Pseudo Noise Patents (Class 375/367)
  • Patent number: 7653156
    Abstract: A method of processing a timing synchronization signal includes selecting an initial sequence of complex numbers and modifying the initial sequence based upon a metric applied to the autocorrelation function to enhance its autocorrelation properties within a predetermined window about the main autocorrelation peak determined by the timing uncertainty of the system. This two-step optimization process produces a new complex sequence used for timing acquisition. It is applied by transmitting the sequence through a medium and correlating the received signal against a known error-free sequence. Only correlation within the window of the bounded timing uncertainty is performed, thus saving valuable computational cycles. Also, because the sidelobe levels of the autocorrelated function are significantly lower within the timing uncertainty window than the sidelobe levels of a non-optimized autocorrelation function of a signal, the likelihood of finding a peak for the wrong timing signal is greatly reduced.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: January 26, 2010
    Assignee: The Boeing Company
    Inventors: Gary A. Ray, James B. Baker
  • Patent number: 7649926
    Abstract: A rake receiver for DS-CDMA UWB system and a DS-CDMA receiver having the same are provided. The rake receiver includes: a channel estimator for estimating a channel having a predetermined chip duration by using a synchronization acquisition sequence; a tracking module for detecting a channel variation and adjusting a synchronization position value when the channel variation is detected; a first switch for selecting one of an output value of an analog-to-digital converter and an output value of a correlator and outputting the selected value; a second switch for selecting one of the output value of the analog-to-digital converter and the output value of the correlator; and a plurality of demodulators having a parallel processing structure to demodulate received signals by using the channel estimation value inputted from the channel estimator, the synchronization position value stored by the tracking module, and an output value of the second switch.
    Type: Grant
    Filed: December 8, 2006
    Date of Patent: January 19, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Kyu-Min Kang, Sang-Sung Choi, Kwang-Roh Park, Sang-In Cho, Sung-Woo Choi, Cheol-Ho Shin
  • Patent number: 7649961
    Abstract: A digital amplifier and method are provided to convert digital base-band signals to a pair of digital switching waveforms switching at a carrier frequency to create a modulated RF signal. The digital amplifier contains variable frequency suppressed carrier PWM generators that produce in-phase and quadrature-phase differential signals, a mixer that combines the differential signals, a decoder that decodes the combined signals, and a power stage that receives signals from the decoder and provides an amplified signal at the carrier frequency using switches. The mixer combines the differential signals such that only one of the differential signals is output in a period. The carrier generators have integral noise shaping and use a random period signal to re-distribute quantization noise to a band outside an RF band of interest and reduce EMI of the RF signal.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: January 19, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Pallab Midya
  • Patent number: 7636380
    Abstract: Orthogonal pulse polarity modulation involves wireless communication in which the polarity of modulating pulses are set responsive to positive and negative character values of a corresponding code sequence. In a described implementation, data is converted to chip waveforms, spectrum lines are removed, and pulses are appropriately shaped. For example, a data bit stream may be converted into chip waveforms using a bit stream-to-symbol segmenter, a symbol-to-code sequence mapper, and a code sequence-to-chip waveform transformer. The polarities of respective individual chips in a given chip waveform match the signs of respective individual characters in a corresponding code sequence.
    Type: Grant
    Filed: May 17, 2004
    Date of Patent: December 22, 2009
    Assignee: Microsoft Corporation
    Inventors: Richard Yuqi Yao, Zihua Guo, Weiyu Xu, Wenwu Zhu
  • Patent number: 7616722
    Abstract: A method for extracting a clock in a clock data recovery system is provided. The method includes the following steps. First, a serial link transmission data is sampled for a plurality of times, and a plurality of pulse signals are generated and sequentially arranged. Then, a mark is inserted after all pulse signals are generated and had been delayed for a predetermined delay time. The predetermined delay time is less than a period between two adjacent pulse signals, and a period between two adjacent pulse signals is divided into two sub-periods by the predetermined delay time. Then, it is checked whether the data status in each sub-period is changed or not, and this operation is repeated for a predetermined number of times. Finally, the clock is extracted when a pulse signal of no data status change within the predetermined number of times is being generated.
    Type: Grant
    Filed: June 8, 2005
    Date of Patent: November 10, 2009
    Assignee: VIA Technologies, Inc.
    Inventors: Chi Chang, Shuyu Lin
  • Patent number: 7613264
    Abstract: A method for implementing a flexible sampling-rate encoder, comprising the steps of (A) sampling an input signal at a regular time-interval to produce sampled data, (B) generating a pseudo-random bit sequence having a plurality of bits, wherein each bit corresponds to a different sampling time, (C) encoding a first set of the sampled data to generate an encoded stream when any bit in the pseudo-random bit sequence is equal to a first value, wherein each bit in the encoded stream corresponds to one of the sampling times defined in step (B), and (D) determining the different sampling time for each sample in the encoded stream.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: November 3, 2009
    Assignee: LSI Corporation
    Inventors: Paul J. Wells, Baptiste Paquier
  • Patent number: 7609751
    Abstract: A first node initiating communications with a second node already in a secure network sends a discovery burst having a preamble portion and a payload portion. The preamble portion is sent at a varying frequency between high and low thresholds that are reflective of Doppler uncertainty between the nodes. The second node continuously listens at a frequency, termed an acquisition frequency. A data sequence in the preamble portion, known to the second node, is received and used to determine the receive instant in the preamble portion, and thereby compare against the known frequency ramp to determine the frequency at which the payload portion will be received. Preferably, the first node varies the preamble portion between thresholds more than once within the time span of a single preamble portion, and the preamble and payload portions are spread with different spreading codes. The preamble portion may also be disguised with noise generated by the first node.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: October 27, 2009
    Assignee: L-3 Communications Corporation
    Inventors: Thomas R. Giallorenzi, Johnny M. Harris, Eric K. Hall, Richard B. Ertel, Dan M. Griffin
  • Patent number: 7602835
    Abstract: A correlator despreads a P/N long code constructed from two or more constituent codes A, B, C having N, M and L elements respectively. In a third stage, L filter taps decorrelate elements of the third constituent code from the input received signal, leaving elements of code AB. The outputs of the third stage delay line are summed and input into a second stage delay line having M filter taps to decorrelate the elements of the second constituent code from the input to the second stage, leaving elements of code A. The outputs of the second stage delay line are summed and input to a first stage delay line having N filter taps. The output of the first stage delay line is summed and input into a shift register. An energy peak in the shift register indicates the phase of the P/N elements in the register is proper.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: October 13, 2009
    Assignee: L-3 Communications Corporation
    Inventors: Samuel C. Kingston, Johnny M. Harris, Thomas R. Giallorenzi, Dan M. Griffin, David W. Thorson
  • Patent number: 7593453
    Abstract: A spread spectrum signal having an associated code is tracked at a receiver. A plurality of components of the spread spectrum signal are despread using the associated code. Each of the plurality of components has a different code phase than all others of the plurality of code phases. Each of the plurality of components is weighted based on a phase difference between that component and a center code phase associated with the plurality of components. A tracking error is determined based on the weighted components.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: September 22, 2009
    Assignee: InterDigital Technology Corporation
    Inventors: Gary R. Lomp, Faith Ozluturk
  • Patent number: 7590195
    Abstract: A detection system and method are disclosed which uses sequential Monte Carlo techniques in a multiple-input multiple-output system. The detection system and method samples a first and second component of the modulation symbols separately, thereby reducing the number of symbol candidates and the computational complexity of the system.
    Type: Grant
    Filed: February 23, 2005
    Date of Patent: September 15, 2009
    Assignee: NEC Laboratories America, Inc.
    Inventors: Xiaodong Wang, Mohammad Madihian
  • Patent number: 7558356
    Abstract: In a cellular network, a GPS receiver includes circuitry that modulates a global positioning system (GPS) timing pulse signal with a carrier signal and transmits the modulated signal to one or more remote base stations. When the modulated timing pulse signal is received at a remote base station it is demodulated and a timing pulse signal corresponding to the GPS timing pulse signal is recovered. The remote base station may be configured to transmit a reply signal back to the GPS receiver, which can then be used to estimate a propagation delay between the GPS receiver and the remote base station.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: July 7, 2009
    Assignee: Airvana, Inc.
    Inventors: Michael D. Pollman, Theodore O. Grosch
  • Patent number: 7555034
    Abstract: Provided is an apparatus and method for detecting timing errors based on characteristics of cyclic correlation. The apparatus and method can detect the timing errors of many users by using the cyclic characteristics of a midamble code at a time and detects the timing errors based on the characteristics of cyclic correlation to reduce the time required for detecting the users and lower the complexity in terms of Hardware. The apparatus includes a detection section controller, a register, a midamble generator, a midamble shifter, an accumulator, an adder, a shift register and a timing error detector.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: June 30, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Eun-Jeong Shin, Nam-Il Kim, Young-Hoon Kim, Seung-Chan Bang, Sang-Woo Nam
  • Patent number: 7545853
    Abstract: A method of acquiring a received spread spectrum signal, especially a GPS signal, is disclosed together with a spread spectrum signal receiver and a cellular telephone incorporating such a receiver. The method comprises the steps of: providing a replica signal containing a pseudorandom noise code, corresponding to that of the spread spectrum signal; providing a subject signal containing two fragments of the spread spectrum signal initially received during respective time periods between which a further time period elapses; and coherently correlating the replica signal with the subject signal over the two fragments.
    Type: Grant
    Filed: September 6, 2004
    Date of Patent: June 9, 2009
    Assignee: NXP B.V.
    Inventors: Iwo-Martin Mergler, Andrew T. Yule, Saul R. Dooley
  • Patent number: 7526010
    Abstract: A composite code is made for example by exclusive-OR'ing each real element of a first constituent code A with each element of a second constituent code B to obtain a basic composite code. To suppress autocorrelation, differing numbers of doping code elements are inserted between code segments made from combining each element of code A with an element of code B. A matched filter first stage removes from its input the A code and any doping code added to it, summing the elements of code A. A matched filter second stage removes from its input the B code and any doping code added at the second level. The summed elements of code B are the input to the first stage. Optionally, the summed elements of the doping code at any level may be delayed and summed with the elements of the A code in the first stage.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: April 28, 2009
    Assignee: L-3 Communications Corporation
    Inventors: Johnny M. Harris, Samuel C. Kingston, Thomas R. Giallorenzi, Dan M. Griffin, David W. Thorson, Richard B. Ertel
  • Patent number: 7519099
    Abstract: A device for detecting data synchronization in data communications includes pseudorandom noise (PN) lock circuits (101, 113, 127). The PN lock circuits (101, 113, 127) receive an input data stream (109). Each of the PN lock circuits (101, 113, 127) is time offset with respect to the other PN lock circuits. Each of the PN lock circuits (101, 113, 127) outputs a PN sequence responsive to the input data stream. For each PN lock circuit, there is provided a component (105, 117, 131) for comparing the PN sequence from the respective PN lock circuit to the input data stream, to determine whether the input data stream and the PN sequence are synchronized. An indication (107, 119, 133) that the data is synchronized is provided when the input data stream and the PN sequence are synchronized.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: April 14, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Timothy R. Miller, Paul R. Runkle
  • Patent number: 7502428
    Abstract: An apparatus is disclosed. The apparatus includes a correlator that correlates a pseudo-noise sequence with a received clip stream in order to generate a correlated output. The apparatus further includes a phase controller coupled to the correlator to generate a histogram of the correlated output over a plurality of bit periods. The apparatus also includes a bit clock generator coupled to the phase controller to recover an original bit stream by using the histogram to adjust a sample position of a bit clock.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: March 10, 2009
    Assignee: Intel Corporation
    Inventor: David Gordon Ballinger
  • Patent number: 7492810
    Abstract: A method and an apparatus is disclosed for efficient cross correlation of a plurality of signal vectors. Incoming data is partitioned into several segments and processed according to an algorithm where data rotation is a function of post-correlation memory size.
    Type: Grant
    Filed: April 4, 2005
    Date of Patent: February 17, 2009
    Assignee: General Electric Company
    Inventor: Daniel D. Harrison
  • Patent number: 7489755
    Abstract: Various embodiments are described to provide for the transmission and reception of data in an improved manner. Data transmission is improved by including in a transmitter a null generator (110) to generate an output data symbol sequence that exhibits nulls in the frequency domain at particular frequencies that an input data symbol sequence does not. A pilot inserter (120) then adds a pilot symbol sequence to this output data symbol sequence to create a combined symbol sequence. Since the pilot symbol sequence exhibits pilot signals corresponding to the nulls of the output data symbol sequence in the frequency domain, the combined symbol sequence exhibits pilots that are orthogonal to the data in the frequency domain.
    Type: Grant
    Filed: February 9, 2005
    Date of Patent: February 10, 2009
    Assignee: Motorola, Inc.
    Inventors: Fan Wang, Amitava Ghosh, Chandrasekar Sankaran, Jun Tan
  • Patent number: 7486755
    Abstract: Described is a system and method for providing a synchronization pattern in a communication system. The method includes generating a synchronization pattern with good randomness properties; packing a signal for transmission with m headers, each header consisting of the synchronization pattern 1/m symbol-time shifted from the previous header; and transmitting the signal. A further method provides for the sampling the transmitted signal with m headers of symbol-time shifted synchronization patterns; and determining symbol timing offset by computing and reordering correlation peaks from the synchronization patterns. A system includes a transmitting system, a receiving system, and a data channel. The transmitted signal includes m headers with 1/m symbol-time shifted synchronization patterns. The receiving system undersamples the transmitted signal with m synchronization patterns to simulate an oversampled synchronization pattern.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: February 3, 2009
    Assignee: Microsoft Corporation
    Inventor: Lawrence J. Karr
  • Patent number: 7480325
    Abstract: A GPS receiver for integrating a GPS signal separately in a series of “A” type and “B” type time segments, the “A” segments alternating with the “B” time segments; combining the squares of the magnitudes of “A” time segment integrations corresponding to code phases for forming “A” type combined magnitudes; combining the squares of the magnitudes of the “B” time segment integrations corresponding to code phases for forming “B” type combined magnitudes; and determining an acquisition code phase of the signal from the strongest of the “A” or “B” combined magnitudes. The “A” time segments and the “B” time segments are one-half the period of the data bits of the signal, thereby ensuring that either the “A” time segments or the “B” time segments avoid the nullifying effect of data bit inversions.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: January 20, 2009
    Assignee: Trimble Navigation Limited
    Inventors: Yiming Yu, Peter Van Wyck Loomis
  • Publication number: 20080317184
    Abstract: The present invention discloses a method for transmitting a synchronization signal in a mobile multimedia system. In the method, a transmitter of the system transmits a synchronization signal sequence at a regular interval. The methods includes: generating a first synchronization signal sequence; generating a second synchronization signal sequence by performing a reversible transform for the first synchronization signal sequence; and transmitting the first and the second synchronization signal sequences in cascade. By the method provided by the present invention for transmitting a synchronization signal in a mobile multimedia system, a channel with wider delay spread can be handled, more precise and stabler synchronization performance can be achieved and the channel estimation module can be helped to get more accurate channel frequency domain response.
    Type: Application
    Filed: June 25, 2008
    Publication date: December 25, 2008
    Inventors: Hui ZHANG, Junyun Yang, Fei Meng, Yu Xu, Jiongliang Li
  • Patent number: 7453920
    Abstract: An uplink signal transmitted by a terminal is received by a satellite wireless communications system. The uplink signal includes a known information element, e.g., a reverse access channel (R-ACH) preamble, spread according to a spreading code specific to a component of a satellite wireless communications system, e.g., a pseudonoise (PN) sequence associated with a satellite beam. A correlation of the received uplink signal with the spreading code over a range of time shifts is determined. The known information element is detected from the determined correlation. The satellite wireless communications system is synchronized with the terminal responsive to detection of the known information element. For example, a delay may be assigned to a receiver of the satellite wireless communications system responsive to detection of the known information element.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: November 18, 2008
    Assignee: ATC Technologies, LLC
    Inventor: Gary G. Churan
  • Patent number: 7447254
    Abstract: A method of transmitting communications codes is used in spread spectrum communications systems. The method includes transmitting a first pseudo-noise code, and transmitting a second pseudo-noise code, wherein the second pseudo-noise code is a time-reversed version of the first pseudo-noise code. A device includes a first shift register to store a first code and a second register to store a second code in a time-reversed version. A comparison circuit then compares the two codes and a result is output.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: November 4, 2008
    Assignee: Cypress Semiconductor Corp.
    Inventors: Robert William Eugene Mack, Stephen O'Connor
  • Patent number: 7433438
    Abstract: A vestigial side band (VSB) synchronization (sync) signal detection circuit and method of generating a VSB sync signal is described. The circuit may include means for generating a first control signal related to sync signal generation, based on receipt of a selected one of an input first data signal and input second data signal, and means for generating a position signal containing information regarding positions of a next field sync and segment sync signals. The circuit may also include a correlator for generating a sign signal to determine a sign of the field sync signal, and a generator for generating a plurality of distinct types of sync signals based on the control signal, position signal and sign signal.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: October 7, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Won-Kyu Paik, Dong-Jo Kim
  • Patent number: 7430262
    Abstract: A method and system for frame synchronization in a digital data transmission. A synchronization word is selected that is suitable for good correlation in a receiver detector. Either traffic bits or control bits are interleaved within the synchronization word in a predetermined pattern that is fixed for consecutive frames. The position of the sync word is varied from frame-to-frame. Also, the interleaved bits that are either traffic or control bits varies substantially between consecutive frames.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: September 30, 2008
    Assignee: Defense Ultra Electronics Canada Inc.
    Inventor: Michel Forté
  • Patent number: 7430263
    Abstract: A timing correction system for fast PN acquisition is provided. The system includes a signal sampler for testing any incoming signal and a real-time clocker coupled to the signal sampler. A parallel correlator is coupled to the real-time clocker for searching for a PN sequence and a burst detector is coupled to the parallel correlator. A chip timing corrector is coupled to the burst detector and a processor is coupled to the chip timing corrector for determining signal timing.
    Type: Grant
    Filed: May 6, 2004
    Date of Patent: September 30, 2008
    Inventors: Patricia F. Batzer, Michael L. Wilson, LaMar K. Timothy
  • Patent number: 7430196
    Abstract: A receiver comprising a processor having an input to receive a sequence of transmission frames conforming to a transmission protocol to represent payload data, a memory arranged to store and to provide to the processor a transmission protocol, a code provider arranged to provide to the processor one or more predetermined codes for association in a predetermined distributed manner within a group of transmission frames of a transmission sequence to represent one or more particular positions in the group of transmission frames, and wherein the processor is arranged to compile at least a portion of one or more distributed codes from a group of transmission frames of a transmission sequence received at the input using the predetermined distributed manner of the one or more predetermined codes received from the code provider, and to compare one or more compiled portions of one or more codes with the one or more predetermined codes received from the code provider to determine one or more particular positions in t
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: September 30, 2008
    Assignee: Nokia Corporation
    Inventor: Seppo Turunen
  • Publication number: 20080226007
    Abstract: A method and apparatus for a receiver to estimate the received power for each transmitting BS. The power measure can be obtained by using some or all receiving antennas.
    Type: Application
    Filed: March 14, 2008
    Publication date: September 18, 2008
    Applicant: LEGEND SILICON CORP.
    Inventors: Lin Yang, Qin Liu
  • Patent number: 7418248
    Abstract: A signal reception device is disclosed that is able to improve interference cancellation capabilities even when signals having different center frequencies exist on the same frequency band. The signal reception device includes an interference suppression unit to generate replicas of plural signals in the received signal and separate the signals by suppressing interference signals. The interference suppression unit includes a signal phase rotator to rotate phases of the signal candidates at preset respective rotational frequencies, the preset rotational frequencies being related to respective center frequencies of the signals in the received signal; a rotational frequency controller to set the preset rotational frequencies; and a replica generator to generate the replicas of the signals by using the phase-rotated signal candidates.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: August 26, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Koji Maeda, Satoru Fukumoto, Hitoshi Yoshino
  • Patent number: 7412018
    Abstract: In a wireless communication system which includes a synchronization signal generator which generates a synchronization sequence, an RF transmitter which transmits the synchronization signal, and one or more receiver that receives the signal, where the synchronization sequence employs M PN codes of the same length that are repeated in a pseudo-random fashion for N code periods. Each receiver incorporates M filters matched to the M PN codes whose outputs are post detection combined in a manner consistent with the pseudo-random code transmission sequence to provide signal detection and synchronization. In another aspect, the synchronization sequence employs M time-shifted versions of a PN code that are repeated in a pseudo-random fashion for N code periods and each receiver incorporates a filter matched to the unshifted PN code and whose output samples are post detection combined in a manner consistent with the pseudo-random code transmission sequence to provide signal detection and synchronization.
    Type: Grant
    Filed: May 19, 2000
    Date of Patent: August 12, 2008
    Assignee: Alcatel USA Sourcing, L.P.
    Inventors: Francis D. Natali, John E. Ohlson
  • Patent number: 7403583
    Abstract: A system and method for using Psuedo-Noise (PN) phase to determine frame start of a data frame is provided. The system and method includes at least two PN component codes, wherein the at least two PN component codes are relatively prime. A received PN composite encoded signal is correlated with at least one of the PN component codes and a frame start is determined. With reference to frame start at least one training sequence bit is located. The training bits may be overwritten on FEC encoded frame data such that a FEC decoder may be used to recover data overwritten by the training sequence bit(s).
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: July 22, 2008
    Assignee: L-3 Communications Corporation
    Inventors: Kent R. Bruening, Zachary C. Bagley, Vaughn L. Mower
  • Patent number: 7386066
    Abstract: A detection device includes an antenna for receiving an incident signal, and for delivering a base signal. A comparator receives the base signal and provides an intermediate signal representative of the sign of the base signal relative to a reference signal. A sampling circuit samples the intermediate signal for providing a digital signal. A digital processing circuit correlates the digital signal with a predetermined correlation signal.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: June 10, 2008
    Assignees: STMicroelectronics SA, STMicroelectronics N.V.
    Inventors: Didier Helal, Thierry Arnaud, Fritz Lebowsky
  • Patent number: 7369600
    Abstract: A communications apparatus and method use tapped delay lines as multiplexers and demultiplexers. In one embodiment, a receiver (100) uses a tapped delay line (110) as a demultiplexer to acquire a burst communication at very high data rates in the range of 2.5 to 80 Gbps with low preamble overhead. A sliding window correlator (114) continually samples the delay line (110) to determine when a PN encoded word is contained therein. The transmission frequency is pre-acquired before any data is present through the use of a ring oscillator frequency calibration loop (130) that is imbedded within the tapped delay line (110).
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: May 6, 2008
    Assignee: Northrop Grumman Corporation
    Inventors: Eric L. Upton, James M. Anderson, Edward M. Garber
  • Patent number: 7366090
    Abstract: A method for generating a preamble sequence in an orthogonal frequency division multiplexing (OFDM) communication system having A subcarriers in a frequency domain. The method comprises generating a length-2×M×N preamble sequence, where 2×M×N is less than A, by using a length-N Golay complementary sequence and a length-M Golay complementary sequence; and assigning elements constituting the preamble sequence to 2×M×N subcarriers among the A subcarriers on a one-to-one mapping basis, assigning null data to the remaining subcarriers excluding the 2×M×N subcarriers from the A subcarriers, and then IFFT-transforming the assigned result into time-domain data.
    Type: Grant
    Filed: April 7, 2004
    Date of Patent: April 29, 2008
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Chang-Ho Suh, Chan-Byoung Chae, Ho-Kyu Choi, Jung-Min Ro, Pan-Yuh Joo
  • Patent number: 7342538
    Abstract: In a local positioning system, the land-based transmitters include free running oscillators or oscillators free of clock synchronization with any remote oscillator. A reference receiver receives the ranging signals from different transmitters and generates timing offset information, such as code phase measurements. The timing offset information is then communicated back to transmitters. The temporal offset information indicates relative timing or phasing of the different transmitted ranging signals to the reference receiver. The transmitters then transmit the temporal offset information with the ranging signals, such as modulating the transmitted code by the timing offset information. A mobile receiver is operable to receive the ranging signals and timing offset information in a same communications path, such as on a same carrier. Position is determined with the temporal offset information and the ranging signals.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: March 11, 2008
    Assignee: Novariant, Inc.
    Inventor: Kurt R. Zimmerman
  • Patent number: 7317776
    Abstract: The invention solves the problem of efficiently generating pseudo noise sequences with an arbitrary offset delay. Novel and improved architectures are used, based on the matrix-vector pseudo noise generators. A first embodiment of this invention includes a plurality of serially connected transition matrix multiplication circuits producing a plurality of output state matrices. A second embodiment of this invention combines a first stage having plurality of matrix multiplication circuits connected to a first multiplexer circuit which selects an state matrix or one of the matrix products with a serial chain of matrix generator circuits including second matrix multiplication circuit and a second multiplexer selecting either a first input or the output of the second matrix multiplication circuit.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: January 8, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Sundararajan Sriram, Vijay Sundararajan
  • Patent number: 7313173
    Abstract: One code is generated by combining (including addition) 2 or more codes, correlation detection method which detects the correlation by multiplying such a generated code by the reception data. In communication system based on W-CDMA method, first spreading code (a·Cp) obtained by multiplying primary synchronization code with a predetermined coefficient and second spreading code (a·Cs) obtained by multiplying secondary synchronization code with a predetermined coefficient are added. Then, the third spreading code (a·Cp+a·Cs) obtained from such an addition is multiplied by the reception data, and correlation value is obtained after integrating the multiplication results. Thus, it is determined whether the reception data has been subjected to STTD diversity.
    Type: Grant
    Filed: April 4, 2002
    Date of Patent: December 25, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Kimiaki Ando
  • Patent number: 7305057
    Abstract: A multichannel filter-based handheld UWB communication transceiver is presented for outdoor operations. Using eleven multichannels with multicarrier modulations, the invented handheld UWB communication transceiver can transmit and receive UWB signals at a data rate up to 7.15 Gcps with scalability capabilities. In addition, the handheld UWB communication transceiver can be controlled in a programmable way to avoid interference with WLAN devices.
    Type: Grant
    Filed: July 7, 2003
    Date of Patent: December 4, 2007
    Inventor: George J. Miao
  • Patent number: 7298779
    Abstract: The present invention relates to the fast code acquisition methods based on signed-rank statistic. In more detail, it presents novel detectors required for PN (PN) code acquisition in DS/SS system. In accordance with the present invention, first, the LOR (LOR) detector is derived and then the LSR (LSR) and MSR (MSR) detectors using approximate score functions are proposed. It is compared the single-dwell scheme without the verification mode using the proposed LSR and MSR detectors with that using the conventional squared-sum (SS) and modified sign (MS) detectors.
    Type: Grant
    Filed: May 28, 2002
    Date of Patent: November 20, 2007
    Assignee: Korea Advanced Institute of Science and Technology
    Inventors: Lick Ho Song, Hong Gil Kim, Chang Yong Jung
  • Patent number: 7289588
    Abstract: A method for generating a preamble sequence in an orthogonal frequency division multiplexing (OFDM) communication system having A subcarriers in a frequency domain. The method comprises generating a length -M×N preamble sequence, where M×N is less than A, by using a length-N Golay complementary sequence and a length-M Golay complementary sequence; and assigning elements constituting the preamble sequence to M×N subcarriers among the A subcarriers on a one-to-one mapping basis, assigning null data to the remaining subcarriers excluding the M×N subcarriers from the A subcarriers, and then IFFT-transforming the assigned result into time-domain data.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: October 30, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Ho Suh, Chan-Byoung Chae, Ho-Kyu Choi, Jung-Min Ro, Pan-Yuh Joo
  • Patent number: 7239813
    Abstract: A bit synchronization circuit composed of a multiphase data sampling unit for converting each received burst data sets to multiphase data trains, a phase determination unit for generating a control signal indicating an optimum phase data train, an output data selector for selectively passing optimum phase data train indicated by the control signal, and a data synchronization unit for converting the optimum phase data train to a data train in synchronization with a reference clock. The phase determination unit repeatedly detecting the optimum phase data train during the same burst data set is received. When optimum phase varies, the output data selector dynamically switches the optimum phase data train to be supplied to the data synchronization unit.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: July 3, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Yusuke Yajima, Toshihiro Ashi, Tohru Kazawa
  • Patent number: 7230910
    Abstract: A channel sounding system employs orthogonal sequences to meet the Cramer-Rao bound in estimating the channel and achieves considerable simplification of the structure necessary to perform the channel sounding. These advantages are achieved by developing orthogonal sequences of substantially arbitrary length as a function of first and second existing orthogonal sequences and using such orthogonal sequences for channel sounding in lieu of M-sequences. The techniques of the invention are especially suited to systems that use multiple antennas at the transmitter and multiple antennas at the receiver, so called multiple-input multiple-output (MIMO) systems.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: June 12, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Eric C. Beck, Markus Rupp
  • Patent number: 7230984
    Abstract: A method for equalizing data and systems utilizing the method. The method of this invention for equalizing (by shortening the channel response) data includes minimizing a function of the data and a number of equalizer characteristic parameters, where the function utilizes cyclic differences of equalized data. Updated equalizer characteristic parameters are then obtained from the minimization and an initial set of equalizer characteristic parameters. Finally, the received data is processed utilizing the equalizer defined by the minimization. The method of this invention can be implemented in an equalizer and the equalizer of this invention may be included in a system for receiving data.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: June 12, 2007
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Richard K. Martin, Jaiganesh Balakrishnan, Wonzoo Chung, C. Richard Johnson, Jr., William A. Sethares
  • Patent number: 7227885
    Abstract: A receiver receives elements of a signal sequence. A state generator generates a sequence of addresses to translate between a pseudonoise sequence and a Walsh sequence. A storage medium, coupled to the receiver and the state generator, stores each element of the signal sequence at a given address according to the sequence of addresses.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: June 5, 2007
    Assignee: Motorola, Inc.
    Inventors: David P. Gurney, Stephen L. Kuffner
  • Patent number: 7209495
    Abstract: A wireless telemetry system includes many radio transmitters using frequency-hopping carriers for intermittently transmitting very short messages indicative of status of stimuli associated with the transmitters. The transmitters can transmit independently of any receiver for receiving from the transmitters and independently of each other. Transmission frequency and time between transmissions are varied according to time-frequency patterns that can be different for each transmitter. Urgent messages, such as alarms, are transmitted at transmission opportunities at intervals smaller than routine transmissions. The transmission opportunities are also according to a time-frequency pattern. Power-up transmissions carry information about future transmission opportunities and/or routine transmissions. Power-up transmissions can also carry information about time-frequency pattern for controlling routine transmissions and/or transmission opportunities.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: April 24, 2007
    Inventor: Andrzej Partyka
  • Patent number: 7187732
    Abstract: Method and apparatus for adjusting the frequency of a voltage controlled oscillator (VCO) at a receiver to synchronize the receiver with the transmitter by correlating a synchronization code channel with training sequences to estimate positive and negative offsets which are employed to estimate an error, which is then filtered. The filter output provides voltage controlling the VCO. The same technique may be employed to control a numeric controlled oscillator (NCO).
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: March 6, 2007
    Assignee: InterDigital Technology Corporation
    Inventor: Alpaslan Demir
  • Patent number: 7173983
    Abstract: A COFDM demodulator including a fast Fourier transform circuit analyzing a received signal in a window corresponding to one symbol, each symbol carrying several phase and amplitude modulated carriers, some of which are shifted in frequency in a predetermined way from one symbol to the next one to form pilots; a bidimensional filter for interpolating, from anchors corresponding to the pilots such as received from several consecutive symbols, the distortion undergone by each carrier; and a circuit for correcting the shifting of the window with respect to an optimal position. The demodulator includes a circuit for correcting each distortion according to window shifting corrections performed respectively for the symbol associated with the distortion and for the symbols associated with the anchors used to interpolate the distortion.
    Type: Grant
    Filed: February 25, 2000
    Date of Patent: February 6, 2007
    Assignee: STMicroelectronics S.A.
    Inventor: Jacques Meyer
  • Patent number: 7116698
    Abstract: A generator of repetitive sets of spreading sequences comprising element (20), for counting and for forming an address and a table (30) containing L sets of S sequences, wherein the address contains q=1+log2S bits, in which one set among L (L=2q) sets is selected and wherein the log2S bits select one sequence among the S sequences in the set.
    Type: Grant
    Filed: June 13, 2001
    Date of Patent: October 3, 2006
    Inventors: Norbert Daniele, Dominique Noguet, Rosolino Lionti, Jean-René Lequepeys
  • Patent number: 7116701
    Abstract: A base station comprises a plurality of antennas. Each of the antennas is separated by a known distance. A first spread spectrum signal is transmitted having a first code. Using the plurality of antennas, a second spread spectrum signal is received having a second code. The second spread spectrum signal is time synchronized with the first spread spectrum signal. A distance determination is made based on in part a timing difference between the second code of the received second spread spectrum signal and the first code of the base station's transmitted first spread spectrum signal. A phase difference of a carrier signal of the second spread spectrum signal as received by each of the plurality of antennas is compared. An angle of the received second spread spectrum signal is determined using the known distance between the antennas and the phase difference. A location of a source of the second spread spectrum signal is determined using the determined angle and the distance determination.
    Type: Grant
    Filed: May 4, 2004
    Date of Patent: October 3, 2006
    Assignee: InterDigital Technology Corporation
    Inventor: David K. Mesecher
  • Patent number: RE40111
    Abstract: A remote power meter monitoring system using spread spectrum transmitters, fast frequency shift keying, spread spectrum receivers and a computer. The spread spectrum transmitter uses a chip code generator, preamble register, address register data register and oscillator coupled to a microprocessor to transmit information in a direct sequence spread spectrum signal. The spread spectrum receiver acquires synchronization of the spread spectrum signal using a microprocessor to despread and detect the transmitted information, which relates to data from a power meter.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: February 26, 2008
    Assignee: M & FC Holding, LLC
    Inventors: H. Britton Sanderford, Robert E. Rouquette