Particular Demodulator Patents (Class 375/324)
  • Patent number: 8005315
    Abstract: A spread spectrum signal demodulating method whereby spread-code synchronous acquisition and carrier synchronous acquisition are performed using FFT at high speed, wherein a received signal, of which the carrier wave is modulated with a signal obtained by spectrum-spreading data with a spread code, is subjected to the FFT and the result of the FFT is stored in a first memory. The FFT result of the received signal stored in the first memory and the result of FFT of the spread code stored in a second memory are read out and multiplied to detect the correlation between the received signal and the spread code. A readout address of either the FFT result of the received signal or the FFT result of the spread code is shifted by an amount corresponding to a carrier frequency of the received signal.
    Type: Grant
    Filed: September 23, 2009
    Date of Patent: August 23, 2011
    Assignee: Sony Corporation
    Inventor: Katsuyuki Tanaka
  • Patent number: 8000411
    Abstract: A method and apparatus for decoding encoded data bits of a wireless communication transmission are provided. A set of a-priori bit values corresponding to known bit values of the encoded data bits may be generated. Decoding paths that correspond to decoded data bits that are inconsistent with the a-priori bit values may be removed from the possible decoding paths to consider, and decoding the encoded data bits by selecting a decoding path from remaining decoding paths of the possible decoding paths that were not removed. Multiple hypotheses, each corresponding to a different set of a-prior bit values may be evaluated, with the decoded data for a hypothesis selected based on the evaluation output for further processing.
    Type: Grant
    Filed: January 4, 2008
    Date of Patent: August 16, 2011
    Assignee: Qualcomm Incorporated
    Inventors: Jong Hyeon Park, Bok Tae Sim, Je Woo Kim, Serguei A. Glazko, Sameer Nanavati, Ju Won Park, Chun Woo Lee, Tae Ryun Chang
  • Patent number: 8000401
    Abstract: A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.
    Type: Grant
    Filed: September 4, 2009
    Date of Patent: August 16, 2011
    Assignee: LG Electronics Inc.
    Inventors: Moon-Il Lee, Bin-Chul Ihm, Jin-Young Chun, Jae-Won Chang, Jin-Hyuk Jung
  • Patent number: 8000382
    Abstract: Certain aspects and embodiments provide for accurate measurement and estimation of imbalances between in-phase (I) and quadrature (Q) components of a complex baseband signal. The accuracy of I/Q phase imbalance estimates may be enhanced by conducting them on a transmitter and a receiver that are connected via a local, loopback connection and by removing cross-spectrum interference in transferred packets. Once these accurate I/Q phase imbalances are determined, they may be used to adjust a signal processed by the transmitter or the receiver to increase the performance and data throughput of communications using the signal.
    Type: Grant
    Filed: January 4, 2008
    Date of Patent: August 16, 2011
    Assignee: Qualcomm Incorporated
    Inventors: Hakan Inanoglu, Leon Metreaud, Mark S. Wallace, Xiangdong Zhang
  • Patent number: 7995860
    Abstract: A spread spectrum signal demodulating method whereby spread-code synchronous acquisition and carrier synchronous acquisition are performed using FFT at high speed, wherein a received signal, of which the carrier wave is modulated with a signal obtained by spectrum- spreading data with a spread code, is subjected to the FFT and the result of the FFT is stored in a first memory. The FFT result of the received signal stored in the first memory and the result of FFT of the spread code stored in a second memory are read out and multiplied to detect the correlation between the received signal and the spread code. A readout address of either the FFT result of the received signal or the FFT result of the spread code is shifted by an amount corresponding to a carrier frequency of the received signal.
    Type: Grant
    Filed: September 23, 2009
    Date of Patent: August 9, 2011
    Assignee: Sony Corporation
    Inventor: Katsuyuki Tanaka
  • Patent number: 7995679
    Abstract: Provided are a method and system for digitizing a sensor model output signal. The system includes a filter, a demodulator coupled to the filter, a DC offset cancellation mechanism coupled to the demodulator, and an analog to digital converter (ADC). The ADC is directly coupled to the demodulator and the DC offset cancellation mechanism.
    Type: Grant
    Filed: April 27, 2005
    Date of Patent: August 9, 2011
    Assignee: Broadcom Corporation
    Inventors: Sumant Ranganathan, Tom W. Kwan, Hung-Sung Li
  • Publication number: 20110188613
    Abstract: Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B99Tb.
    Type: Application
    Filed: February 1, 2010
    Publication date: August 4, 2011
    Inventors: Eric Morgan Dowling, John P. Fonseka
  • Patent number: 7991080
    Abstract: A radio frequency identification (RFID) decoding subsystem includes a pre-decode module and a decode module. The pre-decode module is coupled to process down-converted RFID signals into pre-decoded baseband data. The decode module is coupled to: enable a counting process based on the pre-decoded baseband data to produce a count resultant; and compare the count resultant with a threshold at a data bit interval to produce decoded RFID data.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: August 2, 2011
    Assignee: Broadcom Corporation
    Inventors: Kambiz Shoarinejad, Ahmadreza (Reza) Rofougaran
  • Publication number: 20110182329
    Abstract: A device for decoding code symbols which are interfered with a distortion during a predetermined distortion time interval includes a reliability information generator to provide reliability information based on the code symbols and a decoder to decode the code symbols into code words. The decoder is configured to decode the code symbols based on weighted reliability information, wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval.
    Type: Application
    Filed: January 25, 2010
    Publication date: July 28, 2011
    Applicant: Infineon Technolongies AG
    Inventor: Joachim Wehinger
  • Patent number: 7986754
    Abstract: An apparatus including a first circuit, a second circuit, a third circuit, and a fourth circuit. The first circuit may be configured to generate a demodulated signal in response to a modulated signal and a seed value selected in response to a first control signal. The second circuit may be configured to generate a second control signal in response to the demodulated signal. The third circuit may be configured to generate the first control signal in response to the second control signal, a compensation signal, and the first control signal, where generation of the first control signal includes adding the second control signal, the compensation signal, and a latched version of the first control signal. Generation of the latched version of the first control signal may include sampling the first control signal in response to a clock signal. The compensation signal may compensate for variation in the clock signal.
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: July 26, 2011
    Assignee: LSI Corporation
    Inventor: Dean L. Raby
  • Patent number: 7978789
    Abstract: An FSK modulator and applications thereof are disclosed. The FSK modulator comprises a phase-locked loop, a frequency divider module, an image rejection mixer and a summing module. The phase-locked loop is operably coupled to generate a first oscillation from a reference oscillation. The frequency divider module is operably coupled to divide the first oscillation to produce a second oscillation. The image-rejection mixer is operably coupled to mix the second oscillation with a low intermediate oscillation to produce a mixed data signal, and the summing module is operably coupled to sum the mixed data signal with the first oscillation to produce an FSK modulated signal.
    Type: Grant
    Filed: June 18, 2008
    Date of Patent: July 12, 2011
    Assignee: Broadcom Corporation
    Inventors: Tom Baker, Henrik T. Jenson
  • Patent number: 7978799
    Abstract: A complex signal in which one of two signals that have been generated from a single real signal and that have phases that are shifted 90° with respect to each other is a real part and the other signal is an imaginary part is applied as input to an input terminal. A filter unit generates an output signal that is a complex signal by means of a convolution operation of the input signal, and a filter coefficient that is a real signal and supplies this output signal to an output terminal. A coefficient control unit made up from a common unit and separate units updates the filter coefficients such that the value of the envelope of the output signal approaches a target signal.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: July 12, 2011
    Assignee: NEC Corporation
    Inventor: Osamu Hoshuyama
  • Patent number: 7978787
    Abstract: It is an object of the present invention to prevent an error or malfunction such as nonresponse which is caused due to difference in pulse width in a semiconductor device capable of communicating data wirelessly. In a semiconductor device, a level shift circuit is provided between a data demodulation circuit and each circuit block where demodulated signals are outputted from the data demodulation circuit. In such a manner, voltage amplitude of the demodulated signal is made almost equal to that of the outputted signals from each circuit block. Accordingly, a pulse width of the demodulated signal is made almost equal to that of signals in each circuit block, or a pulse width of the demodulated signal is made almost equal to that of the outputted signals from each circuit block. Accordingly, it is possible to prevent an error or malfunction such as nonresponse which is caused due to difference in pulse width.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: July 12, 2011
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yutaka Shionoiri, Takanori Matsuzaki
  • Publication number: 20110158353
    Abstract: To detect phase mismatches between in-phase and quadrature signals of a quadrature demodulator. The phase mismatches can be detected using the signals obtained by removing high frequency components of output of a multiplier by a low pass filter, the output being the product of the in-phase signals of which low frequency components are removed by a first high pass filter by the quadrature signals of which low frequency components are removed by a second high pass filter.
    Type: Application
    Filed: March 8, 2011
    Publication date: June 30, 2011
    Inventors: Shigenori HAYASE, Kazuyuki Hori
  • Publication number: 20110158352
    Abstract: A multi-stage demodulation circuit receives a given communication signal modulated by a superposition of at least a first modulation scheme and a second modulation scheme, the circuit having a first demodulation stage that demodulates the received communication signal according to the first demodulation scheme, and generates one or more bits representing the first modulation state of the signal. An intermediate demodulation circuit removes the first modulation from the received communication signal to generate an intermediate demodulation signal having only the second modulation. A second demodulation stage demodulates the intermediate demodulation signal according to the second demodulation scheme and generates one or more additional bits representing the second modulation state of the given communication signal.
    Type: Application
    Filed: December 30, 2009
    Publication date: June 30, 2011
    Applicant: NXP B.V.
    Inventors: Harald Witschnig, Lukas Perktold
  • Patent number: 7970077
    Abstract: A method of estimating a symbol that has been transmitted into a channel connecting a modulator for producing modulation symbols and an equaliser, wherein a channel estimate describes said channel and the method comprises: calculating a metric for each of a number of hypotheses of a sequence commencing with the symbol under estimation followed by a number of subsequently transmitted symbols, each symbol in the sequence occupying a respective node of the sequence; and deeming the symbol at the beginning of the hypothesis that has the best metric to be the symbol under estimation; wherein calculating a metric for a given hypothesis comprises: calculating a discrepancy metric at each node of the given hypothesis; and combining the discrepancy metrics of nodes in the given hypothesis to produce the metric; and wherein a discrepancy metric for a given node of a given hypothesis is an assessment of the difference between: a sample received from said channel at a time point corresponding to said given node; and a sa
    Type: Grant
    Filed: August 7, 2008
    Date of Patent: June 28, 2011
    Assignee: Cambridge Silicon Radio Limited
    Inventor: David F. Chappaz
  • Publication number: 20110142156
    Abstract: A system includes a transmitter device that includes a transmitter baseband controller to segment a bit stream into a first segment, a second segment, and a third segment, and generate a first baseband signal that includes the first segment, a second baseband signal that includes the second segment, and a third baseband signal that includes the third segment; and a radio frequency (RF) transmitter to generate a multi-frequency signal based on the first baseband signal, the second baseband signal, and the third baseband signal; and a receiver device that includes an RF receiver to receive the multi-frequency signal, and retrieve the first baseband signal, the second baseband signal, and the third baseband signal from the received multi-frequency signal; and a receiver baseband control to reassemble the bit stream from the received first baseband signal, the received second baseband signal, and the received third baseband signal.
    Type: Application
    Filed: December 15, 2009
    Publication date: June 16, 2011
    Applicant: SONY ERICSSON MOBILE COMMUNICATIONS AB
    Inventor: Jacobus Cornelis HAARTSEN
  • Publication number: 20110134972
    Abstract: An active antenna, a base station, a method for refreshing the amplitude and phase, and a signal processing method are disclosed to simplify the structure of a phase shifter and guarantee the reliability of the phase shifter. The active antenna or the base station includes an antenna dipole array, a transceiver array, a digital processing unit (DPU), and a transceiving calibration unit.
    Type: Application
    Filed: February 14, 2011
    Publication date: June 9, 2011
    Applicant: HUAWEI TECHNOLOGIES CO., LTD.
    Inventors: Yuanrong ZHU, Jianjun CHEN, Zhuobiao HE, Jianfeng WU, Ming XU, Yi ZHANG, Yuntao ZHU, Pinghua HE
  • Patent number: 7957491
    Abstract: Methods and systems for filtering include accessing first and second signals produced from an input signal and producing first and second filtered outputs, which correspond to the first and second signals, based on a filtering characteristic. The filtering characteristic can include a first filtering coefficient weighting the first and second signals. The filtering characteristic can include a second filtering coefficient weighting third and fourth signals, the third and fourth signals being produced prior to the first and second signals. The first and second filtering coefficients can include matrices which have non-symmetrical terms.
    Type: Grant
    Filed: November 4, 2009
    Date of Patent: June 7, 2011
    Assignee: Marvell International Ltd.
    Inventor: Runsheng He
  • Patent number: 7957482
    Abstract: Transmit diversity system in which constellation rearrangement is used. Both diversity signals contain the same data and both are 16-QAM, but the location of the data bits within the constellation is different. This averages the effect of the different levels of reliability of the different constellation points. A method for modifying a quadruple of data bits in a data transmission system using Quadrature. Amplitude Modulation with 16 different modulation states, 16-QAM, using an Antipodal Inverted Constellation AICO) mapping, swapping bits selecting contiguous symbol regions with bits selecting non-contiguous symbol regions. Depending on the particular pre-defined mapping and on the particular permutation of bits, inversion of selected bits may be performed in addition. The quadruples thus obtained are mapped to modulation symbols according to a pre-defined AICO mapping.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: June 7, 2011
    Assignee: Panasonic Corporation
    Inventors: Alexander Golitschek Edler Von Elbwart, Christian Wengerter, Isamu Yoshii
  • Publication number: 20110129008
    Abstract: It is disclosed a method comprising including transmitting indication information indicating network cells of a first type different from network cells of a second type, the transmitting comprising 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
    Type: Application
    Filed: June 24, 2008
    Publication date: June 2, 2011
    Inventors: Mieszko Chmiel, Juergen Michel, Bernhard Raaf
  • Patent number: 7952990
    Abstract: Methods and systems for communication include receiving a signal across a channel, the signal indicative of a preamble and multiple data symbols, determining first channel estimate information of the channel based on the received preamble, using the first channel estimate information to demodulate a data symbol from the multiple data symbols as received, determining a constellation point based on the demodulated data symbol to produce a decoded data symbol, determining second channel estimate information based on the demodulated data symbol and the decoded data symbol, and using the second channel estimate information to demodulate an additional data symbol from the multiple data symbols as received.
    Type: Grant
    Filed: December 1, 2009
    Date of Patent: May 31, 2011
    Assignee: Marvell International Ltd.
    Inventors: Hui-Ling Lou, Kok-Wui Cheong
  • Patent number: 7949035
    Abstract: A Global Position System signal acquiring system and method is provided in this invention. Pluralities of counters are set, each corresponding to a code bin and a frequency bin of the signal. Subsequently, the signal corresponding to the counters is repeatedly received in a unit of time and the counters are accordingly updated for a pre-determined iteration. At last, a maximum value among the counters is found to acquire the signal corresponding to the counter having the maximum value.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: May 24, 2011
    Assignee: Via Technologies, Inc.
    Inventor: Fei Su
  • Patent number: 7944997
    Abstract: An m-code GPS receiver receives m-code GPS communication signals having a multimodal autocorrelation, using an m-code mode identifier unambiguously determining a mode value of one of the m-code modal peaks coherently aligned to a coherent unimodal detected envelope, based on sequential probability estimation in an m-code envelope tracking filter using filter residual estimation or with a coherent m-code and c/a-code tracking filter also based on filter residual estimation, for generating m-code phase errors, for unambiguous and precise m-code code phase tracking in closed feedback loops, for preferred use in navigation systems.
    Type: Grant
    Filed: November 2, 2009
    Date of Patent: May 17, 2011
    Assignee: The Aerospace Corporation
    Inventor: Randal K. Douglas
  • Patent number: 7940851
    Abstract: A radio communication apparatus and an associated method are provided. The apparatus includes a receiving unit configured to receive first data and second data, which are transmitted from a plurality of antennas for spatial-multiplexing using a plurality of blocks, into which a plurality of consecutive subcarriers in a frequency domain are divided. The apparatus further includes a calculating unit configured to calculate a first absolute CQI value per each of the blocks for the first data and a second absolute CQI value per each of the blocks for the second data, and calculate a relative value of the second absolute CQI value with respect to the first absolute CQI value, per each of the blocks. The apparatus still further includes a transmitting unit configured to transmit the first absolute CQI value and the relative value of the second absolute CQI value in the same block.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: May 10, 2011
    Assignee: Panasonic Corporation
    Inventors: Jinsong Duan, Keisuke Ebiko, Ryohei Kimura
  • Patent number: 7940639
    Abstract: An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters.
    Type: Grant
    Filed: December 4, 2009
    Date of Patent: May 10, 2011
    Assignee: AT&T Intellectual Property II, L.P.
    Inventor: Diakoumis Gerakoulis
  • Patent number: 7933362
    Abstract: A multilevel symbol timing signal detector is provided, which is used for reliably detecting the symbol timing of a multilevel QAM signal. When an oversampling I signal is inputted to I-Signal Histogram Generator 610, the signal is subjected to 1-symbol length buffering by computing absolute values. Sampling times corresponding to an oversampling frequency and amplitude data for these times are extracted from the buffered data and the amplitude data is buffered for each sampling time over predetermined intervals. Histograms of the amplitude data for each sampling time are generated based on these buffered amplitude data. Symbol timing is acquired by detecting a sampling time corresponding to the amplitude data with the highest frequency of detection based on the histograms of amplitude data.
    Type: Grant
    Filed: December 5, 2005
    Date of Patent: April 26, 2011
    Assignee: Furuno Electric Company Limited
    Inventor: Shinji Tamura
  • Publication number: 20110090991
    Abstract: The present invention discloses a method and apparatus to provide, effectively and robustly, a phase reference in phase-domain for digital phase-modulated signals. Not only the first-order but also higher order PLLs are delineated for robust and fast tracking of frequency errors and time-varying frequency errors between the transmitter and the receiver. This invention can be applied to any phase-modulated signal such as PSK, DPSK, ?/4-DPSK, and CPM. The decoders with this invention can achieve close to the performance of coherent detection. Reference [1] D. Divsalar and M. K. Simon, “Multiple-symbols differential detection of MPSK,” IEEE Trans. Commun., vol. 38, pp. 300-308, March 1990. [2] Specification of the Bluetooth System, 2.0+EDR, 4 Nov.
    Type: Application
    Filed: October 19, 2009
    Publication date: April 21, 2011
    Inventors: Pansop KIM, Jeng-Hong Chen, Hsin-Hsiang Liu
  • Patent number: 7929643
    Abstract: The method is for estimating the fading coefficients of a plurality of transmission channels on which signals to be sent, generated as a function of a sequence of symbols, are transmitted according to a particular modulation, e.g. AM-PSK modulation. The fading coefficients are estimated by using estimations of the transmitted symbols obtained in advance, thus obtaining DC components of the received signal by coherent demodulation locked to the phases of the transmitted AM-PSK signals, and processing these DC components. The method may not require the choice of a stochastic distribution model of the channel fading, thus it remains efficient even when the channel characteristics vary significantly. Moreover, the method works correctly even if the received stream is disturbed by inter-symbolic interference (ISI) and/or by multi-path fading.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: April 19, 2011
    Assignee: STMicroelectronics S.R.L.
    Inventors: Giuseppe Visalli, Giuseppe Avellone
  • Patent number: 7929641
    Abstract: A signals reception chain including: an input interface receiving a signal and transforming the received signal into at least two signals correlated in phase or in opposite phase, each of the correlated signals being distributed on at least one channel, the channels being identical, at least one analog-digital converter that operates on 1 bit of the signals in phase or in opposite phase, on each of the channels, and a digital processor for processing the converted signals stemmed from the channels, and performing operations between the converted signals in phase or in opposite phase.
    Type: Grant
    Filed: January 3, 2007
    Date of Patent: April 19, 2011
    Assignee: Commissariat A l'Energie Atomique
    Inventor: David Lachartre
  • Patent number: 7929642
    Abstract: A contactless integrated circuit (IC) card can include: an analog interface block operable to demodulate a received radio frequency (RF) signal into multiple versions thereof according to a first plurality of communication protocols, respectively; a controller operable to select from among a second plurality of communication protocols; and a universal asynchronous receiver/transmitter (UART) operable to select one of the demodulated versions of the RF signal according to the selected protocol.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: April 19, 2011
    Inventor: Ki-Yeol Kim
  • Patent number: 7924934
    Abstract: A receiver with a time diversity combining component recovers a digital data signal transmitted over a voice channel of a digital wireless telecommunications network. A feature extraction module receives an audio frequency waveform encoding the digital data signal and generates a feature vector representing the digital data signal. A bit sequence estimation module analyzes the feature vector and generates an estimated bit sequence corresponding to the digital data signal. A memory stores the feature vector if the estimated bit sequence contains errors. A time diversity combining component generates a second estimated bit sequence by analyzing the first feature vector in combination with one or more feature vectors stored in the memory.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: April 12, 2011
    Assignee: Airbiquity, Inc.
    Inventor: Kiley Birmingham
  • Patent number: 7920652
    Abstract: To detect phase mismatches between in-phase and quadrature signals of a quadrature demodulator. The phase mismatches can be detected using the signals obtained by removing high frequency components of output of a multiplier by a low pass filter, the output being the product of the in-phase signals of which low frequency components are removed by a first high pass filter by the quadrature signals of which low frequency components are removed by a second high pass filter.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: April 5, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Shigenori Hayase, Kazuyuki Hori
  • Patent number: 7916804
    Abstract: Aspects of a method and system for a fast-switching Phase-Locked Loop using a Direct Digital Frequency synthesizer may include generating a second signal from a first signal by: translating an inphase component of said first signal in frequency via a filtered fast-switching oscillating signal generated using at least a direct digital frequency synthesizer (DDFS), and translating a corresponding quadrature component of said first signal in frequency via a phase-shifted version of said generated filtered fast-switching oscillating signal. The inphase and quadrature components of the first signal may be multiplied with the filtered fast-switching oscillating signal and a phase-shifted version of the filtered fast-switching oscillating signal, respectively.
    Type: Grant
    Filed: November 30, 2009
    Date of Patent: March 29, 2011
    Assignee: Broadcom Corporation
    Inventor: Ahmadreza Rofougaran
  • Patent number: 7916811
    Abstract: A method for improving burst acquisition in a receiver includes receiving a signal, and performing a sync word search on the signal, wherein the sync word search includes performing a hybrid synchronization technique, the hybrid synchronization technique including both a lower order modulation (e.g., BPSK) detection and correlation process and a higher order modulation (e.g., QPSK) detection and correlation process.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: March 29, 2011
    Assignee: General Instrument Corporation
    Inventors: David P. Gurney, Anthony R. Schooler, Zhuan Ye, Richard DiColli
  • Patent number: 7916809
    Abstract: An object of the present invention is to provide a digital receiving apparatus for providing useful information to its user without interruption when reception quality deteriorates. It includes: an information separating unit 4 for reproducing a stream of demodulation signal S3, and separating it into stream signals S4 on multiplexed respective channels for output; a decoding unit 5 for decoding and outputting the stream signals S4; and a control unit 6 for switching and controlling a stream signal for the decoding unit 5 to decode out of the stream signals on the respective channels, and the control unit 6 switches to the stream signal on another channel and makes the decoding unit 5 decode it when physical information for indicating reception quality under reception and the data type of the stream signal on the channel selected out of the channels do not conform to a predetermined relationship.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: March 29, 2011
    Assignee: Pioneer Corporation
    Inventor: Masahiro Tsushima
  • Patent number: 7916050
    Abstract: Previously, when designing receivers for radio frequency (RF) or wireless communications, designers chose between time-interleaved (TI) analog-to-digital converters (ADCs) for intermediate frequency architectures and dual channel ADCs for direct conversion architectures. Here, similarities between TI ADCs and dual channel ADC were recognized, and an ADC that has the capability of operating as a TI ADCs and dual channel ADC is provided. This allows designer to have greatly increased flexibility during the design process which can greatly reduce design costs, while also allowing the manufacturer of the ADC to realize a reduction in its operating costs.
    Type: Grant
    Filed: October 15, 2009
    Date of Patent: March 29, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Fernando A. Mujica, Charles K. Sestok, Zigang Yang
  • Patent number: 7916049
    Abstract: A disclosed group delay characteristic correcting device corrects group delay characteristics of an analog low-pass filter used to remove aliasing of a digital-analog converter or an analog-digital converter. The group delay characteristic correcting device includes a digital signal processing unit configured to have an all-pass phase circuit at a stage previous to the digital-analog converter or at a stage subsequent to the analog-digital converter so as to correct the group delay characteristics of the analog low-pass filter.
    Type: Grant
    Filed: May 21, 2009
    Date of Patent: March 29, 2011
    Assignee: Fujitsu Limited
    Inventors: Atsushi Honda, Kaoru Yokoo, Yoji Ohashi, Mitsuhiro Azuma
  • Patent number: 7916798
    Abstract: An automatic gain control method and system for use in signal processing of OFDM symbols at a receiver. Two stages of coarse and fine automatic gain control are implemented that adjust different gains in an analog RF processing stage of the receiver. Gain of a low noise amplifier and a mixer are adjusted during a first and coarse automatic gain control stage based on feedback from a digital baseband stage. During a subsequent fine gain control period, the gain of a programmable gain amplifier is adjusted separately for each frequency band used by the OFDM symbols based on a histogram bin that counts the number of output samples of an analog to digital converter whose magnitude falls within certain ranges. Coarse and fine gains are updated after each OFDM symbol.
    Type: Grant
    Filed: August 18, 2006
    Date of Patent: March 29, 2011
    Assignee: Realtek Semiconductor Corp.
    Inventors: Turgut Aytur, Stephan ten Brink, Ravishankar H. Mahadevappa, Ran Yan
  • Patent number: 7916812
    Abstract: Apparatus and methods of determining a modulo count of a synchronization number in a sleep capable system. The synchronization number is stored in a comparison register, and a comparison number equal to the largest power of two multiple of the modulus within a predetermined range is subtracted from the synchronization number. If the difference is zero, the difference is stored in the comparison register, replacing the previous number stored in the register. If the difference is less than zero, the number stored in the register remains unchanged. The comparison number is right shifted, resulting in division by two. The process is repeated for a number of loops equal to the power of two, or until the difference is less than the modulus.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: March 29, 2011
    Assignee: QUALCOMM Incorporated
    Inventor: Kevin Stuart Cousineau
  • Patent number: 7912152
    Abstract: A complex coefficient transversal filter using a SAW filter and a complex frequency converter using the complex coefficient transversal filter are provided, in which a first SAW filter receives a real signal as an input signal and generates a real component of a complex signal, and a second SAW filter receives the real signal as an input signal and generates an imaginary component of the complex signal. Accordingly, feed-through waves between the input and output stages can be cancelled, and a phase difference between real and imaginary signals can be maintained at 90° without a phase shift. In addition, when a low-IF frequency converter is implemented using the complex coefficient transversal filter, an image suppression characteristic is improved. When a zero-IF frequency converter is implemented using the complex coefficient transversal filter, an error vector magnitude (EVM) characteristic is improved.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: March 22, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Takahiro Sato, Tsuyoshi Sugiura
  • Patent number: 7912133
    Abstract: A method and device for transmitting a first and second uplink signal, each having data and control information is provided. The method includes channel encoding the control information of the second uplink signal based on a number of symbols of control information to produce. The channel encoding includes determining the number of symbols in accordance with a payload size of the data of the first uplink signal and a total number of transmissible symbols of a Physical Uplink Shared Channel (PUSCH) of the first uplink signal.
    Type: Grant
    Filed: May 26, 2009
    Date of Patent: March 22, 2011
    Assignee: LG Electronics Inc.
    Inventors: Byeong Geol Cheon, Dae Won Lee, Ki Jun Kim
  • Patent number: 7912144
    Abstract: A modulating means for modulating and/or demodulating data for transmission from a first device to a second device, wherein the modulating means is capable of modulating and/or demodulating data according to at least a first and a second modulation technique.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: March 22, 2011
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Terence Edwin Dodgson, Charles Tibenderana
  • Patent number: 7912165
    Abstract: A method is disclosed, including identifying a preamble in a frame, where the preamble has a preamble length 1. M data items received in succession are stored. The m data items once divided into n portions, where the data items in each portion have respectively been received at successive times and where m and n are natural numbers and the following applies to m and n: m>n, m>1, n>1. The n portions are respectively correlated to the expected values to form component correlation results. Delaying the component correlation results, with at least two component correlation results being delayed by different lengths. The method also includes combining the delayed component correlation results to form a total correlation value. The total correlation value is used to determine whether the m received data items contain the preamble of a frame.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: March 22, 2011
    Assignee: Infineon Technologies AG
    Inventors: Stefan Herzinger, Andreas Menkhoff, Stefan Meier, Norbert Neurohr
  • Publication number: 20110064166
    Abstract: An IQ-imbalance of a complex receiver can be corrected by compensating the in-phase signal component and the quadrature-phase signal component produced by the complex receiver for an IQ-imbalance estimated by analyzing the in-phase signal component and the quadrature-phase signal component. A carrier signal can be received at the complex receiver. An in-phase signal component and a quadrature-phase signal component can be generated from the carrier signal. The generated in-phase signal component and the generated quadrature-phase signal component can be analyzed to estimate an IQ-imbalance. Based on the estimated IQ-imbalance, the in-phase signal component and quadrature-phase signal component can be compensated to correct the IQ-imbalance.
    Type: Application
    Filed: October 16, 2009
    Publication date: March 17, 2011
    Applicant: SiTune Corporation
    Inventors: Mahdi Khoshgard, Vahid Toosi, Marzieh Veyseh
  • Publication number: 20110064165
    Abstract: A demodulation apparatus for a Radio Frequency Identification (RFID) reader includes: a direct current (DC) offset cancellation unit for cancelling DC-offset noise contained in a PSK-modulated or ASK-modulated subcarrier tag signal from the tag signal when the tag signal is received; and a subcarrier digital demodulator for eliminating a subcarrier from the tag signal from which DC-offset noise has been cancelled to demodulate the DC-offset noise-cancelled tag signal.
    Type: Application
    Filed: November 25, 2009
    Publication date: March 17, 2011
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Ji-Hoon BAE, Donghan LEE, Kwang-Soo CHO, Man Sik PARK, Chan-Won PARK, Cheng-Hao QUAN, Won Kyu CHOI, Gil Young CHOI, Jong-Suk CHAE
  • Patent number: 7907680
    Abstract: A Radio Data System (RDS) decoder circuit determines a subcarrier frequency utilizing only a 57 kHz RDS signal of an FM broadcast signal. The RDS decoder includes a zero-intermediate frequency (zero-IF) FM demodulator, a first mixer, a low-pass filter (LPF) unit, a shaping filter unit, a carrier recovery circuit, a digitally controlled oscillator (DCO), a symbol timing recovery circuit, an integrate and dump circuit, a slicer 280, and a differential decoder. The carrier recovery circuit includes a phase error detector and a digital loop filter (DLF). The symbol timing recovery circuit includes a zero-crossing detector, a phase detector and loop filter unit, and a counter.
    Type: Grant
    Filed: January 3, 2008
    Date of Patent: March 15, 2011
    Assignee: Himax Technologies Limited
    Inventors: Tien-Ju Tsai, Chih-Feng Lin, Shih-Chuan Lu
  • Patent number: 7903717
    Abstract: When a receiver (200) receives a signal transmitted from a transmitter, an A/D converter (204) converts the signal into a digital signal having two or more levels by A/D conversion. A zero-level detector (207) converts the signal into a two-level digital signal of positive and negative levels. The converted signals are subjected to spectrum despreading by correlators (206, 208), respectively. Whichever signal has a higher intensity is selected by absolute value detectors (209, 210), a comparator (211), and a switch (212). A decoder (213) decodes the selected signal. In a receiving state where the zero-level detector (207) is selected, the transmitter transmits the transmission signal after the signal is converted into a two-level signal. In a receiving state where the A/D converter (204) is selected, the transmitter transmits the transmission signal after the signal is converted into a signal having two or more levels.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: March 8, 2011
    Assignee: National Institute of Information and Communications Technology, Incorporated Administrative Agency
    Inventors: Satoshi Takahashi, Hiroshi Harada, Chang-Jun Ahn
  • Patent number: 7903749
    Abstract: A system and device communicates data. A modulation and mapping circuit modulates and maps data symbols into a plurality of multiple subcarriers that are orthogonal to each other based on a fixed or variable symbol rate. A frequency domain spreader circuit is operatively connected to the modulation and mapping circuit and spreads the multiple subcarriers over the frequency domain.
    Type: Grant
    Filed: August 16, 2006
    Date of Patent: March 8, 2011
    Assignee: Harris Corporation
    Inventor: Christopher D. Moffatt
  • Patent number: 7903772
    Abstract: A demodulator for use in a receiver converts a digital baseband signal into inbound digital symbols with reduced hardware complexity and reduced power consumption. The demodulator includes a lowpass filter operably coupled to filter the digital baseband signal to produce a filtered digital baseband signal, and an equalizer operating at a first sampling rate to equalize the frequency response of the digital baseband signal such that the receiver overall in-band frequency response approximates the frequency response of a square root raised cosine filter to produce an adjusted digital baseband signal. An interpolator receives the adjusted digital baseband signal at the first sampling rate and interpolates the adjusted digital baseband signal to produce an interpolated digital baseband signal at a second sampling rate, from which the inbound digital symbols can be generated.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: March 8, 2011
    Assignee: Broadcom Corporation
    Inventor: Henrik T. Jensen