Having Matched-filter-type Receiver Patents (Class 375/143)
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Patent number: 8077756Abstract: A disclosed signal transmitting method includes the steps of a) categorizing plural digital signals, obtained by performing A/D conversion on plural analog signals consecutively arranged in a time direction, into plural signal groups in an order starting from lower bits of the plural digital signals, b) performing code spreading on the plural digital signals by using a different spread frequency for each signal group and using different spread codes for each bit, c) multiplexing the spread digital signals, and d) transmitting the multiplexed plural digital signals.Type: GrantFiled: December 5, 2008Date of Patent: December 13, 2011Assignee: Fujitsu LimitedInventor: Hideki Yoshizawa
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Patent number: 8064457Abstract: System and method for filtering a data packet using a combined filter are disclosed. In one aspect, the method includes receiving a data packet and N filters each comprising a mask and value. The method includes receiving a data packet and N (wherein N is an integer and N>1) filters, each filter comprising a bit mask and corresponding bit values. The method further includes generating a common filter mask and the corresponding bit values by taking the overlapping mask bits among portions of the N filters corresponding to the common filter, the common filter being of a length smaller than each filter. The method further includes applying the common filter mask to the data packet to determine whether there is a match between the filtered data packet and each of the N filters.Type: GrantFiled: April 22, 2009Date of Patent: November 22, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Victor Liang, Shiang-feng Lee, David Ho Suk Chung
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Publication number: 20110261805Abstract: An acquisition and tracking apparatus is provided for tracking digitized spread spectrum navigation signals modulated with a spreading code according to any of a set of modulation types including Binary Phase Shift Keying (BPSK) with and without Frequency Domain Multiplexing Access (FDMA), time multiplexed BPSK, Quadrature Phase Shift Keying (QPSK), sine and cosine Binary Offset Carrier (BOC), modified, complex, and time multiplexed BOC (TMBOC), the apparatus comprising a plurality of universal tracking channels, each coupled to an interrupt module. The universal tracking channel includes a carrier demodulation module, a code generation module, a correlator module, a code frequencies generation module, and a subcarrier combining module for efficiently using the correlator resources in the correlation of the data and the pilot components of the signal within a single universal tracking channel. A corresponding method of operation is also provided.Type: ApplicationFiled: April 26, 2010Publication date: October 27, 2011Inventors: René Jr. Landry, Marc-Antoine Fortin, Jean-Christophe Guay
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Patent number: 8045631Abstract: An apparatus for detecting an OFDM symbol encoded with a transmitted sequence including a filter having coefficients based on a simplified version of the transmitted sequence is disclosed. A computer program product having code and a wireless communications apparatus for performing the method are also described herein.Type: GrantFiled: October 26, 2007Date of Patent: October 25, 2011Assignee: QUALCOMM, IncorporatedInventors: Yuheng Huang, Ozgur Dural, Samir S. Soliman, Amol Rajkotia
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Patent number: 8036296Abstract: Certain aspects of a method and system for achieving space and time diversity gain are disclosed. Aspects of one method may include modifying a generalization code of at least one pilot channel, to measure signal strengths for each of a plurality of received multipath signals. A portion of the plurality of received multipath signals may be combined based on the measured signal strengths. The signal strengths of the plurality of received multipath signals may be measured on a primary pilot channel by assigning its generalization code to zero. The signal strengths of the plurality of received multipath signals on a secondary pilot channel may measured by assigning its generalization code to a non-zero value.Type: GrantFiled: September 28, 2006Date of Patent: October 11, 2011Assignee: Broadcom CorporationInventors: Louis Botha, Philip Koekemoer, Sang Hun Sung, Ning Kong
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Patent number: 8036321Abstract: Control systems and methods for independent control of power systems, particularly lighting network branches, and separate control of individual branch components. Multi-branch systems comprise independently controllable branches that inter-communicate via PLC communications. In each branch, components such as ballasts, local control units, sensors, actuators, and repeaters, may exchange commands and queries independently of a branch remote control unit (BRCU). Alternatively, a BRCU may manage or arbitrate communications, or interact with other BRCUs, other control units and external management systems. Ballasts include a multi-channel ballast that enables close-loop control of individual fixtures, or of individual dimmable or non-dimmable lamps within a fixture. The close-loop control is facilitated by sampling circuits/sensors co-located with each controlled fixture or lamp. All controllers are preferably implemented using an integrated digital controller.Type: GrantFiled: July 7, 2009Date of Patent: October 11, 2011Assignee: S.T.L. Energy Solutions and Technologies Ltd.Inventors: Rafael Mogilner, Boris Nogtev, Yuri Kuhlik, Daniel Rubin, Arie Lev, Eytan Rabinovitz
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Patent number: 8019026Abstract: An apparatus, system, method, and article for downlink (DL) preamble processing for initial acquisition are described. The apparatus may include an autocorrelator node to determine an autocorrelation response of samples and to detect a downlink preamble based on the autocorrelation response. The samples may include a periodic sequence having two or more periods. The apparatus may include a frequency domain matched filter processing node to perform downlink preamble recognition based on a maximum peak of a frequency domain matched filter response and on an index of the downlink preamble. Other embodiments are described and claimed.Type: GrantFiled: June 30, 2005Date of Patent: September 13, 2011Assignee: Intel CorporationInventors: Alexander A Maltsev, Alexey Rubtsov, Andrey Pudeyev, Vadim Sergeyev, Sergey Tiraspolsky, Alexey Davydov
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Patent number: 8010055Abstract: The signal to noise ratio performance of a RF communication system can be improved by providing resistance to transmitter self-jamming and eliminating or reducing the need for a transmit rejection filter or other measures such as limiters or blanking switches. An anti-jam low noise amplifier provides enough rejection and jamming immunity to reduce or eliminate the need for the transmit reject filter. Thus, the system noise performance is improved by eliminating the filter and the associated losses which cause signal to noise ratio performance degradation.Type: GrantFiled: February 13, 2008Date of Patent: August 30, 2011Assignee: ViaSat, Inc.Inventor: Kenneth V. Buer
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Patent number: 8009724Abstract: Clear channel assessment (CCA) is a very important issue in Ultra-Wideband (UWB) systems. An effective CCA mechanism will have a large impact on the overall throughput of the communications system. It is disclosed methods and circuits to carry out CCA determinations exploiting the structure of the pulse signal either by using a moving average or by performing a cross-correlation with a locally generated signal.Type: GrantFiled: August 25, 2005Date of Patent: August 30, 2011Assignee: NXP B.V.Inventors: Charles Razzell, Yifeng Zhang
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Patent number: 7991040Abstract: Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal. In an aspect, a method is provided for reducing a peak to average ratio of a transmit waveform. The method includes obtaining a primary scrambler sequence, generating a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining the primary and secondary scrambler sequences to produce a PAR reduction sequence. In another aspect, an apparatus is provided for reducing a peak to average ratio of a transmit waveform. The apparatus includes a secondary generator configured to generate a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining logic configured to combine a primary scrambler sequence and the secondary scrambler sequences to produce a PAR reduction sequence.Type: GrantFiled: September 11, 2006Date of Patent: August 2, 2011Assignee: QUALCOMM IncorporatedInventors: Durk L. van Veen, Fuyun Ling, Raghuraman Krishnamoorthi
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Patent number: 7983324Abstract: The present invention relates to a symbol acquisition apparatus and a method thereof. The method includes: determining a first boundary according to a first preamble symbol and generating a first confidence value according to signal quality of the first preamble symbol; determining a second boundary according to a second preamble symbol and generating a second confidence value according to signal quality of the second preamble symbol; and determining a symbol boundary from the first and the second boundaries according to the first and the second confidence values.Type: GrantFiled: August 18, 2006Date of Patent: July 19, 2011Assignee: Realtek Semiconductor Corp.Inventors: Kuo-Ming Wu, Der-Zheng Liu, Kuang-Yu Yen
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Patent number: 7974335Abstract: A decision feedback equalization apparatus includes a channel estimation unit estimating a channel on received signal based on the received signal and a training sequence; a channel matched filter maximizing SNR from the channel estimated by the channel estimation unit changing channel characteristics of the received signal; a noncausal filter approximating the changed channel; an equalizer input signal storage unit storing received symbols passed through the channel matched and the noncausal filters; a channel equalization unit performing a decision feedback equalization; a Trellis decoder detecting symbol from a channel-equalized signal; a mode selection unit selecting a specific mode; an error signal calculator comparing an output signal of the selected mode with an output signal of the channel equalization unit to calculate an error signal; and a tap coefficient updater updating tap coefficients to the channel equalization unit, an output signal from the storage unit, and an output signal from the TrellisType: GrantFiled: December 26, 2005Date of Patent: July 5, 2011Assignee: Electronics and Telecommunications Research InstituteInventors: Sung-Ik Park, Seung-Won Kim, Soo-In Lee, Hyoung-Nam Kim, You-Seok Lee
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Patent number: 7961776Abstract: A device for decoding a direct sequence spread spectrum-encoded binary message includes a sampler that captures at least one sequence of binary samples corresponding to one bit of the transmitted message. The captured sequence of samples are applied to a filter matched to the spreading code used, thus making it possible to delete the spreading applied to the original message. The device further includes, at the output of the sampler, an error correction block including a memory storing a plurality of binary sequences corresponding to all of the possible values for a captured sequence of samples. A replacement circuit replaces the captured sequence of samples with the stored sequence, thereby minimizing the number of samples different from the captured sequence of samples, and allowing the stored sequence to be applied to the matched filter.Type: GrantFiled: November 28, 2006Date of Patent: June 14, 2011Assignees: STMicroelectronics (Rousset) SAS, Universite de Provence d'Aix-Marseille IInventors: Benoît Durand, Christophe Fraschini, Philippe Courmontagne, Stéphane Meilleire
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Patent number: 7949038Abstract: A method and a system for the acquisition and tracking of BOC(m,n) modulated codes, m/n equal to an integer, in which a correlation function is calculated of the BOC(m,n) modulated code received from a remote transmitter with a code wa locally generated at a receiver terminal according to one from the following the relationships: wa(?)=c(?n)?a·[prn(?n+Tc/2)?prn(?n?Tc/2)] wa(?)=c(?n)?a·[prn(?n+nTc/2m)?prn(?n?nTc/2m)] wa(?)=c(?n)?a·[prn(?n+nTc/4m)+prn(?n?nTc/4m)] wa(?)=c(?n)?a·[prn(?n+3nTc/4m)+prn(?n?3nTc/4m)] w(?)=[prn(?n+nTc/4m)+prn(?n?nTc/4m)] w(?)=[prn(?n+nTc/2m)?prn(?n?nTc/2m)] wherein c(?) is a local replica of the BOC modulated pseudo-random noise code with delay ?n, PRN(?) is a replica of the unmodulated pseudo-random noise code, and a is a predetermined weight coefficient, and the correlation function being at the base of an acquisition test function whereby a code acquisition is recognized for a value of the test function being higher than a predetermined threshold.Type: GrantFiled: December 12, 2007Date of Patent: May 24, 2011Assignee: STMicroelectronics, S.r.l.Inventors: Giuseppe Avellone, Maristella Frazzetto, Ettore Messina
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Patent number: 7929647Abstract: Systems and methods are provided for dynamically analyzing radar pulses at a receiver. A digital signal is provided to an amplitude detector. At least one digital waveform representing an emitter pulse is identified at the amplitude detector. A matched filter associated with the emitter is generated, comprising at least one characteristic of the identified digital waveform.Type: GrantFiled: March 13, 2006Date of Patent: April 19, 2011Assignee: Lockheed Martin CorporationInventor: J. Andrew Johnson
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Publication number: 20110080936Abstract: The technology in this application spreads a signal over an available discontinuous spectrum, such as a radio frequency band, so that the spread signal only occupies the non-contiguous spectrum. In this way, CDMA transmission and reception can be used in a fragmented or non-contiguous spectrum that otherwise would not be useable for direct sequence spreading. Spreading over non-contiguous portions of spectrum is preferably performed without producing unacceptable interference in portions of unavailable spectrum located between the allowed spectrum. By avoiding unacceptable interference in portions of unavailable spectrum located between the allowed spectrum, the unavailable spectrum may be used by other users or services.Type: ApplicationFiled: December 13, 2010Publication date: April 7, 2011Applicant: Telefonaktiebolaget LM Ericsson (publ)Inventor: Paul W. DENT
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Patent number: 7912165Abstract: A method is disclosed, including identifying a preamble in a frame, where the preamble has a preamble length 1. M data items received in succession are stored. The m data items once divided into n portions, where the data items in each portion have respectively been received at successive times and where m and n are natural numbers and the following applies to m and n: m>n, m>1, n>1. The n portions are respectively correlated to the expected values to form component correlation results. Delaying the component correlation results, with at least two component correlation results being delayed by different lengths. The method also includes combining the delayed component correlation results to form a total correlation value. The total correlation value is used to determine whether the m received data items contain the preamble of a frame.Type: GrantFiled: May 25, 2007Date of Patent: March 22, 2011Assignee: Infineon Technologies AGInventors: Stefan Herzinger, Andreas Menkhoff, Stefan Meier, Norbert Neurohr
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Patent number: 7885314Abstract: A cancellation system that delays received Global Positioning System (“GPS”) signals and cancels less than all of the received GPS signals from the delayed version of the received GPS signals. A delay circuit produces a delayed version of the received GPS signals and a demodulator and despreader unit produces a demodulated and despread GPS signal corresponding to one of the received GPS signals. A respreader and remodulator unit produces a remodulated and respread GPS signal from the demodulated and despread GPS signal and a combiner produces a combined GPS signal from the delayed version of the received GPS signals and the remodulated and respread GPS signal. The cancellation system and method may also store the received GPS signals and cancel less than all the received GPS signals from the stored version of the received GPS signals.Type: GrantFiled: May 2, 2000Date of Patent: February 8, 2011Inventors: Kenneth Scott Walley, Paul A. Underbrink, Steven A. Gronemeyer
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Patent number: 7876738Abstract: In order to prevent an incorrect synchronization between a received code-modulated signal and an available replica code, partial correlations are performed between a respective subset of samples of the replica code and samples of the received code-modulated signal associated to the respective subset of samples of the replica code at a specific alignment between the received code-modulated signal and the replica code. The results of the partial correlations are then compared to each other, and it may be decided based on this comparison whether the replica code corresponds to a code employed for code-modulating the received code-modulated signal.Type: GrantFiled: March 2, 2004Date of Patent: January 25, 2011Assignee: Nokia CorporationInventors: David Akopian, Harri Valio
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Patent number: 7852905Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.Type: GrantFiled: June 16, 2004Date of Patent: December 14, 2010Assignee: SiRF Technology, Inc.Inventors: Paul A. Underbrink, Steven A. Gronemyer
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Publication number: 20100290505Abstract: A code converting apparatus is designed to estimate the incoming time and the like of a signal modulated by a spreading sequence composed of m elements in a set A having n kinds of symbols as elements accurately. A symbol sequence memory section 102 stores a converted sequence of symbols obtained by concatenating consecutive 2d symbols at the center of each sequence pattern pi composed of 4d elements in the set A. The converted sequence of symbols is structured so that d symbol immediately preceding the 2d symbols and d symbol immediately following the 2d symbols are identical to d symbol immediately preceding corresponding 2d symbols and d symbol immediately following the corresponding 2d symbols of a corresponding sequence pattern. A symbol sequence specifying section 103 specifies a matching sequence pattern for every consecutive 2d symbols in a symbol sequence obtained by assigning a symbol to the signal in a coding cycle of the spreading sequence.Type: ApplicationFiled: January 30, 2008Publication date: November 18, 2010Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takafumi Nagano, Takashi Iwamoto
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Patent number: 7826577Abstract: A method is provided for frequency acquisition, particularly for initial frequency acquisition, pursuant to a known synchronization sequence for synchronizing a mobile communications device having a local oscillator with previously known transmit frequencies of a base station that transmit in a known channel raster with defined frequency points within a band, wherein the method includes the steps of determining the inband power of the known synchronization sequence via a sensor by scanning a frequency band, performing coarse determination of the local power maximum of the inband power and, thus, of the received carrier frequency over the scanned frequency band, producing a presumed channel frequency at which the base station is transmitting on the basis of knowledge of the channel raster of the transmit frequencies of the base station, performing fine determination of the received carrier frequency by comparison with the known synchronization sequence, and correcting the frequency deviation of the local oscilType: GrantFiled: September 19, 2001Date of Patent: November 2, 2010Assignee: Palm, Inc.Inventors: Bernd Bienek, Andreas Falkenberg, Stephan Karger, Theo Kreul, Albrecht Kunz, Holger Landenberger
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Patent number: 7822108Abstract: The invention provides a Code Division Multiple Access (CDMA) receiver for sampling a received CDMA signal into a plurality of samples. The CDMA receiver comprises a sampling control module, a code generator, and a plurality of despreaders. The sampling control module delays the samples for a plurality of different delay lengths to obtain a plurality of delayed samples respectively corresponding to each of the delay lengths, and adjusts timing of a sampling trigger signal and a code generation trigger signal according to a sampling timing adjustment signal. The code generator generates a despreading code according to the code generation trigger signal. Each of the despreaders is configured for decimating the delayed samples corresponding to each delay lengths according to the sampling trigger signal to obtain a plurality of decimated delayed samples, and despreads the decimated delayed samples with the despreading code to obtain a plurality of output signals.Type: GrantFiled: January 12, 2007Date of Patent: October 26, 2010Assignee: Via Technologies, Inc.Inventors: Sung-Chiao Li, Ching-Chia Hsu, Chi-Yuan Peng
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Patent number: 7796708Abstract: A method for communication using a modulation scheme defined in a signal space includes determining demodulation confidence levels at a plurality of points distributed over the signal space. Weights are assigned to the respective points responsively to the demodulation confidence levels. A signal is received and demodulated using an adaptive loop so as to derive a corresponding signal point in the signal space. The adaptive loop is adjusted responsively to a weight assigned to the derived signal point.Type: GrantFiled: March 29, 2006Date of Patent: September 14, 2010Assignee: Provigent Ltd.Inventor: Uri Yehudai
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Patent number: 7778312Abstract: A receiver includes a baseband processor for selecting a set of demodulation processing delays for received signal demodulation from a larger set of candidate delays. In one embodiment, the baseband processor selects the set of demodulation processing delays by calculating at least one metric for each demodulation processing delay in the set of candidate delays, iteratively reducing the set of candidate delays by eliminating one or more demodulation processing delays from the set as a function of comparing the metrics, and setting the processing delays for received signal demodulation to the candidate delays remaining after reduction. In a Generalized RAKE (G-RAKE) embodiment, the metric corresponds to combining weight magnitudes associated with G-RAKE finger delays. In a chip equalizer embodiment, the metric corresponds to coefficient magnitudes associated with equalization filter tap delays.Type: GrantFiled: April 12, 2006Date of Patent: August 17, 2010Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Douglas A. Cairns, Gregory E. Bottomley
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Patent number: 7773678Abstract: In a method for reducing the dynamic range of a multicarrier transmission signal (12?) which is formed in a transmitter and is composed of two or more carriers, the various signal structure timings of the carriers are determined. A delay unit (100; D0, D1, . . . , DN-1) is then used to set a delay profile between the signal structure timings of various carriers, in such a manner that the signal structures of different carriers or substructures of them are not aligned in time with respect to one another.Type: GrantFiled: June 17, 2005Date of Patent: August 10, 2010Assignee: Infineon Technologies AGInventor: Stefano Marsili
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Patent number: 7756194Abstract: Disclosed is a circuit for decoding code phase modulated (CPM) signals, including a pseudo-noise (PN) code storage device, storing one or more reference PN codes, a peak detector having an output with decoded CPM data, and a correlation block, including a correlation multiplexer, a plurality of shift registers coupled to the correlation multiplexer, a selection circuit coupled to the plurality of shift registers, and a correlator coupled to the code storage device and correlation multiplexer. Also disclosed is a method for operating the circuit in two operating modes for decoding CPM signals.Type: GrantFiled: December 30, 2005Date of Patent: July 13, 2010Assignee: Cypress Semiconductor CorporationInventors: Stephen O'Connor, Robert Mack, David Wright, Ham Prince
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Patent number: 7746962Abstract: The present invention provides a packet detector for use with a packet-based wireless receiver employing a receive antenna for P concurrently transmitted streams, where P is at least two. In one embodiment, the packet detector includes a correlation unit coupled to the single receive antenna and configured to provide a correlation function based on P acquisition fields corresponding to the P concurrently transmitted streams. Additionally, the packet detector also includes a pseudo-magnitude calculator coupled to the correlation unit and configured to calculate a packet detection metric based on the correlation function.Type: GrantFiled: November 17, 2004Date of Patent: June 29, 2010Assignee: Texas Instruments IncorporatedInventors: Michael T. DiRenzo, David P. Magee, Manish Goel
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Patent number: 7746918Abstract: A bit synchronization method and system for a GPS, which receives a satellite signal sent by a satellite to accordingly produce a synchronous signal. Each data bit of the satellite signal consists of N CA-codes. A data buffer receives and stores the data bits of the satellite signal. A matched filter filters the N CA-codes of each data bit in order to compute correlations of the N CA-codes of each data bit, and accordingly output a correlation set corresponding to the data bit, wherein the correlation set has N correlations. A selector selects one with the greatest value from the N correlations and uses the CA-code corresponding to the one with the greatest value as the synchronization signal.Type: GrantFiled: September 11, 2006Date of Patent: June 29, 2010Assignee: Sunplus Technology Co., Ltd.Inventors: Jia-Yi Chen, Ching-Piao Hung
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Patent number: 7733989Abstract: Channel estimation is performed using side information. A signal transmitted over a radio channel includes side information corresponding to a first predetermined signal and a second predetermined signal. The first predetermined signal is different from the second predetermined signal. An estimate of the radio channel is determined using both the first predetermined signal and the second predetermined signal. Using multiple sources of side information improves the accuracy and the efficiency of the channel estimation. One example application is Orthogonal Frequency Division Multiplexing based communications systems.Type: GrantFiled: March 15, 2006Date of Patent: June 8, 2010Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventor: Jiann-Ching Guey
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Patent number: 7715465Abstract: Disclosed is a correlation method to adaptively operate in a time varying phase and a correlator thereof. A correlation method according to the present invention includes performing the first correlation according to a certain reference value and a certain reference interval for correlation of a received signal; calculating an average variation of the received signal through the result of performing the first correlation; deciding a new reference value for the second correlation through the average variation; performing the second correlation according to the new reference value and the reference interval; and selecting the maximum value among the result of performing the second correlation. Accordingly, plural references are decided considering variation of a response signal between tags and also separate plural references are decided considering bit variation of a response signal in the same tag, so that a digital signal can be ideally demodulated in the environment where signal phase variation occurs.Type: GrantFiled: August 17, 2006Date of Patent: May 11, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Artem Moutchkaev, Woo-Shik Kang, Si-gyoung Koo, Ji-hun Koo
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Patent number: 7711038Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.Type: GrantFiled: June 27, 2000Date of Patent: May 4, 2010Assignee: SiRF Technology, Inc.Inventors: Paul A. Underbrink, Steven A. Gronemyer
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Patent number: 7711035Abstract: A frequency domain representation of a whitening filter is made to depend on essentially one unknown, namely, a scaling factor that is based on an estimated ratio of total base station power to the power spectral density (PSD) of inter-cell interference plus noise. In turn, that scaling factor can be computed based on the modeling terms used in a parametric model of the impairment correlations for a received communication signal. Preferably, the model comprises an interference impairment term scaled by a first model fitting parameter, and a noise impairment term scaled by a second model fitting parameter. Further, the scaling factor can be computed by directly estimating total base station transmit power and the PSD of inter-cell interference plus noise. In any case, the whitening filter can be used in whitening a received communication signal in conjunction with channel equalization processing or RAKE receiver processing, for example.Type: GrantFiled: September 17, 2004Date of Patent: May 4, 2010Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Douglas A. Cairns, Leonid Krasny
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Patent number: 7706352Abstract: A pilot structure, a method, and a receiver for multi-carrier cellular communications defining a specific Time Division Multiplexer/Multiplexing pilot pattern and pilot sequence for a sub-frame with short system information. A primary synchronization sequence is configured to be transmitted every predetermine number of sub-frames in a defined bandwidth. A primary common pilot is configured to be transmitted for each sub-frame. Short system information is configured to be transmitted once per frame to define the pilot structure of sub-frames in a frame period to define a structure of a frame period.Type: GrantFiled: October 13, 2006Date of Patent: April 27, 2010Assignee: Nokia CorporationInventors: Mika Rinne, Ülo Parts, Juha Korhonen
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Patent number: 7693236Abstract: An RF receiver apparatus (31) is provided physically separately from a cooperating baseband processor apparatus (32). The RF receiver includes a mixer circuit (33) and an analog IF-to-digital baseband converter (34) formed on an integrated circuit. Sampling frequencies of the analog IF-to-digital baseband converter are controlled by the RF receiver apparatus.Type: GrantFiled: May 8, 2001Date of Patent: April 6, 2010Assignee: Texas Instruments IncorporatedInventors: Samuel D. Pritchett, Jeffrey A. Schlang, Sherif Embabi, Alan Holden, Francesco Dantoni
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Patent number: 7688917Abstract: A configurable all-digital coherent demodulator system for spread spectrum digital communications is disclosed herein. The demodulator system includes an extended and long-code demodulator (ELCD) coupled to a traffic channel demodulator (TCD) and a parameter estimator (PE). The demodulator also includes a pilot assisted correction device (PACD) that is coupled to the PE and the TCD. The ELCD provides a code-demodulated signal to the TCD and the PE. In turn, the TCD provides a demodulated output data signal to the PE. The PACD corrects the phase error of the demodulated output data based on an error estimate that is fed forward from the PE. Accumulation operations in the ELCD, TCD, and PE are all programmable. Similarly, a phase delay in the PACD is also programmable to provide synchronization with the error estimate from the PE.Type: GrantFiled: December 22, 2005Date of Patent: March 30, 2010Assignee: Infineon Technologies AGInventor: Ravi Subramanian
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Patent number: 7684468Abstract: A wireless communication device is provided. The wireless communication device executes digital processing for a received UWB signal with use of an A/D converter having an adequate sample rate and resolution, and thus can obtain precise reception timing information. Since the sample rate of an A/D converted output is high, a timing detection circuit is formed of two-stage matched filters. The former-stage chip matched filter calculates the correlation between an input signal and a template signal. When a correct transmission pulse signal has arrived, the chip matched filter outputs to a frame matched filter an indication as to the presence of a pulse and reception timing. The latter-stage frame matched filter calculates the correlation value between a received frame signal and a spreading code to thereby determine whether the received frame is correct or incorrect, and adequately changes a threshold value of the chip matched filter.Type: GrantFiled: May 2, 2006Date of Patent: March 23, 2010Assignee: Sony CorporationInventors: Yuichiro Shimizu, Yukitoshi Sanada
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Patent number: 7672361Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.Type: GrantFiled: June 16, 2004Date of Patent: March 2, 2010Assignee: SiRF Technology Inc.Inventors: Paul A. Underbrink, Steven A. Gronemyer
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Patent number: 7672415Abstract: A system and method for detecting a presence and frequency offset of a spread spectrum radio frequency signal is disclosed. The method comprises receiving the spread spectrum radio signal. The signal can be sampled to form a plurality of signal samples. Each signal sample can be multiplied by a complex conjugate of a proximate signal sample to form a plurality of signal sample pairs. The signal sample pairs can be summed over a predetermined dwell time period to form a data vector having a magnitude and angle offset to enable detection of the signal and to enable a frequency offset between the spread spectrum radio frequency signal and a receiver frequency reference to be determined.Type: GrantFiled: September 28, 2006Date of Patent: March 2, 2010Assignee: L-3 Communications, Corp.Inventors: Thomas R. Giallorenzi, Johnny M. Harris, Dan M. Griffin, Sam Kingston
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Patent number: 7660342Abstract: A digital processing device is at the input of a radio frequency receiver chain, suited to a transmission system using a direct sequence spectrum spread, comprising analog-to-digital conversion means (ADC) performing an undersampling of a signal received, resulting in an overlapping of the wanted signal by the transmission channel noise, demodulation means connected to the output of the ADC, a low pass filter connected at the output of the demodulation means and a filter matched to the spreading code used, wherein the ADC includes a comparator capable of comparing the amplitude of the undersampled signal to a reference in order to carry out a quantizing of the 1-bit signal, said comparator bringing about the creation of a quantizing noise, and including an additional filtering unit arranged between the low pass filter and the matched filter, implementing a multi-noise, stochastic matched filtering operation.Type: GrantFiled: May 4, 2006Date of Patent: February 9, 2010Assignees: STMicroelectronics (Rousset) SAS, Universite de Provence (AIX Marseilee)Inventors: Benoît Durand, Christophe Fraschini, Philippe Courmontagne, Anne Collard Bovy, Stephane Meillere
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Patent number: 7656932Abstract: A digital processing device for a modulated signal, arranged at the input of a radio frequency receiver chain, suited in particular to a transmission system a direct sequence spread spectrum operation, comprising an analog-to-digital converter performing undersampling of the signal received, leading to an overlapping of the frequency range of the undersampled wanted signal by the frequency range of an interfering signal, demodulation means connected at the output of the analog-to-digital converter in order to bring the undersampled wanted signal back to baseband, a low pass filter connected at the output of the demodulation means and a filter matched to the spreading code used, and an additional filtering unit arranged between the low pass filter and the matched filter, for implementing a stochastic matched filtering operation to improve the signal-to-noise ratio at the input of the matched filter.Type: GrantFiled: May 4, 2006Date of Patent: February 2, 2010Assignees: STMicroelectronics (Rousset) SAS, Universite de Provence (AIX Marseille I)Inventors: Benoît Durand, Christophe Fraschini, Philippe Courmontagne, Anne Collard Bovy, Stephane Meillere
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Patent number: 7653164Abstract: Embodiments of an adaptive in-phase (I) and/or quadrature-phase (Q) imbalance correction for multicarrier wireless communication systems is generally described.Type: GrantFiled: September 15, 2004Date of Patent: January 26, 2010Assignee: Intel CorporationInventors: Jian Lin, Ernest Tsui
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Patent number: 7653118Abstract: A surface acoustic wave (SAW) expander based transmitter and correlator based receiver comprises SAW devices that perform expander or correlator functions based on the types of signals inputted to the SAW devices. The SAW devices incorporate chirp with adaptive interference and programmable coding capabilities. The SAW devices and method of operating the devices allow the implementation of very low power radios that overcome problems with temperature drift, lithography constraints and interference and jamming suffered by prior art implementations.Type: GrantFiled: March 23, 2005Date of Patent: January 26, 2010Assignee: Cypress Semiconductor CorporationInventors: Steve Whelan, Paul Beard
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Patent number: 7649927Abstract: A technique for an equalizer filter with dynamically configurable convolution filter is described. The input to a transmitter chain is modified by an equalizer filter, prior to being applied to the transmitter. The equalizer filter modifies and smoothen the amplitude of the signal. The modified and smoothen signal has its peaks reduced which results in lower Crest Factor. The input to the reconditioning equalizer filter could be a baseband, an intermediate frequency (IF) or radio frequency (RF) signal. In the case of an IF or RF signal, it needs to be down converted to baseband before applied to the equalizer filter.Type: GrantFiled: December 29, 2006Date of Patent: January 19, 2010Inventor: Kiomars Anvari
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Publication number: 20100003936Abstract: A multimode communication device with a shared signal path programmable filter and a method for utilizing a shared signal path programmable filter in a multimode communication device. Various aspects of the present invention comprise a first module adapted to receive a first communication signal (e.g., corresponding to a first communication protocol) and a second module adapted to receive a second communication signal (e.g., corresponding to a second communication protocol). A shared filter, communicatively coupled to the first and second modules, may be adapted to filter the first and/or second communication signals in accordance with a plurality of selectable sets of filter response characteristics (e.g., associated with the first and second communication protocols). A filter control module may be adapted to select a set of filter response characteristics from a plurality of such sets and program the shared filter to filter a communication signal in accordance with the selected set.Type: ApplicationFiled: September 15, 2009Publication date: January 7, 2010Applicant: Broadcom CorporationInventors: Arya Behzad, Ahmadreza Rofougaran
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Patent number: 7643536Abstract: A system provides for remote monitoring using asynchronous code division multiple access (CDMA) communication techniques between a base station and one or more transponders. Each transponder is attached or otherwise associated with an object or an environment to be monitored. Upon receipt of an interrogation signal, a transponder generates and transmits a coded transponder signal containing the monitored data. The coded transponder signal is generated using a spreading code. Each transponder is associated with a unique, mutually exclusive set of spreading codes. Each spreading code is based on a unique transponder address and the monitored data to be sent. A detector asynchronously monitors received signals for any of the available spreading codes. Once the detector detects a particular spreading code, the base station can identify the source transponder and extract the monitored data.Type: GrantFiled: August 10, 2004Date of Patent: January 5, 2010Assignee: Mayo Foundation for Medical Education and ResearchInventors: Timothy Michael Schaefer, Jonathan Darrel Coker, Rick Allen Philpott, Edward Brian Welch, David R. Holmes, III
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Patent number: 7636384Abstract: The present invention discloses a method for detecting orthogonal code CDMA signal implemented mainly through the following steps: estimating the total power of interference to the multi-path signals; performing matched filtering on the multi-path signals and performing maximum ratio combining on the multi-path signals by utilizing the total power of interference to the multi-path signals, to obtain the optimized matched filtering result; and performing joint detection on the optimized matched filtering result. There are two schemes for implementing: if the optimized matched filtering detection scheme is used, only the first two main steps are executed; if the joint detection scheme is used, all of the three steps are executed. In either of above two schemes, the interference code channels involved in the estimation of total power of interference to the multi-path signals are need to be selected, i.e.Type: GrantFiled: July 29, 2004Date of Patent: December 22, 2009Assignee: Da Tang Mobile Communications Equipment Co., Ltd.Inventors: Yingmin Wang, Guiliang Yang, Changguo Sun
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Patent number: 7630447Abstract: The invention relates to a system and a method of digital communication between synchronized submarine devices, system including means of sending a signal in modulated bit form, at least one sender (100) and at least one receiver (200), characterized in that said at least one sender (100) sends a signal enabling both any data to be transmitted to said at least one receiver (200) and a propagation time between said at least one sender (100) and said at least one receiver (200) to be measured.Type: GrantFiled: November 1, 2005Date of Patent: December 8, 2009Assignee: SercelInventors: Gérard Ayela, Christophe L'her
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Publication number: 20090274194Abstract: A set of spread-spectrum units is capable of operating as a base station or as a remote unit. Each spread-spectrum unit includes a base subunit or a remote subunit, each subunit having a receiver for receiving spread-spectrum signals at a first frequency transmitted from the spread-spectrum units; a signal despreader for despreading the spread-spectrum; a demodulator for demodulating the despread-spread-spectrum signals; a combiner for combining the demodulated signals, and a local signal; a converter for converting the combined signal to a base-data signal; a spread-spectrum circuit for processing the base-data signal; and a transmitter for transmitting at a second frequency the processed base-data signal as a base-spread-spectrum signal.Type: ApplicationFiled: July 6, 2009Publication date: November 5, 2009Applicant: INTERDIGITAL TECHNOLOGY CORPORATIONInventor: Donald L. Schilling
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Patent number: RE42219Abstract: A system and method for transmitting a plurality of spread-spectrum signals over a communications channel having fading. The plurality of spread-spectrum signals are radiated by a plurality of antennas, with each antenna preferably spaced by one-quarter wavelength. A plurality of receiver antennas receive the plurality of spread-spectrum signals and a plurality of fading spread-spectrum signals. Each receiver antenna is coupled to a plurality of matched filters having a respective plurality of impulse responses matched to the chip-sequence signals of the plurality of spread-spectrum signals. A RAKE and space-diversity combiner combines, for each respective chip-sequence signal, a respective plurality of detected spread-spectrum signals and a respective multiplicity of detected-multipath-spread-spectrum signals, to generate a plurality of combined signals. The symbol amplitudes can be measured and erasure decoding employed to improve performance.Type: GrantFiled: June 26, 2008Date of Patent: March 15, 2011Assignee: Linex Technologies Inc.Inventor: Donald L. Schilling