Differential Patents (Class 375/244)
  • Patent number: 8363737
    Abstract: In one embodiment, a method includes receiving a carrier signal transmitted by a base station according to either a first data-transmission protocol or a second data-transmission protocol; detecting a first field gap in the carrier signal indicating initiation of a data transmission by the base station; and determining whether a reference duration is present in the carrier signal after the first field gap. The method includes, if the reference duration is present in the carrier signal after the first field gap then, according to the first data-transmission protocol, determining a calibration value for the data transmission based on the reference duration and decoding the data transmission by measuring durations between successive subsequent field gaps and determining whether each duration as measured is a binary 1 or binary 0 based on the calibration value.
    Type: Grant
    Filed: May 27, 2011
    Date of Patent: January 29, 2013
    Assignee: Atmel Corporation
    Inventors: Alexander Kurz, Mathew Neal
  • Patent number: 8344933
    Abstract: A radar system has an antenna. The system includes electronics configured to facilitate communication using radar returns received and transmitted by the antenna. The electronics is configured to extract communications data from a received radar return. The electronics is further configured to provide communications data with an outgoing radar pulse for data transmission.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: January 1, 2013
    Assignee: Rockwell Collins, Inc.
    Inventors: Kevin M. Kronfeld, Daniel L. Woodell, Roy E. Robertson, Venkata A. Sishtla
  • Patent number: 8340445
    Abstract: An image encoding device comprises: a predicted value generation means for predicting target pixel data which is the pixel data of an encoding target pixel to generate predicted value data; a subtractor for calculating the difference value between the target pixel data and the predicted value data to generate difference value data; an encoding mode decision means for determining an encoding mode based on the difference value data and temporarily holding it in a buffer; an encoding target decision means for determining which data of the target pixel or the difference value is used as encoding target data to be encoded based on the encoding mode; a quantization means for applying a quantization processing to the encoding target data based on the encoding mode to generate quantized data; and a fixed-length code generation means for adding the encoding mode to the quantized data to generate a fixed-length code.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: December 25, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masayuki Yamaguchi, Akihisa Yamada, Shinichi Maeta
  • Patent number: 8300711
    Abstract: An adaptive differential pulse-code modulation-demodulation system and method thereof is provided. The method includes steps of modulating an analog audio input signal into a data packet, including a plurality of digital data through adaptive differential pulse-code modulation, an initial value and a scale factor associated with the digital data, to be sent to the communication network, and demodulating the data packet according to the digital data, the initial value and the scale factor, thereby reconstructing the data packet to an analog audio output signal.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: October 30, 2012
    Assignee: MStar Semiconductor, Inc.
    Inventor: Chu-Feng Lien
  • Patent number: 8284848
    Abstract: A differential data transferring system and method uses three level voltages to simultaneously transfer three signals (for example, two data signals and one clock signal) across two transfer line sets (i.e., four transfer lines). Therefore, the differential data transferring method increases transferring efficiency by using fewer transfer lines. Also, according to the differential data transferring system and method, one of two transfer lines forming a transfer line set is controlled to a middle voltage level, while the other transfer line is controlled to either a high voltage or a low voltage. Accordingly, the voltage difference between the two transfer lines may be maintained at a constant amplitude. Additionally, the difference between first and second dividing voltages DC1 and DC2, which are used for generating a reference output data, is controlled to maintain a constant amplitude. Therefore, the differential data transferring system and method may provide improved operation reliability.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: October 9, 2012
    Assignee: TLI Inc.
    Inventors: Jang Jin Nam, Yong Weon Jeon
  • Patent number: 8275075
    Abstract: A system and method implement low complexity maximum likelihood sequence detection. A decision feedback algorithm computes x(M+D+L?1). Optimality examination is performed for x(M), and state values and values of Markov states along paths from states in x(M) to xl(M+L) are computed.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: September 25, 2012
    Assignee: Colorado State University Research Foundation
    Inventor: Jie Luo
  • Patent number: 8199858
    Abstract: The present invention provides an OOB detection circuit capable of making accurate signal determination even in the case where a characteristic fluctuation occurs in an analog circuit, thereby preventing deterioration in the yield of a product. To an amplitude determining circuit, a characteristic adjustment register for changing setting of an amplitude threshold adjustment mechanism for distinguishing a burst and a squelch from each other provided for the amplitude determining circuit is coupled. The characteristic adjustment register is controlled by a self determination circuit. An output of the amplitude determination circuit is supplied to a time determining circuit and also to the self determination circuit. On the basis of the output of the amplitude determining circuit, the self determination circuit controls the characteristic adjustment register.
    Type: Grant
    Filed: December 6, 2008
    Date of Patent: June 12, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Kazuaki Kurooka, Kenichi Shimizu
  • Patent number: 8189692
    Abstract: A voltage memory stores a signal level of a transmission signal from a signal generator at a timing of a clock signal, and outputs the transmission signal. A voltage difference detector detects a signal level of a transmission signal at a timing subsequent to the timing and detects a first signal level difference between the signal level and the signal level from the voltage memory. A maximum value detector, a voltage difference detector and bias voltage sources delay the transmission signal so as to keep a rise time of the transmission signal substantially within a predetermined value range by adding capacitances corresponding to the first signal level differences from the voltage difference detectors to transmission lines.
    Type: Grant
    Filed: September 10, 2007
    Date of Patent: May 29, 2012
    Assignee: Panasonic Corporation
    Inventors: Shin-ichi Tanimoto, Seiji Hamada, Hirotsugu Fusayasu, Ryo Matsubara
  • Patent number: 8165227
    Abstract: A method of modulation, which is applied to a communication system transmitting data in one frequency band using at least two orthogonal subcarriers, is disclosed. The present invention includes the steps of adding information bits indicating an amplitude reference and a phase reference to an input bit sequence by a specific time interval unit and carrying out differential amplitude phase shift keying (DAPSK) on the input bit sequence using the amplitude and phase references. The present invention prevents the waste of power and bandwidth due to insertion of a plurality of pilot toes in the related art 1?-QAM system.
    Type: Grant
    Filed: October 25, 2005
    Date of Patent: April 24, 2012
    Assignee: LG Electronics Inc.
    Inventors: Youn Woo Yun, Ki Jun Kim
  • Patent number: 8149928
    Abstract: Some embodiments include a transmitter having a cycle encoding circuit to receive a data input signal and to provide a full cycle encoded signal in response thereto by continuously joining portions of different encoding signals. Some of the encoding signals have a different frequency than others of the encoding signals and some of the encoding signals have a different phase than others of the encoding signals. Data is represented in data time segments of the full cycle encoded signal and no data time segment has more than one cycle of an encoding signal. In some embodiments, a receiver receives the cycle encoded signal and recovers data of the data input signal.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: April 3, 2012
    Assignee: Intel Corporation
    Inventors: Jed D. Griffin, Jerry G. Jex, Arnaud J. Forestier, Kersi H. Vakil, Abhimanyu Kolla
  • Patent number: 8121200
    Abstract: A multi-level signal uses the third/fourth signal level to signal both a word clock edge and a data word boundary. At the receiver, a level detector detects a transition to or from the third/fourth level as a clock signal transition and the word boundary. The bit clock can be recovered using a conventional clock multiplier. Bi-level signaling is used for data between the word boundaries. Additional signal states are available in the multi-level signal by modulating the pulse width at the third/fourth signal level.
    Type: Grant
    Filed: May 9, 2007
    Date of Patent: February 21, 2012
    Assignee: Intersil Americas Inc.
    Inventor: Dong Zheng
  • Patent number: 8107751
    Abstract: The embodiments of the present invention provide for methods, devices, and systems adapted to perform adaptive quantization processes. The adaptive quantization processes of the present invention are adapted to provide one or more adaptive quantization modes based on one or more previous pixels and their associated coding modes. The output of an adaptive quantization process may include coded data and a coding mode, indicating whether the coded data is pulse code modulation (PCM) data or differential pulse code modulation (DPCM) data.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: January 31, 2012
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Shawmin Lei, Masayuki Yamaguchi, Akihisa Yamada, Shinichi Maeta
  • Patent number: 8085857
    Abstract: A method and an apparatus are described for sensing of a multi-state signal. An embodiment of a method includes driving a digital input line with a signal, the signal alternating between a first state and a second state. The method further includes sensing one or more values of the digital input line, and determining a state of the digital input line based on the sensed values.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: December 27, 2011
    Assignee: Cypress Semiconductor Corporation
    Inventor: Jason Baumbach
  • Patent number: 8077790
    Abstract: A first convolutional coder (building-block trellis coder) is used to establish a minimum squared Euclidian distance (MSED) between signal points within a coded constellation building block. A second convolutional encoder (tiling encoder) is designed to ensure that the building block's MSED is maintained between building blocks once they are tiled onto an integer lattice. When this approach is applied to the trellis code of the WiMAX standard, a 3 dB coding is realized. Recall that Wei's 16-state 4D code suffered from a 1.36 dB due to constellation expansion, resulting in a net 4.66 dB coding gain. Our building block approach recovers 1.33 dB of this loss with only a minor increase in coding complexity. We then use the building block approach to derive simpler and more powerful higher dimensional codes that provide further gains still over the Wei family of multidimensional codes.
    Type: Grant
    Filed: October 23, 2007
    Date of Patent: December 13, 2011
    Inventors: Eric Morgan Dowling, John P. Fonseka
  • Patent number: 8050332
    Abstract: In a communication system, data is selectively transmitted using single-ended or differential signaling. The data is transmitted in relation to a plurality of clock signals having different relative phases. When the data is transmitted using single-ended signaling, data on adjacent signal lines undergo logic transitions at different times in relation to the plurality of clock signals.
    Type: Grant
    Filed: April 16, 2008
    Date of Patent: November 1, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hoe-ju Chung, Jung-bae Lee
  • Patent number: 8045625
    Abstract: An encoding method includes partitioning an input stream into first sub-blocks and second sub-blocks, encoding the second sub-blocks based on a number and location of reference sub-blocks to generate third sub-blocks when at least one of the first sub-blocks corresponds to a forbidden pattern, and rearranging the first sub-blocks and the third sub-blocks to generate an output stream. The reference sub-blocks indicate the second sub-blocks that correspond to a reference pattern and the third sub-blocks includes a redundant information sub-block and non-redundant information sub-blocks. Thus, the encoding method may properly control a direct current (DC) component.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: October 25, 2011
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventor: Il-Won Seo
  • Patent number: 8000412
    Abstract: The present invention relates to a low power serial link employing differential return-to-zero signaling. A receiver circuit consistent with some embodiments includes an input circuit for receiving differential serial data signals that form a differential return-to-zero signaling and a clock recovery circuit. The clock recovery circuit is coupled to the input circuit and includes a logic gate configured to generate a clock signal by using said differential serial data signals.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: August 16, 2011
    Assignee: NetLogic Microsystems, Inc.
    Inventor: Marc Loinaz
  • Patent number: 7983348
    Abstract: A system and method for signal transmission, a signal modulation and a signal demodulation device, and a method for signal transmission are disclosed. One embodiment includes transmitting a first pulse signal via a first line; and transmitting a second pulse signal complementary to the first pulse signal via a second line, wherein the point in time of the transmitting of the second signal relative to the point in time of the transmitting of the first signal is varied as a function of the respective digital data to be transmitted.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: July 19, 2011
    Assignee: Infineon Technologies AG
    Inventor: Harry Siebert
  • Patent number: 7983347
    Abstract: In a signal transmitter for a multiple differential transmission system including the signal transmitter, a signal receiver, and a signal transmission path including first to third signal lines, first to third differential driver transmit first to third output signals and inverted first to third output signals from the first to third output signals responsive to first to third bit information signals, the first output signal and the inverted third output signal are combined and transmitted to the first signal line, the second output signal and the inverted first output signal are combined and transmitted to the second signal line, and the third output signal and the inverted third output signal are combined and transmitted to the first signal line. The first to third differential drivers of the signal receiver detect polarities of terminal voltages generated across terminal resistances connected between adjacent signal lines and output bit information signals.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: July 19, 2011
    Assignee: Panasonic Corporation
    Inventors: Seiji Hamada, Shin-ichi Tanimoto, Hirotsugu Fusayasu
  • Patent number: 7957472
    Abstract: A receiver circuit uses two or more comparators to detect the received data signal. Each comparator is set to compare the data signal to a different reference signal. The output signals of the comparators are received into a detector circuit, which provides a third output signal that establishes the logic state of the received signal based on whether or not the output signals of the comparators are equal. Depending on the logic state of the data signal, one of the comparators provides its output signal sooner than the other. Each comparator may be implemented by a differential amplifier. In one embodiment, the reference signals are threshold voltages which may be provided by the tripping voltages at the trip points for the logic HIGH and LOW states.
    Type: Grant
    Filed: May 7, 2007
    Date of Patent: June 7, 2011
    Assignee: Oracle America, Inc.
    Inventors: Hung Jen (Henry) Wu, Yolin Lih
  • Patent number: 7948407
    Abstract: A high-speed serial interface circuit includes a data receiver circuit, a clock signal receiver circuit, a logic circuit block that includes at least a serial/parallel conversion circuit, a free-running clock signal generation circuit, a clock signal detection circuit, and an output mask circuit. The clock signal detection circuit compares a received clock signal from the clock signal receiver circuit with a free-running clock signal from the free-running clock signal generation circuit to detect whether or not clock signals are transferred through differential clock signal lines. When the clock signal detection circuit has detected that the clock signals are not transferred through the differential clock signal lines, the output mask circuit masks an output signal from the logic circuit block so that the output signal is not transmitted to a circuit in the subsequent stage.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: May 24, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Takemi Yonezawa, Kenichi Oe
  • Patent number: 7945210
    Abstract: The object of the invention, which relates to a method and an arrangement for reducing the mutual interference of network subscribers in radio networks, is to provide a solution by means of which data collisions are reduced and thus the data throughput rate of a radio cell is increased. According to the invention, this object is achieved in terms of the method in that the cell size of a radio cell is adjusted by reducing the receiver sensitivity of one or more devices belonging to the radio cell if the device receives interference which disrupts its communication from another device belonging to a different radio cell.
    Type: Grant
    Filed: December 13, 2005
    Date of Patent: May 17, 2011
    Assignee: NXP B.V.
    Inventor: Volker Aue
  • Patent number: 7933354
    Abstract: An encoding and/or decoding communication system comprises a framer interface, an encoder, a multiplexer, an output driver, and a clock multiplier unit (CMU). The encoder includes an input latch circuitry stage; an output latch circuitry stage; an intermediate latch circuitry stage interposed between the input latch circuitry stage and the output latch circuitry stage, the intermediate latch circuitry stage coupled to the input latch circuitry stage and the output latch circuitry stage; a plurality of encoding logic circuitry stages interposed between the input latch circuitry stage and the output latch circuitry stage, a last one of the plurality of encoding logic circuitry stages placed adjacent to the output latch circuitry stage and coupled to the output latch circuitry stage; and a feedback between the output latch circuitry stage and the last one of the plurality of encoding logic circuitry stages.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: April 26, 2011
    Assignee: Semtech Corporation
    Inventors: Samuel A. Steidl, Peter F. Curran
  • Patent number: 7923710
    Abstract: A signal isolator comprises an isolation barrier, a transmitter, a differentiator, and a recovery circuit. The transmitter is coupled to a first side of the isolation barrier and is configured to receive and convert an information signal to a differential signal that encodes information in the information signal in a single transition edge. The differentiator is coupled to a second side that is isolated from the first side of the isolation harrier and differentiates the differential signal. The recovery circuit is coupled to the differentiator and operates to recover an output information signal based on the information in the single transition edge.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: April 12, 2011
    Assignee: Akros Silicon Inc.
    Inventors: Philip John Crawley, Sajol Ghoshal, John R. Camagna
  • Patent number: 7894536
    Abstract: An error model can be utilized to mitigate errors associated with a conversion system, such as an analog-to-digital or digital-to analog converter. The error model is adaptively calibrated to approximate error characteristics associated with at least a portion of the conversion system, such as a digital-to analog converter. The error model can be generated on-line during system operation or off-line to improve performance of various types of signal converters and systems using such signal converters.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: February 22, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Lars Risbo, Thomas H. Hansen
  • Patent number: 7844292
    Abstract: Systems and methods are disclosed for in-band control signaling using bandwidth distributed encoding to send modulated control carrier signals with analog voice signals in the same voice frequency band. A transmitting device generates control carrier signals spread over a voice frequency band, combines them with analog voice signals in the voice frequency band, and transmits the combined signals over a communication channel. The transmitting device can use a control signal encoder to apply a pseudo-random code to the control carrier signal in order to spread it over a voice frequency band. As such, control signals are sent as in-band signals without significantly degrading the voice signals. A receiving device receives the combined signals within the voice frequency band. The receiving device demodulates the combined signal and uses matching pseudo-random codes to determine if a control signal has been sent. The receiving device also reproduces the voice signals themselves.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: November 30, 2010
    Inventor: Kenneth H. Shamburger
  • Patent number: 7835435
    Abstract: Techniques and technologies are provided for compressing differential samples of bandwidth-limited data and coding the compressed differential samples to reduce bandwidth and power consumption when communicating bandwidth-limited data over a serial interface which couples one integrated circuit to another integrated circuit.
    Type: Grant
    Filed: January 8, 2008
    Date of Patent: November 16, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Samir J. Soni, Pravin Pramakanthan, Clive K. Tang, Bing Xu
  • Patent number: 7813452
    Abstract: A phase detector includes a decimator to decimate a digitized in-phase signal and a digitized quadrature signal to N times a symbol rate, where N is an integer greater than one. A burst detector to detect bursts in an output of the decimator. A carrier offset block to determine an offset angle based on an output of the burst detector. A rotator to generate a rotated signal by rotating the output of the decimator based on the offset angle determined by the carrier offset block. An equalizer to perform coherent demodulation of the rotated signal.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: October 12, 2010
    Assignee: Marvell World Trade Ltd.
    Inventors: Zhongxuan Zhang, Lixin Zhao, Steve Xuefeng Jiang
  • Patent number: 7773697
    Abstract: Where the additional data throughput is added using an amplitude offset or a combination of phase and amplitude offset, the legacy differential demodulator does not recover the amplitude information. The present invention provides a method for demodulating amplitude offsets in a differential modulation system in order to recover the amplitude information. The demodulated amplitude information may be used to recover the additional Level 2 data transmitted as an amplitude offset or combination phase and amplitude offset in a differential multiple phase shift keying (D-MPSK) transmission, such as across adjacent OFDM symbols and/or adjacent frequency subcarriers.
    Type: Grant
    Filed: March 23, 2005
    Date of Patent: August 10, 2010
    Assignee: Delphi Technologies, Inc.
    Inventors: Eric A. Dibiaso, Michael L. Hiatt, Jr., Glenn A. Walker
  • Patent number: 7720159
    Abstract: In some embodiments, the inventions includes a transmitter including a cycle encoding circuit to receive a data input signal and to provide a full cycle encoded signal in response thereto by continuously joining portions of different encoding signals. Some of the encoding signals have a different frequency than others of the encoding signals and some of the encoding signals have a different phase than others of the encoding signals. Data is represented in data time segments of the full cycle encoded signal and no data time segment has more than one cycle of an encoding signal. In some embodiments, a receiver receives the cycle encoded signal and recovers data of the data input signal.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: May 18, 2010
    Assignee: Intel Corporation
    Inventors: Jed D. Griffin, Jerry G Jex, Arnaud J. Forestier, Kersi H. Vakil, Abhimanyu Kolla
  • Patent number: 7697466
    Abstract: At a base station apparatus, known pilot signals for use in channel estimation are transmitted, and in addition thereto MCS pilot signals that are used to perform adaptive modulations respectively corresponding to a plurality of modulation schemes are multiplexed and output. A mobile station apparatus dispreads the respective MCS signals out of the multiplex signal, compares these to known symbols patterns, and sends the MCS pilot signals that show a matching relationship to the base station apparatus as a mobile station reception result. Upon receiving the mobile station reception result from the mobile station apparatus, the base station apparatus selects the modulation scheme of the optimum modulation level for the downlink signals. This configuration makes it possible to switch the modulation schemes in an accurate and simple way.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: April 13, 2010
    Assignee: Panasonic Corporation
    Inventors: Kazunari Hashimoto, Sadaki Futagi, Kenichi Miyoshi
  • Patent number: 7671631
    Abstract: A low voltage differential signal receiving device includes two differential receivers, two oversamplers, a phase locked loop, and a clock edge and data boundary detection & data extraction logic module. Clock and data signals are transmitted via channels having the same circuit layout, so that the clock signal is treated as another type of data signal. A frequency of sampling input clock and data is increased via asynchronous clock, clock transition is detected, and data bytes are extracted from clock and data samples. Therefore, the clock signal and the data signal have the same delay time to avoid any sampling error due to a difference in time sequence between the clock and the data. Meanwhile, due to the accurately increased sampling frequency, the sampled clock and the data signals are not adversely affected by different factors to enable upgraded data transmission efficiency and quality at the same time.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: March 2, 2010
    Assignee: Explore Semiconductor, Inc.
    Inventors: Yung-Jann Chen, Chiu-Feng Lien
  • Patent number: 7663515
    Abstract: A high-speed serial interface circuit includes a data receiver circuit, a clock signal receiver circuit, a logic circuit block that includes at least a serial/parallel conversion circuit, a free-running clock signal generation circuit, a clock signal detection circuit, and an output mask circuit. The clock signal detection circuit compares a received clock signal from the clock signal receiver circuit with a free-running clock signal from the free-running clock signal generation circuit to detect whether or not clock signals are transferred through differential clock signal lines. When the clock signal detection circuit has detected that the clock signals are not transferred through the differential clock signal lines, the output mask circuit masks an output signal from the logic circuit block so that the output signal is not transmitted to a circuit in the subsequent stage.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: February 16, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Takemi Yonezawa, Kenichi Oe
  • Publication number: 20100008431
    Abstract: A method for a mobile station to provide to a base station feedback of channel state information (CSI) regarding a plurality of communication channels between the mobile station and the base station. The method includes: estimating the CSI by calculating a plurality of channel responses each for one of the communication channels; compressing the estimated CSI; and sending the compressed CSI as the feedback to the base station.
    Type: Application
    Filed: December 18, 2008
    Publication date: January 14, 2010
    Inventors: Wen-Rong Wu, Tzu-Han Hsu, Jen-Yuan Hsu, Pang-An Ting
  • Patent number: 7639744
    Abstract: A codec circuit having a programmable digital bandpass filter is disclosed. According to one aspect, a bandpass filter matches the filter characteristics of the codec circuit to a transmitted pulse code modulation (PCM) signal. The codec circuit includes at least one programmable digital high-pass filter connected in series to at least one programmable digital low-pass filter. The setting filter characteristics for the programmable digital high-pass and low pass filters are each set by means of a signal identification device for identifying a PCM signal transmitted through the codec circuit. The filters are set as a function of the transmitted PCM signal in order to vary a bandpass filter characteristic for the programmable digital bandpass filter.
    Type: Grant
    Filed: June 26, 2000
    Date of Patent: December 29, 2009
    Assignee: Infineon Technologies AG
    Inventor: Manfred Kogler
  • Patent number: 7639757
    Abstract: A pulse modulator has a subtraction stage that produces a control error signal from the difference between a complex input signal and a feedback signal. A signal conversion stage converts the control error signal to a control signal. The control signal is multiplied by a complex mixing signal at the frequency ?0 in a first multiplication stage. At least one of the real and imaginary parts of the up-mixed control signal is then quantized by a quantization stage to produce a real pulsed signal. The pulsed signal is then employed to produce the feedback signal for the subtraction stage in a feedback unit. The pulse modulator according to the invention allows the range of reduced quantization noise to be shifted toward a desired operating frequency ?0.
    Type: Grant
    Filed: May 6, 2004
    Date of Patent: December 29, 2009
    Assignee: LITEF GmbH
    Inventor: Guenter Spahlinger
  • Publication number: 20090274220
    Abstract: A method for transforming data to reduce an amount of data in a communication system equipped with several sub-carriers, and a data transmission method using the same are disclosed. The method for transmitting data using a Discrete Cosine Transform (DCT) in a communication system based on a plurality of sub-carriers includes: a) performing a Discrete Cosine Transform (DCT) on first data; b) selecting a predetermined number of data from among the DCT-processed first data, and performing data processing on the selected data; and c) transmitting the data-processed resultant data to a reception end. A method for reducing an amount of overhead of transmission data for use in the multi-antenna communication system is disclosed.
    Type: Application
    Filed: March 19, 2007
    Publication date: November 5, 2009
    Inventors: Young Woo Yun, Hak Seong Kim, Bong Hoe Kim, Joon Kui Ahn, Dong Youn Seo, Jung Hoon Lee, Ki Jun Kim, Suk Hyon Yoon, Eun Sun Kim, Dae Won Lee
  • Publication number: 20090268824
    Abstract: There is provided an information processing apparatus including an encoding unit that represents input data containing mutually different first and second bit values by a plurality of first amplitude values for the first bit value and a second amplitude value that is different from the first amplitude values for the second bit value, does not take an identical value consecutively, and perform encoding so that polarity of the amplitude value is reversed for each cycle, and a transmission unit that transmits a signal encoded by the encoding unit through a predetermined transmission line.
    Type: Application
    Filed: April 22, 2009
    Publication date: October 29, 2009
    Inventor: Kunio Fukuda
  • Patent number: 7609614
    Abstract: The present invention centers upon uplink communication protocols for use primarily with orthogonal frequency division multiple access (OFDMA) communication systems. Aspects of the invention relate to narrow band frequency division multiplexed (NBFDM) modulation protocols primarily for uplink usage in asymmetric OFDMA communication systems. In particular, NBFDM uplinks that use quadrature multiplexed continuous phase modulation are detailed and noncoherent detection schemes are developed to process the uplink channel signals without the need to transmit uplink phase reference signals. Other aspects of the invention relate to burst mode uplink communications in OFDMA systems such as those involving opportunistic beamforming.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: October 27, 2009
    Assignee: Trellis Phase Communications, LP
    Inventors: John P. Fonseka, Eric Morgan Dowling
  • Publication number: 20090245394
    Abstract: A method for data compressing includes compressing an original data with DPCM, compressing again the compressed data with Huffman's encoding for generating a bit-stream, and storing the bit-stream.
    Type: Application
    Filed: May 27, 2008
    Publication date: October 1, 2009
    Inventors: Pei-Ting Tsai, Wen-Min Lu
  • Patent number: 7558326
    Abstract: A communication system including a transmitter, a receiver, and a TMDS-like link, in which video data and auxiliary data (typically including timing data associated with other auxiliary data) are transmitted from the transmitter to the receiver, or in which video data are transmitted over the link from the transmitter to the receiver, and auxiliary data (typically including timing data associated with other auxiliary data) are transmitted from the receiver to the transmitter. In typical embodiments the auxiliary data include one or more streams of audio data.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: July 7, 2009
    Assignee: Silicon Image, Inc.
    Inventors: James D. Lyle, Gyudong Kim, Min-Kyu Kim, Ken-Sue Tan, Paul Daniel Wolf, William C. Altmann, Russel A. Martin
  • Patent number: 7555061
    Abstract: An optical sender is disclosed that operates in a Differential Quadrature Phase Shift Keying modulation scheme for high speed optical transmission and is capable of performing logical calculations at a low speed. The optical sender transmits a Differential Quadrature Phase Shift Keying (DQPSK) signal generated with modulation signals ?k and ?k so that a signal directly output from a signal receiver corresponding to the optical sender is in agreement with data signals Ik and Qk to be transmitted. The signal receiver is capable of modulation by DQPSK, and the modulation signals ?k and ?k are precoded by using the data signals Ik and Qk and the modulation signals one symbol earlier (?k?1 and ?k?1) . The optical sender includes plural precoders that perform logical calculation simultaneously and in parallel on plural data signals one period after another period.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: June 30, 2009
    Assignee: Fujitsu Limited
    Inventors: Toru Katagiri, Takeshi Hoshida, Tomoo Takahara, Kentaro Nakamura, Naoki Kuwata
  • Patent number: 7472057
    Abstract: One or more methods and systems of detecting or identifying one or more types of algorithms used in the encoding of a voice or speech waveform is presented. The system and method may be used as a testing tool to identify whether a voice data stream is encoded using a linear G.711, ?-law G.711, or A-law G.711 algorithm. The system and method are applied to a voice data stream to ensure that a codec with the appropriate algorithm is used to reproduce an audio waveform.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: December 30, 2008
    Assignee: Broadcom Corporation
    Inventor: Darwin Rambo
  • Patent number: 7453855
    Abstract: The present invention considers a direct sequence spread spectrum system wherein every user employs the same spreading code. In a preferred embodiment, received signal is correlated with the training signal. Peaks of correlator output are used to identify the delays corresponding to the significant multipath components. The delays that are within a predetermined number of chips of each other are associated with a hypothesized user. In an alternate embodiment, a user separation technique is used which is based on the observation that after the training period, different users send uncorrelated data. In another alternate embodiment, linear minimum mean squared error (LMMSE) based correlators locked to individual users are employed. These correlators only provide multipath components of their corresponding users as output.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: November 18, 2008
    Assignee: Meru Networks
    Inventor: Upamanyu Madhow
  • Publication number: 20080279288
    Abstract: An interface comprises a converter configured to track process characteristics across an isolation barrier and modify amplitude of a fast differential edge modulation as a function of speed of an active device on a transmitting side of the isolation barrier, and a differentiator configured to differentiate the fast differential edge modulation on a receiving side of the isolation barrier whereby differentiation bandwidth tracks slope rate of the differential edge modulation.
    Type: Application
    Filed: May 11, 2007
    Publication date: November 13, 2008
    Inventors: Philip John Crawley, Sajol Ghoshal
  • Publication number: 20080198938
    Abstract: A method and apparatus for switching data in communication system which comprises of mainly a conversion circuit to receive the source data possessing in a real coding dimension and covert it to converted the data possessing in a tolerable coding dimension; the judgment bits are set in the converted data to designate the data as source data or not. Later on, shifter circuit is used to shift the converted data in certain amount and generates a shifted data; meanwhile, the right side and left side of shifted data are used to start acquiring the real coding dimension to be used respectively as a first data and a second data. Finally, a comparison and selection circuit is used to compare the corresponding judgment bits in the first and the second data and to output an output data, wherein output data is source data with the above-mentioned amount of shift.
    Type: Application
    Filed: February 21, 2007
    Publication date: August 21, 2008
    Inventors: Chen-Yi Lee, Jr-Hau Lu, Chien-Ching Lin, Hsie-Chia Chang, Yar-Sun Hsu
  • Patent number: 7391813
    Abstract: A digital wireless communications device enabling call distance to be increased while avoiding mute processing as far as possible, even if code error occurs in an ADPCM code. The digital wireless communications device may be configured to include: an error detector for detecting code error in an ADPCM code received via a wireless circuit; an ADPCM decoder for generating a PCM signal by decoding the ADPCM code; and a substitution unit for determining that a click noise is generated if the high-speed scale factor and the low-speed scale factor determined by the ADPCM decoder within a predetermined time period after the error detector has judged that there is a code error in the ADPCM code, and the received ADPCM code itself, respectively exceed prescribed threshold values, and for substituting the ADPCM code with a predetermined prescribed code.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: June 24, 2008
    Assignee: Uniden Corporation
    Inventor: Eiji Shinsho
  • Patent number: 7376555
    Abstract: Coding a signal is provided, wherein a first set of values is provided related to subsequent times in a first time interval of the signal, a second set of values is provided related to subsequent times in a second time interval of the signal, the first time interval having an overlap with the second time interval, the overlap including at least two subsequent times of the second interval, wherein at least one of the values of the second set related to the at least two subsequent times in the overlap is encoded with reference to a value of the first set which is closer in time to the at least one value of the second set than any other value in the second set.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: May 20, 2008
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Erik Gosuinus Petrus Schuijers, Arnoldus Werner Johannes Oomen
  • Publication number: 20080080624
    Abstract: Methods and apparatuses for encoding a plurality of bits into a plurality of pairs of simultaneous electrical pulses.
    Type: Application
    Filed: October 2, 2007
    Publication date: April 3, 2008
    Applicant: INFINEON TECHNOLOGIES AUSTRIA AG
    Inventor: Martin Feldtkeller
  • Patent number: 7336713
    Abstract: A DPCM operation which can reduce the size of differential data and a method and an apparatus for encoding data using the DPCM operation are provided. A method for generating differential data includes generating differential data by performing a DPCM operation on quantized data and generating predicted differential data by performing a predicted DPCM operation on the quantized data, generating circular-quantized differential data and circular-quantized predicted differential data by performing a circular quantization operation on the differential data and the predicted differential data so as to reduce their ranges, and selecting one of the circular-quantized differential data and the circular-quantized predicted differential data depending on their magnitudes.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: February 26, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-oak Woo, Seok-yoon Jung, Euee-seon Jang, Mahn-jin Han, Do-kyoon Kim, Shin-jun Lee, Gyeong-ja Jang