Signal Noise Patents (Class 375/227)
  • Patent number: 8665938
    Abstract: A wireless transmission apparatus includes a service processing unit, a duplexer, a radio frequency receiving unit, a frequency synthesizer, and a controller. The controller controls, according to a reduced TR interval, the frequency synthesizer to adjust a frequency of a local oscillation signal which is output by the frequency synthesizer to the radio frequency receiving unit. The service processing unit continues to send a service signal as a self-checking signal, and a part of the self-checking signal leaks into the radio frequency receiving unit through the duplexer. After the radio frequency receiving unit mixes a received signal with the local oscillation signal, a frequency of the self-checking signal included in an output signal falls within a pass-band range of an intermediate frequency receiving unit, which ensures that the self-checking signal can be looped back to the service processing unit, thereby determines whether a fault occurs in its own transmission channel.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: March 4, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Guobin Yu, Hongyong Lin, Yicai Wang
  • Publication number: 20140056342
    Abstract: Described are systems and methods of estimating a Signal-to-Noise (S/N) ratio of an input channel carrying a QAM signal. A Modulation Error Ratio (MER) is calculated for the input QAM signal, but uses only the centermost error values of a constellation of the input QAM signal in generating this modified MER. The modified MER accurately represents the S/N ratio of the input channel carrying the QAM signal. In this way the S/N ratio may be accurately determined using only the received I and Q components of the modulated QAM input signal itself.
    Type: Application
    Filed: August 20, 2013
    Publication date: February 27, 2014
    Applicant: Tektronix, Inc.
    Inventors: Daniel G. Baker, Lakshmanan Gopishankar, George W. Tusing
  • Patent number: 8654894
    Abstract: Disclosed herein are methods of processing transmissions in a wireless communication system to detect whether a transmission unit contains transmitted data, systems for processing transmissions in a digital communications system to detect the same, receivers for processing transmissions in a wireless communications system and computer readable media implementing a method for processing the same. In one embodiment, a method of processing transmissions in a wireless communication system to detect whether a transmission unit contains transmitted data includes: generating an averaged function of bit reliability indicators from a plurality of received samples and applying a test to compare an average of ln cosh(·) (natural logarithm of the hyperbolic cosine) values for the reliability indicators, with a factor proportional to an average signal-to-disturbance ratio of the plurality of samples to determine if the transmission unit contains transmitted data.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: February 18, 2014
    Assignee: ICERA, Inc.
    Inventors: Edward Andrews, Carlo Luschi, Jonathan Wallington
  • Publication number: 20140036980
    Abstract: To assist with the detection of unfiltered device(s), a system observes how the received noise changes between two links as the transmit signal is changed. Harmful unfiltered nonlinear devices will generate significant noise that depends on the transmitted signals; therefore, this additional noise can be quantified to some extent by comparing the observed noise for two different transmit signals. The total noise can be determined from the SNR if the received signal is known. The received signal may be read directly in some non-standard systems, or it may be determined from the known transmit signal and channel attenuation, which is sometimes the case in standard-compliant links, but often with a relatively large error. To circumvent this problem, certain embodiments of this invention only consider the change in noise between two links with the same channel attenuation. This differential comparison makes it unnecessary to accurately know the channel attenuation.
    Type: Application
    Filed: October 10, 2013
    Publication date: February 6, 2014
    Applicant: AWARE, INC.
    Inventor: Christopher CUNNINGHAM
  • Publication number: 20140036981
    Abstract: Using DSL modems as data collectors, the modems processes the data to, for example, allow easier interpretation of the line characteristics. In particular, the modems postprocess the data including calibration, filter compensation, determination of the SNR medley from the bits and gains tables and rate conversion. The interpretation process uses the postprocessed data and determines loop characterization, interferer detection, a data reduction estimation and a data rate estimation. The outputs of these determinations least allow for the characterization of the line conditions between the two modems.
    Type: Application
    Filed: October 10, 2013
    Publication date: February 6, 2014
    Applicant: AWARE, INC.
    Inventors: Murat Belge, Michael A. Tzannes, Halil Padir
  • Patent number: 8644418
    Abstract: A transmitter module for unidirectional communication with a receiver module and a method using the aforementioned. The transmitter module includes a carrier detection portion, a source processing portion coupled to the carrier detection portion and a source transmission portion coupled to the source processing portion. The source processing portion can receive and process an information signal to produce a processed information signal in a manner such that an appropriate carrier signal is modulated with the information signal. The appropriate carrier signal can be based on the detection signals communicated from the carrier detection portion. The source processing portion can further process the information signal in a manner such that the processed information signal is associable with at least one of a unique code and an indication signal. The indication signal is associable with absence of communication of the at least one communication signal in a communication medium.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: February 4, 2014
    Assignee: Creative Technology Ltd
    Inventors: Chee Sin Cheah, Cunsheng Vincent Dong
  • Patent number: 8644413
    Abstract: A system and a method for applying a blind tuning process to M antennas coupled via N beamformers to a multiple input multiple output (MIMO) receiving system having N channels, wherein M>N, are provided herein. The method includes the following steps: Periodically measuring channel fading rate at a baseband level to determine the number of antennas L out of K antennas connected to each one of the beamformers, to be combined at each one of the N beamformers; assigning the antennas to the subset L according to some criteria such as best quality indicator; repeatedly applying a tuning process to L antennas in each one of the N beamformers.
    Type: Grant
    Filed: February 19, 2013
    Date of Patent: February 4, 2014
    Assignee: Magnolia Broadband Inc.
    Inventors: Haim Harel, Eduardo Abreu, Kenneth Kludt
  • Publication number: 20140029654
    Abstract: Method and apparatus for characterizing an impulse noise impairment impacting communications over data links of a network are provided. A test signal comprising a bit stream of a predetermined bit sequence and packet size is configured and transmitted over the data links. The test signal is received, and the bit stream of the test signal as transmitted is compared to a bit stream of the test signal as received to identify differences in bit sequence. Thereafter, characteristics of the impulse noise impairment impacting communications between the data links are estimated based on the detected differences in bit sequence.
    Type: Application
    Filed: July 30, 2012
    Publication date: January 30, 2014
    Applicant: GENERAL INSTRUMENT CORPORATION
    Inventors: Robert J. Thompson, Charles S. Moore, John L. Moran, III, Marc L. Morrissette
  • Patent number: 8638841
    Abstract: A transmitting/receiving system includes two transmitting/receiving apparatuses connected through a transmission cable having two one-direction signal lines. Each apparatus includes a transmitting unit that transmits a signal, a receiving unit that receives a signal, a calculator, a controller, a storage, and an estimating unit. The calculator calculates an Signal to Noise (S/N) ratio of the received signal. The controller controls the calculation by obtaining, as a first value, a strength of a signal caused by a check signal transmitted during absence of a check signal being received, obtaining, as a second value, a strength of a check signal received during absence of a check signal being transmitted, and dividing the second value by the first value. The storage stores relationship between a predetermined transmission-cable S/N ratio and temporal signal fluctuation. The estimating unit estimates temporal signal fluctuation from the calculated S/N ratio and the relationship.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: January 28, 2014
    Assignee: Fuji Xerox Co., Ltd.
    Inventor: Yasuaki Konishi
  • Patent number: 8638895
    Abstract: In one embodiment, receiving an Ethernet signal over a channel, the Ethernet signal comprising a preamble frame, an idle frame, and a data frame, the preamble frame comprising one or more preamble codes; synchronizing to the Ethernet signal based on the preamble frame; replicating the one or more preamble codes; and training a decision feedback equalizer (DFE) based on the one or more replicated codes, the training enabling the DFE to use decision values at the DFE output to track channel variations.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: January 28, 2014
    Assignee: Broadcom Corporation
    Inventors: Ahmad Chini, Mehmet Tazebay, Scott Powell
  • Patent number: 8634452
    Abstract: An integrated circuit device includes a first circuit to receive bits associated with a first data cycle of an electrical input signal, operable to produce a decision regarding logic state of the bits associated with the first data cycle, and a second circuit to receive bits associated with a second cycle of the electrical input signal, to produce a decision regarding logic state of the bits associated with the second data cycle. An equalizing circuit compensates for intersymbol interference affecting the second circuit dependent on an output of the first circuit and compensates for intersymbol interference affecting the first circuit dependent on an output of a circuit other than the first circuit operable to produce a decision regarding logic state of bits of the electrical input signal.
    Type: Grant
    Filed: June 7, 2012
    Date of Patent: January 21, 2014
    Assignee: Rambus Inc.
    Inventors: Jared L. Zerbe, Bruno W. Garlepp, Pak S. Chau, Kevin S. Donnelly, Mark A. Horowitz, Stefanos Sidiropoulos, Billy W. Garrett, Jr., Carl W. Werner
  • Patent number: 8630377
    Abstract: A method of detecting interference in a received sample vector using hidden Markov modelling by first estimating noise variance, where estimating noise variance comprises the steps of receiving a sample vector of noise and interference, sorting the sample vector in the frequency domain by order of increasing magnitude to produce an ordered vector, finding a sub-vector of the ordered vector that minimizes the distance from a noise measure, and estimating the noise variance.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: January 14, 2014
    Assignee: Industrial Research Limited
    Inventor: Alan James Coulson
  • Patent number: 8630335
    Abstract: A method for estimating a Signal to Noise Ratio (SNR) in a received signal including, for a fixed first set of a plurality of samples from the received signal, providing an initial noise estimate, starting with the initial noise estimate, iteratively improving the noise estimate, and estimating SNR based, at least partly, on the fixed first set of samples from the received signal and the noise estimate. Additional related apparatus and methods are also described.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: January 14, 2014
    Assignee: Ceragon Networks Ltd.
    Inventors: Haggai Mizrahi, Isaac Rosenhouse
  • Publication number: 20140010267
    Abstract: A system and method are provided for estimating interference power at a receiver antenna in a communications systems receiver, in which an interference type signal associated with a received radio signal is detected, an in-band interference power associated with the received radio signal is determined, and an interference power at the antenna is estimated using the determined in-band interference power and the detected interference type. Estimating the interference power at the antenna includes interpolating the determined in-band interference power using scaling factors determined by the interference type signal associated with the received radio signal. The system and method determine in-band carrier power associated with the radio signal based on a channel estimate h(k), and the in-band interference information is based on interference samples I(n).
    Type: Application
    Filed: July 5, 2012
    Publication date: January 9, 2014
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Naveen JACOB, Sajal Kumar DAS, Ravi JANDIAL
  • Patent number: 8625685
    Abstract: Certain embodiments utilize raw signals to estimate channel quality, as contrasted to utilizing equalized signals or after channel estimation. For example, signal quality may be estimated by calculating powers of pilot sub-carriers and null sub-carriers of the raw signals. To mitigate channel effect, certain embodiments utilize first and/or second order differentiation schemes.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: January 7, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Jong Hyeon Park, Je Woo Kim
  • Publication number: 20140003481
    Abstract: A method for determining a beamforming vector or a beamforming channel matrix in a communication system including a transmitting station and a receiving station, and a communication system. The transmitting and receiving stations include respective antenna groups and respective codebooks include a plurality of predefined beamforming vectors for the antenna group.
    Type: Application
    Filed: September 10, 2013
    Publication date: January 2, 2014
    Applicant: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Wilhelm KEUSGEN, Michael PETER, Andreas KORTKE
  • Publication number: 20130343445
    Abstract: For voltage values (observed noise sequence) in an electronic power line (communication medium) which are obtained at a predetermined interval, initial values of noise characteristics based on a statistic of the observed noise sequence itself are decided by a moment method (S301 to S307), the noise characteristics (state transition probabilities and state noise power) for maximization of the likelihood of the observed noise sequence are obtained from the initial values by MAP (Maximum A Posteriori) estimation using a Baum-Welch algorithm (S309 to S312), a state sequence is estimated from the obtained noise characteristics, and an impulsive noise at each time point is detected.
    Type: Application
    Filed: August 27, 2013
    Publication date: December 26, 2013
    Applicants: AUTONETWORKS TECHNOLOGIES, LTD., SUMITOMO ELECTRIC INDUSTRIES, LTD., SUMITOMO WIRING SYSTEMS, LTD.
    Inventors: Daisuke UMEHARA, Masahiro MORIKURA, Toshiya HISADA, Shinichi ISHIKO, Satoshi HORIHATA
  • Patent number: 8615210
    Abstract: Methods and apparatus for power measurement in a communication system. In an aspect, a method is provided for power measurement. The method includes selecting between a signal decoding mode and a power measurement mode, decoding an input signal if the signal decoding mode is selected, and calculating a power measurement associated with the input signal if the power measurement mode is selected. In another aspect, an apparatus is provided for power measurement. The apparatus includes means for selecting between an active mode and a power measurement mode, means for decoding an input signal if the active mode is selected, and means for calculating a power measurement associated with the input signal if the power measurement mode is selected.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: December 24, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Ashok Mantravadi, Phani Bhushan Avadhanam, Vinay Murthy
  • Patent number: 8615033
    Abstract: A method for controlling a transmission rate of at least one transceiver, the transceiver including a transmitter and a receiver, includes: determining a signal quality characteristic corresponding to a signal received at the receiver by measuring a difference between one or more reference constellation points and one or more received constellation points, and modifying a transmission rate of the transmitter over a wireless communication channel as a function of the signal quality characteristic.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: December 24, 2013
    Assignee: Agere Systems LLC
    Inventors: Jan Boer, Bas Driesen, Ra'anan Gil, Kai Roland Kriedte
  • Patent number: 8614939
    Abstract: A method and apparatus for crosstalk channel estimation based on a measured signal-to-noise (SNR) of a loaded line. The method for channel estimation includes: loading, on a newly added line K, a combination of K?1 signals sent on lines 1 to K?1; obtaining a measured SNR of the line K loaded with the combination of the K?1 signals sent on the lines 1 to K?1; and calculating crosstalk channels of the line K according to K?1 coefficients of the K?1 signals sent on the lines 1 to K?1 and the measured SNR. Embodiments of the present invention may be used for relevant network communications systems such as xDSL systems.
    Type: Grant
    Filed: October 10, 2012
    Date of Patent: December 24, 2013
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Raphael Cendrillon, Liming Fang
  • Publication number: 20130336376
    Abstract: A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment and calibration computing equipment for receiving and processing test and calibration signals from wireless communications circuitry to be calibrated. During testing and calibration operations, a device may be provided with initial pre-distortion calibration values. The initial pre-distortion calibration values may be generated at least in part based on calibration operations performed for other wireless electronic devices. The device may generate a test signal using the initial pre-distortion calibration values. The calibration system may determine whether the test signal is within an acceptable range of a known reference signal.
    Type: Application
    Filed: June 14, 2012
    Publication date: December 19, 2013
    Inventors: Gary Lang Do, David A. Donovan, Gurusubrahmaniyan Radhakrishnan
  • Patent number: 8611405
    Abstract: A modem or associated computing or testing device is configured to detect the presence of one or more faults that affect DSL communications, and upon their detection, generate, for example, an indication, communication or message that recommends corrective action. In this context, a fault is generally caused by one or more unfiltered devices, impulsive noises, malfunctioning modems, or other factor that does not affect measured attenuation or measured noise, but does affect the signal-to-noise ratio (SNR) of the link. In addition to being able to generate a message guiding a user through corrective action, the system can estimate the rate impact of the detected fault.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: December 17, 2013
    Assignee: Aware, Inc.
    Inventors: Christopher Cunningham, Jianming Zhu
  • Patent number: 8611443
    Abstract: Orthogonal frequency division multiplexing (OFDM) has become a popular transmission method for high speed wireless radio transmission, due to its potential for low complexity of transmitters and receivers. A method and apparatus are contemplated for cancelling additive sinusoidal disturbances of a known frequency in OFDM receivers which arise e.g. from clock signals that are present for frequency reference, mixer control, and A/D converter control, as well as harmonics and mixing products of those periodic signals, coupling into some point in the receiver chain and appearing as rotating complex exponentials superimposed to complex baseband receive signals. According to the inventive method and apparatus an estimation of an amplitude and phase of a disturbing superimposed tone with a known frequency is obtained and the amplitude and phase estimation is used to cancel the spurious tone preventing a degradation of receiver sensitivity while achieving low implementation complexity.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: December 17, 2013
    Assignee: NXP, B.V.
    Inventor: Andreas Bury
  • Patent number: 8604960
    Abstract: Various embodiments of the present invention provide apparatuses and methods for processing data in an oversampled data processing circuit with multiple detectors. For example, an apparatus for processing data is disclosed that includes a first analog to digital converter operable to sample a continuous signal at a first sampling phase to yield a first digital output, a second analog to digital converter operable to sample the continuous signal at a second sampling phase to yield a second digital output, wherein the second sampling phase is different from the first sampling phase, a first detector operable to process the first digital output to yield a first detector output, and a second detector operable to process the second digital output and the first detector output to yield a detected output.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: December 10, 2013
    Assignee: LSI Corporation
    Inventors: Yu Liao, Nayak Ratnakar Aravind
  • Patent number: 8606280
    Abstract: A resource allocation in a broadband wireless communication system is provided. An apparatus for a base station in a broadband wireless communication system includes a manager for managing resources by dividing the resources into a plurality of regions based on a maximum supportable error vector magnitude (EVM) in a frequency axis; and an allocator for allocating resources of a region other than a first region, the region having the smallest maximum supportable EVM, to a service to which a maximum modulation and coding scheme (MCS) level is not applied.
    Type: Grant
    Filed: September 16, 2008
    Date of Patent: December 10, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Joo-Hyun Lee, Young-Hoon Kwon, Sang-Boh Yun, Won-Suk Choi
  • Publication number: 20130322509
    Abstract: A system and a method for applying a blind tuning process to M antennas coupled via N beamformers to a multiple input multiple output (MIMO) receiving system having N channels, wherein M>N, are provided herein. The method includes the following steps: Periodically measuring channel fading rate at a baseband level to determine the number of antennas L out of K antennas connected to each one of the beamformers, to be combined at each one of the N beamformers; assigning the antennas to the subset L according to some criteria such as best quality indicator; repeatedly applying a tuning process to L antennas in each one of the N beamformers.
    Type: Application
    Filed: February 19, 2013
    Publication date: December 5, 2013
    Applicant: Magnolia Broadband Inc.
    Inventors: Haim HAREL, Eduardo ABREU, Kenneth KLUDT
  • Publication number: 20130322508
    Abstract: A fast diversity technique using either an EESM or a capacity computation can determine antenna selection in a wireless communication device. A fast Fourier transform (FFT) for the EESM/capacity computation can be performed with consecutive samples of a single symbol period of a short training field (STF) of a packet received by each antenna. The effective signal-to-noise ratio (SNR) for each antenna can be calculated using the results of the EESM or capacity computation. The antenna with the highest effective SNR is selected.
    Type: Application
    Filed: June 1, 2012
    Publication date: December 5, 2013
    Applicant: Qualcomm Atheros, Inc.
    Inventors: Chin-Hung Chen, Ning Zhang
  • Patent number: 8599911
    Abstract: There is provided a method and apparatus for estimating a signal to noise ratio (SNR) in a wireless communication system. The apparatus selects a preamble signal for each of a plurality of sectors from a reception signal experienced by fast Fourier transform (FFT), outputs a correlation signal by performing a correlation between the preamble signal for each sector and a preamble reference signal, estimates power of the reception signal and noise power for each sector based on the correlation signal, selects a minimum value from among the noise powers for the sectors, outputs a net power for each sector by subtracting the minimum value from the power of the reception signal for each sector, and calculates the SNR by dividing the net power for each sector by the minimum value.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: December 3, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Hyeong Sook Park, Jun Woo Kim, Youn Ok Park
  • Publication number: 20130315288
    Abstract: There are disclosed systems and methods that dynamically vary the word length of data being transmitted through a digital interface. In one embodiment, the method comprises: (i) obtaining at least one parameter indicative of a quality of a signal; (ii) if the at least one parameter indicates that the quality of the signal is above a threshold, then transmitting the data as a number of digital words at a first predetermined word length; (ii) if the at least one parameter indicates that the quality of the signal is below the threshold, then transmitting the data as a number of digital words at a second predetermined word length. The second predetermined word length is different from the first predetermined word length.
    Type: Application
    Filed: May 22, 2012
    Publication date: November 28, 2013
    Applicant: RESEARCH IN MOTION LIMITED
    Inventors: JIANFENG WENG, YANGWEN LIANG, XING QIAN, QING FENG XU, CHRISTOPHER EUGENE SNYDER
  • Patent number: 8594166
    Abstract: There is provided a system for the bidirectional synchronous transmission of data between a device (1) to be tested and a testing device (2) with a device (1) to be tested and a testing device (2) which can be connected together by way of an electric transmission line (3) and by way of an electric ground line (4). The two devices (1, 2) are suitable for sending and receiving data synchronously with a predetermined clock frequency and phase as sequences of first and second voltages which respectively represent a first and second value of a bit on the electric transmission line (3). To receive data a receiving device (1, 2) samples a voltage on the electric transmission line (3) at predetermined sampling phases of the clock to identify whether the first or the second voltage is present.
    Type: Grant
    Filed: July 2, 2009
    Date of Patent: November 26, 2013
    Assignee: Sennheiser electronic GmbH & Co., KG
    Inventor: Dirk Reymann
  • Patent number: 8593525
    Abstract: A phasor-based pulse detection system includes a first multiplier stage configured to apply a first delayed conjugate multiplication operation to an input signal. The system can also include a second multiplier stage coupled to the first multiplier stage and configured to apply a second delayed conjugate multiplication operation to an output of the first multiplier stage, and an absolute value unit coupled to the second multiplier stage and configured to perform an absolute value operation on an output of the second multiplier stage. The system can further include video filter stage coupled to the absolute value unit and configured to perform a video filtering operation on an output of the absolute value unit. The system can also include a hysteresis detector coupled to the video filter stage, the hysteresis detector configured for detecting a signal in a filtered video signal received from the video filter stage.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: November 26, 2013
    Assignee: Lockheed Martin Corporation
    Inventor: James A. Johnson
  • Patent number: 8594168
    Abstract: As a digitized representation of an intermediate frequency television signal moves through a demodulator it undergoes a number of processes, including conversion from an analog signal to a digitized data, digital signal processing of the digitized data, and the like. The rate at which the digitized data moves through the digital signal processor of the demodulator for processing is referred to as the data rate of the DSP. The demodulator can vary the data rate based on a selected television channel, thereby reducing the level of interference at the demodulator resulting from noise.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: November 26, 2013
    Inventors: Gary Cheng, Vyacheslav Shyshkin, Steve Selby
  • Patent number: 8595278
    Abstract: 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: Grant
    Filed: June 23, 2009
    Date of Patent: November 26, 2013
    Assignee: Broadcom Corporation
    Inventors: Kuoruey Han, Peiqing Wang, Linghsiao Wang, Kishore Kota, Arash Farhoodfar
  • Patent number: 8594216
    Abstract: Beamforming may be used in MIMO communication systems to further enhance spectral efficiency. Beamforming refers to beamed transmissions to a single destination (e.g., a station) at a time, to enhance the rate and/or range of transmission. To perform beamforming from a source to one or more destinations, a channel and/or beamforming matrices corresponding to the channel needs to be known at the source, which may be obtained as feedback from the destination. However, the beamforming matrices may not be smooth over frequency as it is fed back from the destination. Therefore, certain aspects of the present disclosure provide beamforming feedback options, resulting in the smoothness of a beamforming matrix.
    Type: Grant
    Filed: August 24, 2011
    Date of Patent: November 26, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Albert Van Zelst, Sameer Vermani, Didier Johannes Richard Van Nee, Hemanth Sampath, Vincent Knowles Jones, IV
  • Patent number: 8588285
    Abstract: A digital subscriber line arrangement includes a downstream modem, an upstream modem and a copper pair connection between the modems. Each modem includes electrical length estimation function code means which causes the respective modem to measure the attenuation of signals transmitted by the other modem at a plurality of different frequencies, and to combine these measurements, or functions thereof, together to form a combined attenuation measure and to use this combined measure to form an electrical length estimation, KL0bis. The downstream modem is operable to transmit its electrical length estimation to the upstream modem, and the upstream modem is operable to generate a definitive electrical length estimation in dependence upon both the received estimation from the downstream modem and the estimation made by the upstream modem. Having generated a definitive electrical length estimation, the upstream modem is operable to transmit this to the downstream modem.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: November 19, 2013
    Assignee: British Telecommunications Public Limited Company
    Inventors: Leslie Derek Humphrey, Andrew David Wallace
  • Patent number: 8582702
    Abstract: An electronic device includes an analog-to-digital converter adapted to receive a radio-frequency signal and adapted to provide therefrom a digital signal, wherein the radio-frequency signal may include an interference signal. The electronic device has a controller adapted to perform a digital measure on the digital signal and adapted to generate therefrom a selection signal having a first value indicating a non-interference condition in the radio-frequency signal and having a second value indicating an interference-condition in the radio-frequency signal. A selector is adapted to transmit the digital signal in case the selection signal has the first value and to transmit a signal replacing the digital signal in case the selection signal has the second value.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: November 12, 2013
    Assignees: STMicroelectronics S.r.l., STMicroelectronics Ltd.
    Inventors: Giuseppe Avellone, Oleksandr Gorbachov, Antonino Calcagno, Salvatore Scaccianoce
  • Patent number: 8582633
    Abstract: One or more processing units confirm existence of narrow band interference in a signal by using an estimate f of the frequency, to check for one or more harmonics. In illustrative embodiments, the estimate f is automatically identified as a second harmonic if a predetermined criterion is satisfied by the signal (in the frequency domain) at either of two frequencies namely (A) frequency f/2 and (B) frequency (M?f)/2 and whichever of these two frequencies is stronger is identified as the fundamental frequency. In several such embodiments, the estimate f is automatically identified as a third harmonic if a predetermined criterion is satisfied by the signal (in the frequency domain) at any of three frequencies namely (C) frequency f/3 and (D) frequency (M?t)/3 and (E) frequency (M+f)/3. If the predetermined criteria are not met at all five frequencies (A)-(E) then f is identified as the fundamental frequency.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: November 12, 2013
    Assignee: Applied Micro Circuits Corporation
    Inventors: Dariush Dabiri, Dongwoon Bai
  • Patent number: 8576902
    Abstract: The present disclosure provides a receiving device including, a receiver configured to receive a signal that is transmitted via a propagation path and is modulated by a predetermined system prescribed by a predetermined standard, a demodulator configured to demodulate a received signal, an estimator configured to estimate a signal-to-noise ratio relating to the propagation path, obtained from a data signal included in the demodulated received signal, and a corrector configured to correct an estimated signal-to-noise ratio in accordance with a transmission parameter obtained from the received signal.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: November 5, 2013
    Assignee: Sony Corporation
    Inventors: Hirofumi Maruyama, Ryo Hasegawa, Katsumi Takaoka
  • Patent number: 8576898
    Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an enable signal when the received passband signal is identified. The enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modem and/or a magnitude of the received passband signal.
    Type: Grant
    Filed: February 1, 2010
    Date of Patent: November 5, 2013
    Assignee: Techwell, Inc.
    Inventors: Khanh Lam, Mark Fimoff, Greg Tomezak, Dennis Mutzabaugh
  • Patent number: 8576691
    Abstract: A method and apparatus for crosstalk channel estimation based on a measured signal-to-noise (SNR) of a loaded line. The method for channel estimation includes: loading, on a newly added line K, a combination of K-1 signals sent on lines 1 to K-1; obtaining a measured SNR of the line K loaded with the combination of the K-1 signals sent on the lines 1 to K-1; and calculating crosstalk channels of the line K according to K-1 coefficients of the K-1 signals sent on the lines 1 to K-1 and the measured SNR. Embodiments of the present invention may be used for relevant network communications systems such as xDSL systems.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: November 5, 2013
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Liming Fang, Raphael Cendrillon
  • Publication number: 20130287068
    Abstract: At least one example embodiment discloses a method of controlling a system. The method includes determining a constant number of bits for each of a plurality of tones, each constant number of bits being constant, obtaining a single parameter from a user of the system, the single parameter being a code rate and transmitting, to the user, data as information bits in the plurality of tones across a channel based on the single parameter, each of the plurality of tones including the constant number of bits.
    Type: Application
    Filed: April 26, 2012
    Publication date: October 31, 2013
    Applicant: ALCATEL-LUCENT USA INC.
    Inventors: Alexei Ashikhmin, Philip A. Whiting
  • Publication number: 20130287066
    Abstract: A receiver circuit provides improved noise estimation processing by at least partially removing receiver frequency error bias. An initial noise estimate is compensated using an error term based on the observed receiver frequency error, and the resulting compensated noise estimate can be used to improve other signal processing in the receiver. For example, the receiver may use compensated noise estimates to generate signal quality estimates, e.g., Signal-to-Interference (SIR) estimates, having improved accuracy. Additionally, or alternatively, the receiver may use the compensated noise estimates to generate RAKE combining weights having improved noise suppression characteristics. In an exemplary embodiment, the initial noise estimate is a noise correlation matrix generated from a received reference signal, e.g., pilot symbols, and the error term is an error matrix directly generated using the observed receiver frequency error and channel estimates taken from the reference signal.
    Type: Application
    Filed: June 26, 2013
    Publication date: October 31, 2013
    Inventor: Anders Wallén
  • Patent number: 8571595
    Abstract: A method for adjusting a gain level for a receiver of a first radio simultaneously operational with a transmitter of a second radio, comprising: determining a signal-to-noise ratio (“SNR”) value for signals received by the receiver from an access point (“AP”); and, when the first radio is associated with the AP and the transmitter is not transmitting, if the SNR value exceeds a SNR threshold, reducing the gain level for the receiver from an initial level and initiating transmission from the transmitter, otherwise maintaining the gain level for the receiver at the initial level and initiating transmission from the transmitter; wherein the SNR threshold is a SNR value above which beacon signals from the AP can be successfully received by the receiver.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: October 29, 2013
    Assignee: BlackBerry Limited
    Inventors: Mohammed Nawaf Smadi, Vytautas Robertas Kezys
  • Publication number: 20130279555
    Abstract: In one aspect, the present invention provides for blindly detecting the presence of one or more secondary pilot signals that are not being used to serve a communication apparatus, such as a User Equipment (UE). Among its several advantages, the approach to blind detection taught herein provides robust detection performance, yet it requires relatively few receiver resources. The contemplated apparatus, in at least one example embodiment, uses its blind detection of secondary pilot signal(s) to trigger suppression of secondary pilot interference, for improved reception performance. In a particular, non-limiting example, the apparatus operates in an HSDPA-MIMO network in a non-MIMO mode and blindly detects secondary pilot signal energy associated with the supporting network providing MIMO service to nearby equipment.
    Type: Application
    Filed: April 20, 2012
    Publication date: October 24, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON
    Inventors: Elias Jonsson, Kazuyoshi Uesaka
  • Publication number: 20130279557
    Abstract: A communications receiver includes a noise analyzer to characterize the composition of the interference and/or distortion impressed onto a transmitted communications signal in the presence of one or more time-varying conditions. The noise analyzer may provide a selection signal indicating the composition of the interference and/or distortion impressed onto a transmitted communications signal in the presence of one or more time-varying conditions to be used by the communications receiver. In an exemplary embodiment, the communications receiver selects at least one set of filter coefficients to compensate for the interference and/or distortion impressed onto a transmitted communications signal in the presence of a particular time-varying interference and/or distortion condition.
    Type: Application
    Filed: March 18, 2013
    Publication date: October 24, 2013
    Inventors: Thomas KOLZE, Bruce J. Currivan
  • Publication number: 20130279556
    Abstract: A receiver comprising: one or more variable gain elements; an automatic gain control (AGC) for controlling a gain of one or more of the one or more the variable gain elements; and a frame detector configured to detect the presence of a frame in a signal received by the receiver and to output a signal to the AGC on detection of a data frame, wherein the AGC is configured to estimate a signal to noise ratio (SNR) of the received signal on receiving an input signal from the frame detector, to calculate a SNR margin between the estimated SNR and a target SNR and to adjust the gain of one or more of the one or more variable gain elements to maintain a positive SNR margin such that in the event of interference with the received signal the one or more variable gain elements do not saturate.
    Type: Application
    Filed: April 23, 2012
    Publication date: October 24, 2013
    Applicant: Cambridge Silicon Radio Limited
    Inventor: Olivier SELLER
  • Publication number: 20130279552
    Abstract: Representative implementations of devices and techniques provide noise reduction between proximate networks by minimizing interference from nearby network communication. A processing module determines a performance condition of a network and communicates with one or more nodes at a nearby network based on the performance condition of the network.
    Type: Application
    Filed: June 23, 2013
    Publication date: October 24, 2013
    Inventors: Feliciano GOMEZ MARTINEZ, Joon Bae KIM, Khashayar MIRFAKHRAEI, Imran HAJIMUSA
  • Patent number: 8565294
    Abstract: An interference classifier is disclosed for determining the type of interference present in a signal. The interference classifier 601 comprises a buffer 602 operable to receive and store data comprising samples of a signal; a scale factor calculator 603 operable to use the signal samples to calculate a scale factor in dependence upon the levels of the signal samples; a normaliser 604 operable to calculate normalised signal samples by using the scale factor to normalise the signal samples; a nonlinear transformer 605 operable to perform a nonlinear transform on the normalised signal samples to calculate transformed signal samples; an averaging circuit 606 operable to calculate an average of the transformed signal samples; and a comparator 607 operable to compare the calculated average of the transformed signal samples to a predetermined threshold level in order to determine the type of interference present in the received signal.
    Type: Grant
    Filed: May 26, 2011
    Date of Patent: October 22, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventor: Wieslaw Jerzy Szajnowski
  • Publication number: 20130266054
    Abstract: A method and apparatus for allocating transmission power in a transmission terminal having at least one antenna of a multi-input multi-output (MIMO) system are provided. The method includes: measuring inter-stream interference of a plurality of streams; measuring inter-user interference of a plurality of users; and determining the transmission power based on the inter-stream interference and the inter-user interference, wherein the transmission power is determined using an iterative water-filling algorithm in which the Karush-Kuhn-Tucker (KKT) system is iteratively applied to all of the plurality of streams and all of the plurality of users. According to the present invention, several receive antennas are mounted in the MIMO system, thereby making it possible to receive multiple streams. In addition, when the multiple streams are received, transmission power may be allocated to each transmission stream.
    Type: Application
    Filed: September 14, 2012
    Publication date: October 10, 2013
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: In Kyeong CHOI, Sok Kyu LEE
  • Patent number: 8553798
    Abstract: This disclosure relates a method and apparatus for generating pre-coding matrix codebook. The method for generating pre-coding matrix codebook, comprising: acquiring a universal set of pre-coding matrixes in a first format; acquiring a universal set of pre-coding matrixes in a second format; selecting a first predetermined number of pre-coding matrixes in the first format from the universal set of pre-coding matrixes in the first format; and selecting a second predetermined number of pre-coding matrixes in the second format from the universal set of pre-coding matrixes in the second format, according to the selected first predetermined number of pre-coding matrixes in the first format.
    Type: Grant
    Filed: March 2, 2012
    Date of Patent: October 8, 2013
    Assignee: Fujitsu Limited
    Inventors: Jian Wang, Jianming Wu, Yi Wang, Hua Zhou, Jun Tian