Plurality Of Synchronization Words Patents (Class 375/366)
  • Patent number: 8494091
    Abstract: Certain aspects of a method and system for satellite communication are disclosed. Aspects of one method may include a receiver that handles digital broadcasting. The receiver may be enabled to dynamically vary spacing between two or more pilots and/or the size of one or more pilots within at least one frame based on a determined symbol rate. The size of each of a plurality of received programs may be determined and the spacing between two or more pilots may be dynamically varied based on the determined size of each of the plurality of received programs.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: July 23, 2013
    Assignee: Broadcom Corporation
    Inventor: Tommy Yu
  • Patent number: 8488539
    Abstract: A method of generating preamble sequence is disclosed. A channel used by a wireless device may be divided into four sub-channels, and the method includes forming a preamble sequence of a first sub-channel, making three replicas of the preamble sequence of the first sub-channel, each replica with a phase rotation of a first angle, a second angle, and a third angle respectively, for forming each preamble sequence of a second sub-channel, a third sub-channel, and a fourth sub-channel, and arranging the preamble sequences of the first, the second, the third, and the fourth sub-channels to form a preamble sequence of the channel.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: July 16, 2013
    Assignee: Ralink Technology Corp.
    Inventors: Yen-Chin Liao, Cheng-Hsuan Wu, Yung-Szu Tu
  • Patent number: 8457180
    Abstract: A positioning system comprises a plurality of controllers, each controller comprising a wideband receiver and a narrow band transmitter, the each controller configured to receive a wideband positioning frame using the wideband receiver from one or more devices and to transmit acknowledgement frames using the narrow band transmitter that include timing and control data for use by the devices to establish timing for transmission of the positioning frame; and at least one device comprising a wideband transmitter and a narrow band receiver, the device configured to transmit a positioning frame to the plurality of controllers using the wideband transmitter and to receive an acknowledgement frame from one or more controllers using the narrow band receiver, extract timing and control information from the frame, and adjust the timing and synchronization of the wideband transmitter using the timing and control information.
    Type: Grant
    Filed: June 1, 2011
    Date of Patent: June 4, 2013
    Assignee: Adeptence, LLC
    Inventors: Ismail Lakkis, Hock Law
  • Patent number: 8437440
    Abstract: A method for generating a data unit for transmission via a communication channel includes generating a preamble of the data unit, including generating a set of more than four training fields and applying a different spatial mapping to each training field in the set of training fields; and generating a data portion of the data unit, wherein the data portion is transmitted using more than four space-time streams, so that a receiver device can receive the data portion via the more than four space-time streams using channel information derived from the set of training fields.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: May 7, 2013
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Sudhir Srinivasa
  • Patent number: 8428209
    Abstract: A frequency offset estimation and correction apparatus including a frame averaging unit to average a plurality of frequency offset values to obtain a frame offset average for each of a plurality of frames, a re-sampling unit to produce a plurality of interpolated frequency offset values uniformly distributed over a time period of a frame of the plurality of frames based on the frame offset average of the frame and a frame offset average of at least one frame that precedes the frame, and an exponential averaging unit to calculate the estimated frequency offset based on the plurality of interpolated frequency offset values weighted by an exponential averaging coefficient.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: April 23, 2013
    Assignee: VT iDirect, Inc.
    Inventors: Ronggang Qi, Sadaf Fardeen, Shan Sivagnanavelu
  • Patent number: 8428108
    Abstract: In a signal processing apparatus a synchronizer acquires synchronization with the spreading code of an intermediate frequency signal converted from a signal received from a satellite in a global positioning system. A demodulator then demodulates a message contained in the intermediate frequency signal. A measuring unit outputs a primary signal to a predetermined signal line, the primary signal expressing positioning results for the apparatus as measured on the basis of the demodulated message. A secondary signal output unit attaches a predetermined header to a secondary signal and outputs the result to the predetermined signal line, the secondary signal containing at least the intermediate frequency signal, or a signal generated from the intermediate frequency signal.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: April 23, 2013
    Assignee: Sony Corporation
    Inventors: Katsuyuki Tanaka, Manabu Nitta, Hideki Takahashi
  • Patent number: 8369386
    Abstract: A receiver includes a receiving unit that receives a signal from a satellite, a frequency conversion-discretization unit that converts the signal received in the receiving unit into an intermediate frequency signal of a frequency bandwidth including 0 Hz, and discretizes the frequency-converted intermediate frequency signal with a predetermined sampling frequency, a filter unit that filters the discretized signal, which is output from the frequency conversion-discretization unit, through a predetermined filter, a synchronization acquisition unit that acquires synchronization of a spreading code in the discretized signal filtered by the filter unit, and a synchronization holding unit that holds the synchronization of the spreading code, which is acquired by the synchronization acquisition unit.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: February 5, 2013
    Assignee: Sony Corporation
    Inventors: Hideki Takahashi, Katsuyuki Tanaka
  • Patent number: 8363771
    Abstract: Provided are a transmission device, a receiving device, and a communication system having a simple configuration and capable of reliably executing the confirmation of a changed bit rate. The communication system 1 sends, to the receiving device 3, a serial data signal Sdata that is set as a constant value across a period of a constant multiple of a cycle of the clock when a bit rate of a serial data signal Sdata in the transmission device 2 is changed. The receiving device 3 that received the serial data signal Sdata receives training data Tdata from the transmission device 2 when it is determined that the serial data signal Sdata is a constant value across a period of a constant multiple of a cycle of the clock, and proceeds to the processing of confirming the changed bit rate.
    Type: Grant
    Filed: October 27, 2009
    Date of Patent: January 29, 2013
    Assignee: Thine Electronics, Inc.
    Inventors: Hironobu Akita, Seiichi Ozawa, Yohei Ishizone, Satoshi Miura
  • Patent number: 8345811
    Abstract: A method of achieving reduced modulation range requirement in a Digitally Controlled Oscillator (DCO) which is deployed as part of a DRP (Digital Radio Processor) and tuned to a tuning frequency range having operating-channel center-frequencies, wherein phase difference between consecutive samples is termed as FCW (Frequency Control Word), uses the steps of digitally modifying and limiting the FCW so that the FCW does not exceed known FCW thresholds, e.g., chosen from ?/2, ?/4, ?/8, and redistributing the FCWs while maintaining a cumulative sum of phases and without significant EVM (Error Vector Magnitude) degradation. The FCW threshold can be chosen arbitrarily and need not be in the form of ?/2n. The method uses a FCW limiting algorithm which reduces supply voltage sensitivity of the DCO and enables significant reduction in area of capacitor bank which would be otherwise needed.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: January 1, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Sarma S. Gunturi, Jawaharlal Tangudu, Sthanunathan Ramakrishnan, Jayawardan Janardhanan, Debapriya Sahu, Subhashish Mukherjee
  • Patent number: 8325868
    Abstract: A passive phase jitter modulation (PJM) tag is charged with power in a continuous wave (CW) section. When receiving a command from a reader, the passive PJM tag must recognize the command and determine exactly when to begin demodulating the command. Only then can the passive PJM tag demodulate the command. To this end, a synchronization apparatus for accurately demodulating a signal input to a PJM tag includes a plurality of correlators correlating a received phase jitter-modulated signal with a template of an internal matched filter which is in the same form as at least a portion of a modified frequency modulation (MFM) flag.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: December 4, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Ji-hoon Bae, Gil-young Choi, Dong-han Lee, Hoon-gee Yang, Jong-suk Chae
  • Patent number: 8320508
    Abstract: A system including an estimation module, a processing module, and a control module. The estimation module is configured to generate a first set of channel estimates for a plurality of subcarriers of a received signal. The processing module is configured to generate a second set of channel estimates for the plurality of subcarriers, in which the second set of channel estimates are generated based on the first set of channel estimates. The control module is configured to estimate a preamble sequence in the received signal based on each of (i) the first set of channel estimates and (ii) the second set of channel estimates.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: November 27, 2012
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Hui-Ling Lou
  • Patent number: 8320437
    Abstract: In a method and a device for decoding a signal, the signal is transmitted via at least one connecting line of a data transmission system, in a user of the data transmission system receiving the signal. It is provided to measure the interval of a change—provided compulsorily in a transmission protocol used in the data transmission system—of the signal from rising to falling or from falling to rising edge. A tendency for an asymmetrical delay of the signal can be ascertained from the measured interval. The sampling of the bits of the received signal can be improved as a function of the interval or of the asymmetrical delay, for example, by setting the sampling instant in variable fashion. Alternatively, the interval or the asymmetrical delay can be utilized for diagnostic purposes.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: November 27, 2012
    Assignee: Robert Bosch GmbH
    Inventors: Florian Hartwich, Andreas-Juergen Rohatschek, Eberhard Boehl
  • Patent number: 8259852
    Abstract: Certain aspects of a method and system for satellite communication are disclosed. Aspects of one method may include a receiver that handles digital video broadcasting. The receiver may be enabled to dynamically vary spacing between one or more pilots within at least one frame based on a determined symbol rate. The size of each of a plurality of received programs may be determined and the spacing between one or more pilots may be dynamically varied based on the determined size of each of the plurality of received programs.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: September 4, 2012
    Assignee: Broadcom Corporation
    Inventor: Tommy Yu
  • Patent number: 8249200
    Abstract: A method and an apparatus are provided for binarizing an input signal, which is capable of reliably correcting an offset of the input signal even when the input signal does not reach a reference level or has a single frequency, a disc driver and a recording medium. The binarizing method includes viterbi-decoding the input signal to obtain a viterbi-decoded signal; slicing the input signal based on a predetermined reference level to obtain a sliced signal; obtaining an offset of the input signal by low-pass filtering the viterbi-decoded signal or the sliced signal; and correcting the offset of the input signal based on the obtained offset. The viterbi-decoded signal is a binary signal of the input signal.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: August 21, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hyun-Soo Park
  • Patent number: 8233898
    Abstract: A wireless communications device may include a portable housing and a temperature-compensated clock circuit carried by the portable housing. The device may further include a wireless receiver carried by the portable housing for receiving timing signals, when available, from a wireless network, and a satellite positioning clock circuit carried by the portable housing. A clock correction circuit may be carried by the portable housing for correcting the temperature-compensated clock circuit based upon timing signals from the wireless network when available, and storing historical correction values for corresponding temperatures. The clock correction circuit may also correct the temperature-compensated clock circuit based upon the stored historical correction values when timing signals are unavailable from the wireless network, and correct the satellite positioning clock based upon the temperature-compensated clock circuit.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: July 31, 2012
    Assignee: Research In Motion Limited
    Inventor: Michael Andrew Goldsmith
  • Patent number: 8229052
    Abstract: An apparatus and method for transmitting/receiving an S-SCH in an Institute of Electrical and Electronics Engineers (IEEE) 802.16m wireless communication system are provided. A method for transmitting, by a transmitter, a Secondary Synchronization CHannel (S-SCH) in a communication system includes generating a sequence depending on a cell IDentification (ID), determining a subcarrier set comprising subcarriers to map the generated sequence, based on a Fast Fourier Transform (FFT) size and a segment ID, and mapping the generated sequence to the subcarriers of the determined subcarrier set.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: July 24, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sung-Eun Park, Jae-Weon Cho, Seung-Hoon Choi, Chi-Woo Lim, Song-Nam Hong
  • Patent number: 8218612
    Abstract: An effective data sequence based timing error detector (EDS-TED) for baseband transmission system using Tomlinson-Harashima Precoder is disclosed. The EDS-TED extracts timing error information embedded in the received signal to build up autocorrelation between the ESD signals and minimize the mean square error between the received and desired EDS so as to improve the performance of the TED in terms of Peak-to-Peak Jitter and TED gain. Thus the quality of the received signal increases and the error rate decreases.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: July 10, 2012
    Assignee: National Taiwan University
    Inventors: Ying-Ren Chien, Hen-Wai Tsao
  • Patent number: 8218681
    Abstract: An OFDM transmitter and receiver realizing high-speed cell search and having a reducible circuit scale. An OFDM transmitter includes an SCH inserting section for constructing a frame where a synchronization sequence in a predetermined position from the head of a first sub-frame is arranged and a synchronization sequence composed of the symbols of the former synchronization sequence and the symbols whose I, Q components are interchanged is arranged in a predetermined position from the head of a second sub-frame adjacent in the time-axis direction to the former sub-frame, an IFFT section, a P-SCH conversion section, and an RF transmitting section for transmitting this frame. Thus, the receiving end of the frame can locate the position of either synchronization sequence and determine the frame timing from that position, thereby increasing the speed of the cell search.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: July 10, 2012
    Assignee: Panasonic Corporation
    Inventor: Yuta Seki
  • Patent number: 8199867
    Abstract: Described is an apparatus for suppressing spurious spectral lines in a frame based bit-serial data stream, in which frames include payload data and frame markers. The apparatus includes means (16) for randomizing first frame marker elements (START) in a first position within each frame and means (18) for correlating second frame marker elements (STOP) in a second position within each frame with the randomized first frame marker element.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: June 12, 2012
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Bengt Erik Jonsson, Per Lars Paul Ingelhag
  • Patent number: 8170166
    Abstract: Apparatus, systems, and methods are provided for transmitting messages over a serial interface. A method comprises receiving a first signal at a first time and receiving a second signal at a second time, the second time being after the first time. If a difference between the second time and the first time is less than a threshold time period, the method comprises generating a first message that is representative of the first signal and the second signal and transmitting the first message over the serial interface. In accordance with one embodiment, the threshold time period is equal to one half of an interface acquisition delay time period associated with the serial interface.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: May 1, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Kenneth E. Stebbings, Vivek Bhan, Daniel B. Schwartz
  • Patent number: 8160169
    Abstract: A system including a magnitude measuring module, an energy normalization module, and a metric generation module. The magnitude measuring module is configured to measure magnitudes of real portions of differentially demodulated signals, wherein the differentially demodulated signals are generated by differential demodulation of signals received from a base station. The energy normalization module is configured to generate a sum of energies of a plurality of subcarriers included in the signals received from the base station. The metric generation module is configured to generate a plurality of metrics for a plurality of symbols included in the signals received from the base station. The metric generation module is further configured to detect, based on the plurality of metrics, a preamble symbol included in the signals received from the base station.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: April 17, 2012
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Qing Zhao
  • Patent number: 8144827
    Abstract: A method of determining a residual frequency offset between a transmitter and a receiver in a transmission of data via a communication channel, is described, wherein the message is transmitted from the transmitter to the receiver via the communication channel and the message comprises at least one short preamble (201), at least one long preamble (202) and user data (203). The at least one long preamble (202) comprises residual frequency offset determination information based on which the residual frequency offset is determined.
    Type: Grant
    Filed: August 13, 2005
    Date of Patent: March 27, 2012
    Assignee: Agency for Science, Technology and Research
    Inventors: Ho Wang Fung, Sumei Sun, Chin Keong Ho, Ying Chang Liang, Yan Wu, Zhongding Lei
  • Patent number: 8126103
    Abstract: A permuted sequences combination uses a frame structure in which two sync words, each comprising M complex symbols, are appended at the frame start. One benefit is the reduction of the large variance of the timing estimation error in the conventional correlation method. In at least one embodiment, the first sync word, {right arrow over (s)}1, is a predetermined constant amplitude zero autocorrelation (CAZAC) sequence. The second sync word, {right arrow over (s)}2, is a permutation of the first such that the combination of the two received sync signal vectors perform sliding window processing where the peak occurs at the correct frame start. The permuted sequences combination can be used in both AWGN channel and multi-path environments.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: February 28, 2012
    Assignee: New Jersey Institute of Technology
    Inventors: Miao Shi, Yeheskel Bar-Ness
  • Patent number: 8116354
    Abstract: A sync detection device and method for a GNSS receiver. In modernized GNSS, each satellite transmits a data signal and a pilot signal. Correlations are performed between a data symbol stream converted from the data signal with possible hypotheses to find a leading edge of a frame of the data signal (i.e. frame sync detection) and between a pilot symbol stream converted from the pilot signal with possible hypotheses to find a leading edge of a code sequence of the pilot signal (i.e. pilot sync detection). The possible hypotheses for the frame sync detection are selected according to a result of pilot sync detection when pilot sync is done. Frame sync can be efficiently achieved since a range of the selected possible hypotheses is quite limited.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: February 14, 2012
    Assignee: Mediatek Inc.
    Inventor: Kun-tso Chen
  • Patent number: 8107561
    Abstract: A method for performing carrier frequency offset estimation and frame synchronization is disclosed herein. In one approach, the method includes performing a first level frequency discrimination on at least one estimated channel tap to generate a frequency discriminated value; estimating a phase error from the frequency discriminated value; and, determining a predetermined frame synchronization pattern from the estimated phase error. A computer program product having code and a wireless communications apparatus for performing the method are also described herein.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: January 31, 2012
    Assignee: QUALCOMM Incorporated
    Inventors: Yuheng Huang, Ozgur Dural, Samir S. Soliman, Amol Rajkotia
  • Patent number: 8107499
    Abstract: A method includes defining a pattern of time intervals, each time interval having a respective assigned communication speed, which alternates among multiple communication speeds supported by a first communication device. Synchronization requests are transmitted over a communication medium from the first communication device to a second communication device at the respective communication speed that is assigned in each interval in accordance with the pattern. While transmitting the synchronization requests, synchronization replies sent over the communication medium in response to the synchronization requests are received only at the respective communication speed that is assigned in each interval. Responsively to receiving the synchronization replies from the second communication device, one or more common communication speeds that are supported by both the first and the second communication devices are identified.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: January 31, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Wei-Jen Huang, Chih-Tsung Huang, Claudio DeSanti
  • Patent number: 8098745
    Abstract: Apparatus and methods for accessing a wireless telecommunications network by transmitting a random access signal. The random access signal includes a random access preamble signal selected from a set of random access preamble signals constructed by cyclically shift selected root CAZAC sequences. The random access signal may be one or more transmission sub-frames in duration, the included random access preamble sequence's length being extended with the signal to provide improved signal detection performance in larger cells and in higher interference environments. The random access signal may include a wide-band pilot signal facilitating base station estimation of up-link frequency response in some situations. Each of the plurality of available random access preamble sequences may be assigned a unique information value. The base station may use the information encoded in the random access preamble to prioritize responses and resource allocations.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: January 17, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Pierre Bertrand, Jing Jiang, Shantanu Kangude, Tarik Muharemovic
  • Patent number: 8098693
    Abstract: The present invention provides a method of early starting the operation of a descrambler. The method comprises the steps of receiving a, synchronous byte of a transport packet in a group of m packets, where m is an integer, generating an alignment index to indicate a location of the synchronous byte, delivering the alignment index to the descrambler, and loading an initialization sequence to the descrambler in accordance with the alignment index and starting an operation of the descrambler.
    Type: Grant
    Filed: May 3, 2006
    Date of Patent: January 17, 2012
    Assignee: Himax Technologies Limited
    Inventors: Tien-Hsin Chang, Shin-Shiuan Cheng
  • Patent number: 8094767
    Abstract: The present invention provides methods and systems for allowing a receiver in a (wireless) communication system to synchronize its timing and frequency subsystems in accordance with a received signal. In accordance with one aspect, a method is provided in which a relative time of arrival of sync values provided in a received signal are determined and used to align the receiver's reference signal(s) accordingly. Other aspects of the invention will become apparent from the detailed description of exemplary embodiments that follows.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: January 10, 2012
    Assignee: Exalt Communications Inc.
    Inventor: Peter Smidth
  • Patent number: 8064558
    Abstract: A receiving apparatus includes a first receiver, a second receiver, a received signal synthesizer connected to the first and second receivers, a synchronizing signal synthesizer connected to the first and second receivers, and a synchronization detector connected to the synchronizing signal synthesizer. In this structure, synchronization determination is performed using a synchronizing signal of either the first or second receiver, and diversity reception is performed using the received signals of the first and second receivers.
    Type: Grant
    Filed: August 28, 2007
    Date of Patent: November 22, 2011
    Assignee: Panasonic Corporation
    Inventors: Yasunobu Tsukio, Hiroaki Ozeki
  • Patent number: 8059630
    Abstract: The present invention provides a unique manner of identifying the Frame boundaries in multiple identical/non-identical Synchronization Channels (SCHs) in different sub-frames via a new sub frame position difference method. The method implements the differences between the different sub-frames carried by the SCH. The sub frame identity, and hence the frame boundary, can be identified by calculating the difference between the positions, based on time or number of slots/sub-frames or any data packets, of the two subsequent slots/sub-frames or any identical data packets.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: November 15, 2011
    Assignee: Samsung Electronics Co., Ltd
    Inventor: Basu Mallick Prateek
  • Patent number: 8054865
    Abstract: A secure information transmission system includes one or more transmitters and one or more receivers. The transmission waveform employed includes highly randomized, independent stochastic processes, and is secured as a separate entity from the information it carries. The signal, using novel modulation methodology reducing impulse responses, has a paucity of spectral information and may be detected, acquired and demodulated only by communicants generating the necessary receiving algorithm coefficients. The physical area of signal reception is restricted to that of each intended communicant, reception areas following movements of mobile communicants. A unique instant in time is used as basis for communications keys to the securing algorithms dynamically generated on a one-time basis and never exchanged or stored by communicants.
    Type: Grant
    Filed: October 28, 2009
    Date of Patent: November 8, 2011
    Inventor: Edward G. Frost
  • Patent number: 8054927
    Abstract: The present invention includes: a synchronous-word detecting unit receives a baseband received signal including a synchronous word and data for each frame, and detects whether or not the synchronous word is coincided with an expected value in the baseband received signal by using an N-(N is an integer of 2 or larger) phase sampling clock; a phase information retaining unit retains phase information accumulatively including results detected for a plurality of frames by the synchronous-word detecting unit, and determines a phase to be sampled on the basis of the retained phase information; a phase selecting unit selects and determines a phase of the sampling clock on the basis of determination by the phase information retaining unit; and a FIFO buffer samples the data from the baseband received signal, and outputs the sampled data.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: November 8, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Shinya Konishi
  • Patent number: 8045667
    Abstract: A deserializer including a plurality of registers, a sync detector, and a lost bit storage unit. If there is a phase difference between an external input data packet and a recovery clock signal transmitted together with the data packet, the sync detector generates an activated sync detect signal. The lost bit storage unit detects a data bit of the data packet corresponding to an activation point of the sync detect signal. The deserializer recovers the data packet by combining the detected data bit with the data packet.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: October 25, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Han-Kyul Lim, Dong-Chul Choi
  • Patent number: 8045657
    Abstract: A method is provided for estimating a frequency offset in a carrier signal caused by the Doppler effect. The method determines a frequency offset estimate by utilizing a multi stage estimation scheme. More specifically, the method determines the frequency offset estimate of a data frame by iteratively estimating the frequency offset by comparing different portions of the preamble. As the length of the sampled patterns varies, the frequency offset estimates vary in accuracy and range. The method may adjust frequency offset estimates that are out of range. Finally, the receiver obtains a frequency offset estimate for the data frame from a weighted combination of frequency offset estimates. This method is applicable in WiFi (IEEE 802.11a/g), WiMax (IEEE 802.16), and WAVE (IEEE 802.11p) systems.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: October 25, 2011
    Assignee: The Regents Of The University Of Michigan
    Inventor: Weidong Xiang
  • Patent number: 8014437
    Abstract: A system for implementing an orthogonal frequency division multiplexing scheme and providing an improved range extension. The system includes a transmitter for transmitting data to a receiver. The transmitter includes a symbol mapper for generating a symbol for each of a plurality of subcarriers and a spreading module for spreading out the symbol on each of the plurality of subcarriers by using a direct sequence spread spectrum. The symbol on each of the plurality of subcarriers is spread by multiplying the symbol by predefined length sequences. The receiver includes a de-spreader module for de-spreading the symbols on each of the plurality of subcarriers. The de-spreader module includes a simply correlator receiver for obtaining maximum detection. The correlator produces an output sequence of a same length as an input sequence and the de-spreader module uses a point of maximum correlation on the output sequence to obtain a recovered symbol.
    Type: Grant
    Filed: June 8, 2010
    Date of Patent: September 6, 2011
    Assignee: Broadcom Corporation
    Inventor: Jason Alexander Trachewsky
  • Patent number: 8005155
    Abstract: A system includes an input, a differential demodulation module, a magnitude measuring module, a summing module, and a metric generator module. The input receives input signals that include s sets of modulated sub-carriers carrying symbols, where s is an integer greater than or equal to 1. The differential demodulation module generates differentially demodulated signals based on the input signals. The magnitude measuring module measures magnitudes of real portions of the differentially demodulated signals. The summing module generates s sums, wherein each of the s sums is a sum of the magnitudes generated based on a respective one of the s sets. The metric generator module generates metrics for the symbols based on the s sums.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: August 23, 2011
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Qing Zhao
  • Patent number: 8000428
    Abstract: An all-digital frequency synthesizer architecture is built around a digitally controlled oscillator (DCO) that is tuned in response to a digital tuning word (OTW). In exemplary embodiments: (1) a gain characteristic (KDCO) of the digitally controlled oscillator can be determined by observing a digital control word before and after a known change (?fmax) in the oscillating frequency; and (2) a portion (TUNE_TF) of the tuning word can be dithered (1202), and the resultant dithered portion (dkTF) can then be applied to a control input of switchable devices within the digitally controlled oscillator.
    Type: Grant
    Filed: November 22, 2002
    Date of Patent: August 16, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Robert B. Staszewski, Dirk Leipold, John Wallberg
  • Patent number: 7991040
    Abstract: Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal. In an aspect, a method is provided for reducing a peak to average ratio of a transmit waveform. The method includes obtaining a primary scrambler sequence, generating a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining the primary and secondary scrambler sequences to produce a PAR reduction sequence. In another aspect, an apparatus is provided for reducing a peak to average ratio of a transmit waveform. The apparatus includes a secondary generator configured to generate a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining logic configured to combine a primary scrambler sequence and the secondary scrambler sequences to produce a PAR reduction sequence.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: August 2, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Durk L. van Veen, Fuyun Ling, Raghuraman Krishnamoorthi
  • Patent number: 7986951
    Abstract: In a bandwidth allocation protocol for a mobile communications network, mobile terminals indicate the total quantity of data awaiting transmission, the maximum delay time of the most urgent portion of the data, and the maximum delay time of the least urgent portion. If a collision occurs between transmission by two mobiles, the mobiles wait for an interval controlled by the network before attempting another contention-based access transmission. The network periodically varies the contention-based access capacity available according to the observed usage level and/or collision rate in the previously allocated contention-based access capacity. The network analyses the forward traffic to individual mobiles and predicts likely return bandwidth requirements.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: July 26, 2011
    Assignee: Inmarsat Global Limited
    Inventors: Paul Febvre, David Denis Mudge
  • Patent number: 7961811
    Abstract: A radio transmitting apparatus and method thereof wherein a guard interval (GI) having a variable length allows a radio receiving apparatus to precisely and easily obtain a symbol synchronization. A GI adding part adds a short GI or a long GI to the head of each of a plurality of data parts. In a case of adding the long GI, the GI adding part copies the symbols of a portion of a second data part, which immediately follows a first data part, including the rear of the second data part, and then adds the copied symbols to the head of the first data part, thereby providing a second GI. Moreover, the GI adding part copies the symbols to a portion of the first data part including the rear thereof, and then adds the copied symbols to the head of the second GI, thereby providing the first GI.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: June 14, 2011
    Assignee: Panasonic Corporation
    Inventors: Kenichi Miyoshi, Akihiko Nishio, Daichi Imamura
  • 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: 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
  • Patent number: 7848363
    Abstract: A system and method for dynamically altering detection criterion value at a receiving device based on the portion of a call signal being received. A receiving device is configured to extract a first call signal portion from the call signal, and compare the first call signal portion to a plurality of call information portions, wherein each call information portion has a detection criterion value. If the first call signal portion matches one of the call information portions, the receiving device adjusts the detection criterion value for at least one of the plurality of call information portions, extracts a second call signal portion from the call signal, and compares the second call signal portion to the plurality of call information portions.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: December 7, 2010
    Assignee: Motorola, Inc.
    Inventors: Harish Natarahjan, Gregory A. Feeney, Kevin L. Good, Gary P. Hunsberger, Daniel J. McDonald
  • 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: 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: 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: 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: 7801227
    Abstract: A composite signal includes a high power beacon signal and low power corresponding wideband synchronization signal and is communicated over a time interval exceeding a single OFDM transmission time interval. A base station transmits one or more different such composite broadcast signals in a recurring timing structure. Each different potential beacon signal, e.g., a single tone signal, is paired with a unique wideband synchronization signal. A wideband synchronization signal includes at least some predetermined null tones and at least some predetermined non-null tones. For a given wideband synchronization signal, the predetermined null tones carry predetermined modulation symbol values, A wireless terminal receives a composite signal, identifies a beacon, determines a corresponding known wideband synchronization signal, compares received to known wideband synchronization signals, and determines at least one of a timing adjustment, frequency adjustment and channel estimation.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: September 21, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Vladimir Parizhisky, Rajiv Laroia, Alexander Leonidov, Tom Richardson, Junyi Li, Sathyadev Venkata Uppala