Locating Predetermined Portion Of Pulse Patents (Class 375/342)
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Patent number: 8144822Abstract: A noise power estimation apparatus is disclosed. The noise power estimation apparatus includes: a part for calculating correlation between a received signal and a pilot signal so as to obtain a received power of the pilot signal for each path; a part for removing a multipath interference component from the received power of the pilot signal by using a predetermined power ratio between the pilot signal and a data signal so as to obtain a corrected received power of the pilot signal; a part for estimating an estimated total power of the pilot signal and the data signal included in the received signal based on the corrected received power and the predetermined power ratio; and a part for subtracting the estimated total power from a total power of the received signal so as to obtain a noise power.Type: GrantFiled: May 8, 2008Date of Patent: March 27, 2012Assignee: NTT DoCoMo, Inc.Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8139681Abstract: A communications signal is received through a propagation channel, down-converted in frequency and then converted into a digital signal. The samples of the digital signal are processed to estimate the information conveyed by the communications signal. The estimated information is then used with knowledge about the propagation channel to model the samples of the digital signal. The modeled samples are compared with actual samples of the digital signal to deduce phase errors in the digital signal. The phase errors are then used to deduce a frequency error in the digital signal that can be used to correct the samples of the digital signal and to correct the down-conversion process.Type: GrantFiled: September 9, 2005Date of Patent: March 20, 2012Assignees: MStar Semiconductor, Inc., MStar Software R&D, Ltd., MStar France SAS, MStar Semiconductor, Inc.Inventors: James Chapman, Simon Richardson, Cyril Valadon, Navid Fatemi-Ghomi
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Patent number: 8139696Abstract: A method is provided of characterising a data stream of binary symbols, the method comprising sampling the stream at a predetermined rate sufficient to capture at least two samples per binary symbol, identifying the shortest continuous run of samples having the same logic level and assigning a symbol rate to the stream on the basis that the identified run is one symbol in length.Type: GrantFiled: July 1, 2005Date of Patent: March 20, 2012Assignees: MStar Semiconductor, Inc., MStar Software R&D, Ltd., MStar France SAS, MStar Semiconductor, Inc.Inventor: Richard Neil Hunt
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Patent number: 8135080Abstract: A receiver circuit in each branch has an FFT unit that performs Fourier transform on OFDM signals. A slave branch FFT window control unit determines whether an undesired wave is a preceding wave or a delay wave, and notifies a master branch of the result. In response to the notification from the slave branch, a master branch FFT window control unit controls a position of an FFT window that indicates a time range in which Fourier transform is performed on OFDM signals.Type: GrantFiled: July 29, 2008Date of Patent: March 13, 2012Assignee: Fujitsu Semiconductor LimitedInventors: Naoto Adachi, Makoto Hamaminato
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Patent number: 8121229Abstract: A guard section length detection method detects whether a preamble signal is received. A short preamble boundary is then detected, then detecting a frame boundary and detecting a guard section length. In the step of detecting the guard section length a second matched filter capable of processing 128 point data sets is detected. Four different 128 point data sets have a distance of 8 points, 16 points, 32 points, and 64 points respectively from the frame boundary to the second matched filter. Four signal correlation values are calculated for determining the guard section length.Type: GrantFiled: July 11, 2007Date of Patent: February 21, 2012Assignee: Industrial Technology Research InstituteInventors: Chun-Chun Kuo, Jen-Yuan Hsu, Chao-Kai Wen, Pang-An Ting
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Patent number: 8121228Abstract: A detector (109) and corresponding method is configured for detecting presence of a data frame. The detector includes a first correlator (123) that is configured to provide a first plurality of correlations corresponding to similarity between data as received and first information, e.g., an ordered set of coefficients, that denotes the data frame and a second correlator (125) that is configured to provide a second plurality of correlations corresponding to similarity between the data as received and second information, e.g., another ordered set of coefficients, that denotes the data frame, where the second information includes a portion of the first information. Further included is decision logic (129) coupled to the first correlator and the second correlator, where the decision logic is configured to provide an indication (111) that the data frame is present based on the first plurality of correlations and the second plurality of correlations.Type: GrantFiled: November 4, 2005Date of Patent: February 21, 2012Assignee: Freescale Semiconductor, Inc.Inventor: Robert M. Gorday
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Patent number: 8116418Abstract: A clock data recovery comprises a phase detector, a phase interpolator, an initial phase detector, and an initial phase decoder. The phase detector receives an incoming data stream and an interpolated clock signal and output an early/late value indicating timing relationship between the incoming data stream and the interpolated clock signal. The phase interpolator receives the early/late signal and at least one reference clock signal and generate an interpolated clock signal considering the early/late value and the at least one reference clock signal. The initial phase detector receives the incoming data stream and output a first data indicating a phase of the incoming data stream. The initial phase decoder receives data indicating a phase of the incoming data stream and select the at least one reference clock signal from a plurality of clock signals considering the data indicating a phase of the incoming data stream.Type: GrantFiled: July 31, 2008Date of Patent: February 14, 2012Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.Inventor: Jinn-Yeh Chien
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Patent number: 8116402Abstract: Systems and methods for cognitive radio are disclosed herein. Specifically, embodiments of the present invention may provide systems, methods and apparatuses for a cognitive radio which is operable to tailor its operation based on one or more criteria, which may pertain to the operating environment of the radio. In one embodiment, a cognitive radio may be operable to determine criteria associated with potentially interfering signals in the operating environment and determine corresponding transmission properties corresponding to protocol, power level, frequency, coding or timing of transmissions, so that these potentially interfering signals may be avoided or otherwise accounted for by transmitting according to these transmission properties.Type: GrantFiled: March 14, 2007Date of Patent: February 14, 2012Assignee: Alereon, Inc.Inventor: James L. Lansford
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Patent number: 8107548Abstract: A digital broadcast transmitting/receiving system and a signal processing method thereof that can improve the receiving performance of the system. A digital broadcast transmitter has a randomizer to randomize an input data stream which has null bytes being inserted at a specified position, a multiplexer to output a data stream formed by inserting specified known data into the position of the null bytes of the randomized data stream, an encoder to encode the data stream outputted from the multiplexer, and a modulator/RF-converter to modulate the encoded data, RF-convert the modulated data and transmit the RF-converted data. The receiving performance of the digital broadcast transmitting/receiving system can be improved even in a multi-path channel by detecting the known data from the received signal and using the known data in synchronization and equalization in a digital broadcast receiver.Type: GrantFiled: October 1, 2009Date of Patent: January 31, 2012Assignee: Samsung Electronics Co., Ltd.Inventors: Hae-joo Jeong, Yong-deok Chang
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Patent number: 8098647Abstract: A method of performing cell search includes receiving a primary synchronization signal (PSS) comprising a primary synchronization code (PSC), and receiving a secondary synchronization signal (SSS) comprising a first secondary synchronization code (SSC) and a second SSC. The first SSC and the second SSC are respectively scrambled by using a first scrambling code and a second scrambling code, and the first scrambling code and the second scrambling code are associated with the PSC. Detection performance on synchronization signals can be improved, and cell search can be performed more reliably.Type: GrantFiled: December 18, 2009Date of Patent: January 17, 2012Assignee: LG Electronics Inc.Inventors: Seung Hee Han, Min Seok Noh, Yeong Hyeon Kwon, Hyun Woo Lee, Dong Cheol Kim, Jin Sam Kwak
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Patent number: 8086257Abstract: In a method of detecting a signal, a control channel associated with a physical channel may be decoded to produce at least one decoding metric. A control channel signal on the control channel may then be detected based on the decoding metric.Type: GrantFiled: August 11, 2005Date of Patent: December 27, 2011Assignee: Alcatel LucentInventors: Rainer Bachl, Francis Dominique, Hongwei Kong, Walid E. Nabhane
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Patent number: 8085884Abstract: A method and apparatus for processing satellite positioning system signals at a mobile receiver is described. In one example, first bit-transitions within satellite navigation data transmitted by at least one satellite are estimated at the mobile receiver. A bit pattern is generated that includes a known preamble and an extended preamble. The extended preamble includes expected data bits within the satellite navigation data. The first bit-transitions are compared with second bit-transitions of the bit pattern to generate match data.Type: GrantFiled: August 15, 2008Date of Patent: December 27, 2011Assignee: Broadcom CorporationInventors: Charles Abraham, Emre Tapucu
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Patent number: 8081719Abstract: A method and system for improving reception in wired and wireless systems through redundancy and iterative processing are provided. A multilayer decoding process may comprise a burst process and a frame process. Results from a first burst process may be utilized to generate a decoded bit sequence in the frame process. The frame process may utilize redundancy information and physical constraints to improve the performance of a decoding algorithm. Results from the frame process may be fed back for a second iteration of the burst process and of the frame process, to further improve the decoding operation. In some instances, the second iteration of the burst process may be based on a gradient search approach.Type: GrantFiled: April 27, 2010Date of Patent: December 20, 2011Assignee: Broadcom CorporationInventors: Arie Heiman, Arkady Molev-Shteiman
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Patent number: 8077592Abstract: Various packet processing systems and methods are disclosed. One method embodiment, among others, comprises providing a legacy long training symbol (LTS), and inserting subcarriers in the legacy LTS to form an extended LTS (ELTS).Type: GrantFiled: July 21, 2005Date of Patent: December 13, 2011Assignee: Intellectual Ventures I LLCInventors: Mark A. Webster, Michael J. Seals
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Patent number: 8077808Abstract: Disclosed is a radio wave receiver including: a receiving unit to receive a radio wave including a time code in which a plurality of types of data pulse different in pulse width from one another are arranged with a predetermined period of time; a detection circuit to detect the time code in the radio wave received by the receiving unit to obtain a detected signal; a low-pass filter to pass low-frequency components in the detected signal detected by the detection circuit, a cutoff frequency of the low-pass filter being twice a transmit frequency of the data pulse or less; and a data distinction unit to distinguish the types of data pulse based on an output of the low-pass filter for at least one specific point of time during a transmit period of data pulse.Type: GrantFiled: January 14, 2009Date of Patent: December 13, 2011Assignee: Casio Computer Co., Ltd.Inventor: Kaoru Someya
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Patent number: 8073045Abstract: An adaptive slicer threshold is derived from averages of maximum and minimum values of the received signal, the method comprising the steps of: —averaging (86) several detected maximum values and averaging several detected minimum values, and —calculating (86) the slicer threshold from these average minimum and maximum values.Type: GrantFiled: December 15, 2004Date of Patent: December 6, 2011Assignee: ST-Ericsson SAInventors: Roland Mattheus Maria Hendricus Van Der Tuijn, Yoann Bouvet
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Patent number: 8073085Abstract: A gain controller for a wireless communication system sets the receiver gain during the initial time duration of a preamble, and for each subsequent symbol computes a new gain value, which is applied at the end of each symbol. An analog to digital converter resolution controller sets the resolution of the ADC to a high resolution during a preamble interval and a first symbol interval, and to a comparatively lower resolution thereafter until the end of the frame. When a new zone is entered, the first symbol of the new zone is sampled at a higher resolution than the subsequent symbols.Type: GrantFiled: July 7, 2007Date of Patent: December 6, 2011Assignee: Redpine Signals, Inc.Inventors: Karthik Vaidyanathan, Partha Sarathy Murali
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Patent number: 8064547Abstract: A receiving apparatus includes a unit detecting a specific-bit sequence included in a data sequence, a unit counting, as a count value n1, a first number of oscillations during a 1-bit-wide period of a first bit of the specific-bit sequence, and to count, as a count value n2, a second number of oscillations during a 1-bit-wide period of a second bit of the specific-bit sequence, a unit generating, when it is determined that the n1 is not less than the (n2?a) and is not more than the (n2+a) (a=1,2, . . . ), a timing of n1/2, fractions of which are carried, for the first bit to a third bit of the specific-bit sequence, and to generate a timing of n1 for a fourth bit and subsequent bits, and a unit acquiring a data sequence from the data sequence at the timing n1/2 and the timing n1.Type: GrantFiled: July 24, 2008Date of Patent: November 22, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Toshiyuki Umeda, Shoji Otaka
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Patent number: 8064557Abstract: A programmable synchronizing unit for a signal receiver has a received data memory for buffering received data, a correlation value data memory for storing correlation values, a data path for correlating the received data with the correlation values, a result data memory for buffering the received data correlated with the correlation values by means of the data path, and a control unit for addressing the received data memory, the result data memory and the correlation value data memory (26) and for controlling the data path as a function of a synchronization program which is stored in a program memory.Type: GrantFiled: November 17, 2000Date of Patent: November 22, 2011Assignee: Infineon Technologies AGInventors: Burkhard Becker, Markus Doetsch, Peter Jung, Tideya Kella, Joerg Plechinger, Peter Schmidt, Sven Simon, Michael Schneider
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Publication number: 20110274220Abstract: A method and corresponding apparatus are provided to reduce the complexity of calculations needed to determine the time of arrival of position reference signals transmitted from multiple cells. A scheduler determines at a given instance what portions of a search grid or search window to search. A timing estimation circuit operating under the control of the scheduler computes timing estimates and reports the timing estimates back to the scheduler. The scheduler uses the timing estimates reported by the detection circuit to scheduler subsequent searches of the search grid or search window.Type: ApplicationFiled: May 10, 2010Publication date: November 10, 2011Applicant: Telefonaktiebolaget L M Ericsson (publ)Inventors: Niklas Andgart, Joakim Axmon
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Patent number: 8050367Abstract: Input average levels and output average levels of digital channel filters 217 and 218 are computed in amplitude calculation circuits 101 and 102. In a gain difference calculation circuit 103, a gain difference of the input levels and the output levels is computed as a multiplier ? so that a difference between the input levels and the output levels are eliminated or adjusted to be within a certain value. The outputs of the digital channel filters 217 and 218 are multiplied by the multiplier ? in multiplier units 104 and 105. The multiplication results are outputted as corrected digital signals to a subsequent digital signal processing circuit.Type: GrantFiled: September 14, 2006Date of Patent: November 1, 2011Assignee: NEC CorporationInventor: Masaki Ichihara
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Patent number: 8045651Abstract: Aspects of a method and system for redundancy-based decoding in 8-PSK GSM systems are provided. A burst process may utilize a gradient search equalization operation to process a received 8-PSK modulated symbol sequence. A frame process may generate a redundancy-based decoded output bit sequence based on the burst process results. Iterative steps of the gradient search equalization operation may be utilized to converge to the burst process results. The redundancy-based decoded output bit sequence of the frame process may be fed back to a subsequent burst process. Results from the subsequent burst process may be utilized to generate a subsequent redundancy-based decoded output bit sequence by a subsequent frame process. The fed-back redundancy-based decoded output bit sequence may be combined with results from a Viterbi equalization operation within the subsequent burst process. Symbol-to-bits and bits-to-symbol conversions may be utilized during the burst process and during the subsequent burst process.Type: GrantFiled: July 11, 2006Date of Patent: October 25, 2011Assignee: Broadcom CorporationInventors: Arie Heiman, Arkady Molev-Shteiman
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Patent number: 8045653Abstract: Detection method and device for a receiver in a digital communication system designed to process a frame comprising a periodic sub-set of length n, said method comprising the following steps:—determining a first vector u having a length n;—determining a second shifted vector v;—calculating a correlation function between said first and second vectors;—calculating a quadratic error function between said first and second vectors;—calculating a first cost function that is a linear combination of both preceding functions and, according to the sign of the result,—calculating a second cost function of frame beginning estimate; and—starting the communication system receiver.Type: GrantFiled: September 15, 2004Date of Patent: October 25, 2011Assignees: STMicroelectronics S.A., Commissariat a l'Energie AtomiqueInventors: Thierry Lenez, Patrice Lenez, legal representative, Jean-Benoit Pierrot, Olivier Isson
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Patent number: 8045654Abstract: A method of detecting a signal in an input channel of a receiver includes applying each of a plurality of pre-detection bandwidths to an input signal. The method can include deriving, in a cascaded fashion, a plurality of pre-detection bandwidths for the input channel, and determining a temporal and spectral extent of pulsed energy in each of the plurality of pre-detection bandwidths. The derivation of the pre-detection bandwidths for the input channel can be performed by dividing the input channel into a sequence of smaller bandwidth sub-channels, so that the number of sub-channels is determined by how much bandwidth and pulse width range is able to be covered by a single detector.Type: GrantFiled: September 26, 2008Date of Patent: October 25, 2011Assignee: Lockheed Martin CorporationInventor: Robert Anderson
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Patent number: 8031815Abstract: A system for processing a received signal having at least one code applied thereto, the received signal having a frequency, the system comprising: first correlator circuitry arranged to correlate the received signal with a first code to provide an output; second correlator circuitry arranged to correlate the received signal with a second code to provide an output, wherein the first code and the second code are different; and processor for processing together the outputs of the first and second correlator circuitry to cancel the frequency.Type: GrantFiled: May 10, 2006Date of Patent: October 4, 2011Assignee: STMicroelectronics (Research & Development) LimitedInventor: Philip Mattos
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Patent number: 8027413Abstract: An observation lock detector block receives I&Q correlations and generates error measurement vectors, each including phase, frequency, code, pseudorange, and covariance residual estimates, and generates validity indicator and confidence indicator vectors, one of which error measurement vectors is an output as a selected error measurement vector with a respective validity indicator and confidence indicator vector, both of which selected vectors are communicated to a navigation solution processor in a ultratightly coupled navigation system for providing improved estimations of a navigation solution, the indicators indicating the usefulness of measurement errors, the prefilter detector block comprising discriminators, sequential filters, observation lock detectors and a measurement selector for selecting measurement vector based on phase, frequency, and code discriminations, the measurement errors being residual estimates that are indicated as valid or invalid for dynamic propagation of the residuals in a naType: GrantFiled: July 11, 2007Date of Patent: September 27, 2011Assignee: The Aerospace CorporationInventors: Walter E. Lillo, Manorama Gollakota, John Lukesh, Randal K. Douglas
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Patent number: 8023579Abstract: A quadrature demodulation device effectively utilizes the result of quadrature detection in order to improve demodulation efficiency. The quadrature modulation device includes a quadrature detector DT which performs quadrature detection on a reception signal obtained by receiving a radio wave from a radio frequency identification tag, to generate an in-phase signal and a quadrature-phase signal, and a demodulation circuit DM which detects a preamble of a particular transition pattern in at least one of the in-phase signal and the quadrature-phase signal and which decodes the at least one of the in-phase signal and the quadrature-phase signal to obtain data succeeding the preamble, the demodulation circuit DM further performing error detection on a decoding result to check for errors.Type: GrantFiled: April 16, 2008Date of Patent: September 20, 2011Assignee: Toshiba Tec Kabushiki KaishaInventors: Kouichi Sano, Yasuo Matsumoto, Masakazu Kato, Takahiro Shimura
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Patent number: 8023576Abstract: A sampling offset estimation apparatus including a pilot sub-carrier refiner, an information sub-carrier refiner, a data sub-carrier refiner, and a sampling offset estimator. The pilot sub-carrier refiner to refine a pilot sub-carrier extracted from a differential demodulated signal, and to generate a reference pilot sub-carrier. The information sub-carrier refiner to refine an information sub-carrier extracted from the differential demodulated signal, and to generate a reference information sub-carrier. The data sub-carrier refiner to refine a data sub-carrier extracted from the differential demodulated signal, and to generate a reference data sub-carrier. The sampling offset estimator to estimate a sampling offset included in the differential demodulated signal, on a basis of the reference pilot sub-carrier, the reference information sub-carrier, and the reference data sub-carrier.Type: GrantFiled: November 19, 2007Date of Patent: September 20, 2011Assignee: SAMSUNG Electronics Co., Ltd.Inventor: Jun-young Jeong
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Patent number: 8023594Abstract: A biphase mark signal receiver includes a data and clock recovery circuit. The data recovery circuit may include a coarse recovery stage and a fine recovery stage. The coarse recovery stage is configured to detect repeating occurrences of a first preamble (e.g., Y-preamble) within a biphase encoded data stream received by the data recovery circuit. The fine recovery stage is configured to generate a recovered data stream, in response to estimating a plurality of timing decision points (e.g., 3UI, 2UI and 1UI) from the repeating occurrences of the first preamble detected by the coarse recovery stage.Type: GrantFiled: July 11, 2008Date of Patent: September 20, 2011Assignee: Integrated Device Technology, inc.Inventors: Qi Li, Xiaoqian Zhang, Zhiyong Guan
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Patent number: 8023592Abstract: Pipelined digital processing circuitry for use with a particle size measurement system, such as that employed in automated hematology systems, measures the ‘center’ amplitude of a pulse produced by a particle or cell passing through a flow cell measurement aperture, such as the detection aperture of a Coulter Principle-based electronic particle analysis system. The circuitry of the invention processes successive pulse samples by means of a half-peak/half-width methodology that analyzes each pulse as its continuously sampled and temporarily stored in memory. Concurrent analysis of the data in memory during storage locates the pulse width at a prescribed percentage (e.g., 50%) of the peak amplitude of the pulse. This pulse width data is then processed to determine the pulse amplitude at the midpoint of the width of the pulse between its mid-peak values on rising edge and fall edge portions of the pulse.Type: GrantFiled: August 24, 2005Date of Patent: September 20, 2011Assignee: Beckman Coulter, Inc.Inventor: Jeffrey L. Rose
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Patent number: 8014456Abstract: A system includes a differential demodulation module that differentially demodulates modulated signals received from R antennas. A first summing module sums the differentially demodulated signals to generate a combined signal. A state detection module detects states of X symbols in the combined signal. A second summing module (i) receives Y preamble sequences each comprising X predetermined symbols and (ii) generates X sums for each of the Y preamble sequences by adding each of the states of the X symbols with corresponding states of the X predetermined symbols of each of Y preamble sequences. The states of the X predetermined symbols are generated by inverting states of derived symbols in derived preamble sequences, which are derived from the Y preamble sequences. Each of the Y preamble sequences is different from others of the Y preamble sequences. R, X, and Y are integers greater than 1.Type: GrantFiled: June 19, 2007Date of Patent: September 6, 2011Assignee: Marvell International Ltd.Inventors: Jongwon Lee, Hui-Ling Lou
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Patent number: 8014480Abstract: Circuitry and methods for supporting serial communications over serial interconnects between circuit modules are provided. A data recovery circuit receives incoming serial data from the serial interconnect path with zero delay. The data recovery circuit includes a data sampler that samples the incoming serial data using a multiphase clock. Data samples are provided to a multiplexer that selects an optimum sampled data signal to use as a recovered data signal. The multiplexer has a control input that receives a phase pointer signal. Control circuitry in the data recovery circuit analyzes the sampled data signals and a current value of the phase pointer to compute a clock phase shift error. If the clock phase shift error exceeds a predetermined value, the phase pointer signal can be updated. The data recovery circuit may be implemented using hardwired circuitry or programmable logic.Type: GrantFiled: March 9, 2007Date of Patent: September 6, 2011Assignee: Altera CorporationInventors: Jingcheng Zhuang, Qingjin Du, Tad Kwasniewski, Rakesh H. Patel
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Patent number: 8014457Abstract: A received signal having pilots is converted to a first signal in the frequency domain having the pilots. The pilots are extracted from the first signal to obtain extracted pilots to form a second signal. The second signal is used to provide a first estimate of a channel. The first estimate is converted to the time domain. Noise is removed from the first estimate in the time domain to provide a second estimate of the channel in the time domain. An autocorrelation of the channel in the frequency domain is determined using the second estimate of the channel. Extension signals are determined using the autocorrelation. The extension signals are appended to the first estimate of the channel to obtain a third estimate of the channel. The third estimate is used to provide a data signal in the frequency domain.Type: GrantFiled: July 31, 2008Date of Patent: September 6, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Ahsan U. Aziz, Leo G. Dehner
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Patent number: 8009773Abstract: A method and system for low-complexity implementation of a Viterbi Decoder with near optimal performance has been disclosed. The Viterbi decoding technique is diagrammatically represented as a trellis. The trellis includes various states at different time instants, and branches connecting these states. Each state has an associated state metric and a survivor path sequence, whereas each branch has a branch metric. The state metric for each current state is checked for crossing a predefined limit. If it crosses the predefined limit, the state metric is updated with a new metric that is obtained by subtracting a constant value from the state metric. Thereafter, the method finds a common path in the trellis at each state and updates the survivor path sequence of each state. The Most Significant Bits (MSBs) of the survivor path sequences of the states at a particular time instant are computed and the original data is decoded, based on the count of ‘0s’ and ‘1s’ in the MSBs.Type: GrantFiled: April 4, 2008Date of Patent: August 30, 2011Assignee: Hellosoft India Pvt. Ltd.Inventors: Sriram Kankipati, Kaushik Barman, Krushna Prasad Ojha
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Patent number: 8005172Abstract: An acquisition apparatus includes: a first phase-calculating section that calculates a first correlation value by performing correlating operation of a reception signal and a reference signal and determines whether or not the first correlation value is equal to or greater than a first threshold; a threshold calculating section that calculates a second threshold by performing averaging operation of the first correlation value and the first threshold when the first correlation value is equal to or greater than the first threshold; and a second phase-calculating section that calculates a second correlation value by performing correlating operation of the reception signal and the reference signal on a basis of a phase of the reference signal which realizes the first correlation value equal to or greater than the first threshold, and determines whether or not the second correlation value is equal to or greater than the second threshold.Type: GrantFiled: September 28, 2007Date of Patent: August 23, 2011Assignee: Kabushiki Kaisha ToshibaInventor: Kyungwoon Jang
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Patent number: 7991360Abstract: A receiving apparatus, a receiving method, and a radio communications system are disclosed. The receiving apparatus is for receiving CDMA signals transmitted by M antennas and received by N antennas, where M and N are positive integers. The receiving apparatus includes a multipath receiving signal demodulating unit for primary demodulation of the CDMA signals received by the receiving antennas to obtain estimated transmission signals, and for obtaining signals in a multipath environment of each path of the receiving antennas based on the estimated results. Further, the receiving apparatus includes a multipath interference canceling unit for deducting signals of the paths other than a target path from the signals received by the receiving antennas to obtain multipath interference cancelled signals. Further, the receiving apparatus includes a demodulator for secondary demodulation of the multipath interference cancelled signals.Type: GrantFiled: March 4, 2005Date of Patent: August 2, 2011Assignees: NTT DoCoMo, Inc., NEC CorporationInventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi, Shousei Yoshida, Masayuki Kimata
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Patent number: 7991090Abstract: Aspects of a method and system for reordered QRV-LST (layered space time) detection for efficient processing for multiple input multiple output (MIMO) communication systems are presented. The method may include receiving an ordered plurality of signals wherein each of the ordered plurality of received signals comprises information contained in an ordered plurality of spatial streams. Each spatial stream may comprise one or more frequency carriers, or tones. Information, or data, contained in a corresponding one of the ordered plurality of spatial streams may be detected. The order in which the information is detected may be determined for each individual frequency carrier.Type: GrantFiled: May 4, 2006Date of Patent: August 2, 2011Assignee: Broadcom CorporationInventors: Joonsuk Kim, Sirikiat Lek Ariyavisitakul, Eric Ojard
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Patent number: 7992067Abstract: Methods and apparatus for coding a digital data string to represent a sequence of acoustic frequencies to be transmitted as an acoustic signal by a genuine acoustic authentication device; related to providing for improving the rate of successfully detecting a valid data string contained in the acoustic signal transmitted by the device. Each of a plurality of groups of bits of the data string are coded to represent a respective frequency value set of one or more acoustic frequencies to be transmitted acoustically to represent the respective group of bits. The number of acoustic frequencies in a frequency value set is less than the number of bits in the respective group of bits that the frequency value set represents. For each of the plurality of groups of bits of the data string, the respective frequency value set is selected according to a predetermined frequency assignation pattern that provides for probabilistic transition coding used for error correction of the acoustic signal.Type: GrantFiled: February 4, 2009Date of Patent: August 2, 2011Assignee: Identita Technologies International SRLInventors: Yannick Le Devehat, David Perron, Olivier Fraysse, Pierre Dumouchel, Rene Landry, Jr., Francois Rivest
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Patent number: 7991083Abstract: A method and system is provided for detecting preambles in a multi-cell communication system. The method detects preambles reliably even in the presence of interference caused by multiple cells reusing the same frequency in the multi-cell communication system. After receiving a signal in the receiving period, the time domain signal is sampled and transformed into the frequency domain vector. The correlation vector is calculated with the frequency domain vector and pseudonoise code of the wireless station. The presence of a preamble is verified if the value in the correlation vector exceeds a predetermined threshold.Type: GrantFiled: November 28, 2006Date of Patent: August 2, 2011Assignee: Cisco Technology, Inc.Inventors: Yanxin Na, Hang Jin
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Patent number: 7991077Abstract: A system including a differential demodulation module that receives modulated signals from R antennas and that differentially demodulates the modulated signals to generate differentially demodulated signals, where R is an integer greater than or equal to 1. A summing module sums the differentially demodulated signals to generate a combined signal. A correlation module correlates the combined signal with derived preamble sequences and generates correlation values based on the correlation. The derived preamble sequences are derived from preamble sequences. Each bit of one of the derived preamble sequences has a first state when a corresponding bit and a bit adjacent to the corresponding bit in a corresponding one of the preamble sequences have opposite states. Each bit has a second state when the corresponding bit and the bit adjacent to the corresponding bit have the same state.Type: GrantFiled: May 25, 2007Date of Patent: August 2, 2011Assignee: Marvell International Ltd.Inventors: Jongwon Lee, Hui-Ling Lou
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Patent number: 7986737Abstract: The invention relates to a method of estimating symbols carried by a digital signal that is received by a receiver over a communication channel (5), said symbols being multiplexed on orthogonal frequency sub-carriers. The inventive method comprises the following steps in relation to each symbol carried by the digital signal, consisting in: performing at least two transforms towards the frequency domain (8,9) on a portion of the received signal essentially corresponding to the symbol, said transforms being performed with a determined time lag (10) therebetween; estimating the parameters (r0, r1, . . . , rn, r?0, r?1, . . . , r?n) of the communication channel from pre-determined binary information contained in the digital signal; and estimating the symbol from a combination of the result of each of the transforms performed and the estimated communication channel parameters.Type: GrantFiled: May 17, 2005Date of Patent: July 26, 2011Assignee: Nortel Networks LimitedInventors: Thierry Lucidarme, Nidham Ben Rached
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Patent number: 7983368Abstract: A sampling clock signal controller for receivers of digital data is disclosed. Specific bit patterns of a data waveform can be identified, and stored time samples of the waveform that correspond to the specific bit patterns can be analyzed to improve the timing of a sampling clock signal. These “time-amplitude” samples on known bit patterns can be utilized to determine if a sample on the data waveform should be taken before the center of the eye pattern, at the center of the eye pattern, or after the center of the eye pattern and by what time change. Accordingly, a single low power clock can be utilized to adjust the timing of the sample clock such that improved communication scan be achieved. Such a single clock system has reduced power requirements and increased accuracy.Type: GrantFiled: December 11, 2006Date of Patent: July 19, 2011Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Daniel J. Friedman, Mounir Meghelli, Thomas H. Toifl
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Patent number: 7974373Abstract: A method and architecture for pulse shaping are provided. The architecture includes a pulse shaping filter having a plurality of memory elements and a plurality of taps connected to the plurality of memory elements wherein a total number of the plurality of taps is independent of a sampling rate. The pulse shaping filter further includes a selector configured to select outputs from the plurality of taps to define a pulse shaped output.Type: GrantFiled: March 13, 2007Date of Patent: July 5, 2011Assignee: Pine Valley Investments, Inc.Inventor: Ajit Kumar Reddy
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Patent number: 7970065Abstract: A communication apparatus includes unit measuring a first interference feature quantity indicating a state of an interference signal in a transmission frequency band (TFB), unit determining from the first interference feature quantity whether the interference signal exists in the TFB, unit acquiring, after measurement of the first interference feature quantity, a transmission channel from a second interference feature quantity measured by the measuring unit, the transmission channel corresponding to at least one of a frequency orthogonal to the interference signal, a time orthogonal to the interference signal, a space orthogonal to the interference signal, and a spreading code orthogonal to the interference signal, and unit performing a first transmission using the TFB when it is determined that no interference signal exists in the TFB, and to perform a second transmission using the transmission channel when it is determined that the interference signal exists in the TFB.Type: GrantFiled: July 12, 2007Date of Patent: June 28, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Tomoya Horiguchi, Tazuko Tomioka
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Patent number: 7970371Abstract: A receiving portion for receiving a wireless signal generated on the basis of a baseband signal having either a predetermined frequency band or a baseband signal having any of partial frequency bands; a signal processing portion for generating the baseband signal; a band shifter for shifting the frequency band of the baseband signal by such an amount of shift that the center frequency of at least a specific partial frequency band is in the vicinity of 0 Hz; a filter portion for outputting a partial signal, which is gained by sampling a signal component of the frequency band having a bandwidth of the specific partial frequency band with approximately 0 Hz as the center frequency, from the baseband signal; and a determining portion for determining the frequency band of the baseband signal on the basis of the partial signal.Type: GrantFiled: May 29, 2008Date of Patent: June 28, 2011Assignee: Sony CorporationInventors: Seiichi Izumi, Norihito Mihota
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Patent number: 7961816Abstract: A device for signal synchronization in a communication system is configured to perform a first sliding correlation for a received signal and a pseudo-random noise (PN) sequence to obtain information on symbol timing, identify a fractional carrier frequency offset (FCFO) using the information on symbol timing and the cyclic extension property of the PN guard interval (GI), and provide a first product by multiplying the received signal with the FCFO. The device is also configured to provide a set of second products by multiplying the first product with each of a set of phases related to integral carrier frequency offsets (ICFOs), perform a second sliding correlation for the PN sequence and each one of the set of the second products to thereby provide a set of peak values, and identify an ICFO by detecting an index number of a maximal value among the set of peak values.Type: GrantFiled: November 28, 2007Date of Patent: June 14, 2011Assignee: Industrial Technology Research InstituteInventor: Chorng-Ren Sheu
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Patent number: 7953185Abstract: A vehicle communication system has a receiving unit on a vehicle side for inputting a demodulated analog signal to determination units based on a received radio signal from a key unit. Then, one of the two determination units outputs a high-check signal that takes a high value when the analog signal is greater than a high threshold and the other determination unit outputs a low-check signal that takes a low value when the analog signal is smaller than a low threshold. Then, a sync. signal generator successively defines a determination period based on the high and low check signals. Then, a binary level of the analog signal is determined by a level determination unit based on the check signals, along with an estimation and a correction of an indefinite signal when the signal level cannot be determined based on a coding rule and the determination by the determination units.Type: GrantFiled: May 29, 2007Date of Patent: May 31, 2011Assignee: Denso CorporationInventor: Masahiro Sugiura
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Patent number: 7949078Abstract: In a high-precision signal detection apparatus and method for a high-speed receiver, signal detection occurs asynchronously of the incoming data. A comparison clock is generated by an oscillator whose effective capacitance is varied by a second, lower speed oscillator connected to the capacitance. This prevents the asynchronous sampling that occurs in a zero-crossing position in the incoming data from remaining in that position in subsequent sampling cycles, so that a valid signal is not missed by the detector.Type: GrantFiled: November 19, 2009Date of Patent: May 24, 2011Assignee: Marvell International Ltd.Inventors: Jafar Savoj, Pierte Roo
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Patent number: 7944997Abstract: An m-code GPS receiver receives m-code GPS communication signals having a multimodal autocorrelation, using an m-code mode identifier unambiguously determining a mode value of one of the m-code modal peaks coherently aligned to a coherent unimodal detected envelope, based on sequential probability estimation in an m-code envelope tracking filter using filter residual estimation or with a coherent m-code and c/a-code tracking filter also based on filter residual estimation, for generating m-code phase errors, for unambiguous and precise m-code code phase tracking in closed feedback loops, for preferred use in navigation systems.Type: GrantFiled: November 2, 2009Date of Patent: May 17, 2011Assignee: The Aerospace CorporationInventor: Randal K. Douglas
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Patent number: 7940865Abstract: A technique for re-acquiring a symbol index in the presence of sleep timer errors in a MediaFLO™ (Forward Link Only) mobile multimedia multicast system comprising a receiver and a transmitter, wherein the method comprises receiving a digital signal comprising a superframe comprising one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols in the receiver comprising a timer; waking up the receiver from a sleep mode of operation by an amount of time equal to a maximum error introduced by the timer plus a time to reacquire a beginning of each OFDM symbol plus a time to reacquire a symbol index; and reacquiring the symbol index.Type: GrantFiled: April 4, 2008Date of Patent: May 10, 2011Assignee: Newport Media, Inc.Inventor: Nabil Yousef