor: Amir Eliaz
-
Patent number: 8976909Abstract: A non-linear detector for detecting signals with signal-dependent noise is disclosed. The detector may choose a data sequence that maximizes the conditional probability of detecting the channel data. Since the channel may be time-varying and the precise channel characteristics may be unknown, the detector may adapt one or more branch metric parameters before sending the parameters to a loading block. In the loading block, the branch metric parameters may be normalized and part of the branch metric may be pre-computed to reduce the complexity of the detector. The loading block may then provide the branch metric parameters and any pre-computation to the detector. The detector may then calculate the branch metric associated with the input signal and output the channel data.Type: GrantFiled: May 23, 2013Date of Patent: March 10, 2015Assignee: Marvell International Ltd.Inventors: Hongxin Song, Seo-How Low, Panu Chaichanavong, Zining Wu
-
Patent number: 8971447Abstract: A data signal delay system may include a delay unit and a phase interpolation unit. The delay unit may include multiple delay elements that each have an element delay. The delay unit may be configured to generate multiple delay signals by delaying a data signal using the delay elements such that each of the delay signals has a different delay. The phase interpolation unit may be coupled to the delay unit and may include a mixer. The mixer may be configured to mix two of the delay signals based on mixing weights selected for the two delay signals to generate a final delayed data signal that is the data signal delayed by a final delay. The mixing weights may be selected based on the final delay.Type: GrantFiled: October 17, 2013Date of Patent: March 3, 2015Assignee: Fujitsu LimitedInventors: Shuo-Chun Kao, Nikola Nedovic
-
Patent number: 8971396Abstract: A method and system are provided for performing Decision Feedback Equalization (DFE) and Decision Feedback Sequence Estimation (DFSE) in high-throughput applications that are not latency critical. In an embodiment, overlapping blocks of samples are used to allow for the parallelization of the computation and the breaking of the critical path. In addition, the overlap of the windows addresses issues associated with performance loss due to what is termed “ramp-up” and “ramp-down” BER loss.Type: GrantFiled: August 22, 2013Date of Patent: March 3, 2015Assignee: PMC-Sierra US, Inc.Inventors: Stephen Bates, Peter John Waldemar Graumann
-
Patent number: 8971394Abstract: Methods and systems are provided in which a network induces different distortions in signals traversing different segments of the network. The distortions may be used to identify locations on the network of devices that transmit and receive the signals. The distortions may be reflected in equalization coefficients programmed into transmitting or receiving devices, which may be used to pre or post filter the signals to compensate for the distortions.Type: GrantFiled: June 8, 2011Date of Patent: March 3, 2015Assignee: Comcast Cable Communications, LLCInventors: Lawrence D. Wolcott, Phillip F. Chang, Bryan Scott Johnston
-
Patent number: 8971210Abstract: A configurable network adapter has N analog front ends, each generating a receiver output and a transmitter input. In a first mode of operation, the analog front end receiver outputs are coupled to a MIMO equalizer, which is coupled to an outer receiver and to a first MAC input, with the first MAC having an output coupled to an outer transmitter, a MIMO modulator, and to the analog front end transmitter inputs. In a second mode of operation, one or more of the analog front ends is directed to a SISO modulator fed by a second outer transmitter coupled to a second MAC transmitter output. An associated one or more of the analog front end receivers is coupled to a SISO equalizer, and thereafter to an outer receiver and to the second lower MAC, thereby providing a first mode for a single MIMO adapter and a second mode for a MIMO plus independent PAN interface.Type: GrantFiled: May 23, 2011Date of Patent: March 3, 2015Assignee: Redpine Signals, Inc.Inventors: Partha Sarathy Murali, Logeshwaran Vijayan
-
Publication number: 20150055631Abstract: 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 having a channel estimation calculator for calculating a time domain channel estimation from a baseband signal, a Fast Fourier Transform processor for translating the time domain channel estimation to a frequency domain channel estimation, a tap weight calculator for calculating a frequency domain tap weight according to the frequency domain channel estimation, an inverse Fast Fourier Transform processor for translating the frequency domain tap weight calculation to a time domain tap weight calculation, and a filter for equalizing the baseband signal according to the time domain tap weight calculation.Type: ApplicationFiled: September 10, 2014Publication date: February 26, 2015Inventor: Arunabha Ghosh
-
Patent number: 8964818Abstract: A short reach communication system includes a plurality of communication SERDES that communicate data over a short reach channel medium such as a backplane connection (e.g., PCB trace) between, for example, chips located on a common PCB. A multi-level modulated data signal is generated to transmit/receive data over the short reach channel medium. Multi-level modulated data signals, such as four-level PAM, reduce the data signal rate therefore reducing insertion loss, power, complexity of the circuits and required chip real estate.Type: GrantFiled: January 11, 2013Date of Patent: February 24, 2015Assignee: Broadcom CorporationInventors: Lorenzo Longo, Vivek Telang
-
Patent number: 8964857Abstract: A transmitting system, a receiving system, and a method of processing broadcast signals are disclosed. The method for processing a broadcast signal in a broadcast receiver comprises receiving a DTV signal including a data group, the data group including mobile service data, segmented known data sequences, long known data sequences and transmission parameter data, compensating carrier frequency offset of the DTV signal and channel-equalizing the carrier frequency offset compensated DTV signal using at least one of the long known data sequences and segmented known data sequences in the data group of the DTV signal, wherein the channel-equalizing includes performing a Error Correction (FEC) decoding on data located between the segmented known data sequences, and estimating Channel Impulse Response (CIR) using the FEC decoded data as known data.Type: GrantFiled: October 19, 2011Date of Patent: February 24, 2015Assignee: LG Electronics Inc.Inventors: Chulkyu Mun, Jinwoo Kim, Inhwan Choi, Byounggill Kim, Wongyu Song
-
Patent number: 8964826Abstract: Feed-forward equalizer (FFE) circuits and methods are provided which implement time domain analog multiplication for adjusting FFE tap weights. For example, a method includes inputting data signals to FFE taps of a current-integrating summer circuit, wherein the data signals are time-delayed versions of an analog input data signal. A capacitance is charged to a precharge level during a reset period of the current-integrating summer circuit. An output current is generated by each FFE tap during an integration period of the current-integrating summer circuit. The output currents from the FFE taps collectively charge or discharge the capacitance during the integration period.Type: GrantFiled: February 9, 2013Date of Patent: February 24, 2015Assignee: International Business Machines CorporationInventors: Ankur Agrawal, John F. Bulzacchelli
-
Patent number: 8964825Abstract: Analog signal current integrators are provided having tunable peaking functions. Analog signal current integrators with tunable peaking functions enable data rate dependent loss compensation for applications in high data rate receiver integrated circuits incorporating advanced equalization functions, such as decision-feedback equalizers. For instance, a current integrator circuit includes a current integrating amplifier circuit comprising an adjustable circuit element to tune a peaking response of the current integrator circuit, and a peaking control circuit to generate a control signal to adjust a value of the adjustable circuit element as a function of an operating condition of the current integrator circuit. The operating condition may be a specified data rate or a communication channel characteristic or both. The adjustable circuit element may be a degeneration capacitor or a bias current source.Type: GrantFiled: February 17, 2012Date of Patent: February 24, 2015Assignee: International Business Machines CorporationInventors: Troy J. Beukema, John F. Bulzacchelli
-
Publication number: 20150049797Abstract: An equalizer that includes equalizer circuitry, a mean squared error (MSE) system, and adaptive control logic includes features that inhibit undesirable convergence to local minima.Type: ApplicationFiled: August 17, 2013Publication date: February 19, 2015Applicant: Avago Technologies General IP (Singapore) Pte. LtdInventors: Georgios Asmanis, Faouzi Chaahoub, Samir Aboulhouda, Sriramkumar Sundararaman, Ajay Kumar Yadav
-
Patent number: 8958287Abstract: Methods and apparatus are provided for directing a beam towards a receiving device in the presence of interference. A beam transmitted by a transmission source is received at a receiving device. The received beam is affected by an interference signal from an interfering source. The receiving device computes a covariance matrix that represents a channel estimate associated with the interfering source. The receiving device modifies a predetermined sounding signal based on the covariance matrix for transmission to the transmission source. The receiving device causes the transmission source to estimate an equivalent channel matrix based on the predetermined sounding signal and the modified predetermined sounding signal. The equivalent channel matrix represents the channel estimate associated with the interfering source and a channel estimate associated with the transmission source.Type: GrantFiled: July 15, 2013Date of Patent: February 17, 2015Assignee: Marvell International Ltd.Inventors: Jungwon Lee, Jihwan P. Choi
-
Patent number: 8958471Abstract: Requests are identified for equalization coefficients and a plurality of coefficient selections are tracked relating to the requests. A matrix is maintained within a grid space that is to represent the coefficients, the matrix representing one or more of the coefficient selections. The matrix is adjusted within the grid space to obtain an adjusted matrix that is to accommodate selection of a particular coefficient outside the matrix. A final coefficient can be selected based on the adjusted matrix.Type: GrantFiled: March 15, 2013Date of Patent: February 17, 2015Assignee: Intel CorporationInventor: Bruce A. Tennant