Particular Demodulator Patents (Class 375/324)
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Patent number: 8532225Abstract: Receiver circuitry for processing a received Very Low Intermediate Frequency signal wherein the receiver circuitry comprises a main processing path. The main processing path comprises mixing circuitry arranged to mix a received VLIF signal with a frequency down conversion signal to produce a main path signal. The receiver circuitry further comprises a direct current cancellation path comprising mixing circuitry arranged to mix a DC element of the received VLIF signal with the frequency down conversion signal to produce a DC cancellation signal. The receiver circuitry still further comprises signal summing circuitry arranged to add the DC cancellation signal in anti-phase with the main path signal.Type: GrantFiled: March 19, 2008Date of Patent: September 10, 2013Assignee: Freescale Semiconductor, Inc.Inventors: Conor O'Keeffe, Norman Beamish, Richard Verellen
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Patent number: 8532227Abstract: Methods and apparatus for FEC frame header detection are provided, suitable for use in a DVB-C2 receiver. A first method comprises demodulating with a quadrature phase shift keying (QPSK) demapper, followed by correlation and symmetry measures for detection of a robust FEC header. A second method comprises demodulating with a 16 quadrature amplitude modulation (QAM) demapper, followed by correlation and symmetry measures for detection of a high efficiency FEC leader. Another embodiment comprises using both the first and second methods to find the FEC header because the first symbol of the FEC frame header may be sent either in robust mode or in high efficiency mode. There is also provided a method and apparatus for generating an alternate decision statistic for determining detection of the FEC frame header.Type: GrantFiled: June 28, 2010Date of Patent: September 10, 2013Assignee: Thomson LicensingInventors: Hou-Shin Chen, Wen Gao
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Patent number: 8532224Abstract: A signal processing circuit comprises a frequency up-conversion circuit (14, 60) for performing up-conversion with a first local oscillator frequency and a frequency down-conversion circuit (16) for performing down-conversion with a second local oscillator frequency. A digital signal processor (10) controls supply first signals representing a first complex signal to the up-conversion circuit, and receives second signals representing a second complex signal. The digital signal processor controls a compensation of I/Q mismatch of results of up-conversion and/or down-conversion. The digital signal processor (10) switches to a calibration mode for selecting a parameter of said compensation. In the calibration mode the first and second local oscillator frequencies have a frequency offset with respect to each other.Type: GrantFiled: December 19, 2008Date of Patent: September 10, 2013Assignee: St-Ericsson SAInventors: Remco Van De Beek, Domine Leenaerts, Charles Razzell, Jozef R. M. Ervoet
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Patent number: 8526897Abstract: According to one aspect of the present invention, a controller is coupled to at least first and second signal processors (at least one of which includes analog demodulation circuitry and another of which includes digital demodulation circuitry). The controller may operate to disable the first signal processor responsive to a control signal that indicates that a second signal (corresponding to a demodulator output) is available from the second signal processor.Type: GrantFiled: November 3, 2010Date of Patent: September 3, 2013Assignee: Silicon Laboratories Inc.Inventor: Matthew Henson
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Patent number: 8525937Abstract: An apparatus for calibrating an audio-visual (AV) signal includes a controller for generating a control signal, a controllable filter for selectively filtering the AV signal in response to the control signal to output either the AV signal or a filtered AV signal; and a calibrator for generating a group of calibrating coefficients according to the filtered AV signal and calibrating the AV signal according to the group of calibrating coefficients.Type: GrantFiled: August 24, 2011Date of Patent: September 3, 2013Assignee: MStar Semiconductor, Inc.Inventors: Wen Chieh Yang, Ching Fu Lan, Jen Hsing Wang, Yi Hsuan Lai, Chin Fu Ho, Hsin Chuan Kuo, You Tsai Cheng, Tai Lai Tung
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Patent number: 8526543Abstract: A system and method are provided for removing quadrature imbalance errors in received data. The method accepts an unbiased training sequence in a quadrature demodulation receiver. An unbiased training sequence has a uniform accumulated power evenly distributed in a complex plane, and includes predetermined reference signals (p) at frequency +f and predetermined mirror signals (pm) at frequency ?f. The unbiased training sequence is processed, generating a sequence of processed symbols (y) at frequency +f, representing complex plane information in the unbiased training sequence. Each processed symbol (y) is multiplied by the mirror signal (pm), and an unbiased quadrature imbalance estimate Bm is obtained at frequency (?f). Using quadrature imbalance estimates, channel estimates, and processed symbols, an imbalance-corrected symbol can be generated.Type: GrantFiled: July 11, 2011Date of Patent: September 3, 2013Assignee: QUALCOMM IncorporatedInventors: Rabih Chrabieh, Samir S Soliman
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Patent number: 8526527Abstract: 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: GrantFiled: January 23, 2012Date of Patent: September 3, 2013Assignee: Panasonic CorporationInventors: Jinsong Duan, Keisuke Ebiko, Ryohei Kimura
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Patent number: 8526540Abstract: A method and device is provided for detecting data symbols in a received radio signal. Each data symbol is allocated transmit-side a symbol value-specific PN sequence of successive PN chips in the chip clock, and the allocated PN sequences are offset QPSK modulated. The method for incoherent detection includes converting the received radio signal into a complex baseband signal sampled in the chip clock, generating a demodulated signal by differential demodulation of the complex baseband signal, calculating correlation results by correlating the demodulated signal with the derived sequences, and deriving the values of the data symbols by evaluating the correlation results. Each derived sequence is assigned to a PN sequence allocable transmit-side and includes derived chips, whose values correspond to a logic linking of particular PN chips of the PN sequence allocable transmit-side that is assigned the derived sequence. The invention relates furthermore to a corresponding receiving unit.Type: GrantFiled: June 13, 2012Date of Patent: September 3, 2013Assignee: Atmel CorporationInventors: Frank Poegel, Eric Sachse, Michael Schmidt
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Patent number: 8520725Abstract: A data equalizing circuit includes an equalizer configured to control a gain of data according to a value of a control code and output a controller gain; and a detection unit configured to divide n cycles of the data into N periods, count data transition frequencies for n/N periods while changing the value of the control code, calculate dispersion values of data transition frequencies for 1/N periods of the data from the data transition frequencies for the n/N periods, and finally output the value of the control code corresponding to a largest dispersion value, wherein n is equal to or greater than 2 and is set such that boundaries of the respective n/N periods of the data have different positions in the 1 UI data.Type: GrantFiled: February 28, 2012Date of Patent: August 27, 2013Assignee: SK Hynix Inc.Inventors: Chun Seok Jeong, Jae Jin Lee, Chang Sik Yoo, Jang Woo Lee, Seok Joon Kang
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Patent number: 8520706Abstract: In current transmitting methods, an instantaneous interruption of a transmission data may occur at the time of switching a system. A sending method of the present invention is a sending method for transmitting a data string signal to a primary system and a backup system in which: a first periodic signal which becomes a reference signal and a second periodic signal with a longer cycle period than the first periodic signal are generated; a data string signal is synchronized with the first periodic signal; and the data string signal synchronized with the first periodic signal is multiplexed by a cycle period synchronized with the second periodic signal to transmit it to the primary system and the backup system.Type: GrantFiled: February 5, 2009Date of Patent: August 27, 2013Assignee: NEC CorporationInventor: Shinji Tanimoto
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Patent number: 8520720Abstract: A spread spectrum communication system includes a first and a second antenna, a first and a second radio frequency demodulator, a first and a second analog-to-digital converter, a first and a second filter, a clear channel assessment device, and a selection device. The radio frequency demodulators convert radio frequency signals to baseband signals, respectively. The analog-to-digital converters convert baseband signals to digital signals, respectively. The filters filter the first and second digital signals to generate filtered signals, respectively. The clear channel assessment device generates a channel assessment signal and a path selection signal according to signal characteristics of the filtered signals. The selection device refers to at least one of the channel assessment signal and path selection signal to selectively output one of the filtered signals, or generate no signal output.Type: GrantFiled: June 12, 2011Date of Patent: August 27, 2013Assignee: Realtek Semiconductor Corp.Inventors: Yu-Nan Lin, Yin-Shao Chang
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Patent number: 8519875Abstract: Various embodiments allow for background calibration of channel-to-channel mismatch errors. In certain embodiments calibration is accomplished by comparing the output of I-ADCs against the output of a reference ADC and correlating the difference to a known function to obtain a correction signal that can be used to correct channel-to-channel mismatch errors.Type: GrantFiled: April 10, 2012Date of Patent: August 27, 2013Assignee: Maxim Integrated Products, Inc.Inventors: Matthew Allen Zornig Straayer, Hae-Seung Lee
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Publication number: 20130216005Abstract: A computer-implemented system and method for blind demodulation of an offset QPSK input signal, involving repeatedly performing a set of operations, including: (a) applying a phase correction to the input signal based on an estimate of a carrier phase offset of the input signal to obtain a first modified signal; (b) shifting a quadrature component of the first modified signal by half a symbol period relative to an inphase component to obtain a second modified signal; (c) extracting a first sequence of symbols from the second modified signal, where the extraction includes estimating a symbol timing offset from the second modified signal; (d) performing hard-decision demodulation on the first sequence of symbols to obtain a second sequence of reference symbols; (e) computing a phase difference between the first sequence of symbols and second sequence of reference symbols; and (f) updating the carrier phase offset estimate using the phase difference.Type: ApplicationFiled: February 17, 2012Publication date: August 22, 2013Inventors: Sartaj Chaudhary, Vijaya Yajnanarayana, I Zakir Ahmed
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Patent number: 8514981Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.Type: GrantFiled: October 29, 2008Date of Patent: August 20, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Yong-deok Chang, Hae-joo Jeong, Joon-soo Kim
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Patent number: 8514950Abstract: A communication apparatus may include a demodulation unit, a waveform memory unit, a decoding unit, an encoding unit, a modulation unit, and a transmission unit. The demodulation unit demodulates a received signal to create a demodulated signal. The waveform memory unit stores the demodulated signal and a waveform of the demodulated signal. The decoding unit decodes the demodulated signal to create a decoded signal. The encoding unit encodes the decoded signal to create an encoded signal. The modulation unit modulates one of the encoded signal to create a modulated encoded signal and the demodulated signal to create a modulated demodulated signal. The transmission unit transmit one of the modulated encoded signal and the modulated demodulated signal according to a reception state of the received signal.Type: GrantFiled: December 18, 2009Date of Patent: August 20, 2013Assignee: Canon Kabushiki KaishaInventors: Norihito Aoki, Tetsuo Kanda
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Patent number: 8514987Abstract: A method and circuitry for detecting a frequency offset (?) between data at a transmission symbol rate (fTx) transmitted from a transmitter and a reception sampling frequency (fRx) operating in a receiver on the basis of hard decision based on a binary number in the receiver. The receiver uses a converter to make binary hard decisions performs n times oversampling, then obtains a symbol decision value, calculates a timing correlation value for each plurality of partition phases, and calculates a cumulative timing correlation value for a specific period or number of additions. The receiver determines whether its sampling frequency is higher or lower than a correct symbol rate, appropriately shifts a sampling position, and makes reception while maintaining the correct sampling position thereby enables data deviation caused by a frequency offset to be compensated on the fly.Type: GrantFiled: December 21, 2010Date of Patent: August 20, 2013Assignee: International Business Machines CorporationInventors: Yasunao Katayama, Daiju Nakano
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Patent number: 8509358Abstract: The device is used for decoding convolution-encoded reception symbols. In this context, transmission data are modulated with a modulation scheme to form symbols, which are encoded with a transmission filter to form convolution-encoded transmission symbols. A convolution-encoded transmission symbol contains components of several symbols arranged in time succession. These transmission symbols are transmitted via a transmission channel and received as reception symbols. The Viterbi decoder decodes the reception symbols by use of a modified Viterbi algorithm. Before running through the Viterbi decoder, the reception symbols are processed by a state-reduction device, which determines additional items of information relating to possible consequential states of the decoding independently of the decoding through the Viterbi decoder in every state of the decoding. The state-reduction device uses the additional items of information to restrict the decoding through the Viterbi decoder to given consequential states.Type: GrantFiled: August 22, 2008Date of Patent: August 13, 2013Assignee: Rohde & Schwarz GmbH & Co. KGInventor: Claudiu Krakowski
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Patent number: 8509320Abstract: A communication circuit is provided which transmits an information bit string from a transmission unit to a reception unit. The transmission unit includes a first modulation circuit that modulates a first carrier wave by a start bit to generate a first frequency signal, a second modulation circuit that modulates a second carrier wave by the information bit string to generate a second frequency signal, and a transmission circuit that transmits the first and second frequency signals from a transmitting antenna. The reception unit includes a reception circuit that receives a signal from the transmission unit, a first detector circuit that detects a signal of the first carrier wave to demodulate the start bit, a second detector circuit that detects a signal of the second carrier wave to demodulate the information bit string, and a detection circuit that is synchronized by the start bit and reads the information bit string.Type: GrantFiled: June 2, 2011Date of Patent: August 13, 2013Assignee: Toyota Boshoku Kabushiki KaishaInventors: Hideki Uno, Koji Yamada, Yuya Makino
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Patent number: 8509354Abstract: Improved spur reduction architectures that improve linearity in direct radio frequency (RF) receiver architectures. Non-uniform sampling in the form of sampling clock phase (or frequency) modulation is used to induce phase (or frequency) modulation on signals that are being received from a given Nyquist zone. At the output of the ADC (analog-to-digital converter), the signals are de-modulated to remove the induced modulation based on the Nyquist zone that is being received. The de-modulation process results in non-desired spurious artifacts (interfering leakage signals and ADC spurs) being spread in the frequency domain. Strong spurious artifacts may be removed after measuring the induced modulation and de-modulating. For the case of weak spurious artifacts, the de-modulation for the desired Nyquist zone spread these signals in the frequency domain. Induced modulation on signals may also provide a dithering effect on the ADC.Type: GrantFiled: December 2, 2009Date of Patent: August 13, 2013Assignee: L—3 Communications Integrated Systems L.P.Inventors: Gerald L. Fudge, Ross E. Bland, Sujit Ravindran, Mark A. Chivers
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Publication number: 20130202062Abstract: Systems and methods for detecting collisions in radio frequency tags in accordance with embodiments of the invention are disclosed. In one embodiment, a receiver system 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, a collision detector configured to calculate a decision metric from a set of soft metrics generated by the multiple symbol noncoherent soft output detector and detect a collision when the decision metric satisfies a predetermined criterion.Type: ApplicationFiled: March 15, 2013Publication date: August 8, 2013Applicant: Mojix, Inc.Inventor: Mojix, Inc.
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Patent number: 8503574Abstract: A transmitter includes an encoding module, an adaptive hierarchical signal mapping module and a transceiver module. The encoding module receives an input signal and encodes the input signal. The input signal includes data to be transmitted. The adaptive hierarchical signal mapping module modulates the encoded signal according to one or more hierarchical level distance ratios to obtain modulated symbols. The hierarchical level distance ratio defines distances between the modulated symbols. The transceiver module generates a radio frequency signal according to the modulated symbols and transmits the radio frequency signal to an air interface.Type: GrantFiled: May 24, 2010Date of Patent: August 6, 2013Assignee: National Taiwan UniversityInventors: Jing-Shown Wu, Hen-Wai Tsao, Yang-Han Lee, Yu-Lin Shiao
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Patent number: 8503578Abstract: A method of processing first and second corresponding signals having a delay therebetween. The method includes introducing a plurality of different delays between the first and second signals, successive delay amounts differing from each other by less than the interval between chip boundaries, and for each introduced delay, summing samples of the second signal which are obtained at the times of, at least, chip boundaries between bits of the first signal which have the same state, to obtain a value; thereby to obtain a representation of how the value varies according to the introduced delay, which representation contains a level change associated with an introduced delay which bears a predetermined relationship to the delay between the first and second signals.Type: GrantFiled: March 27, 2008Date of Patent: August 6, 2013Assignee: Mitsubishi Electric CorporationInventor: Nongji Chen
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Patent number: 8503559Abstract: A system and method for non-uniform bit allocation in the quantization of channel state vectors is provided. A method for communications node operation includes receiving a bit-allocation profile for use in quantizing channel state information, measuring a communications channel between the communications node and a controller, generating channel state information based on the measurement, computing a bit representation of the channel state information, transmitting the bit representation to the controller, and receiving a transmission from the controller. The computing makes use of quasi-tail-biting trellis decoding, and the computing is based on the bit-allocation policy. The transmission makes use of the channel state information transmitted by the communications node.Type: GrantFiled: September 11, 2012Date of Patent: August 6, 2013Assignee: FutureWei Technologies, Inc.Inventors: Chun Kin Au-Yeung, Shahab Sanayei
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Publication number: 20130195224Abstract: A receiver is described. The receiver includes a filter configured to receive a quadrature phase shift keying (“QPSK”) signal. Further, the receiver includes an amplifier coupled with the filter. And, a QPSK decomposition filter is coupled with the amplifier. The QPSK decomposition filter is configured to generate a first BPSK signal based on the QPSK signal and a second BPSK signal based on the QPSK signal.Type: ApplicationFiled: January 30, 2013Publication date: August 1, 2013Applicant: Innophase Inc.Inventor: Innophase Inc.
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Patent number: 8498364Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.Type: GrantFiled: October 29, 2008Date of Patent: July 30, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Yong-deok Chang, Hae-joo Jeong, Joon-soo Kim
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Patent number: 8494102Abstract: Methods and corresponding systems for providing and demodulating an orthogonal modulated signal where demodulation includes separating a sampled orthogonal modulated signal into in phase and quadrature samples, deriving first and second equalizer coefficients based on corresponding in phase and quadrature samples and further, respectively, based on a first and second training sequence, programming a first plurality of equalizer filters with the first equalizer coefficients and a second plurality of equalizer filters with the second equalizer coefficients; and processing, after programming with first and second coefficients, the in phase samples and the quadrature samples through a first and second plurality of equalizer filters to provide demodulated symbols.Type: GrantFiled: September 9, 2010Date of Patent: July 23, 2013Assignee: Freescale Semiconductor, Inc.Inventors: Weizhong Chen, Leo G. Dehner
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Patent number: 8488719Abstract: A wireless communications device may be configured to perform a first demodulation based upon a first sampling rate of a received signal to generate a first demodulated signal and determine therefrom whether a first error value is not greater than a first threshold, and, if so then decode the first demodulated signal. If the first error value is greater than the first threshold, a second demodulation is performed based upon a second sampling rate of the received signal greater than or equal to the first sampling rate to generate a second demodulated signal and determine therefrom whether a second error value is not greater than a second threshold, and, if so, then decode the second demodulated signal. If the second error value is greater than the second threshold, the second demodulation is performed at least one additional time with at least one change thereto.Type: GrantFiled: August 12, 2010Date of Patent: July 16, 2013Assignee: Harris CorporationInventors: John W. Nieto, William N. Furman
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Patent number: 8489134Abstract: A method is provided in one example implementation and the method includes interacting, via a first communication resource manager located in a first domain, with a second communication resource manager located in a second domain. The method further includes determining whether to establish a link for multicasting between users in the first domain and users in the second domain, and the link between the domains is established based on presence data of at least one user in the first domain and at least one user in the second domain.Type: GrantFiled: September 2, 2008Date of Patent: July 16, 2013Assignee: Cisco Technology, Inc.Inventors: Zeeshan Khan, Keith Edmund O'Brien, Shmuel Shaffer
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Patent number: 8483339Abstract: Provided is a communication apparatus and a communication process method that improve reception quality when receiving a signal using a plurality of antennas. The communication apparatus includes an RF tuner that receives a wireless signal by the plurality of antennas, a noise amount detection unit that measures the amount of noise of each antenna according to the wireless signal received by the RF tuner, and a time-division timing generation unit that switches a selection of the plurality of antennas by time-division. The time-division timing generation unit periodically switches the plurality of antennas. Further, the time-division timing generation unit makes a selection so that the antenna with the best reception quality has a relatively longer selected period than the other antennas.Type: GrantFiled: November 23, 2010Date of Patent: July 9, 2013Assignee: Renesas Electronics CorporationInventor: Masao Watanabe
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Patent number: 8483335Abstract: A hybrid receiver apparatus, a method, and a computer readable storage media encoded with a program are provided. The hybrid receiver apparatus a first receiver processor and a second receiver processor and a signal input by the hybrid receiver apparatus is processed by both the first receiver processor and the second receiver processor. The hybrid receiver apparatus includes a combiner unit combining data output from the first receiver processor with data output from the second receiver processor based on a weight values assigned to the data.Type: GrantFiled: January 30, 2009Date of Patent: July 9, 2013Assignee: Nokia Siemens Networks OyInventors: Khairul Hasan, Eric Jones, Bruce Lee, Mikko Saily, Sathiaseelan Sundaralingam
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Patent number: 8483647Abstract: Data is received that has been transmitted via a combination of radio frequency signals using carrier aggregation, each radio frequency signal occupying a respective radio frequency band, the bands being arranged in two groups separated in frequency by a first frequency region, the first of the two groups occupying a wider frequency region than the second group. Embodiments provide a method and apparatus for downcoverting the radio frequency signals using quadrature mixing to give inphase and quadrature components, and the inphase and quadrature components are filtered using a first bandpass filter bandwidth to give first bandpass filtered inphase and quadrature components and filtered using a second bandpass filter bandwidth, different from the first bandpass filter bandwidth, to give second bandpass filtered inphase and quadrature components.Type: GrantFiled: November 15, 2012Date of Patent: July 9, 2013Assignee: Renesas Mobile CorporationInventors: Jouni Kristian Kaukovuori, Aarno Tapio Parssinen, Antti Oskari Immonen
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Patent number: 8483303Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.Type: GrantFiled: October 29, 2008Date of Patent: July 9, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Yong-deok Chang, Hae-joo Jeong, Joon-soo Kim
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Patent number: 8477880Abstract: In a multi-input multi-output communication system receiving signals transmitted through a plurality of transmission antennas by using a plurality of reception antennas, a matrix determining a position of a symbol to be detected from a received signal is calculated at a first symbol detection step, and from the subsequent step, a matrix at the current step is acquired through a simple relationship from the matrix calculated at the previous step to determine a position of a symbol to be detected.Type: GrantFiled: December 2, 2009Date of Patent: July 2, 2013Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research InstituteInventors: Young Jo Bang, Young Ha Lee, Jung Pil Choi, Hoon Lee, Seungjae Bahng, Youn Ok Park, Il Min Kim
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Patent number: 8477248Abstract: A system and method for demodulating signals are disclosed. In a particular embodiment, the method includes receiving a signal at an input and determining a first noise estimate of the signal. The method also includes providing a first output indicating a second noise estimate of the signal at a primary carrier frequency and providing a second output indicating a third noise estimate of the signal at a secondary carrier frequency.Type: GrantFiled: July 9, 2007Date of Patent: July 2, 2013Assignee: Sigmatel, Inc.Inventors: Jon David Hendrix, Jeffrey Donald Alderson, Glen Ragan
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Patent number: 8477893Abstract: A receiver includes a select module, an enable module, and a receiver module. The select module is configured to detect (i) a number of antennas in the receiver, or (ii) a number of enabled receiver paths in the receiver. The select module is also configured to generate a receiver select signal and an adjustment signal based on (i) the number of antennas detected, or (ii) the number of enabled receiver paths detected. The enable module is configured to, based on the receiver select signal, (i) determine that at least one of the enabled receiver paths is an unnecessary receiver path, and (ii) disable the at least one of the enabled receiver paths. The receiver module is configured to, based on the adjustment signal, adjust a bandwidth of the receiver or coefficient values of the receiver.Type: GrantFiled: February 27, 2012Date of Patent: July 2, 2013Assignee: Marvell World Trade Ltd.Inventors: Zhiyu Yang, Hongyuan Zhang
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Patent number: 8477884Abstract: A reception apparatus including: a detection unit detecting extrinsic information based on a tentative symbol decision signal, a channel estimation signal, a noise variance estimation signal, and a received signal that are obtained from a previous iteration process; a Cyclic Redundancy Check (CRC) aided channel decoding unit outputting an interleaved bit or a posteriori information thereof based on the extrinsic information; a tentative symbol decision unit determining a tentative transmission symbol based on an output of the CRC aided channel decoding unit; a channel estimation unit estimating a channel based on an output of the tentative symbol decision unit; and a noise variance estimation unit estimating a noise variance based on the output of the tentative symbol decision unit and an output of the channel estimation unit is provided.Type: GrantFiled: December 11, 2008Date of Patent: July 2, 2013Assignee: Electronics and Telecommunications Research InstituteInventors: Seong Rag Kim, Junyoung Nam, Hyun Kyu Chung
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Patent number: 8477889Abstract: A method and apparatus for compensating a modulation imbalance effect in a communication device. In one embodiment, at least three sets of modulation imbalance parameters (MIPs) are estimated by executing an auto balance sequence. The at least three sets of MIPs correspond to a baseband signal configured to have at least three configurable frequencies, each of the at least three sets of MIPs corresponds to one of at least three configurable frequencies. The auto balance sequence is configured to provide an offset signal generated within a communication device to trigger generation of each one of the at least three configurable frequencies. The at least three sets of MIPs are filtered to select a filtered set. The modulation imbalance effect is compensated by using the filtered set to reduce distortion of the baseband signal in the communication device.Type: GrantFiled: February 25, 2010Date of Patent: July 2, 2013Assignee: Texas Instruments IncorporatedInventors: Jaiganesh Balakrishnan, Prashant Kota
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Patent number: 8477876Abstract: A method for searching a digital transmission having unknown carrier and symbol frequencies in a modulated reception signal, includes performing successive trials of several carrier and symbol frequencies, using decreasing values of the symbol frequency, demodulating the reception signal with the tried carrier frequency, filtering the demodulated signal in a band having a width corresponding to the currently tried symbol frequency, and producing samples of the filtered signal. For each currently tried symbol frequency, forming a complex indicator having a real component and an imaginary component established from the successive samples of the filtered signal such that they have cyclostationary properties and that one of the components tends to cancel when the other component tends towards a relative maximum, building the spectrum of the variation of the complex indicator, searching for a singular spike in the spectrum, and determining the real symbol frequency from the frequency of the spike.Type: GrantFiled: December 23, 2011Date of Patent: July 2, 2013Assignee: STMicroelectronics (Grenoble) SASInventor: Jacques Meyer
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Patent number: 8472560Abstract: A mixed-mode signal detection apparatus suitable for ISO/IEC 14443 Type A and Type B RFID proximity card applications. The apparatus combines switched capacitor sampling and digital post processing to recover information from Amplitude Shift Keying (ASK) modulated signals. A phase detector triggers a pulse generator, which is used to signal sample and hold units that store the peak value of each carrier signal cycle. The samples are used to form a discrete version of the modulation signal and are post-processed digitally to recover encoded signal information.Type: GrantFiled: November 2, 2010Date of Patent: June 25, 2013Assignee: SecureKey Technologies Inc.Inventors: Afshin Rezayee, Yue Yang
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Patent number: 8472564Abstract: An automatic zero-crossing signal demodulation and classification device for rapidly identifying unknown modulation in a signal identifies unknown modulation in a signal, demodulates differential phase shift keying signals and automatically recognizes certain phase shift keying signals. This is accomplished by eliminating unknown term fc in differential phase estimation, introducing a symbol rate tracking mechanism, applying hysteresis nonlinearity to eliminate phase shaping effect and using weighted average to estimate phase difference. Better estimates are accomplished by using hysteretic nonlinear function to detect zero-crossing points in eliminating false detecting of zero-crossing points caused by additive noise, and calculating differential phase without directly using center frequency to simplify estimation process.Type: GrantFiled: April 2, 2012Date of Patent: June 25, 2013Assignee: The United States of America as represented by the Secretary of the ArmyInventor: Wei Su
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Patent number: 8467478Abstract: An apparatus includes a selection unit that selects an estimation target path to be used to estimate a propagation channel estimation value, among a plurality of paths based on a characteristic value of each path; a determination unit that determines an estimated reception time at which a signal as a target of estimation of the propagation channel estimation value among signals propagating through the estimation target path is received; an estimation unit that estimates an amplitude and a phase of the signal propagating through the estimation target path at the estimated reception time as a propagation channel estimation value of the estimation target path; and a processing unit that performs an interpolation/extrapolation process using the propagation channel estimation value of the estimation target path to estimate the propagation channel estimation value at a time other than the estimated reception time of the signal propagating through the estimation target path.Type: GrantFiled: March 30, 2011Date of Patent: June 18, 2013Assignee: Fujitsu LimitedInventors: Makoto Yoshida, Yasuharu Amezawa, Kazuyuki Ozaki
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Patent number: 8467462Abstract: To suppress effects produced on other terminals as much as possible, while obtaining the advantage of soft-combining. A multicarrier receiving apparatus that receives a packet comprised of at least a propagation path estimation symbol and a scrambled information symbol to demodulate, and has propagation path estimating sections 3-a and 3-b that respectively estimate propagation paths of radio signals transmitted from a plurality of transmission antennas, scramble multiplying sections 5-a and 5-b that respectively perform the same scrambling on propagation path estimation values output from the propagation path estimating sections 3-a and 3-b as scrambling provided in the information symbol on the transmission antennas sides, an adding section 3-c that adds scrambled propagation path estimation values, and a propagation path compensating section 7 that performs propagation path compensation of the information symbol included in the received packet using a signal output from the adding section 3-c.Type: GrantFiled: November 15, 2006Date of Patent: June 18, 2013Assignee: Sharp Kabushiki KaishaInventors: Yasuhiro Hamaguchi, Minoru Kubota, Shimpei To, Shoichi Shitara, Kimihiko Imamura
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Publication number: 20130148967Abstract: A distortion compensator, an optical receiver and a transmission system including an operation selectively compensating for linear waveform distortion exerted on an optical signal via a plurality of distortion compensators and compensating for nonlinear waveform distortion exerted on the optical signal using nonlinear distortion compensators.Type: ApplicationFiled: February 11, 2013Publication date: June 13, 2013Applicant: FUJITSU LIMITEDInventor: FUJITSU LIMITED
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Patent number: 8462890Abstract: A method and apparatus for jointly decoding a first and second message is disclosed. The signaling scenario illustrated by FIG. 1 and using the codeword properties defined herein, the various embodiments may combine multiple messages under the hypothesis that the value of a message portion corresponding any subsequent observed transmission is different. Accordingly a first buffer may store the first observed message frame (509) and a second buffer may sum the LLR's of subsequent observed frames (513). In the embodiments disclosed, two decoding hypotheses are required only; a first where the two buffers are combined directly (513) and a second where the difference codeword bit LLR's of the first buffer (509) are inverted before combining with those of the second buffer (519). A maximum of N transmissions is allowed by the receiver (523), after which a decoding failure is declared.Type: GrantFiled: July 23, 2008Date of Patent: June 11, 2013Assignee: Motorola Mobility LLCInventors: Kenneth A. Stewart, Michael E. Buckley, Olivier Peyrusse, Jeffrey C Smolinske
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Patent number: 8462887Abstract: 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: GrantFiled: August 19, 2011Date of Patent: June 11, 2013Assignee: Marvell International Ltd.Inventors: King Chun Tsai, Patrick Clement, David Cousinard
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Patent number: 8462889Abstract: A system and method for receiving a RF signal, comprising a device for digitizing, without prior alteration of frequency, an analog RF representation of each of a plurality of RF signals to produce a respective plurality of digital RF signals having a respective associated RF digital clock, the plurality of digital RF signals having a sufficiently high respective associated clock rate to preserve an information content of an information communication present in the analog RF representation; a switch matrix adapted to concurrently switch the plurality of digital RF signals and associated digital RF 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 produce processed representations of information contained in respective analog RF representations.Type: GrantFiled: December 28, 2007Date of Patent: June 11, 2013Assignee: Hypres, Inc.Inventor: Deepnarayan Gupta
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Patent number: 8462837Abstract: A device of dynamic communication of information allows, on the average, non-integer bits per symbol transmission, using a compact code set or a partial response decoding receiver. A stream of selectable predetermined integer bits, e.g., k or k+1 data bits, is grouped into a selectable integer number of bit vectors which then are mapped onto corresponding signal constellations forming transmission symbols. Two or more symbols can be grouped and further encoded, so that a symbol is spread across the two or more symbols being communicated. Sequence estimation using, for example, maximum likelihood techniques, as informed by noise estimates relative to the received signal. Each branch metric in computing the path metric of a considered sequence at the receiver is weighted by the inverse of the noise power. It is desirable that the constellation selection, sequence estimation and noise estimation be performed continuously and dynamically.Type: GrantFiled: October 14, 2011Date of Patent: June 11, 2013Assignee: Broadcom CorporationInventors: Thuji Simon Lin, Steven Jaffe, Robindra Joshi
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Patent number: 8462886Abstract: According to one embodiment, a mobile wireless terminal device includes a receiver detecting a beacon and a communication module detecting a base station identification. The receiver comprises an accumulation module accumulating levels of a sampling received wireless signal to obtain a reception profile, a correlation module detecting a shift amount maximizing a correlation between a present reception profile and a past reception profile, a first detector detecting a beacon, when a difference between the detected shift amount and a default amount is larger than a predetermined amount, in accordance with a difference between a shifted profile by the default amount, and the present reception profile, and a second detector which detects a beacon, when the difference is not larger than the predetermined amount, in accordance with a difference between a shifted profile by the detected shift amount, and the present reception profile.Type: GrantFiled: October 6, 2011Date of Patent: June 11, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Yuki Hayashi, Kengo Kurose
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Patent number: 8462896Abstract: A reception unit receives data from communication apparatuses. A transmission unit transmits data to the communication apparatuses. A control unit determines, in an adaptive way, which modulation and coding schemes to use to transmit and receive data. At a first stage, a modulation and coding scheme with a low transmission rate or a modulation and coding scheme that minimizes power requirements is selected from among a plurality of candidates therefor. At a second stage, the modulation and coding scheme of at least one of the communication apparatuses is changed to another scheme having a higher transmission rate, when it is impossible to allocate sufficient resources for the modulation and coding schemes selected at the first stage.Type: GrantFiled: July 20, 2012Date of Patent: June 11, 2013Assignee: Fujitsu LimitedInventors: Junichi Suga, Keiichi Nakatsugawa
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Publication number: 20130142286Abstract: A wireless communications device includes a receiver, and a demodulator coupled downstream from the receiver and configured to use a continuous phase modulation (CPM) waveform to non-coherently demodulate a received signal. The demodulator is configured to generate waveform banks, each waveform bank having a respective different frequency offset associated therewith, determine a correlation output metric for each waveform bank, select a waveform bank for demodulating the received signal based upon the correlation output metrics of the waveform banks, and demodulate the received signal using the selected waveform bank and the associated frequency offset.Type: ApplicationFiled: December 6, 2011Publication date: June 6, 2013Applicant: Harris Corporation, Corporation of the State of DelawareInventors: James A. Norris, John W. Nieto