Frequency Or Phase Control Using Synchronizing Signal Patents (Class 375/362)
  • Patent number: 8514997
    Abstract: Methods and systems for a receiver with undersampling mixing using multiple clock phases are disclosed and may include undersampling a received wireless signal utilizing multiple undersamplers and clocking each of the undersamplers with a separate clock signal. Each of the clock signals may be at a sampling frequency but with a different phase angle. The difference of the phase angle between each of the clock signals may be adjusted and may be determined by the number of undersamplers. A gain ratio may be configured for two signals summed to generate each of the clock signals for the phase angle adjusting. The two signals may include in-phase and quadrature signals. Each of the summed signals may be normalized utilizing limiters. The sampling frequency may be an integer sub-harmonic of the received signal. The undersamplers may include track and hold or sample and hold circuits.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: August 20, 2013
    Assignee: Broadcom Corporation
    Inventors: Ahmadreza Rofougaran, Maryam Rofougaran
  • Patent number: 8514985
    Abstract: Apparatus for locating a specific point in a received signal of cyclical nature, the apparatus comprising correlating means (16) for correlating the received signal with a code that is potentially present in the received signal, processing means (20,22,18) for multiplying the correlation result with a time-offset, complex-conjugated version of itself and filtering means (24,26,28) for low pass filtering the multiplication result to produce a signal suited to analysis for determination of said point and estimation of the frequency error.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: August 20, 2013
    Assignee: Cambridge Silicon Radio Limited
    Inventor: Candido Levita
  • Patent number: 8504864
    Abstract: A method is provided for synchronizing time in an unsynchronized vehicle controller area network system. A master control unit receives a global time from a time synchronization source. The master control unit estimates a respective time delay in transmitting messages by electronic control units on each controller area network bus. The time delay is a difference between a time when a message is generated by a respective electronic control unit for transmission on a respective controller area network bus and a time when the message is transmitted on the respective controller area network bus. The global time is adjusted for each respective controller area network bus based on the estimated time delays associated with each respective controller area network bus. Global time messages from the master control unit are transmitted to each electronic control unit that include the adjusted global times for an associated controller area network bus.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: August 6, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Sandeep Menon, Chaminda Basnayake
  • Publication number: 20130195235
    Abstract: An apparatus includes a first clock source, a second clock source and circuitry configured to supply a clock signal to a circuit. The circuitry operates to change the clock signal from one frequency to another different frequency. This change is made in a manner whereby no clock signal is supplied during a period of time when the change from the one frequency to the another different clock frequency is being made.
    Type: Application
    Filed: January 17, 2013
    Publication date: August 1, 2013
    Applicants: STMicroelectronics (Grenoble 2) SAS, STMicroelectronics (Research & Development) Limted
    Inventors: STMicroelectronics (Research & Development) Limited, STMicroelectronics (Grenoble 2) SAS
  • 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: 8488503
    Abstract: A magnetic field communication method is provided for managing node with low power consumption which enhances performance and efficiency of a magnetic field area network in the low frequency region. The magnetic field communication method for managing node with low power consumption of the present invention is accomplished in a low-frequency wireless network that is comprised of a MFAN-C and at least one MFAN-N wherein a physical layer is comprised of a preamble, a header, and a payload, and the preamble is comprised of a wake-up sequence and a synchronization sequence. The wake-up sequence is only added to the preamble of the frame that is transmitted from the MFAN-C when the MFAN-N is being activated from the hibernation mode. The wake-up sequence is modulated using ASK modulation, and the synchronization sequence is modulated using BPSK modulation.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: July 16, 2013
    Assignee: Korea Electronics Technology Institute
    Inventors: Yun-Jae Won, Seung-Ok Lim, Sun-Hee Kim, Kyu-Sung Hwang
  • Patent number: 8483341
    Abstract: A signal generation system maintains a phase relationship between output signals of first and second signal generators even when the sampling clock frequency is changed. The signal generators are coupled via a communication means including a dedicated cable where the delay amount of the communication means is known and fixed. The first signal generator provides sampling clock, sequence clock and trigger/event signals to the second signal generator and CPUs of the generators share information via the cable. When the frequency of the sampling clock is changed, the CPU of the first or second signal generator calculates the clock number of the frequency changed sampling clock equivalent to the delay amount of the communication means. A delay circuit of the first signal generator 100 delays the waveform data by one sampling clock based on the calculated value for adjusting phase relationship between the waveform data in the signal generators 1.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: July 9, 2013
    Assignee: Tektronix International Sales GmbH
    Inventors: Yasuhiko Miki, Hideaki Okuda
  • Patent number: 8483579
    Abstract: A high-accuracy phase detector circuit compatible with a 1/N rate architecture is provided. The phase detector circuit has as many as N track-and-hold circuits for tracking and holding N-phase clock signals CLK—1 to CLK_N in synchronization with a rising edge of input data signal DIN. Out of the N-phase clock signals CLK—1 to CLK_N outputted from as many track-and-hold circuits, only the one whose rising edge is most synchronized with a rising edge of the input data signal DIN is selected and outputted as a phase difference signal.
    Type: Grant
    Filed: August 10, 2009
    Date of Patent: July 9, 2013
    Assignee: Hitachi, Ltd.
    Inventor: Koji Fukuda
  • Patent number: 8467490
    Abstract: A communication system includes: a transmitter adapted to transmit a synchronizing clock and serial data synchronous with the synchronizing clock over a line at low amplitude; and a receiver adapted to receive the serial data and synchronizing clock from the transmitter. The receiver includes an amplifier adapted to amplify the received synchronizing clock of low amplitude to restore the clock to its original amplitude, a latched comparator adapted to latch the received serial data in synchronism with a reproduction clock, and a phase-locked circuit.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: June 18, 2013
    Assignee: Sony Corporation
    Inventors: Takaaki Yamada, Hiroki Kihara, Tatsuya Sugioka, Hisashi Owa, Taichi Niki, Yukio Shimomura
  • Patent number: 8467488
    Abstract: A method of synchronizing two electronic devices connected by a wireless link with at least one path including a transmission channel and a reception channel. The two devices are included in a network, such as a mobile telephone network. Synchronization information is transmitted directly from one electronic device to the other, as a clock pilot signal, via the channels. After recovery, the clock pilot signal is used for synchronization of a reference frequency of the receiving electronic device.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: June 18, 2013
    Assignee: E-Blink
    Inventors: Alain Rolland, Stéphane Blanc, Jean-Christophe Plumecoq
  • 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: 8447003
    Abstract: A source device counts a clock CLKpixel for pixel data using a transmitting counter, adds a counted value Csource(t) of the transmitting counter at a timing of transmitting a video packet Pvideo to the sink device to a header part of the video packet Pvideo as a time stamp value Csource(t), and transmits the video packet Pvideo to the sink device. The sink device receives the video packet Pvideo, extracts the time stamp value Csource(t) from the header part of the video packet Pvideo, generates a fixed reference clock CLKref based on the counted value Csource(t) of the transmitting counter using a first PLL, circuit, and generates the clock CLKpixel for the pixel data of the source device based on the reference clock CLKref using a second PLL circuit.
    Type: Grant
    Filed: March 24, 2008
    Date of Patent: May 21, 2013
    Assignee: Panasonic Corporation
    Inventors: Akihiro Tatsuta, Makoto Funabiki, Hiroshi Ohue
  • Patent number: 8446978
    Abstract: According to an aspect of an embodiment, a communication system includes a transmission apparatus with a coding section that generates multi-level-coded signals and transmits the multi-level-coded signals; and a deskew signal generation section that generates and transmits a deskew signal related to the multi-level-coded signals. The communication system also includes a receiving apparatus with a decoding section that decodes the multi-level-coded signals to generate decoded signals, and a deskew processing section that performs deskew processing for compensating skew among the decoded signals of the multiple channels. The deskew signal generation section generates the deskew signal that has been framed by extracting a part of the data from each of the channels of the input signals, adding framing data for enabling a receiving apparatus to recognize which channel the extracted data has been extracted from, and performing rate conversion.
    Type: Grant
    Filed: May 2, 2012
    Date of Patent: May 21, 2013
    Assignee: Fujitsu Limited
    Inventor: Naoki Kuwata
  • Patent number: 8442104
    Abstract: Provided is a signal processing apparatus including: an equalizer circuit that amplifies a predetermined frequency band of an input signal and outputs an output signal; a sampler circuit that samples the output signal amplified by the equalizer circuit with the output signal being offset in an amplitude direction using a multiphase clock system; an area information calculation circuit that calculates area information of an eye opening in an eye diagram of the output signal based on the output signal sampled by the sampler circuit; and a control circuit that controls amplification of the equalizer circuit based on the area information of the eye opening calculated by the area information calculation circuit.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: May 14, 2013
    Assignee: Renesas Electronics Corporation
    Inventor: Kanji Takeda
  • Patent number: 8442176
    Abstract: Computer-readable media, apparatus and other embodiments associated with performing comma alignment with scrambled data are described. One example method includes controlling an apparatus to generate a data stream that facilitates achieving and determining alignment in a device. The data stream includes sequences of N random portions of Y-bit characters followed by a Z-bit alignment character, N, Y and Z being integers. Another example method includes controlling an apparatus to receive and examine the data stream. The method also includes generating an alignment signal upon determining an alignment for recovered data in the device.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: May 14, 2013
    Assignee: Cisco Technology, Inc.
    Inventor: Matthew Todd Lawson
  • Publication number: 20130108000
    Abstract: A method performed by a device for performing synchronization between devices for a Device-to-Device (D2D) communication is provided. The method includes setting, according to a process of the device, the device to a group of devices for performing a dynamic switching; outputting a synchronization signal corresponding to the set group as a signal for setting synchronization in a physical layer; controlling, upon receiving another synchronization signal from another device, the outputting of the synchronization signal by applying a time offset according to a relation between the set group that includes the device and the group that includes the another device; and setting, if the synchronization signal and the another synchronization signal are converged, synchronization of the device based on a time point where the synchronization signal is output.
    Type: Application
    Filed: October 24, 2012
    Publication date: May 2, 2013
    Applicant: Samsung Electronics Co., Ltd.
    Inventor: Samsung Electronics Co., Ltd.
  • Publication number: 20130107999
    Abstract: Techniques for synchronization of clocks in nodes in a network are described. In one example, a node times or measures a synchronization timeout period. During the synchronization timeout period, the node may hear a beacon. In that event, the node may reset its clock using a time indicator found within the beacon. If the node does not hear a beacon before the end of the synchronization timeout period, the node may send a beacon request to one of its parents. In response, the parent node will broadcast a beacon, which may be heard by other nodes in the vicinity of the parent node. Upon receipt of the beacon and an included time indicator, the node will update its clock. Upon clock update, another synchronization timeout period is then started and the cycle is repeated, thereby maintaining synchronization of the clock with clocks of other nodes.
    Type: Application
    Filed: February 2, 2012
    Publication date: May 2, 2013
    Applicant: Itron, Inc.
    Inventors: Bastien Mainaud, Viet-Hung Nguyen, Fabrice Monier, Jerome Bartier
  • Publication number: 20130107998
    Abstract: A method and an interface unit is provided to maintain timing synchronization between a first Radio Equipment Controller (REC) and a second REC operating with a multi-standard base station. The first REC receives a synchronization signal and synchronized data output is generated from the synchronization signal. A clock signal is then generated from the synchronized data output. At the second REC, the synchronized data output is received and a synchronization source is then reconstructed from the first clock signal. A timing and frequency component of a second clock signal is then aligned to that of the reconstructed synchronization source, such that the second REC can maintain synchronization with the first REC.
    Type: Application
    Filed: November 2, 2011
    Publication date: May 2, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Jaroslaw Przada, Glen Rempel, Ken Huisman
  • Patent number: 8433005
    Abstract: A robust initial frame detection and symbol synchronization system and methodology are provided. In particular, a first pilot is employed in conjunction with three acquisition stages. In the first stage, an attempt is made to observe the leading edge of the correlation curve associated with the first pilot symbol. In the second stage, a determination is made as to whether a leading edge was detected in the first stage by attempting to observe a flat portion and/or trailing edge of the correlation curve. Furthermore, during this second stage, a frequency loop can be updated to account for frequency offset. The third stage is for observing the trailing edge of the curve if it was not already observed in stage two. Upon detection and confirmation of receipt of the first pilot, a second pilot can subsequently be employed to acquire fine symbol timing.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: April 30, 2013
    Assignee: Qualcomm Incorporated
    Inventor: Alok Kumar Gupta
  • 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: 8428206
    Abstract: A method and system of fine timing synchronization for an OFDM signal. The OFDM signal is coarse timing synchronized, generating a synchronization sequence and a CFR (Channel Frequency Response). The synchronization sequence is removed. A correlation coefficient of the correlation between the CFR applied to a number of carriers and the number of carriers with different window shifts is calculated. The largest window shift corresponding to a downsampling factor is indicated by the lowest correlation coefficient greater than a threshold. The CFR is downsampled by the downsampling factor, and an inverse FFT is performed on the downsampled CFR with a reduced number of calculations reduced by the downsampling factor, transforming the CFR into a CIR. A fine timing synchronization position is determined from the CIR and is utilized by an FFT unit within an OFDM receiver to accurately receive OFDM symbols of the OFDM signal.
    Type: Grant
    Filed: March 5, 2009
    Date of Patent: April 23, 2013
    Assignee: NXP B.V.
    Inventor: Yan Li
  • Publication number: 20130094615
    Abstract: Methods and apparatus are disclosed, such as those involving an inter-chip interface configured to receive and process electronic data. One such interface includes a receiver circuit that includes a clock tree configured to receive a clock signal at a clock tree input. The clock tree distributes a plurality of clock signals delayed from the clock signal such that one or more of the clock signals have a delay different from the delays of the other clock signals. The receiver circuit further includes a plurality of data input latches configured to receive a plurality of data elements over two or more different points in time. This configuration at least partially reduces crosstalk and simultaneous switching output noise.
    Type: Application
    Filed: December 7, 2012
    Publication date: April 18, 2013
    Applicant: MICRON TECHNOLOGY, INC.
    Inventor: MICRON TECHNOLOGY, INC.
  • Patent number: 8416903
    Abstract: Double data rate (“DDR”) circuitry or the like is modified or enhanced to include edge detection capability. During edge detection mode the circuitry is supplied with serial training data that includes successive pairs of equal-valued bits. Several, differently-phased, candidate clock signals are used one after another in order of increasing phase to clock the DDR circuitry. Adjacent bits in the training data that should be equal-valued are captured by the DDR circuitry and compared. Any candidate clock signal that causes the bits thus compared to be unequal is flagged as having phase close to edges in the data. The approximate phase of data edges is thereby indicated by the phase (or phases) of the candidate clock signal (or signals) causing the bits compared as described above to be unequal.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: April 9, 2013
    Assignee: Altera Corporation
    Inventors: John Oh, Samson Tam, Curt Wortman, Jean Luc Berube
  • Patent number: 8416900
    Abstract: A method and circuit for dynamically changing the frequency of clock signals. The method including: detecting an edge of a first clock signal operating at a first frequency using a second clock signal operating at a second frequency; detecting an edge of the second clock signal using the first clock signal; detecting coincident edges of the first and the second clock signals; and changing the second frequency to a third frequency different from the second frequency upon detection of the coincident edges.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: April 9, 2013
    Assignee: International Business Machines Corporation
    Inventors: David Wills Milton, Jason Edward Rotella
  • Patent number: 8411806
    Abstract: In a method for decoding plurality of information streams corresponding to a plurality of layers, where the plurality of information streams have been transmitted via a multiple input multiple output (MIMO) communication channel, a plurality of received signals are processed to decode information corresponding to a first layer. A plurality of modified received signals are generated using the decoded information corresponding to the first layer and the plurality of received signals. Bit metric values are generated for a second layer using MIMO maximum likelihood (ML) demodulation and using the plurality of modified received signals and channel and modulation information for interfering signals. Information corresponding to the second layer is decoded using the generated bit metric values.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: April 2, 2013
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Hui-Ling Lou
  • Publication number: 20130077724
    Abstract: An embodiment of the invention comprises a digital phase detector with substantially zero phase offset. The digital phase detector receives a clock signal and a reference clock signal and provides a phase indicator signal to identify whether the clock signal leads or lags the reference clock signal. An embodiment of the invention comprises a method that adds substantially zero phase offset in processing an input clock signal and a delayed clock signal to generate a control signal. The control signal is processed in a variable delay line to generate the delayed clock signal. In an embodiment, a first processor comprises a delay locked loop having a digital phase detector, the digital phase detector comprising a first differential sense amplifier cross-coupled to a second differential sense amplifier, the digital phase detector receiving a clock signal and generating one or more delayed clock signals, a control signal, and a gated data signal.
    Type: Application
    Filed: September 23, 2011
    Publication date: March 28, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Daniel M. Dreps, Kyu-hyoun Kim, Glen A. Wiedemeier
  • Patent number: 8407508
    Abstract: A serial bus clock frequency calibration system and a method thereof are disclosed herein. The system utilizes a first frequency calibration device, a second frequency calibration device and a third frequency calibration device to share the same oscillator as so to perform multi-stage clock frequency resolution calibrations for different frequency-tuning ranges. This can bring an optimal frequency resolution, greatly reduce system complexity and save element cost.
    Type: Grant
    Filed: September 16, 2010
    Date of Patent: March 26, 2013
    Assignee: Genesys Logic, Inc.
    Inventors: Wei-te Lee, Shin-te Yang, Wen-ming Huang
  • Patent number: 8407379
    Abstract: An efficient low latency buffer, and method of operation, is described. The efficient low latency buffer may be used as a bi-directional memory buffer in an audio playback device to buffer both output and input data. An application processor coupled to the bi-directional memory buffer is responsive to an indication to write data to the bi-directional memory buffer reads a defined size of input data from the bi-directional memory buffer. The input data read from the bi-directional memory buffer is replaced with output data of the defined size. In response to a mode-change signal, the defined size of data is changed that is read and written from and to the bi-directional memory buffer. The buffer may allow the application processor to enter a low-powered sleep mode more frequently.
    Type: Grant
    Filed: October 31, 2011
    Date of Patent: March 26, 2013
    Assignee: Research In Motion Limited
    Inventors: Scott Edward Bulgin, Cyril Martin, Bengt Stefan Gustavsson
  • Patent number: 8405533
    Abstract: In one embodiment, the present invention includes a de-serializer to receive serial data at a first rate and to output a parallel data frame corresponding to the serial data aligned to a frame alignment boundary in response to a phase control signal received from a feedback loop coupled between the de-serializer and a receiver logic coupled to an output of the de-serializer. Other embodiments are described and claimed.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: March 26, 2013
    Assignee: Intel Corporation
    Inventors: Ehud Shoor, Dror Lazar, Assaf Benhamou
  • Publication number: 20130070881
    Abstract: A phase locked loop and an associated alignment method are provided. A disclosed phase locked loop receives a reference signal to provide a feedback signal. The phase locked loop is first opened. When the phase locked loop is open, a frequency range of an oscillating signal from a voltage-controlled oscillator is substantially selected. The feedback signal is provided according to the oscillation signal. After the frequency range is selected, the phase locked loop is kept open and the phases of the reference signal and the feedback signal are substantially aligned. The phase locked loop is then closed after the reference signal and the feedback signal are aligned.
    Type: Application
    Filed: September 11, 2012
    Publication date: March 21, 2013
    Applicant: MStar Semiconductor, Inc.
    Inventors: Cheng-Chieh Lin, Jian-Yu Ding, Yao-Chi Wang
  • Patent number: 8391432
    Abstract: A method of serializing a data stream includes passing a series of data words from a source in a first clock domain to a serializer in a second clock domain and passing valid signals from the source to the serializer indicating when each of the data words is available from the source. The serializer divides each of the data words into a plurality of portions for serial transmission. The method also includes synchronizing the serializer and the source based on the first of the valid signals.
    Type: Grant
    Filed: August 8, 2005
    Date of Patent: March 5, 2013
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Carson D. Henrion, Daniel A. Berkram
  • Patent number: 8385318
    Abstract: A transmitter includes an amplitude adjustment unit multiplying an amplitude adjustment sequence value for adjusting amplitude with a synchronization channel transmitted from a base station for establishing synchronization with a mobile station.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: February 26, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Kenichi Higuchi, Mamoru Sawahashi, Yoshihisa Kishiyama
  • Patent number: 8385493
    Abstract: Disclosed is a system and method for improving the linearity of a clock and data recovery (CDR) circuit. In one embodiment, a data stream is received, and the phase of a clock signal is adjusted using two interpolators. The phase of the output signal of the second interpolator is adjusted simultaneously with, and complementary to, adjusting the phase of the first interpolator. The first interpolator's output signal is injected into a first delay cell in a delay loop having a plurality of delay cells, and the output of the second interpolator is inactivated. When the maximum phase of the first interpolator's output signal is reached, the second interpolator's output signal is injected into another one of the delay cells, and the first interpolator's output signal is inactivated. The data stream is then recovered using the output of the delay loop as a clock signal.
    Type: Grant
    Filed: April 7, 2010
    Date of Patent: February 26, 2013
    Assignee: Agere Systems LLC
    Inventors: Christopher Abel, Joseph Anidjar, Vladimir Sindalovsky, Craig Ziemer
  • Patent number: 8385371
    Abstract: A frame synchronizer, frame synchronization method and demodulator which can more positively establish frame synchronization of an input signal which is likely to have a plurality of frame lengths. A differential correlation detector calculates a differential correlation value with no pilot which is associated with the absence of a pilot signal inserted in the input signal and a differential correlation value with a pilot which is associated with the presence of a pilot signal inserted in the input signal. Frame period confirmation counters perform, based on the differential correlation values with no pilot, frame synchronization control appropriate to the input signals whose frame lengths are 21690 and 32490 symbols, respectively. The frame period confirmation counters 1 perform, based on the differential correlation values with a pilot, frame synchronization control appropriate to the input signals whose frame lengths are 22194 and 33282 symbols, respectively.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: February 26, 2013
    Assignee: Sony Corporation
    Inventors: Hideyuki Matsumoto, Tetsuhiro Futami, Atsushi Makita, Takashi Yokokawa, Doan Tien Dung, Yuichi Mizutani
  • Patent number: 8385494
    Abstract: A method includes synchronizing a received signal with at least two orthogonal frequency division multiplexed OFDM training signals having only in-phase values and being real in the time domain and determining a frequency offset correction from the synchronization of the received signal and training symbols responsive to a cross-correlation between said training symbols to enable estimating all possible frequency offsets for correction for enabling OFDM demodulation of said received signal.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: February 26, 2013
    Assignee: NEC Laboratories America, Inc.
    Inventors: Shu-Hao Fan, Jianjun Yu
  • Patent number: 8385394
    Abstract: Disclosed herein are embodiments of an improved built-in self-test (BIST) circuit and an associated method for measuring phase and/or cycle-to-cycle jitter of a clock signal. The embodiments of the BIST circuit implement a Variable Vernier Digital Delay Locked Line method. Specifically, the embodiments of the BIST circuit incorporate both a digital delay locked loop and a Vernier delay line, for respectively coarse tuning and fine tuning portions of the circuit. Additionally, the BIST circuit is variable, as the resolution of the circuit changes from chip to chip, and digital, as it is implemented with standard digital logic elements.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: February 26, 2013
    Assignee: International Business Machines Corporation
    Inventors: Brandon R. Kam, Stephen D. Wyatt
  • Patent number: 8374264
    Abstract: Disclosed herein is a signal processing apparatus, including: a computation device operable to perform transform computation adapted to Fourier-transform a time domain OFDM i.e., Orthogonal Frequency Division Multiplexing signal into a frequency domain OFDM signal; a processing device operable to perform carrier frequency offset detection adapted to detect an estimated carrier frequency offset that is an error of a carrier used for demodulation of the OFDM signal; and a carrier frequency offset correction device operable to perform carrier frequency offset correction adapted to correct the carrier frequency offset of the frequency domain OFDM signal in accordance with the estimated carrier frequency offset.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: February 12, 2013
    Assignee: Sony Corporation
    Inventors: Kenichi Kobayashi, Yuken Goto, Takuya Okamoto, Lachlan Bruce Michael
  • Publication number: 20130034197
    Abstract: The present invention provides a method of synchronising the frequency of a slave clock to that of a master, preferably using a packet network.
    Type: Application
    Filed: August 5, 2011
    Publication date: February 7, 2013
    Applicants: Khalifa University of Science, Technology, and Research, Emirates Telecommunications Corporation, British Telecommunications plc
    Inventors: James Aweya, Saleh Al Araji
  • Patent number: 8363764
    Abstract: For reconstructing a data clock from asynchronously transmitted data packets, a control loop is provided which includes a controlled oscillator. An input signal of the control loop is generated on the basis of the received data packets. At least one high-pass type filter is provided in a signal path of the control loop. The data clock for the synchronous output of data is generated on the basis of an output signal of the controlled oscillator.
    Type: Grant
    Filed: August 6, 2007
    Date of Patent: January 29, 2013
    Assignee: Lantiq Deutschland GmbH
    Inventor: Ronalf Kramer
  • 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: 8355455
    Abstract: Channel estimates respectively associated with OFDM pilot symbols are used to estimate additional parameters such as change in channel phase over time, change in channel phase over frequency, and frequency selectivity.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: January 15, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Mohammad M. Mansour, Sundeep Rangan, Siddharth Ray, Vincent Loncke, Pramod K. A. Rao, Joshua L. Koslov
  • Patent number: 8355480
    Abstract: A memory controller receives data and phase-providing signals from a memory device. The phase-providing signal is not a clock signal, but is used by the memory controller to phase align a local data-sampling signal with the incoming data. The memory controller samples the data signal with the data-sampling signal. The memory controller can perform maintenance operations to update the phase relationship between the phase-providing and data-sampling signals.
    Type: Grant
    Filed: March 6, 2012
    Date of Patent: January 15, 2013
    Assignee: Rambus Inc.
    Inventors: Scott C. Best, Richard E. Warmke, David B. Roberts, Frank Lembrecht
  • Patent number: 8351558
    Abstract: The disclosure provides an effective means for fine-resolution determination of the frequency content of an RF signal using low speed digital circuits. The disclosure relates to a method and apparatus for decomposing a high frequency RF signal into several low frequency signals or data streams without loss of any information and without the use of extraneous circuit components such as local oscillators, mixers or offset phase-locked loops. Single or multiple phase oscillator outputs are fed directly to a single or multiple direct RF frequency-to-digital (DrfDC) circuits. The front end of the DrfDC circuit decomposes a high frequency signal into several low frequency signals without loss of any information. The low frequency signals are processed by the back-end of the DrfDC and converted into digital data streams. The digital data streams are then combined and averaged to represent the frequency of the input RF signal.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: January 8, 2013
    Assignee: Panasonic Corporation
    Inventors: Richard H. Strandberg, Paul Cheng-Po Liang
  • 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: 8345783
    Abstract: Phase tracking in an OFDM symbol comprises determining a sufficient statistic for CFO and SFO estimation from a differential metric between a current OFDM symbol and a previous OFDM symbol transmitted on the same frequency band. The sufficient statistics corresponding to positive pilot tones are combined with those corresponding to negative pilot tones to estimate the CFO and SFO.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: January 1, 2013
    Assignee: Olympus Corporation
    Inventors: Dumitru Mihai Ionescu, Haidong Zhu, Abu Amanullah
  • Patent number: 8331518
    Abstract: A wireless communication apparatus is provided for receiving packets transmitted with delay amounts different for the respective transmission branches. The wireless communication apparatus includes a plurality of reception branches, a synchronous processing unit for detecting synchronous timing independently for the respective reception branches; and a signal processing unit for performing decoding processing and other kinds of processing subsequent to the synchronous timing for the respective reception branches.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: December 11, 2012
    Assignee: Sony Corporation
    Inventors: Ryou Sawai, Hiroaki Takahashi
  • Patent number: 8325864
    Abstract: A first phase adjustment circuit adjusts phases of a data decision clock signal and a first boundary decision clock signal according to a phase adjustment amount based on an output signal of a data decision circuit and an output signal of a first boundary decision circuit. A second phase adjustment circuit adjusts a phase of a second boundary decision clock signal according to a result of adding the phase adjustment amount and a phase adjustment amount offset. An adaptive equalization control circuit adjusts an equalization coefficient of an equalization circuit according to a data width of an output signal of the equalization circuit based on a logical comparison result between the output signal of the data decision circuit and an output signal of a second boundary decision circuit when the phase adjustment amount offset is changed.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: December 4, 2012
    Assignee: Fujitsu Limited
    Inventor: Hisakatsu Yamaguchi
  • 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: 8325861
    Abstract: A circuit includes a frequency synthesizer, N phase mixers coupled to the frequency synthesizer, a plurality of receivers, and a calibration circuit. The frequency synthesizer is to receive a reference clock signal and is to output a primary clock signal. A respective phase mixer in the N phase mixers is to output a respective secondary clock signal having a corresponding phase. A respective receiver in the plurality of receivers is coupled to two of the N phase mixers, and at a respective time is to receive data in accordance with the respective secondary clock signal from one of the two phase mixers coupled to the respective receiver. The calibration circuit is to calibrate a secondary clock signal output by a respective phase mixer in the N phase mixers by adjusting the phase of the secondary clock signal of the respective phase mixer.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: December 4, 2012
    Assignee: Rambus, Inc.
    Inventors: Kun-Yung Chang, Fariborz Assaderaghi
  • Publication number: 20120300889
    Abstract: A device for controlling frequency synchronization includes a processor for controlling a frequency-controlled clock signal on the basis of received timing messages so as to achieve frequency-locking between the frequency-controlled clock signal and a reference clock signal. For the purpose of finding such timing messages which have experienced similar transfer delays and thus are suitable for the frequency control, the processor is configured to control a phase-controlled clock signal on the basis of the timing messages so as to achieve phase-locking between the phase-controlled clock signal and the reference clock signal, and to select the timing messages to be used for the frequency control on the basis of phase-error indicators related to the phase control. Thus, the phase-controlled clock signal is an auxiliary clock signal that is utilized for performing the frequency control.
    Type: Application
    Filed: May 22, 2012
    Publication date: November 29, 2012
    Applicant: TELLABS OY
    Inventors: Kenneth HANN, Mikko LAULAINEN