Synchronization Word Patents (Class 375/365)
  • Patent number: 7965804
    Abstract: A method for word synchronization can be applied to asynchronous devices including SERDES devices connected across serial lines. A state transition methodology characterizes the state of the device based on control characters received consistently across the serial lines and channels the system to a state of word synchronization. Loss of synchronization and transmission errors lead to a re-establishment of synchronization.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: June 21, 2011
    Assignee: Pluris, Inc.
    Inventors: Angshuman Saha, Steven Farnworth, Russell R. Tuck, III, Deepak Mansharamani
  • Patent number: 7953190
    Abstract: The present invention provides architectures and methods which enables faster and more power efficient detection of channel parameters used by a communication system. Various parallel preamble correlator structures are able to perform searches for multiple preambles in parallel. The received samples are correlated with different delays between the samples corresponding to the different possible channel parameters that may be used by the communication system. Processing elements used in the preamble search may be shared among the parallel preamble search sections of a given architecture to reduce costs and power consumption. Decimation and filtering may also be used to reduce the interference from adjacent channels.
    Type: Grant
    Filed: May 2, 2008
    Date of Patent: May 31, 2011
    Inventors: Bhaskar Patel, Arumugam Govindswamy
  • Patent number: 7953199
    Abstract: Provided is a synchronization error tracking device and method. The method and system estimates and corrects the synchronization error generated by time and frequency offsets during the data transmission interval and uses a module designed for initial synchronization or channel estimation without adding a new correlation operator. Further, a combining mark value and a synchronization position value acquired during the synchronization process are used.
    Type: Grant
    Filed: November 2, 2009
    Date of Patent: May 31, 2011
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Kyu-Min Kang, Sang In Cho, Sung Woo Choi, Sangsung Choi
  • Patent number: 7953198
    Abstract: A frame synchronization is proposed for a multi-band communication system, wherein a data signal exchanged between a transmitter and a receiver is organized in system frames having a preamble section which contains a frame synchronization section that is composed of a number of symbol frames, each of which is in turn composed of a defined number of slots, whereby each slot corresponds to an individual transmission frequency band. The method comprises steps for transmitting the data signal containing a synchronization signal in one or more slots of every other symbol frame of the frame synchronization section, processing only data signal components selected from transmission frequency bands required for the synchronization signal transmission, and subtracting the processed data signal from its shifted copy, whereby the copy is shifted by one symbol frame.
    Type: Grant
    Filed: January 22, 2010
    Date of Patent: May 31, 2011
    Assignee: Sony Deutschland GmbH
    Inventors: Juns-Uwe Jurgensen, Richard Stirling-Gallacher
  • Patent number: 7936856
    Abstract: A synchronization circuit includes a correlator, an energy calculator, a post-processing unit, and a decision device. The correlator correlates a received sequence r(t) with a local sequence c(i) to obtain a correlation result h(t). The energy calculator calculates an energy function of the correlation result h(t), and filters the energy function of the correlation result by a channel impulse response wc(l) to obtain a filtered energy function e(t), where l is the index of the channel impulse response. The post-processing unit applies weighting function wa(t) to the filtered energy e(t) to obtain a weighted energy function e?(t), wherein the weighting function wa(t) weights a central portion of the filtered energy function e(t). The decision device selects a maximum energy value from the weighted energy function e?(t), and the time index t with maximum energy value is the time shift of the received sequence and the local sequence.
    Type: Grant
    Filed: September 13, 2007
    Date of Patent: May 3, 2011
    Assignee: Mediatek Inc.
    Inventors: Chun-Ming Kuo, I-Ping Chang, Chi-Yeh Yu, Shih-Kung Chang, Ho-Chi Huang
  • Patent number: 7933256
    Abstract: A method for midamble estimation comprises the steps of receiving a burst of symbols, selecting a subset of the burst of symbols that comprises a first midamble symbol, calculating, for each symbol in the subset, a corresponding midamble estimation error, and determining the lowest calculated midamble estimation error to locate the first midamble symbol. A receiver comprises an antenna configured to receive a burst of symbols, a timing estimator configured to select a subset of the burst of symbols that comprises a first midamble symbol, a midamble estimator configured to calculate, for each symbol in the subset, a corresponding midamble estimation error, and a processor configured to select the symbol in the subset corresponding to a lowest calculated midamble estimation error as the first midamble symbol.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: April 26, 2011
    Assignee: Qualcomm Incorporated
    Inventors: Farrokh Abrishamkar, Divaydeep Sikri
  • Publication number: 20110090998
    Abstract: A Phase-Locked Loop (PLL) includes a Phase-to-Digital Converter (PDC), a programmable digital loop filter, a Digitally-Controlled Oscillator (DCO), and a loop divider. Within the PDC, phase information is converted into a stream of digital values by a charge pump and an Analog-to-Digital Converter (ADC). The stream of digital values is supplied to the digital loop filter which in turn supplies digital tuning words to the DCO. A number of types of ADCs can be used for the ADC including a continuous-time delta-sigma oversampling Digital ADC and a Successive Approximation ADC. The voltage signal on the charge pump output is a small amplitude midrange voltage signal. The small voltage amplitude of the signal leads to numerous advantages including improved charge pump linearity, reduced charge pump noise, and lower supply voltage operation of the overall PLL.
    Type: Application
    Filed: October 20, 2009
    Publication date: April 21, 2011
    Applicant: QUALCOMM Incorporated
    Inventor: Gang Zhang
  • Patent number: 7924953
    Abstract: Provided is an apparatus and method for detecting a time-frequency code in an MB-OFDM UWB system. The apparatus includes a controller for providing a band selection signal to the RF receiver and outputting a preamble selection signal at regular symbol periods to calculate a cross correlation value for a predetermined time period more than a beacon frame interval when a time-frequency code search start signal is received; and a cross correlator for storing information on preamble patterns, selecting a preamble stored depending on the preamble selection signal, and calculating a cross correlation value for a digital signal transferred through the RF receiver, wherein the controller determines a time-frequency code using a preamble where a peak occurs as a time-frequency code that is currently in use when a peak signal is inputted based on the calculated cross correlation value, and transmits the determined time-frequency code to the MAC receiver.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: April 12, 2011
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung-Woo Choi, Cheol-Ho Shin, Kyu-Min Kang, Sang-Sung Choi
  • Patent number: 7912165
    Abstract: 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: Grant
    Filed: May 25, 2007
    Date of Patent: March 22, 2011
    Assignee: Infineon Technologies AG
    Inventors: Stefan Herzinger, Andreas Menkhoff, Stefan Meier, Norbert Neurohr
  • Patent number: 7881343
    Abstract: A communications system includes a wireless telephony network and a wireless Local Area Network (LAN), both accessible by a mobile communications device (16). To facilitate transitioning of the mobile communications device to the wireless LAN from the wireless telephony network, the wireless LAN includes a beacon transmitter, which generates a synchronization channel having a pattern unique to the wireless LAN. The Wireless LAN synchronization channel is received at a first receiver in the mobile communications device together with a synchronization channel from the wireless telephony. The wireless LAN synchronization channel enables the mobile communication device to synchronize with, for transitioning to, the wireless LAN.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: February 1, 2011
    Assignee: Thomson Licensing
    Inventors: Guillaume Bichot, Jun Li, Wen Gao, Philippe Gilberton
  • Publication number: 20110007857
    Abstract: A communication device includes a current information storage unit 130 that stores the bit boundary signal at each of timings at which a sampling clock is updated, a past information storage unit 140 that takes in and stores a signal stored in the current information storage unit 130 when a variation point of a reception signal is detected, and does not update a signal stored therein when no variation point of the reception signal is detected, and a clock selection unit 44 that selects CLKSEL2 used for the sampling of the reception signal from N-phase clocks based on a signal stored in the current information storage unit 130 when a variation point of the reception signal is detected, and selects CLKSEL3 based on a signal stored in the past information storage unit 140 when no variation point of the reception signal is detected.
    Type: Application
    Filed: June 4, 2010
    Publication date: January 13, 2011
    Applicant: NEC Electronics Corporation
    Inventors: Shinya Konishi, Norio Arai, Osamu Ohnishi
  • Patent number: 7869552
    Abstract: In a receiving apparatus for receiving communication data from a transmitting apparatus, specific code patterns are inserted in the communication data at predetermined intervals. The receiving apparatus includes a first frequency difference measurement device for measuring a first frequency difference between a receiving clock of the receiving apparatus and a transmission clock provided to the communication data, based on one of the specific code patterns and another of the specific code patterns which is positioned later; and a frequency adjustment device for adjusting a frequency of the receiving clock based on the measured first frequency difference so that the frequency substantially coincides with a frequency of the transmission clock.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: January 11, 2011
    Assignee: Olympus Corporation
    Inventor: Masaharu Yanagidate
  • Patent number: 7844279
    Abstract: The present invention relates to a method for measuring radio channel quality in a radio communication system. In the method a modulated signal is received over a communication channel. The modulated signal has been modulated by using modulation parameters. A decoder decodes (305) the modulated signal and forms decoded data. The decoder creates (306) a decoder performance indicator (PS) that depends on the decoded data. Then a radio channel quality indicator (RCQI) is created, the radio channel quality indicator being essentially independent of the modulation parameters.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: November 30, 2010
    Assignee: Dibcom
    Inventors: Jean-Philippe Sibers, Stéphane De Marchi
  • Patent number: 7839962
    Abstract: The present invention relates to a method for synchronizing a signal frame transmitted by a transmitter of a telecommunication system to a receiver adapted to synchronize said signal frame from a synchronization sequence included in said signal frame.
    Type: Grant
    Filed: April 2, 2007
    Date of Patent: November 23, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventors: Bruno Jechoux, Loic Brunel
  • Patent number: 7835428
    Abstract: A MODEM device includes a detector configured to detect a synchronization signal transmitted from a source MODEM in a resynchronization process of a primary channel and a timer configured to count up starting from a beginning of a detection of the synchronization signal, and send information to forcibly move into a receiving mode for receiving image data when a time period from the beginning to a completion of the detection of the synchronization signal exceeds a predetermined time period.
    Type: Grant
    Filed: August 9, 2006
    Date of Patent: November 16, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masashi Tokuda, Hirofumi Nishi
  • Patent number: 7826577
    Abstract: 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 oscil
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: November 2, 2010
    Assignee: Palm, Inc.
    Inventors: Bernd Bienek, Andreas Falkenberg, Stephan Karger, Theo Kreul, Albrecht Kunz, Holger Landenberger
  • Patent number: 7826567
    Abstract: Receivers (1) for receiving frequency signals are, to improve their time synchronization accuracy, provided with synchronization stages (20) for performing a coarse time synchronization through autocorrelating samples of a group of preamble symbols (t1,t2,t3) and a fine time synchronization through crosscorrelating samples of a further group of preamble symbols (t10,G1) with predefined samples. The synchronization stages (20) also perform a coarse and a fine frequency synchronization through detecting and accumulating phases of samples of a yet further group of preamble symbols (t8,t9) and of another group of preamble symbols (T1,T2). The synchronization stages (20) have buffering units (21) and controlling units (22) for controlling mixing units (11) and transformating units (12) in processing stages (10). The preamble symbols have ten short preamble symbols (t1-t10), a guard interval preamble symbol (G 1) and two training symbols (T 1,T2).
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: November 2, 2010
    Assignee: NXP B.V.
    Inventors: Paulus Wilhelmus Franciscus Gruijters, Lucas Hendrikus Gerardus Tan
  • Patent number: 7826579
    Abstract: A clock generator circuit for generating synchronization signals for a multiple chip system. The clock generator circuit comprises generation of a synchronization signal from a reference clock and chip global clock with edge detection logic. In high performance server system design with multiple chips, a common practice for server systems is to use feedback clock and delayed reference clock to generate the synchronization signal. The generated synchronization signal is transferred to latches clocked by the global clock to be used for chip synchronization functions. As the system clock frequency is pushed higher, the phase difference between generated synchronization signal clocked by feedback clock and receiving latch clocked by global clock is becoming such a large portion of cycle time that this signal cannot be transferred deterministically.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: November 2, 2010
    Assignee: International Business Machines Corporation
    Inventors: Charlie C. Hwang, Wiren D. Becker, Timothy G. McNamara, Ching-Lung Tong
  • Patent number: 7822163
    Abstract: A technique for synchronizing a device for communication is based on an accumulated sum of values or absolute values. The absolute value can be of either the sum or difference of a plurality of symbols. In one embodiment, the absolute values of the sum or difference of three symbol pairs are accumulated, and the accumulated total compared to a threshold value to determine whether the symbols are at the end of a predetermined sequence of symbols. When the comparison to the threshold value is positive, the three symbol pairs are the last six symbols in the predetermined sequence. In practice, the invention can be implemented in a number of different environments including, for example, in a WiMedia MBOA network environment. In the WiMedia MBOA environment, the predetermined sequence can comprise the preamble of a WiMedia MBOA packet.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: October 26, 2010
    Assignee: Olympus Corporation
    Inventor: Abu S. Amanullah
  • Patent number: 7808419
    Abstract: A digitizer includes an analog to digital converter (ADC), a sampling frequency generator, and a controller. The ADC samples an IF signal to generate a digital signal. The sampling frequency generator is connected to the ADC and provides a sampling clock of variable frequency to the ADC. The controller is connected to the sampling frequency generator and determines frequency of the sampling clock.
    Type: Grant
    Filed: October 22, 2008
    Date of Patent: October 5, 2010
    Assignee: Mediatek Inc.
    Inventors: Yi-Fu Chen, Ming-Luen Liou, Cheng-I Wei, Chun Hua Ho
  • Patent number: 7809337
    Abstract: An apparatus and method for adjusting transmission phasing in a point-to-point communication link is disclosed. The relative phases of the transmissions from each antenna are adjusted before transmission to give optimum gain when received by two or more antenna elements and a signal combining element. The signal includes a data component, consisting of a subset of the subcarriers modulated with the input data, which is common to transmissions from all antenna elements; and a phase reference component consisting of a subset of the subcarriers that are modulated with a predetermined phase. The signal combining element is operable to receive the components and extract phase information.
    Type: Grant
    Filed: February 26, 2007
    Date of Patent: October 5, 2010
    Assignee: Motorola, Inc.
    Inventor: Peter N. Strong
  • Patent number: 7792233
    Abstract: A packet preamble search method is disclosed for locating a packet preamble with multiple predetermined patterns of a regular form within a received transmission signal with sequential multiple patterns. The pattern of the received transmission signal and the predetermined pattern of the packet preamble have the same length with even bits. The pattern of the transmission signal is sequentially compared with the predetermined pattern. A hit count is increased and a miss count is reset when the pattern of the transmission signal matches the predetermined pattern. The miss count is increased and the hit count is decreased when the pattern of the transmission signal does not match the predetermined pattern. The hit count and the miss count are reset when the hit count is less than or equal to the miss count. An address matching procedure is activated when the hit count exceeds or is equal to a threshold value.
    Type: Grant
    Filed: July 3, 2006
    Date of Patent: September 7, 2010
    Assignee: Princeton Technology Corporation
    Inventors: Jia-Yu Yang, Wen-Jan Lee, Kwo-Wei Chang
  • Patent number: 7792217
    Abstract: The present invention is directed to a system and method for channel estimation for a communication channel such as, for example, that found in a wireless communication network. One or more synchronization and channel estimate symbols can be combined to compute a refined channel estimate.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: September 7, 2010
    Assignee: Olympus Corporation
    Inventors: Ghobad Heidari-Bateni, Abu Amanullah, Dumitru Mihai Ionescu
  • Patent number: 7787579
    Abstract: A frame synchronous circuit operable in a dedicated short-range communication system, applicable to several modulation schemes, includes a UW detector for detecting a UW word from received data, an operation setting register group for specifying the operations of an on-board unit, a synchronous manager for controlling synchronization, an unlimited synchronization continuation register for maintaining the unlimited continuation of the synchronization, and an FCMC data analyzer for analyzing FCMC data. The operation setting register group can control synchronization by using not only operational information obtained from the FCMC data but also another operational information retrieved from an input device such as a CPU or terminal connected to the on-board unit. Consequently, debug and test operations can be performed without receiving any FCMC data.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: August 31, 2010
    Assignee: Oki Semiconductor Co., Ltd.
    Inventors: Kentaro Toda, Motoatsu Yoshikawa
  • Patent number: 7782844
    Abstract: The present invention provides a method and apparatus for detecting and decoding data. The method comprises: receiving a set of data signals from an external data source; detecting a size of said received set of data signals; decoding said received set of data signals; extracting a destination address from said set of data signals; comparing said destination address extracted from said data signals to a known data value; determining whether said received data signals should be received by a host circuitry based upon said comparison of said destination address extracted from said data signals to a known data value; generating at least one status signal alerting said host circuitry of said determination that said received data signals should be received by said host circuitry; and waking up said host circuitry upon a determination that said received set of data is addressed to said host circuitry.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: August 24, 2010
    Assignee: GlobalFoundries, Inc.
    Inventor: David W. Smith
  • Patent number: 7778307
    Abstract: A wireless communication device for receiving a frame (200) corresponding to a transmission time interval, the frame having a control channel (210) including at least two control channel elements (212, 214) and an embedded bit sequence, the location of which indicates a portion of the control channel used for radio resource assignment, wherein the portion of the control channel used for radio resource assignment may be less than the entire control channel of the frame having the embedded bit sequence, and wherein the at least two frames may use different portions of the control channel for radio resource assignment.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: August 17, 2010
    Assignee: Motorola, Inc.
    Inventors: Ravi Kuchibhotla, Brian K. Classon, Robert T. Love, Ravikiran Nory, Kenneth A. Stewart, Yakun Sun, Michael E. Buckley
  • Patent number: 7778370
    Abstract: Frame synchronization methods and systems suited for packet communications systems, and particularly time frequency hopping packet communication systems, are disclosed. Frame synchronization is performed by performing a first correlation on information of received symbols and performing a second correlation on results of the first correlation. In systems with repeating synchronization information modulated by a cover sequence, the results of the second correlation may be used to determine symbol numbering of symbols in a packet.
    Type: Grant
    Filed: August 16, 2006
    Date of Patent: August 17, 2010
    Assignee: Realtek Semiconductor Corp.
    Inventors: Turgut Aytur, Stephan ten Brink, Ravishankar H. Mahadevappa, Ran Yan
  • Patent number: 7769120
    Abstract: Methods and apparatuses for dynamically adjusting sync windows are described. A default sync window is set; a data signal is input; detecting if parts of the data signal within the sync window form a sync pattern; accumulating a count of the sync pattern within and without the sync window; and reducing the sync window when the count of sync pattern within the sync window achieves a first threshold value, and increasing the sync window when the count of the sync pattern outside the sync window achieves a second threshold value.
    Type: Grant
    Filed: December 21, 2004
    Date of Patent: August 3, 2010
    Inventors: Jay Hu, Mel Lai, Shih-Lung Ouyang
  • Patent number: 7756230
    Abstract: A method for synchronizing on a pulsed waveform sequence including pulsed waveforms. An impulse radio receiver is provided including a radio frequency (RF) front end connected to a demodulator, and the demodulator is connected to a processing unit. Power is provided to at least a portion of an RF component such as the RF front end and/or the demodulator, during time windows sufficient for testing an hypothesis regarding timing of the pulsed waveforms. The powering is controlled by the processing unit. Preferably, testing the hypothesis includes accumulating a signal of the pulsed waveforms, correlating with the pulsed waveforms, or accumulating the correlation result of the pulsed waveforms. Preferably, others functions of the receiver are powered or enabled subsequent to the testing. Preferably, the impulse radio receiver is an ultra-wide band receiver.
    Type: Grant
    Filed: May 15, 2005
    Date of Patent: July 13, 2010
    Assignee: Sandlinks Systems Ltd.
    Inventors: Dan Raphaeli, Gideon Kaplan
  • Patent number: 7742537
    Abstract: A time domain symbol timing synchronization circuit is disclosed, which comprises: an autocorrelation function calculator for calculating cyclic prefix autocorrelation functions and an offset time estimator for searching peak positions of cyclic prefix autocorrelation functions to indicate symbol boundary of received communication symbols. The offset time estimator compares a current peak position and a previous peak position. If (a) the difference of the positions is larger than a threshold and (b) the current peak is smaller than a reference average peak, the current peak is determined as false; the offset time estimator weeds out and replaces the current peak position by the previous peak position; and the current peak is not introduced in the reference average peak calculation.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: June 22, 2010
    Assignee: Alpha Imaging Technology Corp.
    Inventors: Chih-Chia Wang, Shu-Mei Li, Chingwo Ma, Hsin-Chin Hsu, Yi-Sheng Lin
  • Publication number: 20100131972
    Abstract: A method and apparatus for synchronizing Digital Multimedia Broadcasting (DMB) are provided. An operation method of a first Mobile Station (MS) for synchronizing DMB includes sending a broadcast channel synchronization request message to a second MS, receiving a broadcast channel synchronization request grant message from the second MS, after broadcast channel synchronization, receiving information on a broadcast channel viewed by the second MS, tuning to the broadcast channel viewed by the second MS based on the broadcast channel information received from the second MS, and displaying the broadcast channel viewed by the second MS.
    Type: Application
    Filed: November 20, 2009
    Publication date: May 27, 2010
    Applicant: SAMSUNG ELECTRONICS CO. LTD.
    Inventor: Ki-Jong BYUN
  • Patent number: 7720106
    Abstract: A circuit for synchronizing symbols of a received OFDM signal includes a unit configured to detect cross-correlation of a received signal to generate a value of the cross-correlation, a unit configured to obtain synchronous summation of the value of the cross-correlation performed at predetermined intervals, a unit configured to obtain received electric power of the received signal, an autocorrelation electric power obtaining unit configured to obtain autocorrelation electric power of the received signal, a threshold obtaining unit configured to obtain a synchronous summation threshold responsive to the received electric power, and a symbol timing detecting unit configured to identify timing of a peak of the synchronous summation as symbol timing in response to detecting, at the timing of the peak, that the autocorrelation electric power is smaller than the received electric power multiplied by a predetermined factor and that the synchronous summation is larger than the synchronous summation threshold.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: May 18, 2010
    Assignee: Fujitsu Limited
    Inventor: Liang Zhou
  • Patent number: 7720177
    Abstract: A known sequence of symbols is located within a transmitted sequence of symbols by estimating the phase differences between offset symbols within a portion or more of the transmitted sequence, estimating the phase differences between offset symbols in the known sequence, and determining that the symbols within the portion or more of the transmitted sequence are the known sequence if the phase difference estimates determined from the symbols within the portion or more of the transmitted sequence are substantially equal to the phase difference estimates determined from the known sequence.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: May 18, 2010
    Assignee: Trident Microsystems (Far East) Ltd.
    Inventors: Chi-Ping Nee, Durgaprasad Kashinath Shamain, Gdaliahou Kalit, Abraham Krieger
  • Patent number: 7719442
    Abstract: A multi-mode multi-parallelism data exchange method and the device thereof are proposed to apply to a check node operator or a bit node operator. The proposed method comprises the steps of: duplicating part or all of an original shift data as a duplicated shift data; combining the original shift data and the duplicated shift data to form a data block; and using a data block as the unit to shift this data block so as to conveniently retrieve shift data from the shifted data block. With a maximum z factor circuit and duplication of part of data, specifications of different shift sizes can be supported. The functions of shifters of several sizes can therefore be accomplished with the minimum complexity.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: May 18, 2010
    Assignee: National Chiao Tung University
    Inventors: Chih-Hao Liu, Chien-Ching Lin, Chen-Yi Lee, Hsie-Chia Chang, Yarsun Hsu
  • Patent number: 7720131
    Abstract: A method and apparatus are provided for decoding a wireless signal from a set of samples with an embedded training sequence. The method includes the steps of determining a first frequency offset from the samples where the first frequency offset is assumed to be less than a Nyquist frequency of the training sequence and calculating a first carrier to interference ratio based upon the first frequency offset. The method further includes the steps of determining a second frequency offset from the samples by subtracting an absolute value of the first frequency offset from an integer multiple of the Nyquist frequency and giving the second frequency offset a sign opposite that of the first frequency offset, calculating a second carrier to interference ratio based upon the second frequency offset and selecting one of the first and second frequency offsets based upon a relative values of the calculated carrier to interference ratios.
    Type: Grant
    Filed: June 27, 2007
    Date of Patent: May 18, 2010
    Assignee: PC-Tel, Inc.
    Inventors: Vikash Srivastava, Meng Chen
  • Patent number: 7720187
    Abstract: Methods and apparatus for reducing discrete power spectral density (PSD) components of wideband signals transmitting blocks of data are disclosed. Discrete components are reduced by acquiring N symbols of pseudo-random data, each symbol having K bits; selecting one bit from each of the acquired symbols to generate N selected bits; selectively inverting a respective element in one of the data blocks responsive to the selected bits; acquiring one or more bits of pseudo-random data to replace a corresponding one or more respective bits of the acquired N symbols of pseudo-random data; and repeating for successive blocks of data.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: May 18, 2010
    Assignee: Panasonic Corporation
    Inventors: Shaomin Samuel Mo, Alexander G. Gelman
  • Patent number: 7715511
    Abstract: A frame synchronization method is disclosed. The method comprises correlating a stream with a pattern to generate a correlated result c(t). A first peak and a second peak are selected from the correlated result c(t), wherein the first peak is the peak with highest amplitude, and the second peak is the peak occurring later than the first peak with the second highest amplitude. The peak ratio of the two peaks is computed, and the position of the frame boundary is determined according to the ratio.
    Type: Grant
    Filed: January 19, 2007
    Date of Patent: May 11, 2010
    Assignee: Mediatek USA Inc.
    Inventor: Po-Yuen Cheng
  • Patent number: 7715510
    Abstract: A Method to maintain Synchronization Tracking in TDD Wireless Communication comprises the steps: divide a midamble into two parts, then detect the first part and the second part of the midamble; perform an auto-correlation property operation between the two parts and a part corresponding to a local midamble and obtain two peaks; compare the amplitude of the two peaks; advance or retard a local timer based on the result of the comparison. The interlaced sampling method will harm the SNR of channel estimation only very slightly. By using this method, the sample frequency can be decreased to only one time of the chip rate of a TD-SCDMA system while still maintaining the ability to track the downlink synchronization.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: May 11, 2010
    Assignee: ST-Ericsson SA
    Inventors: Jingxin Liang, ZHiyu Zhang
  • Patent number: 7711074
    Abstract: A synchronization extraction apparatus for a communication system and a method thereof are disclosed. A frame synchronization is obtained in a manner that the sum of an input signal and a delay signal is obtained without obtaining a simple correlation value between the input signal and the delay signal, and then a correlation value between a summed signal and the delay signal is obtained. The synchronization extraction apparatus and method can reduce the implementation complexity and power consumption in obtaining the frame synchronization, and thus increase the battery cycle of a terminal provided with the synchronization extraction apparatus or method.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: May 4, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Yong Lee, Yun-Sang Park, Bong-Gee Song
  • Patent number: 7688904
    Abstract: A method and system for transmitting signals between communication nodes is presented. The method includes generating a first waveform that includes a shaped portion; generating a second waveform that includes a shaped portion; and combining the first and second waveforms including overlapping the shaped portion of the first waveform with the shaped portion of the second waveform and adding the overlapped portions of the waveforms. The method includes generating a signal including the combined first and second waveforms. At least one of the first and second waveforms includes a characteristic signature configured for synchronizing with the signal.
    Type: Grant
    Filed: February 3, 2006
    Date of Patent: March 30, 2010
    Assignee: Intellon Corporation
    Inventors: Lawrence W. Yonge, III, Timothy J. VanderMey
  • Patent number: 7688878
    Abstract: A spread-spectrum preamble synchronization peak detection system performs multiple statistical tests based on instant and time-averaged channel condition measurements to identify the synchronization peak. In a normalized peak-to-average test, a peak-to-average ratio measurement is normalized by a signal-to-noise ratio measurement to form a new statistical measure which effectively eliminates the impact of the wide dynamic range of the signal-to-noise ratio of the received samples. A transition SNR test is used to eliminate potential false alarms caused by spurious PARN peaks during the transition period at the onset of preamble arrival. Code-phase aligned time-averaging is used to estimate the signal and noise levels over a sliding window. The code-phase alignment of samples effectively separates signal and noise samples in the averaging process, and resulting in more accurate signal and noise measurements.
    Type: Grant
    Filed: March 16, 2006
    Date of Patent: March 30, 2010
    Assignee: The Boeing Company
    Inventors: Xinyu Wang, Marcus R Gahler, Igor Elgorriaga, Robert P. Higgins, Paul R. Norris
  • Patent number: 7684519
    Abstract: A method for adjusting a DC offset slice point in an RF receiver is provided and may comprise estimating DC offset using a combination of fast tracking of an input signal and slow tracking of an input signal. If both are used, the fast tracking may be executed prior to executing the slow tracking. The fast tracking may acquire synchronizing signals transmitted before a payload. Additionally, noise tolerance may be increased in the fast tracking and the slow tracking by using tracking envelopes. The fast tracking may average acquisition envelopes and tracking envelopes using a fast tracking weighting factor to a sum of the acquisition envelopes and a slow tracking weighting factor to a sum of the tracking envelopes. Additionally, the slow tracking may average the tracking envelopes.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: March 23, 2010
    Assignee: Broadcom Corporation
    Inventors: Hea Joung Kim, Brima Ibrahim, Henrik Tholstrup Jensen
  • Patent number: 7684466
    Abstract: A wired spread spectrum communication device, a method for communication thereof and a wired spread spectrum communication system capable of enabling easy establishment of synchronism are disclosed. In a transmitter unit of the wired spread spectrum communication device, a spreading code generator generates spread spectrum signals that are based on specified spreading codes, a strobe signal generator and a timing gate output the spread spectrum signals as sync signals at specified timings, and an adder superposes the sync signals to the spread information signals, while the adder further sends the information signals that have been superposed with the sync signals as transmitting signals to transmission paths.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: March 23, 2010
    Assignee: Ibiden Industries Co., Ltd.
    Inventors: Shigenobu Sasaki, Mitsusato Kawashima
  • Patent number: 7680229
    Abstract: A method of determining a synchronous phase includes receiving a correlation sequence, and selecting one or more correlated signals from the correlation sequence. Then, when the number of selected correlated signals is odd, the synchronous phase corresponding to a central correlated signal is selected.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: March 16, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Rahul Garg
  • Patent number: 7675980
    Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: March 9, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuguhide Aoki, Daisuke Takeda, Takahiro Kobayashi, Yasuhiko Tanabe
  • Patent number: 7675991
    Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: March 9, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuguhide Aoki, Daisuke Takeda, Takahiro Kobayashi, Yasuhiko Tanabe
  • Patent number: 7672413
    Abstract: A synchronism pattern detecting timing recorder (20) records a synchronism pattern detecting timing at which a synchronism pattern is detected in reception data, a synchronism decider (12) collates the reception data with reference data to decide whether or not the reception data is consistent in phase with the reference data, and a timing generator (22) operates, when the synchronism decider (12) gives a decision for inconsistency in phase, for a match between the synchronism pattern detecting timing recorded in the synchronism pattern detecting timing recorder (20), as a subsequent one, and a timing of a synchronism pattern of the expectation data, and the subsequent synchronism pattern detecting timing in record is used to render the phases consistent, allowing for a rapid synchronization to be obtained, without the need of waiting a detection of synchronism pattern, even with an inconsistency in phase due to a false synchronism pattern.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: March 2, 2010
    Assignee: Advantest Corporation
    Inventor: Kazuhiro Shimawaki
  • Publication number: 20100046404
    Abstract: A User Equipment (UE) receives and samples communication signals, where the communication signals have a time frame format, a transmission chip rate and a synchronization code associated with a time slot that includes a midamble that indicates a modulation of the synchronization code where a specified modulation of received synchronization codes identifies the timing for a timeslot in which data is to be received. The UE preferably includes a synchronization code determination circuit, a midamble determination circuit, and a phase modulation sequence detection circuit operatively associated with the midamble determination circuit. The UE can be configured for use with the low chip rate option of the Third Generation Partnership Project (3GPP) Universal Mobile Telecommunication System (UMTS) standards that employ a predefined set of downlink SYNC codes that point to midambles which indicate SYNC code modulation sequence to enables reading of data in a subsequent Broadcast Channel (BCH) message.
    Type: Application
    Filed: October 26, 2009
    Publication date: February 25, 2010
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Alpasian Demir, Fatih M. Ozluturk
  • Patent number: 7668275
    Abstract: A frame synchronization is proposed for a multi-band communication system, wherein a data signal exchanged between a transmitter and a receiver is organized in system frames having a preamble section which contains a frame synchronization section that is composed of a number of symbol frames, each of which is in turn composed of a defined number of slots, whereby each slot corresponds to an individual transmission frequency band. The method comprises steps for transmitting the data signal containing a synchronization signal in one or more slots of every other symbol frame of the frame synchronization section, processing only data signal components selected from transmission frequency bands required for the synchronization signal transmission, and subtracting the processed data signal from its shifted copy, whereby the copy is shifted by one symbol frame.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: February 23, 2010
    Assignee: Sony Deutschland GmbH
    Inventors: Jens-Uwe Jürgensen, Richard Stirling-Gallacher
  • Patent number: RE41774
    Abstract: A data transmission process with auto-synchronised correcting code, auto-synchronised coder and decoder, corresponding transmitter and receiver. According to the invention, synchronisation management signals (HS, SS, ID) are formed and, under the control of these signals, a header is inserted before a data group and after it a correcting code. At receive end, these synchronisation management signals are reconstituted, the presence of a header is detected and any erroneous symbols are corrected. The invention also provides for an auto-synchronised coder and a decoder and for a transmitter and a receiver using them.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: September 28, 2010
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Marc Laugeois, Didier Lattard, Jean-Remy Savel, Mathieu Bouvier des Noes