Particular Demodulator Patents (Class 375/324)
  • Patent number: 8861659
    Abstract: A data receiving circuit and a data receiving method accurately acquire a data signal corresponding to information data from a high speed high density transmitted signal. An increase or a decrease of the level of one of a amplified data signal and a level converted data signal that is transmitted from one, referred to as one processing stage, of an amplification processing stage and a level converting processing stage, is fed back to a stage preceding the one processing stage. The amplification processing stage supplies, to a first line, an amplified data signal obtained by performing an amplification processing on a received data signal, and the level converting processing stage transmits, via a second line, a level converted data signal obtained by performing a level converting processing on the amplified data signal.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: October 14, 2014
    Assignee: Lapis Semiconductor Co., Ltd.
    Inventors: Hideaki Hasegawa, Kouji Takeda, Toshio Itou, Yuuichi Ike
  • Patent number: 8855240
    Abstract: Channel estimation and data detection in a wireless communication system in the presence of inter-cell interference is provided.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: October 7, 2014
    Assignee: BlackBerry Limited
    Inventors: Chandra S. Bontu, Amin Mobasher
  • Patent number: 8848847
    Abstract: 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: Grant
    Filed: April 10, 2012
    Date of Patent: September 30, 2014
    Assignee: Intel Mobile Communications GmbH
    Inventors: Christoph Schultz, Markus Hammes, Rainer Kreienkamp
  • Patent number: 8848842
    Abstract: An embodiment of a decoder is disclosed. For this embodiment of the decoder, a first estimation unit and a second estimation unit are for iterative decoding. A scheduler is to receive a mode select signal to provide either an indication of first scheduling information or second scheduling information to the first estimation unit and the second estimation unit responsive to the mode select signal.
    Type: Grant
    Filed: August 16, 2012
    Date of Patent: September 30, 2014
    Assignee: Xilinx, Inc.
    Inventor: Christopher H. Dick
  • Patent number: 8848852
    Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter has at least three transmit antennas and includes a feedback decoding portion configured to recover at least one group-based channel quality indicator provided by a feedback signal from a receiver, wherein each group-based channel quality indicator corresponds to one of a set of transmission layer groupings. The transmitter also includes a modulator portion configured to generate at least one symbol stream and a mapping portion configured to multiplex each symbol stream to at least one transmission layer grouping. The transmitter further includes a pre-coder portion configured to couple the transmission layers to the transmit antennas for a transmission. The receiver includes a decoder portion which is configured to use decoded signals from at least one group to decode the other groups.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: September 30, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Eko N. Onggosanusi
  • Patent number: 8848828
    Abstract: A distortion compensation circuit for compensating for the distortion characteristics of an amplifier, includes a distortion compensating coefficient calculating element and a distortion compensating operation element. The distortion compensating coefficient calculating element calculates a distortion compensating coefficient to be used for compensation of the distortion characteristics by comparing an input signal with the output signal amplified by the amplifier. The distortion compensating operation element performs a distortion compensating operation on the input signal, using a variably set bit format and the distortion compensating coefficient calculated by the distortion compensating coefficient calculating element.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: September 30, 2014
    Assignees: NEC Corporation, Hitachi Kokusai Electric Inc.
    Inventors: Junya Ashita, Teppei Shoji
  • Patent number: 8842787
    Abstract: A receiver is set forth that includes a tuner circuit and a converter circuit. The tuner circuit provides an analog signal corresponding to a modulated signal that is received on a selected channel. The converter circuit includes a sample clock that is used to convert the analog signal to a digital signal at a conversion rate corresponding to the frequency of the sample clock. The sample clock is selectable between at least two different clock frequencies.
    Type: Grant
    Filed: June 10, 2013
    Date of Patent: September 23, 2014
    Assignee: Marvell International Ltd.
    Inventors: King Chun Tsai, Patrick Clement, David Cousinard
  • Patent number: 8842770
    Abstract: A method is for decoding a pulse signal modulated through a transmitted reference modulation scheme. The modulated pulse signal may include, repetitively, a reference pulse followed by an information pulse delayed with a delay. The method may include subtracting or adding from the modulated pulse signal, a version of the modulated pulse signal delayed with the delay for obtaining a processed signal, and performing a non-coherent detection on the processed signal.
    Type: Grant
    Filed: April 17, 2013
    Date of Patent: September 23, 2014
    Assignee: STMicroelectronics N.V.
    Inventors: Gian Mario Maggio, Chiara Cattaneo, Philippe Rouzet
  • Patent number: 8837613
    Abstract: The present invention relates to orthogonal frequency-division multiplexing (OFDM) communication systems with multiple transmit antennas receive antennas, and in particular to methods for inserting scattered pilots (SPs) into the transmit signals of such OFDM systems, for estimating channel properties on the basis of the scattered pilots, a multi-antenna OFDM transmitter, and an OFDM receiver. In this context, it is the particular approach of the present invention to keep the same SP pattern like in the single-transmitter case, to partition the pilots into as many subsets as there are transmitters (transmit antennas), and to interleave these subsets both in time and in frequency. In this manner, the granularity of pilots of the same subset is reduced. This offers increased flexibility in designing the scattered pilot patterns and greater accuracy of the estimated channel properties.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: September 16, 2014
    Assignee: Panasonic Corporation
    Inventors: Mihail Petrov, Tomohiro Kimura, Mikihiro Ouchi
  • Patent number: 8837641
    Abstract: The present invention provides a digital broadcast receiver which reduces the time needed for channel scans by performing efficient channel scanning when broadcasts in a plurality of broadcast protocols are received. As a first phase channel scan, a first controller and a second controller divide a plurality of channels included in an overlapping frequency band of a first broadcast protocol and a second broadcast protocol, and execute parallel channel scans. After the first phase channel scan, the first controller scans channels in which electrical signals generated from electromagnetic waves received by a second tuner in the first phase channel scan could not be demodulated by a second demodulator, and the second controller scans channels in which electrical signals generated from electromagnetic waves received by a first tuner could not be demodulated by a first demodulator.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: September 16, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Keiichi Shirasuka, Soichiro Matsumoto
  • Patent number: 8837625
    Abstract: A method of transmitting control information in a wireless communication system is provided. The method includes configuring downlink control information including a plurality of information fields according to a format of scheduling for transmission of a single codeword in a spatial multiplexing mode, wherein the plurality of information fields include a precoding matrix indicator (PMI) confirmation filed for indicating whether precoding is performed on downlink data by using a PMI reported by a user equipment and a transmitted precoding matrix indicator (TPMI) information field for indicating a codebook index, and at least one of the PMI confirmation field and the TPMI information field indicates an offset value of power for the downlink data transmission or interference information for the downlink data transmission, and transmitting the downlink control information.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: September 16, 2014
    Assignee: LG Electronics Inc.
    Inventors: Hyun Soo Ko, Jaho Koo, Jae Hoon Chung, Moon Il Lee
  • Publication number: 20140254722
    Abstract: A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal.
    Type: Application
    Filed: May 30, 2014
    Publication date: September 11, 2014
    Applicant: Microsoft Corporation
    Inventors: Bradley John Morris, Arthur Thomas Gerald Fuller
  • Patent number: 8831141
    Abstract: A leading edge associated with a received signal is detected to provide, for example, time of arrival information for a ranging algorithm. In some aspects, a method of leading edge detection involves sampling a received signal, generating a drift compensated signal based on the samples, reconstructing the received signal based on the drift compensated signal, and identifying a leading edge associated with the received signal based on the reconstructed signal.
    Type: Grant
    Filed: September 22, 2010
    Date of Patent: September 9, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Petru Cristian Budianu, Amal Ekbal, David Jonathan Julian
  • Patent number: 8831155
    Abstract: A method of identifying radar in a wireless device includes detecting an event corresponding to receipt of a signal by the wireless device. The event can include an analog to digital converter (ADC) saturation, a radio frequency (RF) saturation, and/or an ADC power high condition. Notably, the gain change in the wireless device is delayed for a first predetermined time period. Data preceding the event for the first predetermined time period can be buffered. A first low-resolution fast Fourier transform (FFT), wherein low-resolution FFTs are referred to as short FFTs, can be performed with the buffered data. The first short FFT can be processed. When results of the processing indicate the signal is radar, the radar can then be identified.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: September 9, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Tevfik Yucek, Kai Shi, Susinder Rajan Gulasekaran, Richard Melvin Mosko, Jr.
  • Patent number: 8824533
    Abstract: It is disclosed a method including transmitting indication information indicating network cells of a first type different from network cells of a second type, the transmitting including a) broadcasting control information, the indication information to be transmitted being an indication flag, b) assigning a set of synchronization information to the network cells of the first type, and broadcasting control information, the indication information to be transmitted being the synchronization information, c) reserving at least one signaling code information for the network cells of the first type, the indication information to be transmitted being the signaling code information, d) transmitting signaling information subjected to modulation by at least one predefined phase modulation or scrambling by at least one predefined scrambling sequence, the modulation or scrambling being indicative of network cells of the first and second types, and/or e) transmitting i) a PSS and a RS, ii) a SSS and a RS, or iii) a PSS and
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: September 2, 2014
    Assignee: Nokia Siemens Networks Oy
    Inventors: Mieszko Chmiel, Juergen Michel, Bernhard Raaf
  • Patent number: 8817936
    Abstract: A system for synchronizing IQ demodulators includes IQ demodulators, phase-controlling devices, a reference signal, a phase detector, and a control device. The phase-controlling devices are each associated with one of the IQ demodulators for outputting an output signal to its associated IQ demodulator having a phase controlled by the associated phase-controlling device. The phase detector is in communication with the output signals for determining whether the phase of any of the output signals is out-of-phase with a reference phase of the reference signal. The control-device is in communication with the phase-controlling devices programmed, internally or externally, to send a control signal to the associated phase-controlling device for any of the output signals which are out-of-phase with the reference phase of the reference signal so that the associated phase-controlling device synchronizes the phase of the output signal to being in-phase with the reference phase of the reference signal.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: August 26, 2014
    Assignee: The Boeing Company
    Inventor: David Charles Dominguez
  • Patent number: 8817911
    Abstract: Wireless communication wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. An encoding operation encodes and outputs transmitting data (bit string) and a bit converting operation converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’. A modulating operation modulates the bit string inputted from the bit converting operation by using a single modulation mapper and a plurality of data symbols are generated.
    Type: Grant
    Filed: November 4, 2013
    Date of Patent: August 26, 2014
    Assignee: Panasonic Intellectual Property Corporation of America
    Inventors: Kenichi Miyoshi, Hidetoshi Suzuki, Katsuhiko Hiramatsu, Christian Wengerter, Alexander Golitschek Edler von Elbwart
  • Patent number: 8817910
    Abstract: Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. These are used to provide differing BER performances among bits sent from a transmitter to a receiver.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: August 26, 2014
    Assignee: Blackberry Limited
    Inventors: Shouxing Qu, Yan Xin, Johanna Lisa Dwyer, Paul Carpenter
  • Patent number: 8817915
    Abstract: A wideband microwave digital receiver comprises an antenna, an amplifier, and a digital IFM device for measuring the frequency of the received signal or signals. A consistency indicator indicates the consistency of the frequency measurements and is calculated by analyzing the values taken by said measurements obtained over two consecutive transforms. The presence of signal pulses at the input of the receiver is detected when said indicator signals the consistency of at least one frequency measurement.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: August 26, 2014
    Assignee: Thales
    Inventor: Thierry Briand
  • Patent number: 8817916
    Abstract: Methods and apparatus are provided for performing log-likelihood ratio (LLR) computations in a pipeline. Portions of a metric used to compute LLR values are computed in one pipeline part. The portions correspond to all permutations of some received signal streams. The portions are combined with one permutation x2 of the received signal stream that was not included in the previous pipeline computation in a subsequent pipeline part to produce M values associated with a particular bit position. At each subsequent clock cycle, a different permutation of x2 is combined with the previously computed portions producing different M values. State values corresponding to different values of bit positions of the received stream are computed by finding the minimum among the M values, in each clock cycle, that affect a particular bit position. The state values are combined to compute the LLR values for the bit position in a final pipeline part.
    Type: Grant
    Filed: October 28, 2013
    Date of Patent: August 26, 2014
    Assignee: Marvell International Ltd.
    Inventors: Konstantinos Sarrigeorgidis, Yanni Chen, Leilei Song, Kedar Shirali
  • Patent number: 8817895
    Abstract: An apparatus includes a digital data transmitter capable of sequentially exciting different sets of one or more propagation modes in a physical communication channel. Each set of one or more propagation modes has a different spatial distribution of transmitted energy in the channel. The digital data transmitter is configured to sequentially change the excited set of one or more propagation modes to transmit a different value of data to the communication channel.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: August 26, 2014
    Assignee: Alcatel Lucent
    Inventor: Peter J. Winzer
  • Patent number: 8811540
    Abstract: A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal.
    Type: Grant
    Filed: June 11, 2013
    Date of Patent: August 19, 2014
    Assignee: Microsoft Corporation
    Inventors: Bradley John Morris, Arthur Thomas Gerald Fuller
  • Patent number: 8811537
    Abstract: Provided are a receiving apparatus and method for a wireless communication system using multiple antennas. A receiving method for a wireless communication system using multiple paths, the receiving method comprising: receiving signals through a predetermined number of multiple paths; sensing a carrier according to saturation state degrees of the signals, and providing saturation state information; calculating automatic gain components of the received signals by using the received signals and the saturation state information of the received signals; and performing a noise matching process to amplify noises on the predetermined multiple paths according to the automatic gain components during a predetermined period.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: August 19, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Il-Gu Lee, Jung-Bo Son, Je-Hun Lee, Eun-Young Choi, Sok-Kyu Lee
  • Patent number: 8811543
    Abstract: Disclosed are a receiving apparatus and a receiving method. More particularly, disclosed are a receiving apparatus and a receiving method in an OFDM system. The receiving apparatus in the OFDM system includes a receiver for receiving wireless signals transmitted through wireless channels, a transformer for transforming the wireless signals into signals of a frequency domain, an inverse transformer for inversely transforming reference signals into signals of a time domain based on a number of reference signals included in the signals of the frequency domain and an arrangement interval of the reference signals included in the signals of the frequency domain, and a determiner for determining a delay spread based on the inversely transformed signals of the time domain.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: August 19, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Young Ha Lee, Hye Kyung Jwa, Dae Ho Kim
  • Patent number: 8811536
    Abstract: A system and method for receiving a radio frequency signal, comprising a device for digitizing, without prior alteration of frequency, an analog radio frequency representation of each of a plurality of radio frequency signals to produce a respective plurality of digital radio frequency signals having a respective associated radio frequency digital clock, the plurality of digital radio frequency signals having a sufficiently high respective associated clock rate to preserve an information content of an information communication present in the analog radio frequency representation; a switch matrix adapted to concurrently switch the plurality of digital radio frequency signals and associated digital radio frequency clock to ones of a plurality of digital signal processors; and a control adapted to selectively automatically control the concurrent switching of a plurality of digital signals and associated digital clock to the respective plurality of digital signal processors; wherein the digital signal processors
    Type: Grant
    Filed: June 6, 2013
    Date of Patent: August 19, 2014
    Assignee: Hypres Inc.
    Inventor: Deepnarayan Gupta
  • Patent number: 8804859
    Abstract: An apparatus of processing a time domain synchronous orthogonal frequency-division-multiplexing (TDS-OFDM) signal is provided. The apparatus includes a receiving block and a demodulating block. The receiving block receives the TDS-OFDM signal, and generates a down-converted signal according to the received TDS-OFDM signal. The demodulating block is coupled to the receiving block, and demodulates the down-converted signal to generate a transport stream. The demodulating block has a transmission parameter signaling (TPS) decoder implemented for performing a TPS decoding operation to generate a TPS decoding result and verifying a spectrum direction of the received TDS-OFDM signal according to the TPS decoding result.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: August 12, 2014
    Assignee: MediaTek, Inc.
    Inventor: Shun-An Yang
  • Patent number: 8804875
    Abstract: Compressing a variable phase component of a received modulated signal with a second harmonic injection locking oscillator, and generating a delayed phase-compressed signal with a fundamental injection locking oscillator, and combining the phase-compressed signal and the delayed phase-compressed signal to obtain an estimated derivative of the variable phase component, and further processing the estimated derivative to recover data contained within the received modulated signal.
    Type: Grant
    Filed: June 24, 2013
    Date of Patent: August 12, 2014
    Assignee: Innophase Inc.
    Inventors: Yang Xu, Sara Munoz Hermoso
  • Patent number: 8805554
    Abstract: A notch filter includes first, second, and third difference modules, a delay module, and a gain module. The first difference module calculates a first difference between a control signal in a pulse width modulation (PWM) system and a feedback value. The second difference module calculates a second difference between the first difference and a delayed second difference. The delay module generates the delayed second difference by introducing a one period delay to the second difference, wherein the period is based on a Nyquist frequency of the control signal. The gain module generates the feedback value by applying a gain to the delayed second difference. The third difference module generates a filtered control signal by calculating a difference between the signal and the feedback value, wherein the filtered control signal is used to control an operating parameter of the PWM system.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: August 12, 2014
    Assignee: Maxim Integrated Products, Inc.
    Inventors: Paul Walker Latham, II, Stewart Gall Kenly, II, Mansur Kiadeh
  • Patent number: 8792591
    Abstract: Disclosed herein are systems and methods for accurate removal of I/Q mismatch in received signals of an analog FM receiver. The analog FM receiver includes a down-converter, a calibration circuit that estimates I/Q mismatch values, and a compensation circuit that uses the estimated mismatch values to reduce the effects of I/Q mismatch. In one aspect, the calibration circuit uses an adaptive dual-parameter compensation scheme to iteratively correct the received signals by approximating a coefficient value and an amplitude value that minimize the signals' amplitude variation from the amplitude value. In another aspect, phase and amplitude mismatch parameters can be determined using the coefficient value.
    Type: Grant
    Filed: November 3, 2011
    Date of Patent: July 29, 2014
    Assignee: Marvell International Ltd.
    Inventor: Chris Cheng-Chieh Lee
  • Patent number: 8787505
    Abstract: A system including a differential demodulation module that generates differentially demodulated signals based on having differentially demodulated received signals. A first summing module generates a combined signal, including a plurality of symbols, by adding the differentially demodulated signals. A second summing module generates a plurality of sums for each of a plurality of derived preamble sequences, which are derived from preamble sequences. Each of the derived preamble sequences includes a plurality of derived symbols. One of the plurality of sums generated for one of the derived preamble sequences is a sum of a first portion of one of the plurality of symbols of the combined signal and a second portion of one of the derived symbols of the one of the derived preamble sequences.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: July 22, 2014
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Hui-Ling Lou
  • Patent number: 8781050
    Abstract: Provided is a symbol timing estimating apparatus and method that may generate at least one sampled preamble signal by sampling a preamble signal with changing a phase of the preamble signal based on a symbol speed, calculate a power value of each of the at least one sampled preamble signal, and estimate a symbol timing of a sampled preamble signal having a maximum power value by comparing each power value among the at least one sampled preamble signal.
    Type: Grant
    Filed: September 9, 2010
    Date of Patent: July 15, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventor: Jae-Ho Lee
  • Publication number: 20140192933
    Abstract: Exemplary embodiments relates to a demodulator for frequency-shift keyed signals by using the Goertzel algorithm according to the general recursive calculating rule, where c re = 2 * cos ? ( 2 * ? * f g f s ) with the sampling frequency fs and the specified frequency fg. To reduce the mathematical complexity in feed-power-limited devices, it is proposed that the sampling frequency fs is an integral multiple of the frequency fg of a specified discrete spectral component.
    Type: Application
    Filed: January 10, 2014
    Publication date: July 10, 2014
    Applicant: ABB Technology AG
    Inventor: Stefan POOK
  • Patent number: 8774288
    Abstract: A receiver includes a positive pulse determination circuit and a negative pulse determination circuit. The positive pulse determination circuit outputs a first L-level between when a pulse signal having a negative amplitude is detected and when neither a pulse signal having a positive amplitude nor a pulse signal having a negative amplitude is detected; otherwise a first H-level if a pulse signal having a positive amplitude is detected during another period. The negative pulse determination circuit outputs a second L-level between when a pulse signal having a positive amplitude is detected and when neither a pulse signal having a positive amplitude nor a pulse signal having a negative amplitude is detected; otherwise a second H-level is output if a pulse signal having a negative amplitude is detected during the other period.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: July 8, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Koichi Takeda, Shunichi Kaeriyama
  • Patent number: 8774320
    Abstract: Consistent with the present disclosure, optical signals are modulated in accordance with a higher order QAM modulation format, such as 8-QAM, to carry customer data, for example. The optical signals are converted to corresponding electrical signals, which are then subject to further processing. In particular, phase data associated with the higher order QAM constellation is processed, such that the outer points of the constellation are rotated to have the same phase as the inner points. As a result, both the inner and outer points resemble a constellation, and both may be more readily processed using feedforward or feedback carrier recovery. After such carrier recovery, the phase data is further processed so that the outer points are rotated back and the customer data can be extracted from the phase data.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: July 8, 2014
    Inventors: Han Henry Sun, Kuang-Tsan Wu
  • Patent number: 8774710
    Abstract: A method for setting a signal detection threshold according to one embodiment includes determining a measure of a noise floor in a signal derived from a radio frequency signal received by an antenna using a same circuit used to detect a subcarrier signal during transmitting and prior to sending a command to a transponder to respond; and setting a signal detection threshold above the noise floor. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented.
    Type: Grant
    Filed: June 21, 2011
    Date of Patent: July 8, 2014
    Assignee: Intelleflex Corporation
    Inventors: Dean Kawaguchi, Manu H. R. Rao
  • Patent number: 8774321
    Abstract: A clock data recovery circuit includes: a demodulation filter that receives a transmission signal transmitted by two orthogonal carrier waves having I and Q phases and executes demodulation to obtain a demodulated wave having an phase and a demodulated wave having a Q phase from the transmission signal; a first determination circuit that determines whether an absolute value of one of the two demodulated waves is greater than an eye opening maximum value at an ideal clock phase of the transmission signal; a second determination circuit that determines whether the one demodulated wave is greater than zero; a third determination circuit that determines whether the other one of the two demodulated waves is greater than zero; and a phase comparison unit that detects whether a phase of a clock signal included in the transmission signal is leading a phase of a data signal included in the transmission signal, based on determination results obtained by the first to third determination circuits.
    Type: Grant
    Filed: September 7, 2010
    Date of Patent: July 8, 2014
    Assignee: NEC Corporation
    Inventors: Kazuhisa Sunaga, Kouichi Yamaguchi
  • Patent number: 8767844
    Abstract: A data processing device (100, 300) is described forming part of a receiver for a multicarrier communications system. The data processing device is configured to process at least one observed symbol to generate an information bit estimate for the symbol, and includes a channel prediction stage configured to receive an observed symbol and at least one feedback signal representing an estimate of a transmitted symbol and to generate a channel prediction. At least one initial processing stream (104) is configured to process the observed symbol on the basis of a channel prediction calculated at a respective time by the channel prediction stage and to output a signal representing an estimate of a transmitted symbol corresponding to the observed symbol for feed back into the channel prediction stage.
    Type: Grant
    Filed: May 24, 2007
    Date of Patent: July 1, 2014
    Assignee: Cohda Wireless Pty. Ltd.
    Inventors: Paul Dean Alexander, Alexander James Grant, David Victor Lawrie Haley
  • Patent number: 8767891
    Abstract: A reception signal integrating method includes: calculating, in receiving a satellite signal, when a reception signal of the satellite signal is time-divided at an assumed period obtained by estimating code period time of a spread code of the satellite signal, a coefficient representing a period shift between a true period and the assumed period of the spread code using first portions and second portions having an assumed period different from that of the first portions in the reception signal; and integrating the reception signal using the coefficient.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: July 1, 2014
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Yamagata, Norio Teruuchi
  • Patent number: 8767881
    Abstract: A signal processing apparatus is disclosed which includes: a detection section configured such that based on a result of the error correction of a signal generated by a single carrier system, the detection section detects the presence or absence of spectrum inversion in the signal; and a selection section configured such that if the detection section detects the spectrum inversion, the selection section selects the spectrally inverted signal as the signal subject to the error correction, and that if the detection section does not detect the spectrum inversion, then the selection selects the spectrally uninverted signal as the signal subject to the error correction.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: July 1, 2014
    Assignee: Sony Corporation
    Inventors: Takashi Yokokawa, Ryoji Ikegaya, Yuji Shinohara
  • Publication number: 20140177758
    Abstract: A timing recovery apparatus for compensating a sampling frequency offset of an input signal is provided. The timing recovery apparatus includes a timing error corrector configured to generate an output signal according to the input signal and a calibration signal, a gain controller configured to adjust at least one of a signal edge low-frequency error component and a signal edge high-frequency error component of the output signal and accordingly generate an adjusted signal, a timing error detector configured to generate an error signal according to the adjusted signal, and a calibration signal generator coupled to the timing error detector and the timing error corrector, for generating the calibration signal according to the error signal and outputting the calibration signal to the timing error corrector to compensate the sampling frequency offset of the input signal.
    Type: Application
    Filed: December 18, 2013
    Publication date: June 26, 2014
    Applicant: MStar Semiconductor, Inc.
    Inventors: Ko-Yin Lai, Chun-Chi Su, Chih-Cheng Kuo, Chia-Sheng Peng
  • Patent number: 8760334
    Abstract: In an ultra-wideband (“UWB”) receiver, a received UWB signal is periodically digitized as a series of ternary samples. The samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, estimates of the channel impulse response (“CIR”) are developed. When a start-of-frame delimiter (“SFD”) is detected, the best CIR estimate is provided to a channel matched filter (“CMF”) substantially to filter channel-injected noise.
    Type: Grant
    Filed: February 25, 2013
    Date of Patent: June 24, 2014
    Assignee: DecaWave Ltd.
    Inventors: Michael McLaughlin, Ciaran McElroy, Sinbad Wilmot, Tony Proudfoot
  • Patent number: 8761277
    Abstract: Channel estimation for high mobility OFDM channels is achieved by identifying a set of channel path delays from an OFDM symbol stream including carrier data, inter-channel interference noise and channel noise; determining the average channel impulse response for the identified set of channel path delays in each symbol; generating a path delay curvature for each channel path delay in each symbol based on stored average channel impulse responses for the identified channel path delays; estimating the carrier data in the symbols in the OFDM symbol stream in the presence of inter-channel interference noise and channel noise from the OFDM symbol steam and the average impulse responses for the identified channel path delays; reconstructing the inter-channel interference noise in response to the path delay curvature, the identified set of channel path delays and estimated carrier data to produce a symbol stream of carrier data and channel noise with suppressed inter-channel interference noise.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: June 24, 2014
    Assignee: Analog Devices, Inc.
    Inventors: Haim Primo, Yosef Stein, Wei An
  • Publication number: 20140169502
    Abstract: A receiver receives payload data from a downstream signal, and includes a filter to receive the downstream signal, and including signalling data identifying downstream resources for the payload data, and an analogue to digital converter to receive the downstream signal from the filter and to convert it into a sampled digital form. A demodulator demodulates the digital form of the downstream signal to recover the payload data and the signalling data. The signalling data includes a mode switch signal to indicate an active mode or a sleep mode for the receiver. A controller detects the mode switch signal to control the analogue to digital converter to switch sampling rates in response thereto, and to control the filter to switch frequency bands. The frequency bands perform anti-alias filtering for respective sampling rates.
    Type: Application
    Filed: October 15, 2013
    Publication date: June 19, 2014
    Applicant: Sony Corporation
    Inventor: Martin Lovell
  • Patent number: 8755471
    Abstract: The present invention provides a method and apparatus for autonomously detecting whether a reference signal within an OFDM signal transmitted by a remote transmitter is or is not muted for a given transmission time. Muting or puncturing may be applied to all or only a portion of the reference signal. The method, which may be carried out in an appropriately configured radio apparatus, includes receiving the OFDM signal and calculating a first comparison metric from signal samples of the OFDM signal corresponding to a first set of resource elements of the OFDM signal, and calculating a second comparison metric from signal samples of the OFDM signal corresponding to a second set of resource elements of the OFDM signal.
    Type: Grant
    Filed: October 11, 2010
    Date of Patent: June 17, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Muhammad Kazmi, Iana Siomina
  • Patent number: 8750441
    Abstract: A method includes obtaining an input signal and demodulating phase contamination in the input signal to generate a baseband signal. The method also includes modulating the input signal based on the baseband signal to generate an output signal, where the output signal has less phase contamination than the input signal. The phase contamination could be demodulated using a phase demodulator or a frequency modulation (FM) detector. A portion of the input signal could be down-converted to a lower frequency, and the phase contamination in the down-converted portion of the input signal could be demodulated. Additional phase contamination in the output signal can be demodulated and used to regulate a level of the baseband signal used during modulation of the input signal. The output signal could have less phase noise or period jitter than the input signal.
    Type: Grant
    Filed: December 19, 2011
    Date of Patent: June 10, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Lawrence H. Zuckerman
  • Patent number: 8750433
    Abstract: A demodulation circuit includes a hard decision process unit and a soft decision process unit. The hard decision process unit is configured to perform a hard decision process using a demodulated signal, and the demodulated signal is a demodulated received signal. The soft decision process unit is configured to determine a range of assignment with respect to a transitioning part in the demodulated signal, calculate a likelihood value of a bit, and perform a soft decision process.
    Type: Grant
    Filed: April 9, 2012
    Date of Patent: June 10, 2014
    Assignee: Fujitsu Limited
    Inventors: Naoto Adachi, Masataka Umeda
  • Patent number: 8750425
    Abstract: A method for identifying the modulation scheme of a software defined radio in real-time without pilot symbols between transmitters and receivers, includes providing a predetermined look-up table (LUT) in the software-defined radio wherein the LUT is prepared by pre-calculating discrete likelihood ratio test (DLRT) function values; storing the pre-calculated DLRT values in said LUT; and indexing the pre-calculated DLRT values by addresses.
    Type: Grant
    Filed: May 3, 2012
    Date of Patent: June 10, 2014
    Assignee: The United States of America, as represented by the Secretary of the Army
    Inventor: Wei Su
  • Patent number: 8750406
    Abstract: One embodiment relates to a receiver circuit for multi-level amplitude signaling which includes at least three amplitude levels for each symbol period. The receiver circuit includes a peak detector, a reference voltage generator, and a comparator circuit. The peak detector is arranged to detect a peak voltage of the multi-level amplitude signal, and the reference voltage generator uses the peak voltage to generate multiple reference voltages. The comparator circuit uses the multiple reference voltages to detect an amplitude level of the multi-level amplitude signal. Other embodiments and features are also disclosed.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: June 10, 2014
    Assignee: Altera Corporation
    Inventors: Mingde Pan, Weiqi Ding, Sergey Shumarayev, Peng Li, Masashi Shimanouchi
  • Patent number: 8750362
    Abstract: A method, apparatus and computer program product are configured to provide calibration accuracy in an analog filter. In this regard, a method is provided that includes estimating a cutoff frequency for an analog filter. The method further includes causing a filter tuning word to be modified based on the estimated cutoff frequency for the analog filter. The method also includes determining a residual cutoff frequency mismatch for the analog filter. The method also includes causing an equalizer configuration to be selected for a digital filter based on the determined residual cutoff frequency mismatch.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: June 10, 2014
    Assignee: Broadcom Corporation
    Inventors: Markus Nentwig, Aarno Parssinen
  • Patent number: 8743939
    Abstract: A nonlinear echo compensator comprises a mapping circuit that includes a weighting circuit that generates a weighted signal based on a current symbol and a prior symbol and a function generating circuit that selects one of N functions based on the weighted signal, where N is an integer greater than one. The mapping circuit generates a driving signal based on the selected one of the N functions and the weighted signal. A canceling circuit generates a nonlinear echo compensation signal based on the driving signal.
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: June 3, 2014
    Assignee: Marvell International Ltd.
    Inventors: Xiaopeng Chen, Runsheng He, Shuran Wei