By Filtering (e.g., Digital) Patents (Class 375/350)
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Patent number: 8594173Abstract: The application relates to a method for determining at least one updated filter coefficient of an adaptive filter (22) adapted by an LMS algorithm. According to the method, filter coefficients of a first whitening filter (25?) are determined, in particular filter coefficients of an LPC whitening filter. The first whitening filter (25?) generates a filtered signal. A normalization value is determined based on one or more computed values obtained in the course of determining the filter coefficients of the first whitening filter (25?). The normalization value is associated with the energy of the filtered signal. At least one updated filter coefficient of the adaptive filter (22) is determined in dependency on the filtered signal and the normalization value. Preferably, updated filter coefficients for all filter coefficients of the adaptive filter (22) are determined.Type: GrantFiled: August 24, 2009Date of Patent: November 26, 2013Assignee: Dolby Laboratories Licensing CorporationInventors: Robert L Andersen, Grant Davidson
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Patent number: 8588340Abstract: To optimize an adaptive equalizer with a simple controlling circuit, the receiving device includes a number counting part counting, in a range of detection having a predetermined width, a sampling result corresponding to the input signal being shaped by an equalizer circuit at a determination timing indicated by a clock signal obtained in a CDR circuit, a zone scanning part scanning the range of detection in a scanning zone including a variation range of the input signal; a coefficient altering part altering an equalizer coefficient set to the equalizer circuit; a peak detecting part detecting a peak value of a number of appearances of the sampling result according to alteration of the equalizer coefficient and scanning of the range of detection; and a coefficient specifying part specifying the equalizer coefficient being used when detecting the peak value in the peak detecting part as a first coefficient.Type: GrantFiled: June 3, 2011Date of Patent: November 19, 2013Assignees: Fujitsu Limited, Fujitsu Semiconductor LimitedInventors: Yasumoto Tomita, Hisakatsu Yamaguchi, Satoshi Kawahara
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Patent number: 8588353Abstract: In conventional radio frequency (RF) systems, transmitters will usually convert baseband signals to RF so as to be transmitted. As part of the conversion process, the transmitters will perform digital predistortion (DPD), which uses feedback from a power amplifier. However, there are usually mismatches between the in-phase (I) and quadrature (Q) paths within with feedback loop. Traditional IQ correction filters were ineffective at providing adequate compensation for these mismatches, but here a filter is provided that provides adequate out-of-band compensation by use of frequency selectivity.Type: GrantFiled: April 1, 2011Date of Patent: November 19, 2013Assignee: Texas Instruments IncorporatedInventors: Zigang Yang, Lars Jorgensen, Lei Ding
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Publication number: 20130301766Abstract: An impulse noise mitigation circuit (INMC) may set a cut-off frequency of each of two high pass filters to bound a frequency bandwidth of a desired signal, wherein a first of the two filters allows frequencies higher than the frequency bandwidth of the desired signal, and a second of the two filters allows frequencies lower than the frequency bandwidth of the desired signal. The INMC may compute and store a mean magnitude separately for a first signal response of the first filter and a second signal response of the second filter. The INMC may select the first filter for impulse noise mitigation when the mean magnitude of the second filter is greater than the mean magnitude of the first filter. The INMC may select the second filter for impulse noise mitigation when the mean magnitude of the first filter is greater than the second filter.Type: ApplicationFiled: July 15, 2013Publication date: November 14, 2013Inventors: Andy Lo, Sugbong Kang
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Patent number: 8582681Abstract: A signal receiver apparatus includes a waveform shaping data storage device storing waveform shaping data of a signal transmitted with a given timing from a signal transmitter device of a plurality of signal transmitter devices which are coupled to the signal receiver apparatus for each of the plurality of signal transmitter devices, and a waveform shaping device reading waveform shaping data of the signal transmitter device in the plurality of signal transmitter device from the waveform shaping data storage device when a signal from the signal transmitter device is received, and shaping a waveform of a received signal from the signal transmitter device.Type: GrantFiled: March 24, 2009Date of Patent: November 12, 2013Assignee: Spansion LLCInventors: Akira Shimamura, Koichi Mita, Hideshi Fujishima, Takashi Arai, Shunichi Ko, Takuya Terasawa, Koji Mikami, Naoya Komada
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Patent number: 8582676Abstract: Method and apparatus for achieving high precision sampling recovery at a relatively low sampling rate. The apparatus includes: a sampling rate conversion module for converting the sampling rate of a received signal to an required sampling rate; a time domain impulse response estimation module for estimating a time domain impulse response of a transmission channel according to data output by the sampling rate conversion module; a high order interpolation module for performing high order interpolation to one or more selected transmission paths after obtaining the time domain impulse response; and a sampling error information extraction module for extracting sampling phase offset information and sampling frequency offset information based on interpolation results and drifts in two consecutive interpolation results of the high order interpolation step. The apparatus is capable of realizing fast high precision locking of sampling phase and correction of sampling frequency offset at a relatively low sampling rate.Type: GrantFiled: August 27, 2012Date of Patent: November 12, 2013Assignee: Omnivision Technologies (Shanghai) Co., Ltd.Inventor: Yun Zhang
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Patent number: 8582635Abstract: In described embodiments, a Floating Tap, Feed Forward Equalizer (FT-FFE) achieves performance comparable to a full size, long FFE when equalizing wire line channels in, for example, SerDes receivers. A FT-FFE might be employed as a standalone datapath equalizer, or might be employed in conjunction with other equalization techniques.Type: GrantFiled: March 2, 2012Date of Patent: November 12, 2013Assignee: LSI CorporationInventors: Tomasz Prokop, Chaitanya Palusa
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Patent number: 8582636Abstract: An apparatus and method for implementing an equalizer which combines the benefits of a decision feedback equalizer (DFE) with a maximum-a-posterori (MAP) equalizer (or a maximum likelihood sequence estimator, MLSE) to provide an equalization device with significantly lower complexity than a full-state MAP device, but which still provides improved performance over a conventional DFE. The equalizer architecture includes two DFE-like structures, followed by a MAP equalizer. The first DFE forms tentative symbol decisions. The second DFE is used thereafter to truncate the channel response to a desired memory of L1 symbols, which is less than the total delay spread of L symbols of the channel. The MAP equalizer operates over a channel with memory of L1 symbols (where L1<=L), and therefore the overall complexity of the equalizer is significantly reduced.Type: GrantFiled: February 2, 2010Date of Patent: November 12, 2013Assignee: Broadcom CorporationInventors: Stephen Allpress, Quinn Li
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Patent number: 8576966Abstract: 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 alarm signal when disruption or loss of the received passband signal is identified. An 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 modern and/or a magnitude of the received passband signal.Type: GrantFiled: September 9, 2011Date of Patent: November 5, 2013Assignee: Techwell, Inc.Inventors: Mark Fimoff, Khanh Lam, Dennis Mutzabaugh, David Ritter, Greg Tomezak
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Patent number: 8576934Abstract: A receiving device includes a channel estimating section that performs a correlating process for a received reference signal in which a single carrier signal was transformed into a frequency domain signal and a pre-stored reference signal so as to obtain estimated channel values; a compensation coefficient computing section that computes compensation coefficients corresponding to residual multipath interferences based on a bit likelihood; a weight computing section that computes equalized weights based on the estimated channel values and the compensation coefficients; an equalizing filter that generates an equalized signal by equalizing process for the received signal that is the frequency domain signal based on the equalized weights; a residual interference replica generating section that generates residual multipath interference replicas based on frequency domain symbol replicas, the estimated channel values, and the equalized weights; and a subtracting section that subtracts the residual multipath interferType: GrantFiled: July 2, 2010Date of Patent: November 5, 2013Assignee: NEC CorporationInventor: Masayuki Kimata
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Patent number: 8576965Abstract: Certain embodiments of the present disclosure support techniques for interference cancellation in a multi-mode wireless modem that supports coexistence of different radio technologies.Type: GrantFiled: July 7, 2010Date of Patent: November 5, 2013Assignee: QUALCOMM IncorporatedInventors: Madihally J. Narasimha, Je Woo Kim, Nitin Kasturi, Parvathanathan Subrahmanya
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Publication number: 20130287148Abstract: A method of operation of a communication system includes: receiving an input signal having an input primary codeword and an input parallel codeword; calculating a primary codeword signal by removing a parallel soft information average of the input parallel codeword from the input signal; filtering a residual parallel interference of the input parallel codeword from the primary codeword signal with a primary whitening filter to generate a primary codeword estimation of the input primary codeword; and calculating a primary detected soft information for the primary codeword estimation for communicating with a device.Type: ApplicationFiled: April 30, 2012Publication date: October 31, 2013Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Hyukjoon Kwon, Jungwon Lee, Inyup Kang
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Patent number: 8571156Abstract: A receiver apparatus (1) for receiving a signal over a fading channel comprises a frequency domain interpolation unit (16) with a filter unit (10), a power comparison unit (20), and a processing unit (21). The filter unit (10) comprises a first filter element (11), which is a reference filter, and a second filter element (12). The first filter element (11) is arranged as large-band filter. The power comparison unit (20) compares the power of the signal filtered with said second filter element (12) with the power of the signal filtered with said first filter element (11). The processing unit (21) determines an appropriate filter length for a third filter element (13) of the filter unit (10) on the basis of this comparison. Thereby, a trade-off is made between an additional power received due to a long echo and an additional Gaussian noise power.Type: GrantFiled: May 27, 2008Date of Patent: October 29, 2013Assignee: NXP, B.V.Inventor: Yann Casamajou
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Patent number: 8571152Abstract: The present invention discloses an apparatus and method for power-saving switch on a pair of configurable analog-to-digital converters. The apparatus mainly comprises an antenna, an antenna switch, a zero-IF RF receiver, and a baseband demodulator. By using a first and a second control signal to control the ON/OFF states of a plurality of switches and a plurality of stage units in the configurable analog-to-digital converters, and the third control signal to control the ON/OFF states of a plurality of LNA stages and the gain of a plurality VGAs, the power saving of the analog-to-digital converter is easily achieved.Type: GrantFiled: May 22, 2012Date of Patent: October 29, 2013Assignee: ISSC Technologies Corp.Inventors: Jeng-Hong Chen, Chin-Chang Chang, Kuang-Hu Huang, Chih-Ching Huang, Che-Kang Sun, Chun-Yuan Huang
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Patent number: 8564724Abstract: A method of noise filtering of a digital video sequence to reduce ghosting artifacts, the method including computing motion values for pixels in a frame of the digital video sequence based on a reference frame, computing blending factors for the pixels based on the motion values, generating filtered output pixel values by applying the blending factors to corresponding pixel values in the reference frame and the frame, wherein selected filtered output pixel values are converged toward corresponding pixel values in the frame to reduce ghosting artifacts, and outputting the filtered frame.Type: GrantFiled: April 4, 2010Date of Patent: October 22, 2013Assignee: Texas Instruments IncorporatedInventors: Wei Hong, Harmeet Singh
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Patent number: 8565358Abstract: A system provides closed-loop gain control in a WCDMA mode and open loop control in an EDGE/GSM mode. Gain control is distributed across analog devices and a digital scaler in a wireless receiver. In the WCDMA mode, a loop filter generates an error signal that is forwarded to analog and digital control paths. The analog control path includes a first adder, a programmable hysteresis element, and a lookup table. The analog control signal is responsive to thresholds, which when used in conjunction with a previous gain value determine a new gain value. The digital control path includes a second adder, a programmable delay element, and a converter. A control word is responsive to a difference of the error signal, a calibration value, and the analog control signal. Blocker detection is provided in the WCDMA mode of operation. A controller sets system parameters using a state machine.Type: GrantFiled: January 30, 2012Date of Patent: October 22, 2013Assignee: Skyworks Solutions, Inc.Inventors: Jaleh Komaili, John E. Vasa, Thomas Obkircher
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Patent number: 8565338Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.Type: GrantFiled: August 8, 2012Date of Patent: October 22, 2013Assignee: Intel Mobile Communications GmbHInventors: Peter Singerl, Thomas Blocher, Thomas Poetscher, Andreas Wiesbauer
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Patent number: 8559556Abstract: The present invention provides a method of bandpass sampling which particularly includes the single-sideband signal conversion procedure prior to the sampling process in the purpose of lowering the required sampling frequency. Conversion of the bandpass RF signal into a single-sideband spectrum signal which has the spectrum components only in either the positive or the negative frequency domain is accomplished by bandpass-filtering, or more effectively by using a Hilbert transformer. This invention includes a method of finding the minimum sampling frequency for simultaneous frequency down-conversion of multiple RF bandpass signals.Type: GrantFiled: February 23, 2010Date of Patent: October 15, 2013Assignee: Korea University Research and Business FoundationInventors: Jinwoo Park, Chung Gu Kang
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Patent number: 8559573Abstract: A communications circuit includes a filter module with a sampling window, a control module, and an input buffer. The control module has a ray parameter interface to obtain information regarding significant ray changes that make it desirable to re-position the sampling window. The control module determines re-positioning parameters, responsive to this information, which reflect the re-positioning of the sampling window. The input buffer obtains samples of a received signal and outputs received signal data to the filter module. The filter module obtains the re-positioning parameters from the control module, and the filter module and control module temporally re-position the sampling window in duration and/or location in accordance with the re-positioning parameters, and output a filtered chip.Type: GrantFiled: December 27, 2005Date of Patent: October 15, 2013Assignee: Agere Systems LLCInventors: Rami Banna, Tomasz T. Prokop, Long Ung, Dominic Wing-Kin Yip
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Patent number: 8559574Abstract: A system for detecting and minimizing interference in a radio receiver includes a plurality of bandpass filters having different response characteristics, a power detector configured to compare a power output of a first bandpass filter and a second bandpass filter, and logic to cascade a third bandpass filter when the difference in power output between the power output of the first bandpass filter and the power output of the second bandpass filter exceeds a threshold amount.Type: GrantFiled: February 6, 2012Date of Patent: October 15, 2013Assignee: Intel CorporationInventors: Ying Shi, James P. Young
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Patent number: 8559571Abstract: An embodiment of the present invention includes a calibration system employed in a multi-input-multi-output (MIMO) system for beamforming and receiving a plurality of streams. The system includes a first calibration circuit responsive to inphase (I) and quadrature (Q) pairs of stream and operative to calibrate each I and Q pair and a second calibration circuit responsive to the calibrated I and Q pairs for all streams, wherein the first and second calibration circuits perform calibration in the time domain.Type: GrantFiled: August 17, 2007Date of Patent: October 15, 2013Assignee: Ralink Technology CorporationInventors: Chien-Cheng Tung, Thomas Edward Pare, Jr.
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Patent number: 8559551Abstract: An input signal to a filter device is allowed to be written into one of a plurality of sequentially connected cells if the input signal is not the zero-valued sample. Each cell receives the input signal and multiplies the input signal by one of a plurality of weight coefficients. The input signal is stopped to be written into any of the cells if the input signal is the zero-valued sample. A result of a filtering operation is output from the last cell.Type: GrantFiled: February 21, 2008Date of Patent: October 15, 2013Assignee: Fujitsu LimitedInventor: Alexander N. Lozhkin
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Publication number: 20130266102Abstract: A radio frequency (RF) receiver includes a digital tuning engine; I-path and Q-path analog filters, tuned by the digital tuning engine; and a digital compensation circuit. The digital tuning engine executes a RC (resistor-capacitor) time constant calibration to adjust respective cut-off frequencies of the I-path analog filter and the Q-path analog filter. The digital tuning engine executes a filter mismatch calibration to match the I-path analog filter and the Q-path analog filter. The digital tuning engine executes a filter residual mismatch calibration to match an I-path response from the I-path analog filter to the digital compensation circuit and a Q-path response from the Q-path analog filter to the digital compensation circuit.Type: ApplicationFiled: March 13, 2013Publication date: October 10, 2013Applicant: MEDIATEK Inc.Inventors: Sheng-Hong Yan, Sheng-Hao Chen, Cheng-Po Liang, Jen-Che Tsai
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Publication number: 20130266101Abstract: One embodiment of the present invention relates to a combined mixer filter circuit. The circuit includes a sampler, a plurality of filter branches, and a coefficient generator. The sampler is configured to provide a sampled signal by sampling a received signal at a specified rate. The plurality of filter branches has selectable filter coefficients. The plurality of filter branches are configured to receive the sampled signal and generate a mixed and filtered output signal without a separate mixer component. The coefficient generator is coupled to the plurality of filter branches. The coefficient generator is configured to assign filter coefficient values to the selectable filter coefficients to yield a selected mixing function for the mixed filtered output signal.Type: ApplicationFiled: April 10, 2012Publication date: October 10, 2013Applicant: Intel Mobile Communications GmbHInventors: Christoph Schultz, Markus Hammes, Rainer Kreienkamp
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Patent number: 8553821Abstract: A receiver may be operable to generate estimates of transmitted symbols using a sequence estimation process that may incorporate a non-linear model. The non-linear model may be adapted by the receiver based on particular communication information that may be indicative of non-linearity experienced by the transmitted symbols. The receiver may generate a reconstructed signal from the estimates of the transmitted symbols. The receiver may adapt the non-linear model based on values of an error signal generated from the reconstructed signal, and the values of the error signal may be generated from a portion of the generated estimates that may correspond to known symbols and/or information symbols. The values of the error signal corresponding to the known symbols may be given more weight in an adaptation algorithm, and the values of the error signal corresponding to the information symbols may be given less weight in the adaptation algorithm.Type: GrantFiled: January 31, 2013Date of Patent: October 8, 2013Assignee: MagnaCom Ltd.Inventor: Amir Eliaz
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Patent number: 8553622Abstract: The disclosure provides an apparatus and method for suppressing interference caused by coexistence of World Interoperability for Microwave Access (WiMAX) and Wireless Fidelity (WiFi). When a user receives the RF signal from a wireless network by using the apparatus, a WiMAX filtering module filters out the WiFi RF signal received through a WiMAX antenna; the WiMAX RF signal is converted into the WiFi RF signal, and the out-of-band interference signal from the WiFi RF signal is filtered out by a WiFi filtering module, then the filtered WiFi RF signal is transmitted to the user through a WiFi antenna.Type: GrantFiled: May 14, 2010Date of Patent: October 8, 2013Assignee: ZTE CorporationInventor: Jiaojiao Yang
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Patent number: 8553823Abstract: A method for identifying signals of the same origin is described. The signals are identified based upon a method of system analysis, wherein an accumulated value of an attenuation weighted by power of an incoming channel, the so-called correspondence coefficient, is used as the criterion whether two signals are of the same origin.Type: GrantFiled: November 27, 2007Date of Patent: October 8, 2013Assignee: Siemens Convergence Creators GmbHInventor: Wolfgang Tschirk
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Patent number: 8553791Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying data that is designated for wireless transmission to a remote computing device. A digital signal that encodes the data for transmission across a band of radio frequency channels is generated. Multiple radio frequency channels in the band that are available are determined. The digital signal is filtered to substantially reduce a power level of the digital signal at frequencies that correspond to channels in the band that have not been determined to be available. The filtered digital signal is converted to an analog signal. The analog signal is provided to an analog transmitter that isolates the band of channels to generate an isolated analog signal and that wirelessly transmits the isolated analog signal over the multiple available channels using one or more antennas.Type: GrantFiled: August 28, 2012Date of Patent: October 8, 2013Assignee: Google Inc.Inventors: E. Daniel McCloskey, C. Philip Gossett
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Patent number: 8553822Abstract: Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, time filtering is utilized. Time filtering is utilized to combat excess delay spread effects in channel estimation. The time filtering is performed in the presence of staggered pilots and helps in improving the channel estimate in the presence of excess delay spread.Type: GrantFiled: December 22, 2004Date of Patent: October 8, 2013Assignee: QUALCOMM IncorporatedInventors: Dhananjay Ashok Gore, Ashok Mantravadi, Fuyun Ling, Krishna Kiran Mukkavilli, Raghuraman Krishnamoorthi
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Patent number: 8548105Abstract: Techniques for performing joint time-frequency automatic gain control (AGC) by a receiver are described. In an aspect, the receiver may transform time-domain samples with a fast Fourier transform (FFT) to obtain frequency-domain symbols and may detect for saturation of the frequency-domain symbols. The receiver may adjust a gain based on whether saturation is detected and may apply the gain prior to the FFT. In one design, the receiver may use a nominal value for a setpoint if saturation is not detected and may reduce the setpoint if saturation is detected. The receiver may adjust the gain based on the setpoint, which may determine the average power of the time-domain samples. In another design, the receiver may determine the gain based on a gain offset and may vary the gain offset based on whether saturation is detected. For both designs, the receiver may apply the gain on digital samples and/or an analog signal prior to the FFT.Type: GrantFiled: July 27, 2009Date of Patent: October 1, 2013Assignee: QUALCOMM IncorportedInventor: Roberto Rimini
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Patent number: 8548028Abstract: A minimum mean square error (MMSE) equalizer corresponding to a plurality of receive antennas is generated using (i) channel information for a first plurality of users including a desired user, (ii) a ratio of white noise power to noise power due to code division multiple access (CDMA) signals corresponding to the first plurality of users, (iii) channel information for a second plurality of users served by another base station, and (iv) a ratio of noise power due to CDMA signals corresponding to the second plurality of users to noise power due to CDMA signals corresponding to the first plurality of users. CDMA signals received by a plurality of antennas are filtered using the MMSE equalizer. The CDMA signals are despread using a spread code corresponding to the desired user.Type: GrantFiled: March 26, 2012Date of Patent: October 1, 2013Assignee: Marvell World Trade Ltd.Inventor: Daniel Yellin
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Patent number: 8548033Abstract: Carrier frequency offset is determined by sample-to-sample phase shifts of a digital radio signal. The CFO range is divided into a number of intervals and creates as many parallel derived streams as there are interval endpoints by pre-compensating (“back rotating”) the input by the sample-to-sample phase shift corresponding to the particular endpoint. Magnitude and phase values are computed of the correlation of a preamble pattern period with the preamble segment of each derived stream in parallel. The largest resulting magnitude value(s) are used to zoom in on the actual CFO present in the input stream. Improved accuracy in the presence of noise may be obtained by repeating the search for a shorter interval centered on the prior CFO value. Final CFO and phase values from corresponding correlation computations then determine the actual CFO and corresponding sample-to-sample phase shift to be applied for pre-compensation (“back rotation”) in an open-loop AFC.Type: GrantFiled: December 20, 2011Date of Patent: October 1, 2013Assignee: Microchip Technology IncorporatedInventors: Jozsef G. Nemeth, Peter Szilveszter Kovacs
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Patent number: 8548038Abstract: In described embodiments, a Serializer-Deserializer (SerDes) receiver includes a pattern detector that allows for detection of insufficiently randomized pattern periods and low activity periods. A freeze of equalization adaptation during these periods might occur by embedding disqualifying patterns into adaptation data. Some embodiments also allow for detection of long intervals of freeze, and so delay a freeze de-assertion in order for a clock and data recovery (CDR) circuit of the receiver to regain lock to the serial data. Embedding freeze information in the receive data allows for precise synchronization of receive data and freeze.Type: GrantFiled: December 6, 2011Date of Patent: October 1, 2013Assignee: LSI CorporationInventors: Vladimir Sindalovsky, Mohammad S. Mobin, Lane A. Smith, Amaresh V. Malipatil, Pervez M. Aziz
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Patent number: 8548032Abstract: A method and apparatus for detecting a radar signal is provided. The method includes collecting a plurality of pulses based on a reference time or a reference pulse collection count, classifying the plurality of pulses into groups based on similarity of pulse widths, classifying the groups into a short-pulse type and a long-pulse type and calculate the number of groups in each type, and determining whether a radar signal exists based on a number of groups in each type.Type: GrantFiled: December 17, 2010Date of Patent: October 1, 2013Assignee: Samsung Electronics Co., Ltd.Inventor: Ji Tae Kim
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Publication number: 20130251081Abstract: According to one embodiment, an adjacent-channel interference reject filter comprises a short-pulse inverter which includes a short-pulse sensor configured to detect a pulse in an intermediate frequency signal supplied to the device. The short-pulse sensor detects pulses having a pulse width less than or equal to some predetermined width. The short-pulse inverter also includes a pulse inverter configured to invert the pulse detected by the short-pulse sensor. The adjacent-channel interference reject filter may also include an inversion controller to control the inverting of detected short pulses. An adjacent-channel interference reject filter may be included in various devices such as wireless communication devices.Type: ApplicationFiled: March 8, 2013Publication date: September 26, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoshiharu NITO, Tsuneo SUZUKI
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Publication number: 20130251082Abstract: An objective is to provide a digital receiver and a method of compensating waveform that are capable of compensating waveform distortion without increasing the circuit size. A digital receiver 100 according to the present invention includes distortion compensation filters 103 that compensate waveform distortion included in an input signal, skew compensation amount setting units 106 for setting a skew compensation amount used for compensating phase distortion among the waveform distortion, amplitude compensation amount setting units 107 for setting an amplitude compensation amount used for compensating amplitude of the input signal that attenuates upon the compensation of the phase distortion using the skew compensation amount, and filter coefficient calculation circuits 108 for determining a filter coefficient to be set to the distortion compensation filters 103 based on the skew compensation amount and the amplitude compensation amount.Type: ApplicationFiled: October 1, 2012Publication date: September 26, 2013Applicant: NEC CORPORATIONInventor: Junichi Abe
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Patent number: 8542142Abstract: A digital equalizer with a reduced number of multipliers for correction of the frequency responses of an interleaved ADC is disclosed. An exemplary interleaved analog to digital converter with digital equalization includes a composite ADC including M time interleaved sub-ADC, a demultiplexer, samples repositioning unit, a first PreFIRs transformer, a second PreFIRs transformer, K double buffer FIR filters, a PostFIRs transformer, a samples sequence restoration unit, and a multiplexer, coupled in series and providing an equalized, frequency response-corrected output.Type: GrantFiled: February 21, 2013Date of Patent: September 24, 2013Assignee: Guzik Technical EnterprisesInventors: Anatoli B. Stein, Semen P. Volfbeyn, Valeriy Serebryanskiy
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Patent number: 8542627Abstract: A method for determining values for use by radio resource management functions is disclosed. Air interface actual values and predictive values are obtained and stored. A timestamp indicating a time when each actual value or predictive value is obtained is generated and stored. The actual values and the predictive values are processed to provide an output value.Type: GrantFiled: June 20, 2011Date of Patent: September 24, 2013Assignee: InterDigital Technology CorporationInventors: Christopher R. Cave, Angelo A. Cuffaro, Teresa J. Hunkeler, Maged M. Zaki, Guodong Zhang, Juan Carlos Zuniga
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Publication number: 20130243135Abstract: Correction of quadrature errors associated with digital communications systems. A correction network may correct a difference between a transmission characteristic of an in-phase signal path and a transmission characteristic of a quadrature signal path. The quadrature signal path may be for the transmission of in-phase and quadrature parts of a signal and the signal comprising frequency components within a baseband. The correction network may include an in-phase input port, a quadrature input port, an in-phase output port and a quadrature output port. Each input port may be connected to each output port by a digital filter network, which may include a set of filter tap coefficients and configuration means for configuring values of the coefficients. Frequency dependent quadrature impairments, e.g., due to the analogue components of a quadrature up-converter or down-converter, may be corrected by suitable control of the coefficients.Type: ApplicationFiled: April 2, 2012Publication date: September 19, 2013Applicant: ROCKSTAR BIDCO LPInventors: Paul Murray Row, Dorian Thomas Charles Davies
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BROADCAST RECEIVING APPARATUS AND METHOD FOR REMOVING INTERFERENCE SIGNAL OF ANALOG BROADCAST SIGNAL
Publication number: 20130243067Abstract: A broadcast receiving apparatus and method are provided, the appartus including a signal receiver which receives an analog broadcast signal in a radio frequency (RF) band; a sync signal detector which detects a sync signal area of the received broadcast signal; an interference signal detector which compares the sync signal area of the broadcast signal with a predetermined reference signal and detects an interference signal component; and an interference signal remover which removes the interference signal component from the broadcast signal based on the interference signal component detected from the sync signal area.Type: ApplicationFiled: February 21, 2013Publication date: September 19, 2013Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Se-jun KIM, Gyo-nyun KIM, Chan-sub PARK -
Patent number: 8537885Abstract: In described embodiments, a variety of down-sampling techniques are employed to generate a more constrained set of floating-tap positions when compared to floating-tap Decision Feedback Equalization (DFE) architectures that allow unconstrained 1T resolution or separated floating-tap positions. Down-sampling is employed to constrain the floating-tap positions rather than positions occurring with 1T resolution or spacing. Two broad down-sampling techniques, phase pruning and phase amalgamation, are applied to a variety of exemplary DFE implementations. Although the tap positions are more constrained, the architectures select floating-tap positions containing dominant reflection inter-symbol interference (ISI) terms.Type: GrantFiled: March 2, 2012Date of Patent: September 17, 2013Assignee: LSI CorporationInventors: Pervez Aziz, Hiroshi Kimura, Amaresh Malipatil
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Patent number: 8537882Abstract: A method, a system, and a device for rapidly exiting training are provided. The method includes: in a training procedure of a Vectored-Digital Subscriber Line (DSL) filter, comparing a feedback error value of the filter and/or a swing range of a filter coefficient with a preset threshold, and determining whether the filter meets a convergence condition according to a comparison result; and exiting the training procedure of the filter when the filter meets the convergence condition. The method, system, and device are applicable to a training procedure of a Vectored-DSL precoder or canceller, so as to rapidly exit the training procedure.Type: GrantFiled: April 29, 2011Date of Patent: September 17, 2013Assignee: Huawei Technologies Co., Ltd.Inventors: Liming Fang, Raphael Cendrillon, Pengrui Zhang
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Patent number: 8537924Abstract: Data is transmitted over multiple input multiple output (MIMO) channels. Plural bit streams are modulated into multiple data symbol vectors. Each vector has a transmission rank with one vector for each MIMO channel. Transmission rank is the number of elements in a data symbol vector corresponding to the number of data streams being transmitted in parallel over each MIMO channel. The multiple data symbol vectors are preceded into multiple precoded symbol vectors using a plurality of precoder cycling sets, one set for each transmission rank including multiple different precoders. The precoders in each precoder cycling set are well-separated with respect to a plurality of distance measures. The precoding includes precoding each data symbol vector of a transmission rank with a precoder belonging to the precoder cycling set of that transmission rank. The precoded symbol vectors are then transmitted over the MIMO channels.Type: GrantFiled: May 7, 2008Date of Patent: September 17, 2013Assignee: Telefonaktiebolaget LM Ericsson (Publ)Inventors: George Jöngren, David Hammarwall, Patrick Svedman
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Patent number: 8537949Abstract: Transmitter waveform dispersion penalty (“TWDP”) is decreased in a transmitter. A binary data signal is received for transmission over a channel that exhibits TWDP. The data signal is shifted less than a full clock cycle to generate at least one post cursor signal. The post cursor signal is subtracted from the data signal to generate a transmitter output data signal for transmission over the channel. In addition to decreasing TWDP, data dependent jitter is also reduced for data transmission across a channel that exhibits a multi-pole transmission characteristic. A main data signal and at least one cursor signal, which is shifted at least a portion of a clock period from the main data signal, is generated. The cursor signal is filtered to filter out effects based on the second pole of the multi-pole transmission characteristic. The main data signal is subtracted from the filtered cursor signal to generate the transmitter output data signal.Type: GrantFiled: June 30, 2010Date of Patent: September 17, 2013Assignee: NetLogic Microsystems, Inc.Inventors: Halil Cirit, Stefanos Sidiropoulos
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Patent number: 8537944Abstract: An apparatus comprises a filter unit comprising a plurality of different filters each configured to filter a first signal when selected. The apparatus may further comprise a control unit configured to select one of the plurality of filters depending on a strength of the first signal. Related methods may also be performed.Type: GrantFiled: November 9, 2007Date of Patent: September 17, 2013Assignee: Infineon Technologies AGInventor: Andreas Menkhoff
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Patent number: 8537886Abstract: Systems and methods are disclosed for employing an equalization technique that improves equalizer input sensitivity and which reduces power consumption. In particular, an equalization architecture is described that includes a continuous-time linear equalizer and a decision feedback equalizer, each with offset cancellation that enables the equalizer to be used at high data rates. In addition, the equalization structure has a power-saving mode for bypassing the decision feedback equalizer. These offset cancellation and power-saving features are enabled and controlled using programmable logic on a programmable device.Type: GrantFiled: July 5, 2012Date of Patent: September 17, 2013Assignee: Altera CorporationInventors: Xiaoyan Su, Sriram Narayan, Sergey Shumarayev
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Publication number: 20130235961Abstract: An apparatus and a method for removing RX DC in a wireless communication system are provided. A receiver apparatus includes a local oscillator, a mixer for converting a received signal to a baseband signal using a frequency provided from the local oscillator, and a DC compensator, comprising an operational amplifier and a low pass filter, for compensating DC in an output signal of a frequency converter by adjusting a pass band size of the low pass filter.Type: ApplicationFiled: March 5, 2013Publication date: September 12, 2013Applicant: SAMSUNG ELECTRONICS CO. LTD.Inventors: Yeo-Joon YOON, Tae-Hui CHO, Hyung-Weon PARK
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Publication number: 20130235918Abstract: A system and method is provided for filtering and amplifying a signal where amplification can be distributed between stages of a filter and gain can be assigned throughout the filter to optimize system performance. Such a system can be implemented in the baseband section of RF receivers. VGAs can be implemented between filter stages, such as biquads, or VGAs can be incorporated in filter stages. Substantially linear VGAs comprising a parallel resistor array can be incorporated in the circuitry of the filter stages to reduce distortion. Gain can be assigned dynamically in the amplification stages to improve noise and/or linearity performance. For example, gain assignments can be implemented so that high power undesired signal components are filtered out before amplification to prevent component saturation, and low power signals are amplified before they are filtered to improve noise performance.Type: ApplicationFiled: April 23, 2013Publication date: September 12, 2013Inventors: Saeid Mehrmanesh, Vahid Mesgarpour Toosi
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Publication number: 20130235910Abstract: Provided is a communication apparatus including a port that connects a power line, along which power is transmitted at a given frequency, to an external apparatus, a transmitter that transmits, via the power line, a carrier signal obtained by modulating a transmit signal that has been obtained by encoding a processing command for executing a given process, at a carrier frequency higher than the frequency of the power, and a communication filter, connected between the power line and the transmitter, that at least blocks signals at the frequency of the power, while not blocking signals at the carrier frequency.Type: ApplicationFiled: February 19, 2013Publication date: September 12, 2013Applicant: Sony CorporationInventor: Takanori Washiro
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Patent number: 8532240Abstract: In described embodiments, a transceiver includes an eye monitor, clock and data recovery, and adaptation modules. Data sampling clock phase and error clock phase determined from a data eye are decoupled in the transceiver during a sampling phase correction process. Decoupling these clock phases during the sampling phase correction process allows relative optimization of system equalization parameters without degradation of various adaptation algorithms. Such adaptation algorithms might be employed for received signal gain and equalization such as, for example, Decision Feedback Equalizer (DFE) adaptation. Deriving the data sampling clock and error clock phases from the same clock generation source and with independent clock control enables an iterative sampling phase correction process that allows for accelerated clock and data recovery (CDR) without disturbing the data eye shape.Type: GrantFiled: January 3, 2011Date of Patent: September 10, 2013Assignee: LSI CorporationInventors: Paul Tracy, Mohammad Mobin, Ye Liu, Lane A. Smith