Particular Demodulator Patents (Class 375/324)
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Patent number: 8369471Abstract: A plurality of sub-channel response estimates corresponding to a plurality of contiguous sub-channels in a communication channel are determined, and a plurality of weight coefficients are determined. The plurality of sub-channel response estimates are multiplied with the plurality of weight coefficients to generate a plurality of weighted sub-channel response estimates. A filtered sub-channel response estimate for one of the plurality of contiguous sub channels is generated using the plurality of weighted sub-channel response estimates.Type: GrantFiled: October 16, 2009Date of Patent: February 5, 2013Assignee: Marvell International Ltd.Inventors: Rohit U. Nabar, Arul Durai Murugan Palanivelu
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Patent number: 8369386Abstract: A receiver includes a receiving unit that receives a signal from a satellite, a frequency conversion-discretization unit that converts the signal received in the receiving unit into an intermediate frequency signal of a frequency bandwidth including 0 Hz, and discretizes the frequency-converted intermediate frequency signal with a predetermined sampling frequency, a filter unit that filters the discretized signal, which is output from the frequency conversion-discretization unit, through a predetermined filter, a synchronization acquisition unit that acquires synchronization of a spreading code in the discretized signal filtered by the filter unit, and a synchronization holding unit that holds the synchronization of the spreading code, which is acquired by the synchronization acquisition unit.Type: GrantFiled: June 16, 2010Date of Patent: February 5, 2013Assignee: Sony CorporationInventors: Hideki Takahashi, Katsuyuki Tanaka
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Patent number: 8369457Abstract: Disclosed herein is a demodulation apparatus including: an operation determination block configured to determine whether the demodulation apparatus operates as part of either a first device or a second device with which the demodulation apparatus communicates, the first device being configured to ASK-modulate and transmit data, the second device being configured to load-modulate and transmit data; and first and second demodulation control blocks.Type: GrantFiled: September 21, 2010Date of Patent: February 5, 2013Assignee: Sony CorporationInventors: Kazuhisa Funamoto, Kazukuni Takanohashi, Kazuhiro Oguchi
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Publication number: 20130028303Abstract: A receiver includes an antenna interface, a frequency translation bandpass filter (FTBPF), a sample and hold module, and a down conversion module. The antenna interface is operable to receive a received wireless signal from an antenna structure and to isolate the received wireless signal from another wireless signal. The FTBPF is operable to filter the received wireless signal to produce an inbound wireless signal. The sample and hold module is operable to sample and hold the inbound wireless signal in accordance with an S&H clock signal to produce a frequency domain sample pulse train. The down conversion module is operable to convert the frequency domain sample pulse train into an inbound baseband signal.Type: ApplicationFiled: September 29, 2011Publication date: January 31, 2013Applicant: BROADCOM CORPORATIONInventors: AHMADREZA (REZA) ROFOUGARAN, HOOMAN DARABI
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Patent number: 8363755Abstract: A signal receiving apparatus includes: an acquisition section configured to acquire an Orthogonal Frequency Division Multiplexing signal resulting from combination of a plurality of signals transmitted by a plurality of signal transmitting apparatus by adoption of an Orthogonal Frequency Division Multiplexing method; and a demodulation section configured to carry out partial processing of processing to demodulate the Orthogonal Frequency Division Multiplexing signal acquired by the acquisition section by making use of either first pilot signals or second pilot signals where the first pilot signals are pilot signals extracted from the Orthogonal Frequency Division Multiplexing signal acquired by the acquisition section as signals having the same phase for all the signal transmitting apparatus, and the second pilot signals are pilot signals extracted from the Orthogonal Frequency Division Multiplexing signal acquired by the acquisition section as signals having different phases depending on the signal transmittType: GrantFiled: May 27, 2010Date of Patent: January 29, 2013Assignee: Sony CorporationInventors: Suguru Houchi, Naoki Yoshimochi, Takuya Okamoto, Yuken Goto, Takashi Yokokawa
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Patent number: 8358721Abstract: A base station transmits a control channel transmitted before information channels upon performing differential coding between control channels of adjacent frequencies. A terminal apparatus performs transmission path estimation on the basis of a pilot while decoding the control channel having undergone the differential coding. The information channels are decoded on the basis of information obtained by decoding the control channel and a transmission path estimation result on the pilot.Type: GrantFiled: April 2, 2009Date of Patent: January 22, 2013Assignee: Fujitsu Toshiba Mobile Communications LimitedInventors: Yutaka Asanuma, Shigeo Terabe
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Patent number: 8358684Abstract: A demodulation circuit including: a first error calculation section configured to calculate a first error in accordance with a blind method; a second error calculation section configured to calculate a second error in accordance with a DD method; an update section configured to update filter coefficients for first and second filters based on the first or second error, the first filter filtering an input signal to generate a first signal, the second filter filtering a signal representing a hard decision value for a post-equalization signal to generate a second signal; a control section configured to, in the case where the update section is updating the filter coefficients based on the second error, controlling the filter coefficients to be updated based on the first error, when the degree of the second error has exceeded a first threshold; and a generation section configured to generate the post-equalization signal based on the first and second signals.Type: GrantFiled: March 18, 2009Date of Patent: January 22, 2013Assignee: Sony CorporationInventor: Katsumi Takaoka
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Patent number: 8355473Abstract: Certain embodiments of the present disclosure propose methods and systems for classifying the Doppler spread based on the output of the frequency-tracking loop (FTL) discriminator in WiMAX systems to improve the performance of the channel estimation. The Doppler spread may be classified as low, medium or high based on the statistics of the output of the discriminator in the fine-tracking mode.Type: GrantFiled: April 19, 2009Date of Patent: January 15, 2013Assignee: QUALCOMM IncorporatedInventors: Junqiang Li, Je Woo Kim, Madihally J. Narasimha
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Patent number: 8355469Abstract: A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal, derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. A subtractor then subtracts the digital phase-locked loop feedback from the linear ramp to provide the input to the loop filter.Type: GrantFiled: July 8, 2011Date of Patent: January 15, 2013Assignee: Tektronix, Inc.Inventors: Daniel G. Baker, Barry A. McKibben, Michael D. Nakamura, Evan Albright, Scott E. Zink, Michael S. Overton
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Patent number: 8355468Abstract: A carrier frequency estimation method and apparatus is provided for improving frequency estimation performance in an Orthogonal Frequency Division Multiplexing (OFDM) communication system. The frequency estimation method for a wireless communication system includes summing correlations of four pairs of reference symbols transmitted at different frequency-time resource blocks in a pattern, each pair including two closest reference symbols; calculating a statistical value (E) by accumulating the summed correlation in a frequency direction; and estimating a frequency offset using an angle extracted from the statistical value (E).Type: GrantFiled: November 27, 2009Date of Patent: January 15, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Hee Jin Ro, Jong Han Lee
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Patent number: 8345802Abstract: A receiver for a digital modulated signal which receives a multi-carrier modulated signal and demodulates a receiving signal by converting it from a time region into a frequency region by Fourier transform is provided. The receiver comprises a Fourier transformer which performs Fourier transform of the receiving signal and an interference removing circuit which reduces an inter-symbol interference or an inter-carrier interference of the receiving signal. The removing circuit is disposed in a front stage of the Fourier transformer.Type: GrantFiled: June 22, 2006Date of Patent: January 1, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Masaki Nishikawa
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Patent number: 8345803Abstract: Systems and methodologies are described that facilitate dynamically allocating demodulation resources of a wideband receiver to provide improved demodulation of simultaneously received signals. Signal-to-noise ratio (SNR) and/or packet error rate (PER) can be measured for the plurality of carriers to determine which demodulators related to the carriers require more resources than others to demodulate signals at a specified signal quality. Where the SNR of a related carrier is high and/or PER is low, the demodulator can require fewer resources than where the SNR of a related carrier is low and/or PER is high. In this regard, the resources are dynamically allocated among the demodulators and reallocated where SNR/PER changes and/or additional resources are made available.Type: GrantFiled: October 2, 2008Date of Patent: January 1, 2013Assignee: QUALCOMM IncorporatedInventors: Gregory R. Lie, Abhay A. Joshi, Yu-Chuan G. Lin, Lijun Lin
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Patent number: 8345801Abstract: A system and method for signal mismatch compensation in a wireless receiver is disclosed. The method includes receiving an in-phase (I) signal and a quadrature (Q) signal corresponding to the I signal, the Q signal having an ideal phase offset of 90 degrees from the I signal, where there is a phase and gain mismatch between the I signal and Q signal. The method adjusts the phase offset between the I signal and the Q signal to minimize the IQ power, where the IQ power is the average-time power of a digital baseband in-phase (DB-I) signal and a digital baseband quadrature (DB-Q) signal, corresponding to the I signal and Q signal, respectively. The method adjusts the gain of the Q signal to minimize the IQ power, whereby the phase and gain mismatch between the I signal and Q signal is minimized.Type: GrantFiled: November 10, 2005Date of Patent: January 1, 2013Inventor: Weon-Ki Yoon
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Publication number: 20120326657Abstract: One aspect of the present invention includes a bi-phase communication receiver system. The system includes an analog-to-digital converter (ADC) configured to sample a bi-phase modulation signal to generate digital samples of the bi-phase modulation signal. The system also includes a bi-phase signal decoder configured to decode the bi-phase modulation signal based on the digital samples. The system further includes a preamble detector comprising a digital filter configured to evaluate the digital samples to generate an output and to detect a preamble of the bi-phase modulation signal for decoding the bi-phase modulation signal based on the output.Type: ApplicationFiled: December 27, 2011Publication date: December 27, 2012Inventor: Eric Gregory Oettinger
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Patent number: 8340219Abstract: Provided are a receiver and a receiving method for a scalable bandwidth in a mobile station of an Orthogonal Frequency Division Multiplexing (OFDM) system. The receiving method includes the steps of: (a) filtering a received RF signal; (b) oscillating a frequency according to a center frequency control signal to output a local oscillation frequency; (c) down-converting the filtered RF signal by using the local oscillation frequency; (d) scalable-filtering the down-converted signal while adjusting a bandwidth according to a bandwidth control signal; (e) controlling gain of the scalable-filtered signal; (f) converting the gain-controlled analog signal into a digital signal by using a sampling frequency matching with a corresponding bandwidth according to an ADC control signal; and (g) demodulating the converted digital signal, outputting the center frequency control signal, the bandwidth control signal, and the ADC control signal according to control information received from an upper layer.Type: GrantFiled: October 10, 2007Date of Patent: December 25, 2012Assignees: Electronics and Telecommunications Research Institute, Samsung Electronics Co., Ltd.Inventors: Moon-Sik Lee, Nam-Il Kim, Hyeong-Geun Park, Il-Gyu Kim, Young-Hoon Kim, Seung-Chan Bang
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Patent number: 8340225Abstract: 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: GrantFiled: October 16, 2009Date of Patent: December 25, 2012Assignee: SiTune CorporationInventors: Mahdi Khoshgard, Vahid Toosi, Marzieh Veyseh
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Patent number: 8340223Abstract: A receiver includes: an amplifier that amplifies a received broadband signal up to a predetermined level; a first switch that switches an output signal from the amplifier; a signal generator that generates a signal for controlling a switching operation of the first switch; an integration capacitor that integrates an output signal from the first switch; a comparator that compares an output voltage from the integration capacitor with a predetermined voltage; and a reset circuit that discharges electrical charges accumulated in the integration capacitor based on a comparison result from the comparator.Type: GrantFiled: September 19, 2008Date of Patent: December 25, 2012Assignee: NEC CorporationInventor: Akio Tanaka
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Patent number: 8335279Abstract: Apparatuses, systems, and methods that align channel filters for dual tuners are disclosed. An embodiment may comprise an IC having two tuners. Each tuner may have a low-noise amplifier, a mixer with a local oscillator, and channel filter. To perform a channel filter alignment, a bandwidth controller may cross-couple the local oscillator of each tuner to the input of the mixer of the opposite tuner. The bandwidth controller may adjust the frequencies of the local oscillators to produce different configuration tone frequencies at the outputs of the mixers, which are inputs to the channel filters. The bandwidth controller may then determine an amplitude difference between two separate measurements of a channel filter output and, based on a comparison of the measurements with predicted values, increment or decrement the filter bandwidth for each tuner and store parameters for the channel filters which create the largest signal amplitudes.Type: GrantFiled: July 24, 2009Date of Patent: December 18, 2012Assignee: Intel CorporationInventors: Nicholas P. Cowley, Keith Pinson, Isaac Ali
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Patent number: 8335272Abstract: A MIMO transmitter has a modulator (40,41,42, 120, 122) a demultiplexer 100 arranged to divide the information into one or more demux streams for transmission over different ones of the channels, and a diversity splitter (110) to derive one or more sub-streams of the same information. A decorrelator (120) such as a scrambler (150, 155) decorrelates the sub-streams before or after the modulation. The arrangement is configurable to vary in use a ratio of demultiplexing and of diversity splitting. This balances between the gains from diversity and spatial multiplexing, without needing major changes to the transmit and receive processing.Type: GrantFiled: October 20, 2006Date of Patent: December 18, 2012Assignees: Koninklijke Philips Electronics N.V., Sharp CorporationInventor: Keith Roberts
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Patent number: 8331496Abstract: The present invention relates to a phase recovery device, phase recovery method and receiver for 16 QAM data modulation.Type: GrantFiled: October 1, 2010Date of Patent: December 11, 2012Assignee: Fujitsu LimitedInventors: Meng Yan, Zhenning Tao, Shoichiro Oda
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Patent number: 8331495Abstract: As disclosed herein, a “super receiver” structure enriches the information provided for decoding modem bits included in a received sequence of symbols. In particular, an equalizer circuit provides joint metrics to a decoder circuit, where the joint metrics advantageously reflect joint bit probabilities. However, the metrics are computed without need for complex joint probability calculations. The decoder circuit “fuses” the joint metrics with corresponding side information, which indicates the likelihood that one or more bits represented by the joint metric take on a particular value. Such fusing biases the soft value estimation for the other bits represented by the joint metric, thus enabling the decoder to operate on refined soft values in its bit decoding operations.Type: GrantFiled: August 17, 2009Date of Patent: December 11, 2012Assignee: Telefonaktiebolaget L M Ericsson (Publ)Inventor: Ali S. Khayrallah
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Patent number: 8332450Abstract: A method of computing a vector angle by using a CORDIC and an electronic apparatus using the same are disclosed. The electronic apparatus mainly includes a phase error detector, a loop filter, a small-area iteration LUT module and a phase compensation circuit. The phase error can be locked by using the error function in the phase error detector, and even the phase error can be locked to the minimum so that the error oscillates up-and-down about the zero level. The first transfer function in the loop filter can determine the baseband and the converging speed. Moreover, if the shifting technique is used, the operation of the first transfer function is speeded up. By using a phase-locking loop in association with looking up the above-mentioned LUT, the method is able to get fast converging and higher accuracy for the computation.Type: GrantFiled: March 26, 2009Date of Patent: December 11, 2012Assignee: Industrial Technology Research InstituteInventor: Ming-Ho Lu
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Publication number: 20120307943Abstract: Ano signal period detecting unit (10) detects a no signal period in which no receiver signal is received. A capture unit (7) captures a synchronous timing of the receiver signal on the basis of a correlation value which is worked out by a delayed correlation computing unit (6). Further, the capture unit (7) cancels the capture of the synchronous timing in the case where this no signal period is detected by the no signal period detecting unit (10).Type: ApplicationFiled: July 21, 2010Publication date: December 6, 2012Applicant: PANASONIC CORPORATIONInventors: Naoki Umeda, Mituru Maeda
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Patent number: 8327244Abstract: Systems and methods for processing and decoding TCM/BCM-coded signal vectors. A multi-dimensional signal vector is received by, for example, a TCM or BCM decoder. The TCM/BCM decoder identifies the closest signal points in the signal constellation set, or “nearest neighbors,” for each dimension of the received signal vector. The TCM/BCM decoder then forms a test set that includes a plurality of multi-dimensional test vectors, where each dimension of each test vector is based on an identified nearest neighbor. In particular, each test point in the test set is based on a different combination of the nearest neighbors. The TCM/BCM decoder can compute branch metrics based on only the test points in the test set, and can make detection decisions using the computed branch metrics.Type: GrantFiled: October 17, 2011Date of Patent: December 4, 2012Assignee: Marvell International Ltd.Inventors: Gregory Burd, Xueshi Yang
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Patent number: 8325857Abstract: The present invention employs hierarchical modulation to simultaneously transmit information on different modulation layers using a carrier RF signal. Initially, first data to be transmitted is assigned to a first modulation layer and second data is assigned to a second modulation layer. In one embodiment of the present invention, the first and second data are assigned based on reliability criteria. The first and second modulation layers are hierarchical modulation layers of the carrier RF signal. Once assigned, the first data is transmitted using the first modulation layer of the carrier RF signal and the second data is transmitted using the second modulation layer of the carrier RF signal. In one embodiment of the present invention, information may be transmitted to one end user using one modulation layer, and information may be transmitted to a different end user using a different modulation layer.Type: GrantFiled: January 12, 2012Date of Patent: December 4, 2012Assignee: Apple Inc.Inventors: Ming Jia, Jianglei Ma, Peiying Zhu, Wen Tong, Curt Dodd
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Patent number: 8325832Abstract: An analog multi-tone receiver includes an interface for receiving a data transmission signal containing N sub-channel signals corresponding to N active sub-channels. The receiver includes a plurality of samplers to sample, during each time interval of a sequence of time intervals, the received signal in parallel to produce a plurality of data sets, each sampler having a distinct threshold level. The receiver includes a decoder to jointly decode the plurality of data sets to determine a plurality of data symbols including at least one data symbol for each of the N active sub-channels.Type: GrantFiled: February 11, 2009Date of Patent: December 4, 2012Assignee: Rambus Inc.Inventor: Amir Amirkhany
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Patent number: 8320502Abstract: A digital demodulating apparatus comprises circuit components constituting a tuner that applies channel select processing to a received signal, and a demodulator that demodulates the signal to which the tuner has applied channel select processing; a power supply unit that supplies power to each circuit component; a reception condition detecting unit that detects a reception condition when the tuner receives the signal; a power adjusting unit that adjusts the power to be supplied to each circuit component by the power supply unit, on the basis of a result of the detection by the reception condition detecting unit; a fading environment estimating unit that estimates a fading environment when the tuner receives the signal; and a power controlling unit that controls the power adjusting unit on the basis of a result of the estimation by the fading environment estimating unit so that the number of times of adjustments of the power by the power adjusting unit per unit time changes in accordance with the variabilityType: GrantFiled: May 6, 2008Date of Patent: November 27, 2012Assignee: Sharp Kabushiki KaishaInventors: Takae Sakai, Nobuyoshi Kaiki
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Patent number: 8320867Abstract: An object of the present invention is to increase measurement precision for measuring errors of a quadrature demodulator. An error measurement device 10 receives an I signal and a Q signal from a quadrature demodulator 4 for demodulating a signal to be demodulated including multiple carrier signals respectively different from each other in frequency, and measures a gain imbalance which is a ratio of the amplitude of the Q signal to the amplitude of the I signal.Type: GrantFiled: January 12, 2009Date of Patent: November 27, 2012Assignee: Advantest CorporationInventor: Takashi Shimura
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Publication number: 20120294391Abstract: A control signal receiver includes a converting circuit and a synchronization detection circuit. The converting circuit generates a complex control symbol stream including transmission configurations by converting an input signal. The synchronization detection circuit generates a first bit stream by applying a first determination criterion to the complex control symbol stream and generates a first synchronization signal by comparing the first bit stream with a reference synchronization word. The synchronization detection circuit generates a second bit stream by applying the first determination criterion and a second determination criterion to the complex control symbol stream in that order and generates a second synchronization signal by comparing the second bit stream with the reference synchronization word. The synchronization detection circuit outputs one of the first synchronization signal and the second synchronization signal as asynchronization enable signal.Type: ApplicationFiled: May 15, 2012Publication date: November 22, 2012Inventor: Jun-Young JEONG
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Patent number: 8315338Abstract: 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: GrantFiled: March 8, 2011Date of Patent: November 20, 2012Assignee: Hitachi, Ltd.Inventors: Shigenori Hayase, Kazuyuki Hori
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Patent number: 8311176Abstract: A system and method for performing clock and data recovery. The system sets the phase of a recovered clock signal 30 according to at least three estimates of the rate of change of an offset between the frequency of the data transmitter clock and the frequency of a receiver clock 15.Type: GrantFiled: September 5, 2007Date of Patent: November 13, 2012Assignee: Rambus Inc.Inventors: Hae-Chang Lee, Thomas H. Greer, III, Jade M. Kizer, Brian S. Leibowitz, Mark A. Horowitz
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Patent number: 8311155Abstract: Demodulator includes reception quality evaluation circuit for evaluating the quality of a received signal by comparison with a first reference value, and outputting an evaluation signal; and driving circuit receiving the evaluation signal. If reception quality evaluation circuit evaluates that the quality of the received signal is acceptable, power supply from driving circuit to DC offset control loop is stopped. This offers a high-frequency receiver that reduces power consumption.Type: GrantFiled: December 24, 2008Date of Patent: November 13, 2012Assignee: Panasonic CorporationInventors: Takashi Umeda, Hiroaki Ozeki, Akira Fujishima
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Patent number: 8311087Abstract: Methods and apparatus for providing monitoring of voice quality and diagnostic data related to voice quality on a wireless device. Monitoring thresholds can be implemented that allow for additional precautionary measures and/or further monitoring to occur if a threshold level of voice quality performance is experienced. The results of the voice and diagnostic monitoring can be communicated to the service provider who can then collect, analyze and generate reports to assess and determine quality-related problems experienced by the communication network.Type: GrantFiled: November 17, 2009Date of Patent: November 13, 2012Assignee: QUALCOMM IncorporatedInventors: Kenny Fok, Tia Manning Cassett, Eric Chi Chung Yip
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Patent number: 8306156Abstract: Methods and apparatuses to detect spectrum inversion based on estimated frequency offset in carrier signal. In one embodiment, a receiver includes an I/Q swap module to output an in-phase component and a quadrature-phase component; a frequency offset estimator to determine an offset in carry frequency of the in-phase and quadrature-phase components; and a spectrum inversion detector coupled to the frequency offset estimator and the I/Q swap module. The spectrum inversion detector is configured to signal the I/Q swap module to swap the in-phase component and the quadrature-phase component when an absolute value of the offset in carry frequency is above a predetermined threshold.Type: GrantFiled: October 17, 2007Date of Patent: November 6, 2012Assignee: Montage Technology Group LimitedInventor: Li Zhang
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Publication number: 20120275546Abstract: Multiple symbol noncoherent soft output detectors in accordance with embodiments of the invention are disclosed. In a number of embodiments, the multiple symbol noncoherent soft output detector uses soft metrics based on the Log Likelihood Ratio (LLR) of each symbol to provide information concerning the reliability of each detected symbol. One embodiment of the invention includes a receiver configured to receive and sample a phase modulated input signal, and a multiple symbol noncoherent soft output detector configured to receive the sampled input signal and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols.Type: ApplicationFiled: March 7, 2012Publication date: November 1, 2012Applicant: Mojix, Inc.Inventor: Dariush Divsalar
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Patent number: 8300734Abstract: In a frequency converting system, an input signal x(t) is supplied to a signal branching section for dividing a predetermined frequency domain into M bands, extracting signal components of the respective divided bands. The respective signal components and local signals each including a frequency difference corresponding to a predetermined intermediate frequency with respect to a center frequency of each band are input to a frequency converting part. The signals of the respective divided bands are converted into signals of intermediate frequency bands each including the predetermined intermediate frequency as the center frequency, the conversion outputs are sampled by using a common clock signal, whereby the conversion outputs are converted into digital signals. Further, after being subjected to phase correction processing, the digital signals are subjected to frequency conversion and combination processing by a signal regeneration part.Type: GrantFiled: September 9, 2009Date of Patent: October 30, 2012Assignee: Anritsu CorporationInventors: Masaaki Fuse, Hitoshi Sekiya
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Method and apparatus for phase reference tracking of digital phase modulated signals in the receiver
Patent number: 8300736Abstract: 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. 2004.Type: GrantFiled: October 19, 2009Date of Patent: October 30, 2012Assignee: ISSC Technologies Corp.Inventors: Pansop Kim, Jeng-Hong Chen, Hsin-Hsiang Liu -
Patent number: 8301103Abstract: A method for demodulating an RF input signal using an envelope detector and synchronous switching of the input signal before entering and after leaving the envelope detector, the envelope detector having a non-linear transfer function acting essentially as a squaring function. The invention also relates to an electronic receiver circuit performing such a method, and to an RF receiver comprising such an electronic receiver, and to an electronic device comprising such an RF receiver, and to the use of such an RF receiver as a wake-up receiver.Type: GrantFiled: September 10, 2010Date of Patent: October 30, 2012Assignee: Stichting IMEC NederlandInventors: Xiongchuan Huang, Guido Dolmans
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Patent number: 8300685Abstract: Embodiments include a decision feedback equalizer (DFE) that includes a first comparator configured to receive as inputs a soft value and a first threshold, a second comparator configured to receive as inputs the soft value and a second threshold, a selector configured to select an output of either the first comparator or the second comparator as a DFE output based on one or more previous bits output by the selector; an error calculator configured to determine an error for the first comparator and the second comparator, and a threshold adjuster configured to adjust the first threshold and the second threshold, the first threshold and the second threshold each being a non-linear combination of one or more previous outputs of the selector.Type: GrantFiled: August 27, 2007Date of Patent: October 30, 2012Assignee: Broadcom CorporationInventors: Chung-Jue Chen, Vasudevan Parthasarthy, Sudeep Bhoja
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Patent number: 8300728Abstract: The invention is a method of transmitting a radio signal using a complex envelope elimination and restoration technique. The method includes receiving a radio frequency (RF) signal. Further, the method includes separating the RF signal into an in-phase baseband signal (I) and a quadrature baseband signal (Q). Still further, the method includes decomposing the (I) signal into a in-phase magnitude component and a in-phase phase component while decomposing the Q signal into a quadrature magnitude component and a quadrature phase component. Alternatively, the source signal could be digital baseband information. Digital signal processing could generate the phase and magnitude reference signals for the system.Type: GrantFiled: September 24, 2008Date of Patent: October 30, 2012Assignee: Rockwell Collins, Inc.Inventors: Theodore J. Hoffmann, David W. Cripe
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Patent number: 8290091Abstract: Teachings presented herein offer a technique for using a demodulator to improve a demodulation process. For example, a demodulation unit according to an embodiment of the present invention may be a multi-stage demodulator and may include: a demodulator configured to receive a baseband signal and configured to produce modem bit likelihood values based on the received baseband signal; a decoder configured to receive and process the modem bit likelihood values to produce improved modem bit likelihood values; a candidate value generator configured to produce, based on the improved modem bit likelihood values, candidate symbol values for a group of one or more symbols; and a detector configured to receive the baseband signal and the candidate symbol values and configured to produce one of (a) final modem bit estimates and (b) candidate symbol values for a group of symbols.Type: GrantFiled: December 1, 2009Date of Patent: October 16, 2012Assignee: Telefonaktiebolaget L M Ericsson (Publ)Inventors: Stephen Grant, Gregory E. Bottomley, Florent Munier
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Patent number: 8279986Abstract: Provided are: plural circuit components including a circuit component which constitutes a receiving unit receiving a signal sequence which is arranged so that a desired signal and a signal different from the desired signal are lined up in time series, the desired signal indicating desired data which includes at least one of text data, sound data, image data, and a computer program product; and an operating parameter changing unit which changes an operating parameter of at least one of the plural circuit components, during a period in which the receiving unit receives the signal different from the desired signal.Type: GrantFiled: February 26, 2009Date of Patent: October 2, 2012Assignee: Sharp Kabushiki KaishaInventor: Nobuyoshi Kaiki
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Patent number: 8279989Abstract: A baud rate acquisition circuit (10) for synchronizing a sampling signal with an input signal operates in broad rate sweeping and a rate fine tuning phases. In the rate sweeping phase, a timing error detector (24) examines the sampling signal generated by a decimator (16). If the sampling signal is outside a rate acquisition range from the target rate, a rate sweeping algorithm selects a new sampling rate. In response to the sampling rate within the rate acquisition range, the timing error detector (24) examines the asymmetry thereof to generate a rate correction signal to synchronize the sampling signal with the input signal. Next in the rate fine tuning phase, a multiplexer (22) routes the sampling signal through a square root filter (18). By examining the waveform shaped signal, the time error detector (24) synchronizes the sampling signal with the input signal with high accuracy.Type: GrantFiled: August 2, 2006Date of Patent: October 2, 2012Assignee: Entropic Communications, Inc.Inventors: Bo Shen, Liping Chen
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Patent number: 8279954Abstract: A method and apparatus is disclosed herein for forward-backward SOMA techniques. In one embodiment, the apparatus is a receiver comprising: an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each tone, where the SOMA-based MIMO joint demapper is operable to identify a best candidate among a number of candidates by searching a detection tree for each tone using a forward pass through the detection tree, where only a number of best alternatives from every level of the tree are expanded and where soft-output related information is collected and stored, and to perform a second pass, following the forward pass, during which soft-output is computed for each bit; and an outer decoder operable with the SOMA-based inner decoder to perform iterative decoding.Type: GrantFiled: December 15, 2008Date of Patent: October 2, 2012Assignee: NTT DoCoMo, Inc.Inventors: Haralabos Papadopoulos, Carl-Erik W. Sundberg
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Publication number: 20120236969Abstract: In a multiple-input multiple-output (MIMO) system, multiple receive antennas produce a received signal vector, Y, which includes an element for each of the receive antennas. In an embodiment of a de-mapping method performed within a MIMO receiver, a quadrature phase shift keying (QPSK) search is performed within a search space that includes the full constellation of symbol points. Based on the results of the QPSK search, the search space is reduced to fewer than all of the quadrants, and the received signal vector data is scaled and transformed to the reduced search space. A lower-level QPSK search is performed, and the process is repeated until the modulation order is reduced to a QPSK constellation. Hard or soft decisions corresponding to the search results may then be passed to a decoder.Type: ApplicationFiled: May 25, 2012Publication date: September 20, 2012Inventor: John S. Sadowsky
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Patent number: 8270545Abstract: Certain embodiments of the present disclosure relate to a method for tracking of a carrier frequency offset. A soft combined frequency tracking discriminator is proposed as a part of the closed loop structure that can provide fast tracking of the frequency offset in an initial pull-in mode, and can also track small residual frequency variance in a fine-tracking mode.Type: GrantFiled: March 1, 2009Date of Patent: September 18, 2012Assignee: QUALCOMM IncorporatedInventors: Junqiang Li, Madihally J. Narasimha, Je Woo Kim
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Patent number: 8270544Abstract: According to one aspect of the present invention, an apparatus is provided to enable weather band radio signals to be received and processed using a digital signal processor (DSP). The DSP can include functionality to implement both frequency modulation (FM) demodulation and weather band data demodulation, i.e., specific area encoding (SAME) demodulation. In one such embodiment, soft decision samples of a SAME message can be combined, and based on a combined result, a hard decision unit can generate a bit value of weather band data.Type: GrantFiled: January 3, 2012Date of Patent: September 18, 2012Assignee: Silicon Laboratories Inc.Inventor: Junsong Li
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Patent number: 8270522Abstract: A receiver comprises a demodulator to estimate channel impulse response and timing synchronization information for the received signal and to select a modulation technique for demodulating the received signal; and a channel decoder to produce a binary sequence from the received signal demodulated according to the selected modulation technique; wherein the demodulator: demodulates the received signal according to a first modulation technique and a second modulation technique to produce a first demodulated signal and a second demodulated signal, respectively; calculates a minimum distance between a first reconstructed signal including the training sequence and the first demodulated signal to estimate the channel impulse response and timing synchronization information; calculates a minimum distance between a second reconstructed signal including the training sequence and the second demodulated signal to estimate the channel impulse response and timing synchronization information; compares the minimum distance coType: GrantFiled: April 13, 2009Date of Patent: September 18, 2012Assignee: Altobridge LimitedInventors: Kai Xie, Sattar Elyasi
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Patent number: 8265192Abstract: A multilevel QAM demodulator includes a phase difference calculation unit calculating a phase difference signal based on the common phase signal and orthogonal signal after the phase rotation compensation, a phase shift amount calculation unit calculating a phase shift amount indicating a degree of a phase shift based on the common phase signal and orthogonal signal after the phase rotation compensation and phase noise compensation, and a correction unit correcting the phase difference signal based on the phase shift amount. A phase rotation is performed for the phase noise compensation based on the phase difference signal corrected by the correction unit.Type: GrantFiled: December 5, 2008Date of Patent: September 11, 2012Assignee: NEC CorporationInventor: Yuuzou Suzuki
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Patent number: 8265211Abstract: The method of improving the carrier-to-noise ratio for a receiver with diversity, and the associated device, consists, after extracting, by phase shifting, the noise component of the signals to be demodulated, in optimizing the cancellation of the useful component via a feedback loop acting on the phase shifter and in summing the noise component in phase and in phase opposition with these signals to improve the carrier-to-noise ratio.Type: GrantFiled: January 10, 2007Date of Patent: September 11, 2012Assignee: Thomson LicensingInventors: Jean-Luc Robert, Jean-Yves Le Naour, Jean-François Pintos