Signal Noise Patents (Class 375/227)
  • Patent number: 8553752
    Abstract: Embodiments of a system for determining and optimizing the performance a signaling system are described. During operation, the system captures or measures a single-bit response (SBR) for the signaling system. Next, the system constructs an idealized inter-symbol-interference-free (ISI-free) SBR for the signaling system which is substantially free of inter-symbol-interference (ISI). The system then calculates an ISI-residual from the captured SBR and the idealized ISI-free SBR. Next, the system constructs a calibration bit pattern for the signaling system that is based substantially on the ISI-residual. Finally, the system uses the calibration bit pattern to calibrate, optimize and determine an aspect of the performance of the signaling system.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: October 8, 2013
    Assignee: Rambus Inc.
    Inventors: Wendemagegnehu Beyene, Kevin S. Donnelly, Mark A. Horowitz
  • Patent number: 8554152
    Abstract: An apparatus and a method for estimating a channel in a mobile communication system are provided. The apparatus includes a channel estimation unit for determining a channel estimation value using a channel power for each of a plurality of fingers, and a noise estimation unit for selecting a scheme for estimating a thermal noise power according to a channel environment among schemes for determining a plurality of thermal noise powers, and for estimating a noise using the channel estimation value in the selected scheme.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: October 8, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyo-Chul Kwak, Myung-Kwang Byun, Yu-Suk Yun, Sung-Kwon Jo
  • Publication number: 20130259109
    Abstract: Disclosed are various embodiments providing processor configured to determine a received signal strength indication (RSSI) value for each of the plurality of channel taps. The processing circuitry identifies a maximum RSSI value among the RSSI values and may adjust a variable threshold range according to the maximum RSSI value. The RSSI value for each channel tap may be scaled according to a corresponding per tap noise power.
    Type: Application
    Filed: November 1, 2012
    Publication date: October 3, 2013
    Applicant: BROADCOM CORPORATION
    Inventors: Bin Liu, Taikun Cheng, Severine Catreux
  • Patent number: 8548036
    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: Grant
    Filed: June 21, 2010
    Date of Patent: October 1, 2013
    Assignees: Autonetworks Technologies, Ltd., Sumitomo Wiring Systems, Ltd., Sumitomo Electric Industries, Ltd.
    Inventors: Daisuke Umehara, Masahiro Morikura, Toshiya Hisada, Shinichi Ishiko, Satoshi Horihata
  • Patent number: 8548387
    Abstract: A method and apparatus for providing uplink signal-to-noise ratio (SNR) estimation in a wireless communication system. A first signal is received over a first channel and a second signal is received over a second channel, where the second signal is received at a higher signal power level than said first signal. A signal-to-noise ratio (SNR) of the second signal is measured, and the SNR of the first signal is determined based at least in part upon the measured SNR of the second signal.
    Type: Grant
    Filed: January 2, 2007
    Date of Patent: October 1, 2013
    Assignee: Qualcomm Incorporated
    Inventor: Durga P. Malladi
  • Patent number: 8548105
    Abstract: 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: Grant
    Filed: July 27, 2009
    Date of Patent: October 1, 2013
    Assignee: QUALCOMM Incorported
    Inventor: Roberto Rimini
  • Patent number: 8542071
    Abstract: Chaotic oscillator-based random number generation is described. In an example, a circuit includes a negative differential resistance (NDR) device to receive an alternating current (AC) bias. The circuit further includes a capacitance in parallel with the NDR device, the capacitance having a value such that, in response to a direct current (DC) bias applied to the NDR device and the capacitance, a voltage across the capacitance oscillates with a chaotic period. The circuit further includes a random number generator to generate random numbers using samples of the voltage across the capacitance.
    Type: Grant
    Filed: October 25, 2011
    Date of Patent: September 24, 2013
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Matthew D Pickett, Gilberto Medeiros Ribeiro, R Stanley Williams
  • Publication number: 20130243062
    Abstract: Apparatuses, methods and systems of receive signal detection of a multi-carrier signal are disclosed. One method includes receiving a multi-carrier signal, determining a characteristic of each sub-carrier of the multi-carrier signal, and selecting a one of a plurality of receive signal detection techniques for each sub-carrier of the multi-carrier signal based on the determined characteristic of the sub-carrier.
    Type: Application
    Filed: March 16, 2012
    Publication date: September 19, 2013
    Applicant: POSEDGE INC.
    Inventors: Meesaraganda Surendra Raju, Mohan Karnam, Sujai Chari
  • Publication number: 20130243064
    Abstract: A method and system for actively selecting antenna sets for a client are disclosed. In a first aspect, the method comprises sending a first channel packet from a transmitter to a receiver and sending a second channel packet corresponding to the received first channel packet from the receiver to the transmitter. The method includes collecting statistics of an antenna set related to the sending of the first and the second channel packets. The method includes comparing the collected statistics to previously collected statistics of another antenna set to select one of the antenna set and the another antenna set. In a second aspect, the system comprises a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the processor to carry out the steps of the method.
    Type: Application
    Filed: March 19, 2012
    Publication date: September 19, 2013
    Applicant: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: John WONG, Thomas E. PARE, JR., Gary A. ANWYL, Kiran ULN, Chih-Liang CHANG
  • Patent number: 8539288
    Abstract: Systems and methods are provided for determining a successive interference cancellation (SIC) decoding ordering in a multiple input multiple output transmission (MIMO) system with retransmissions. A plurality of codewords is transmitted in a current transmission time. Some of the codewords may have been previously transmitted in previous transmission attempts according to a retransmission protocol. The plurality of codewords is received and an ordering metric is computed for a received codeword based on channels associated with multiple transmission attempts of the codeword. A decoding ordering of the codewords is determined based on the computed ordering metric. Performance parameters such as Packet Error Rate (PER), channel gain, and/or equalizer-output Signal-to-Interference and Noise Ratio (SINR) may be used to evaluate a channel quality for each one of the transmission attempts of the codeword. The ordering metric may be updated recursively with each transmission attempt.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: September 17, 2013
    Assignee: Marvell International Ltd.
    Inventors: Yakun Sun, Jungwon Lee
  • Patent number: 8537942
    Abstract: Circuitry and method for reduce test time for wireless signal systems by using dynamic adaptive correction of DC offsets generated by the test instrument. The data signal is sampled for downstream processing including during pre-, inter-, or post-packet time intervals where no packet-data signal is occurring and where the device's power amplifier is turned off. The sampled data signal is measured for a DC offset occurring during these inter-packet time gaps. Compensating DC offset values are stored in a table indexed by frequency, gain and temperature range. When a subsequent test is carried out at that frequency, gain, and temperature range, the stored compensation value is used to correct the signal. DC offsets continue to be measured, stored and applied to captured signals, continuously refining the compensation values and decreasing the need for time-intensive calibrations. When a measured DC offset exceeds pre-determined limits, the instrument undergo a calibration step.
    Type: Grant
    Filed: January 24, 2012
    Date of Patent: September 17, 2013
    Assignee: Litepoint Corporation
    Inventors: Christian Volf Olgaard, Ruizu Wang, Erdem Serkan Erdogan
  • Publication number: 20130230085
    Abstract: The present disclosure is directed at a method and apparatus for generating a metric for use in any one or more of lock detection, SNR estimation, and modulation classification. To generate the metric, an input angle in the form of a symbol phase or a difference in symbol phases is used to evaluate a base function. The base function relates possible metrics to possible input angles using a triangle wave having its maxima or minima at ideal input angles, and the other of its maxima or minima at angles midway the ideal input angles. Described are embodiments that are one or more of non-data aided; that may be implemented relatively efficiently in hardware; that can function using one sample/symbol; that can achieve relatively good detection certainty using relatively few estimates; and that can be used to implement modulation classifiers, lock detectors, and SNR estimators that are resilient to imperfections in automatic gain control.
    Type: Application
    Filed: November 1, 2011
    Publication date: September 5, 2013
    Inventor: Yair Linn
  • Publication number: 20130230087
    Abstract: A signal quality metric is determined for each of multiple signal paths. Each of the signal paths corresponds to a respective antenna. The determined signal quality metric is modified for one or more signal paths. A subset of the signal paths is selected for receiving a signal based at least in part on the determined signal quality metrics. The selecting is biased based at least in part on the modified signal quality metrics.
    Type: Application
    Filed: April 18, 2013
    Publication date: September 5, 2013
    Applicant: Broadcom Corporation
    Inventors: Rajendra Tushar Moorti, Min Chuin Hoo, Jason Alexander Trachewsky
  • Publication number: 20130230086
    Abstract: A delay between a first signal and a second signal is estimated. The first signal and second signals are received and for each of a plurality of candidate delays between the signals, a correlation value is determined. Based on the correlation values, one of the candidate delays is selected to be used as an estimate of the delay between the first and second signals.
    Type: Application
    Filed: May 9, 2012
    Publication date: September 5, 2013
    Applicant: Microsoft Corporation
    Inventor: Karsten Vandborg Sorensen
  • Publication number: 20130223502
    Abstract: Method, receiver and computer program product for processing a signal transmitted over a wireless network from a plurality of spatially separated transmit antennas of a transmitter using a Multiple-Input Multiple-Output transmission. The signal is received at a plurality of receive antennas, the signal comprising a plurality of data streams. The channel quality for each of the data streams in the received signal is determined and based on the determined channel quality of the data streams, the number of independent data streams that can be supported in the Multiple-Input Multiple-Output transmission of the signal is determined. An indication of the determined number is transmitted to the transmitter.
    Type: Application
    Filed: April 12, 2011
    Publication date: August 29, 2013
    Applicant: NVIDIA TECHNOLOGY UK LIMITED
    Inventors: Tarik Tabet, Carlo Luschi
  • Publication number: 20130223501
    Abstract: Apparatus, methods, and programs products are disclosed that perform the following techniques: in a receiver comprising first and second stages, each stage at least decoding information corresponding to a user equipment, wherein the second stage performs decoding only if the first stage completes decoding with a fail, predicting whether decoding performed by the second stage for the user equipment will complete with a pass or fail; and prior to completion of the second stage, sending an indication of the predicted pass or fail to the user equipment.
    Type: Application
    Filed: June 5, 2012
    Publication date: August 29, 2013
    Inventors: Suresh Kalyanasundaram, Shirish Nagaraj, Raghavendra M. Ramakrishna
  • Publication number: 20130223503
    Abstract: Techniques, apparatus and systems for providing radio frequency wireless communications based on time reversal of the channel impulse response of an RF pulse in a transmission channel between an RF transmitter and an RF receiver to enhance reception and detection of an RF pulse at the RF receiver against various effects that can adversely affect and complicate the reception and detection of the RF pulse at the RF receiver.
    Type: Application
    Filed: April 1, 2013
    Publication date: August 29, 2013
    Applicant: ZIVA CORPORATION
    Inventor: Ziva Corporation
  • Patent number: 8520761
    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: August 27, 2013
    Assignee: Fujitsu Limited
    Inventors: Jian Wang, Jianming Wu, Yi Wang, Hua Zhou, Jun Tian
  • Patent number: 8521092
    Abstract: A system and method for testing wireless transceivers in a virtual wireless environment including emulating an RF environment, creating virtual spectrum users having selectable transmission parameters and physical characteristics and evaluating the operation of the wireless transceiver in the virtual wireless environment.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: August 27, 2013
    Assignee: Echo Ridge LLC
    Inventors: Joseph Kennedy, John Carlson
  • Publication number: 20130215948
    Abstract: Disclosed is an adaptive transmit and receive method and device in a multiple-antenna wireless communication system. A transmit mode comprises different main transmit modes each of which includes one or both of a sub-transmit mode based on STBC and a sub-transmit mode based on SM. A receiver calculates an STBC performance parameter and a SM performance parameter, and a transmitter uses the parameters to determine a main transmit mode with maximum data rates and select a sub-transmit mode for minimizing power consumption. The transmitter channel-encodes, modulates and antenna-maps input data according to the selected transmit mode, and outputs results to the receiver. The receiver antenna/symbol-demodulates and channel-decodes the received data.
    Type: Application
    Filed: March 18, 2013
    Publication date: August 22, 2013
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventor: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
  • Publication number: 20130215951
    Abstract: At least one example embodiment discloses a method of determining crosstalk in a multiple-input-multiple output (MIMO) system. The method includes receiving, from at least one first remote node, upstream pilots on an upstream channel, determining upstream channel coefficients based on the received pilots, transmitting, to the at least one first remote node, downstream pilots on a downstream channel, receiving, from the at least one first remote node, loopback pilots on the upstream channel, the loopback pilots being loopback signals of the downstream pilots, and determining downstream channel coefficients based on the received downstream pilots.
    Type: Application
    Filed: February 17, 2012
    Publication date: August 22, 2013
    Applicant: ALCATEL-LUCENT USA INC.
    Inventor: Carl Nuzman
  • Patent number: 8514737
    Abstract: A method and an apparatus for estimating a Carrier-to-Noise Ratio (CNR) at a Base Station (BS) in a wireless access system are provided. In the method, a preamble signal received from at least one neighbor BS is converted to a frequency response of a preamble sequence and Inverse Fast Fourier Transform (IFFT)-processing the preamble signal, an estimation period of the IFFT-processed preamble signal, corresponding to a Fast Fourier Transform (FFT) size, is divided into a predetermined number of blocks, carrier power values of the blocks are accumulated for a predetermined number of frames, an average of timing offsets of the frames corresponding to a position of a block having a maximum average of accumulated carrier values is determined to be a timing offset of the preamble signal, a carrier power value of the preamble signal is calculated using the timing offset, and a CNR of the preamble signal is estimated using the carrier power value.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: August 20, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyon-Seung Lee, Byoung-Ha Yi, Ki-Young Han, Chung-Ryul Chang
  • Patent number: 8514909
    Abstract: Noise measurements are made within a fraction of a single symbol period of a longest orthogonal code symbol. A control processor identifies an unoccupied code having a spreading factor that is less than a longest spreading factor for the system. A despreader measures symbol energy based on the unoccupied code and a noise estimator generates noise estimations based on the measured symbol energies. The subscriber station uses similar techniques in order to perform channel estimations within a period that is a fraction of a symbol period of a longest-spreading-factor code.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: August 20, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Da-Shan Shiu, Durga Malladi Prasad, Srikrishna Bhashyam
  • Patent number: 8514921
    Abstract: A method for accessing aircraft interference path loss in an aircraft. A plurality of radio frequency signals that are stepped through a plurality of frequencies in a frequency range is transmitted from a plurality of locations within an interior of the aircraft. Radio frequency signals present at a receive antenna are received in response to transmitting the plurality of radio frequency signals to form a plurality of measurements. An average of averages curve is generated from the plurality of measurements. A peak to average ratio is identified. Field uniformity is identified. A standard error for the average of averages curve is determined. An upper bound for the aircraft interference path loss in the aircraft is predicted using the average of averages curve, the peak to average ration, the field uniformity, and the standard error.
    Type: Grant
    Filed: July 16, 2008
    Date of Patent: August 20, 2013
    Assignee: The Boeing Company
    Inventors: Nathaniel Thomas Horton, Kenneth Patrick Kirchoff, Dennis Michael Lewis
  • Patent number: 8514978
    Abstract: Receiving a modulated carrier signal that is modulated using a reference signal, wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer. Further including routing the modulated carrier signal through a receiver system to generate a processed signal, receiving the processed signal at the digitizer, digitizing the processed signal at the digitizer, and determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: August 20, 2013
    Assignee: National Instruments Corporation
    Inventors: Daniel S. Wertz, Charles L. Corley, II, Kunal H. Patel
  • Patent number: 8509295
    Abstract: Embodiments of the present disclosure provide a method for predicting bit errors in a communication channel, comprising generating a model representative of the communication channel, formulating enhanced noise at a first noise level that is higher than a second noise level, the second noise level corresponding to a level of noise that the communication channel experiences during a general operation of the communication channel, simulating an operation of the model by injecting the enhanced noise into the model, determining actual bit errors of the model when the model is simulated with the enhanced noise, and estimating a bit error rate (BER) when the model of the communication channel is operated with noise of the second level. Other embodiments are also described and claimed.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: August 13, 2013
    Assignee: Marvell Israel (M.I.S.L) Ltd.
    Inventor: Iddo Diukman
  • Publication number: 20130202020
    Abstract: A method for generating interference signals and a device to carry out said method, in which an interference signal (1) is added in a signal combination and separation network (3) with a desired signal (4) that carries a test message, the sum signal being sent to a device being tested (5). The interference signal (1) is generated with a single source connected to a signal divider and conditioner block (7) that attenuates additional interference produced by the source of generation of interference signals (1), while providing as many interference signals (1) as the device (5) under test has antennas (Rx, Rx/Tx), and in which each interference signal (1) is sent to a respective amplification and isolation block (8), which adjusts the power level of the interference signal (1) and attenuates the reverse intermodulation products produced by the transmission of signals by the device (5) under test.
    Type: Application
    Filed: April 19, 2013
    Publication date: August 8, 2013
    Applicant: AGILENT TECHNOLOGIES, INC
    Inventor: AGILENT TECHNOLOGIES, INC
  • Patent number: 8503545
    Abstract: A ZIF direct-conversion OFDM receiver capable of estimating and correcting an I/Q imbalance in a baseband signal. A complex down-conversion is performed on a received signal r(t). The received signal r(t) is divided into an In-phase signal (I) and Quadrature-phase signal (Q). An I/Q imbalance is introduced by the local oscillator such that the I/Q imbalance includes an amplitude imbalance factor (?) and phase imbalance factor (?). The I and Q signals are amplified, filtered and digitized. The digitized I and Q signals are processed via a Fast Fourier Transform (FFT). An I/Q compensation algorithm estimates the values of the amplitude imbalance factor (?) and, the phase imbalance factor (?) based on a time expectation calculation. The imbalance factors are applied to the baseband signal to recover the signal of interest x(t). The OFDM receiver outputs the signal of interest x(t) to an information display device.
    Type: Grant
    Filed: August 27, 2007
    Date of Patent: August 6, 2013
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Yan Li, Azzedine Touzni
  • Patent number: 8503946
    Abstract: The current invention relates to a method of determining a quality of a received signal, wherein the method comprises receiving a signal comprising a first part and a second part and wherein at least the second part of the received signal comprises a scrambling sequence period; and determining a first noise-and-interference power of the first part of the received signal by removing a second noise-and-interference power of the second part of the signal, wherein the scrambling sequence period is utilized in the removal. The invention further relates to a corresponding device and system. Thereby, the invention is able to, among other things, reduce neighbor cell reference symbol interference in a dense network.
    Type: Grant
    Filed: July 10, 2009
    Date of Patent: August 6, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Bengt Lindoff, Bo Lincoln
  • Publication number: 20130195164
    Abstract: Systems and methods are described for enhancing the audio quality of an FM receiver. In embodiments described herein, a stop band noise signal is extracted from an L+R or L?R signal produced by an FM stereo decoder. A channel quality measure is calculated based on the stop band noise signal and is used to control whether a pop suppression technique is applied to the L+R signal. The channel quality measure and the stop band noise signal are also leveraged to perform single-channel noise suppression in the frequency domain on the L?R signal and on the L+R signal. The channel quality measure is also used to control the application of a fast fading compensation process that replaces noisy segments of the L?R and L+R signal with replacement waveforms generated via waveform extrapolation.
    Type: Application
    Filed: January 31, 2012
    Publication date: August 1, 2013
    Applicant: BROADCOM CORPORATION
    Inventors: Juin-Hwey Chen, Thomas F. Baker, Evan S. McCarthy, Jes Thyssen, Walter J. Wihardja, David C. Garrett
  • Publication number: 20130195163
    Abstract: Systems and methods are described for enhancing the audio quality of an FM receiver. In embodiments described herein, quadrature L?R demodulation is applied to a composite baseband signal output by an FM demodulator to obtain an L?R noise signal. A channel quality measure is calculated based on the L?R noise signal and is used to control whether a pop suppression technique is applied to an L+R signal obtained from the composite baseband signal to detect and remove noise pulses therefrom. The channel quality measure and the L?R noise signal are also leveraged to perform single-channel noise suppression in the frequency domain on an L?R signal obtained from the composite baseband signal and on the L+R signal. The channel quality measure is also used to control the application of a fast fading compensation process that replaces noisy segments of the L?R and L+R signal with replacement waveforms generated via waveform extrapolation.
    Type: Application
    Filed: January 31, 2012
    Publication date: August 1, 2013
    Applicant: Broadcom Corporation
    Inventors: Juin-Hwey Chen, Thomas F. Baker, Evan S. McCarthy, Jes Thyssen, Walter J. Wihardja, David C. Garrett
  • Patent number: 8498365
    Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: July 30, 2013
    Assignee: Broadcom Corporation
    Inventors: Thomas Kolze, Bruce Currivan, Jonathan Min
  • Patent number: 8494038
    Abstract: A receiver circuit detects an eye margin within a differential signal having a true component and a complement component. A transmitter circuit adjusts a phase between the true component and the complement component of the differential signal, based on the eye margin, to improve the eye margin. Improving the eye margin results from a reduction in common mode noise within the differential signal.
    Type: Grant
    Filed: December 19, 2010
    Date of Patent: July 23, 2013
    Assignee: International Business Machines Corporation
    Inventors: Nickolaus J. Gruendler, Bhyrav Mutnury, Terence Rodrigues
  • Patent number: 8494040
    Abstract: A method for testing a radio frequency (RF) receiver may include measuring a plurality of bit error levels for the RF receiver at a given RF frequency. The method may further include applying a Huber function to the measured plurality of bit error levels to generate a bit error ratio (BER) estimate for the RF receiver. The method would also include using the BER estimate to generate a sensitivity for the RF receiver.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: July 23, 2013
    Assignee: Research In Motion Limited
    Inventors: Yihong Qi, Michael Certain, Perry Jarmuszewski, Qingmai Zhou
  • Patent number: 8494039
    Abstract: The present invention provides a method and apparatus reporting a channel quality indicator of a communication system, including: detecting a first measurement reflecting a first communication quality of the communication system; providing a series of thresholds and mapping functions, each mapping functions in association with a bin defined by two adjacent thresholds, so the first measurement is mapped to the channel quality indicator by the mapping function in association with the bin which matches the first measurement; and updating at least one of the thresholds according to a second measurement which reflects a second communication quality of the communication system.
    Type: Grant
    Filed: May 23, 2011
    Date of Patent: July 23, 2013
    Assignee: MediaTek Inc.
    Inventor: Pei-Shiun Chung
  • Publication number: 20130182746
    Abstract: The present invention proposes an LTE eNodeB receiver channel estimation technique that is referred to as reduced complexity minimum mean squared error (MMSE) technique for channel estimation. From the invention's assumptions, estimations and modified calculations, the present invention generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates HLS is as follows: (Formula I) which generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates. As a second aspect of the present invention, it is desired that the SNR be estimated within ?3 dB of the actual channel SNR. As a third aspect of the invention, an adaptive method of data channel interpolation from RS channel is being proposed in this invention.
    Type: Application
    Filed: September 15, 2012
    Publication date: July 18, 2013
    Inventors: John P. Panicker, Gray Boudreau, Michael Petras, Ed Illidge
  • Patent number: 8488724
    Abstract: Certain disclosed embodiments pertain to suppressing interference in a wireless communication system. For example, a method of suppressing interference can include receiving one or more first signals including components from a plurality of sub-channels. Each of the first signals can be converted into a respective plurality of first sub-band frequency components. A respective spatial filter can be determined for each frequency sub-band using one or more corresponding first sub-band components for each respective spatial filter. One or more second signals including components from the plurality of sub-channels can be received. Each of the second signals can be converted into a respective plurality of second sub-band frequency components. A corresponding plurality of filtered sub-band components can be generated by applying the respective spatial filters to the corresponding second sub-band components for each of the second signals.
    Type: Grant
    Filed: May 14, 2010
    Date of Patent: July 16, 2013
    Assignee: Silvus Technologies, Inc.
    Inventors: Babak Daneshrad, Jean-Francois (JF) Frigon, Anish Narendra Shah, Weijun Zhu
  • Publication number: 20130177044
    Abstract: Certain aspects of a method and system for achieving space and time diversity gain are disclosed. Aspects of one method may include modifying a generalization code of at least one pilot channel, to measure signal strengths for each of a plurality of received multipath signals. A portion of the plurality of received multipath signals may be combined based on the measured signal strengths. The signal strengths of the plurality of received multipath signals may be measured on a primary pilot channel by assigning its generalization code to zero. The signal strengths of the plurality of received multipath signals on a secondary pilot channel may measured by assigning its generalization code to a non-zero value.
    Type: Application
    Filed: March 5, 2013
    Publication date: July 11, 2013
    Applicant: Broadcom Corporation
    Inventor: Broadcom Corporation
  • Publication number: 20130177062
    Abstract: In order to improve radio characteristic in a transmitter, there are included a ?? modulation means that ?? modulates a given input signal; and a control means that changes parameters of the ?? modulation means in accordance with a given condition.
    Type: Application
    Filed: September 2, 2011
    Publication date: July 11, 2013
    Applicant: NEC CORPORATION
    Inventors: Shinichi Hori, Toshio Hayashi, Daisuke Nagai
  • Publication number: 20130170533
    Abstract: In a multiple-input multiple-output (MIMO) wireless system supporting Coordinated Multi-Point (CoMP) transmission and having a first base station, a second base station, and a user equipment, a communications method implemented in the first base station is disclosed. In an aspect, the communications method includes exchanging, with the second base station through local information exchange, first information about a first channel between the first base station and the user equipment and second information about a second channel between the second base station and the user equipment, and computing at least one of a precoding matrix, a receiver filter, and a projection matrix, wherein the user equipment estimates the first information and the second information, and shares the first information and the second information with the first base station. Other apparatuses and some methods for wireless communications also are disclosed.
    Type: Application
    Filed: September 27, 2012
    Publication date: July 4, 2013
    Applicant: NEC Laboratories America, Inc.
    Inventor: Nec Laboratories America, Inc.
  • Patent number: 8467797
    Abstract: In order to reduce interference between cells through hopping and use frequencies in a good propagation situation, a scheduler section 102 carries out scheduling for determining to which user data should be sent using CQI from each communication terminal apparatus, selects a user signal to be sent in the next frame and determines in which subcarrier block the data should be sent. An MCS decision section 103 selects a modulation scheme and coding method from the CQI of the selected user signal. A subcarrier block selection section 110 selects a subcarrier block instructed by the scheduler section 102 for each user signal. For the respective subcarrier blocks, FH sequence selection sections 111-1 to 111-n select hopping patterns. A subcarrier mapping section 112 maps the user signal and control data to subcarriers according to the selected hopping pattern.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: June 18, 2013
    Assignee: Panasonic Corporation
    Inventors: Akihiko Nishio, Katsuhiko Hiramatsu, Isamu Yoshii
  • Patent number: 8457218
    Abstract: A method limits the effect of repetitive electrical impulse noise in a communication system. The presence of the repetitive electrical impulse noise is detected during communication service. If the repetitive electrical impulse noise is detected, then a message is transmitted which signals that the repetitive electrical impulse noise is present. Other systems and methods are disclosed.
    Type: Grant
    Filed: October 6, 2011
    Date of Patent: June 4, 2013
    Assignee: Lantiq Deutschland GmbH
    Inventors: Axel Clausen, Vladimir Oksman
  • Patent number: 8457215
    Abstract: A receiver suppresses noise simultaneously using a noise suppressor and an automatic gain controller (AGC). The receiver divides a received signal into an audio period and a non-audio period, analyzes whether the noise characteristic of the non-audio period corresponds to a non-static noise or a static noise, and if the noise characteristic corresponds to the static noise, analyzes whether the static noise is caused by a network or a transmitter side terminal. In accordance with the analyzed noise characteristic, the noise suppressor firstly suppresses the noise by determining the noise suppressing intensity, and sends a signal, from which the noise has been firstly suppressed, to the AGC. The AGC secondly suppresses the noise included in the signal. In this case, the threshold value of the AGC is controlled in real time in accordance with the noise characteristic.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: June 4, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Beak-Kwon Son, Sang-Ki Kang, Dong-Won Lee
  • Patent number: 8457183
    Abstract: The present invention discloses a method for adjusting a tunable compensation filter within a communication device. The method includes the following steps: generating at least a detecting signal according to at least a pole of the tunable compensation filter; generating a transmitted signal according to the detecting signal; receiving the transmitted signal via a loop switch; generating a filtered signal by filtering the transmitted signal; generating a received signal by compensating the filtered signal; generating at least an indicating signal by comparing the detecting signal with the received signal; and determining whether to adjust at least a coefficient of the tunable compensation filter or not according to the indicating signal.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: June 4, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventor: Ming-Chung Huang
  • Patent number: 8457181
    Abstract: Methods and apparatus for maintaining the maximum achievable data rate on a DSL line, up to and including a rate to which a user subscribes is described. Performance monitoring is conducted on the DSL line on an ongoing basis to determine noise margins in each direction. Each noise margin is compared against pre-determined decreasing/increasing thresholds to determine whether the line characteristics dictate a data rate change without loss of synchronization. The invention supports dynamic provisioning changes including application driven service level change requests, e.g., new bandwidth-on demand services. In some embodiments, a combination of existing and new embedded operations channel (EOC) messages are used to implement the modem data rate changes. New EOC messages may be implemented using some of the reserved and/or vendor proprietary Opcodes currently permitted. Modem assigned data rate changes are implemented without a disruption of service, e.g.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: June 4, 2013
    Assignee: Intellectual Ventures II LLC
    Inventors: Terrence E Remy, James E. Sylvester
  • Patent number: 8457188
    Abstract: An apparatus, including a detection unit configured to perform a non-linear detection on a receive signal, a first estimator configured to estimate a first quality measure based on the receive signal, and a second estimator configured to estimate a second quality measure dependent on the first quality measure and a performance measure of the detection unit is provided.
    Type: Grant
    Filed: June 27, 2007
    Date of Patent: June 4, 2013
    Assignee: Nokia Corporation
    Inventors: Karl Majonen, Markku J. Heikkilä
  • Publication number: 20130136166
    Abstract: Embodiments describe a method of measuring noise and interference within transceivers of an OFDM wireless transmission system, or similar communication system, including a number of receivers communicating with one or more base stations in cell or sector arrangements. The transmitter schedules a transmission burst for a non-existent user (receiver) using wireless transmission traffic. In an OFDM system, this corresponds to a certain set of subcarriers in the time/frequency arrangement. Thus, in the receive frame structure, the data and pilot subcarriers are guaranteed to be only noise and interference from adjacent sectors. The receiver can accurately measure the noise and interference without needing to cancel out the transmitted signal. Therefore, the system is assured that there is no desired signal as part of this measurement. The noise and interference measurement process can be appropriately scheduled so that it does not impact the overall throughput of the system.
    Type: Application
    Filed: January 25, 2013
    Publication date: May 30, 2013
    Applicant: Broadcom Corporation
    Inventor: Broadcom Corporation
  • Publication number: 20130128940
    Abstract: Certain aspects provide a method for determining decoding order and reconstruction weights for decoded streams to be cancelled in a MIMO system with successive interference cancellation, based on estimates of the channel characteristics, the received composite signal and parameters of the system.
    Type: Application
    Filed: December 18, 2012
    Publication date: May 23, 2013
    Applicant: QUALCOMM Incorporated
    Inventor: QUALCOMM Incorporated
  • Patent number: 8446939
    Abstract: A receive signal processor jointly detects two or more symbols in a signal-of-interest in the presence of one or more other MIMO signals. The signal-to-interference-plus-noise ratio for each signal-of-interest is determined by computing per-subcarrier signal-to-interference-plus-noise ratios for a plurality of subcarriers allocated to the signals-of-interest, and computing a total signal-to-interference-plus-noise ratio for the subcarriers based on the per-subcarrier signal-to-interference-plus-noise ratios of the subcarriers. A controller determines one or more transmission formats for uplink transmissions based on the signal-to-interference-plus-noise ratios. The process of computing per-subcarrier signal-to-interference-plus-noise ratio reflects the amount of MIMO interference already cancelled or still remaining in the signal arriving at the joint detector.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: May 21, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Yi-Pin Eric Wang, Jung-Fu Cheng
  • Patent number: RE44244
    Abstract: A system that adapts wireless link parameters for a wireless communication link. A measure is determined of errors occurring in communication over a wireless link. In a case that the measure of errors corresponds to more errors than a first predetermined threshold, communication changes from a first set of wireless link parameters to a second set of wireless link parameters. The second set of wireless link parameters corresponds to higher error tolerance than the first set of wireless link parameters. In a case that the measure of errors corresponds to fewer errors than a second predetermined threshold, communication changes from the first set of wireless link parameters to a third set of wireless link parameters. The third set of wireless link parameters corresponds to lower error tolerance than the first set of wireless link parameters. Preferably, the measure of errors is determined by monitoring a number of NACK messages and a number of ACK messages that occur.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: May 28, 2013
    Assignee: Wi-Lan, Inc.
    Inventors: Subir Varma, Reza Majidi-Ahy, Joseph Hakim, Wendy Chiu Fai Wong