Correcting Or Reducing Quantizing Errors Patents (Class 375/243)
  • Patent number: 8050334
    Abstract: According to the present invention, a shift amount Sj?1 of the previous frame is held in a shift amount buffer of an integer signal coder. At least as many last sample values in the previous frame as the number of an order P used in linear predictive analysis are held in a sample buffer of the integer signal coder. The last P sample values in the previous frame held in the sample buffer of the integer signal coder are corrected in an interframe correction section by Sj-Sj?1 on the basis of the shift amount Sj of the current frame and the shift amount Sj?1 of the previous frame determined by a shift amount determining section.
    Type: Grant
    Filed: July 7, 2006
    Date of Patent: November 1, 2011
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Noboru Harada, Takehiro Moriya
  • 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: 7983346
    Abstract: A method of encoding/decoding a digital signal using linear quantization by sections, and an apparatus for the same are provided. The method of encoding includes: converting a digital input signal, and removing redundant information from the digital signal; allocating a number of bits allocated to each predetermined quantized unit considering the importance of the digital signal; dividing the distribution of signal values into predetermined sections based on the predetermined quantized units, and linear quantizing data converted pin the operation of converting the digital input signal by sections; and generating a bit stream from the linear quantized data and predetermined side information. Therefore, a sound quality is improved compared to a sound quality produced by conventional linear quantizing devices and a complexity of a non-linear quantizing device is reduced.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: July 19, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Junghoe Kim, Dohyung Kim, Shihwa Lee, Sangwook Kim
  • Patent number: 7979271
    Abstract: Methods and devices are used for switching between sound signal coding modes and for producing from a decoded target signal, an overlap-add target signal in a current frame coded according to a first mode. On a coder side, switching is at the junction between a previous frame coded according to a first coding mode and a current frame coded according to a second coding mode, a sound signal is filtered through a weighting filter to produce a weighted signal in the current frame, and a windowed zero-input response of the weighting filter is removed from the weighted signal. On a decoder side, a current frame of the target signal is first windowed, a left portion of a resulting window is skipped, and then a windowed zero-input response of the weighting filter is added to the decoded target signal to reconstruct the overlap-add target signal.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: July 12, 2011
    Assignee: Voiceage Corporation
    Inventor: Bruno Bessette
  • Patent number: 7974333
    Abstract: A semiconductor apparatus includes a signal source 7 that outputs a signal of predetermined frequency, a frequency divider 15 that receives the output signal of the signal source and is capable of switching the output signal to two or more frequency division ratios, a delta-sigma modulator 16 that controls the frequency division ratio of the frequency divider, and a bandpass filter 17 that receives an output of the frequency divider. The frequency of the input signal of the frequency divider is divided by the frequency division ratio controlled by the delta-sigma modulator, and quantization noise appearing in the output of the frequency divider generated by the delta-sigma modulator is attenuated with the bandpass filter. The semiconductor apparatus easily can convert a signal output by a single signal source to a signal of predetermined frequency and supply a plurality of signals of predetermined frequency using a simple configuration with reduced chip size.
    Type: Grant
    Filed: June 27, 2006
    Date of Patent: July 5, 2011
    Assignee: Panasonic Corporation
    Inventor: Masakatsu Maeda
  • Patent number: 7953185
    Abstract: A vehicle communication system has a receiving unit on a vehicle side for inputting a demodulated analog signal to determination units based on a received radio signal from a key unit. Then, one of the two determination units outputs a high-check signal that takes a high value when the analog signal is greater than a high threshold and the other determination unit outputs a low-check signal that takes a low value when the analog signal is smaller than a low threshold. Then, a sync. signal generator successively defines a determination period based on the high and low check signals. Then, a binary level of the analog signal is determined by a level determination unit based on the check signals, along with an estimation and a correction of an indefinite signal when the signal level cannot be determined based on a coding rule and the determination by the determination units.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: May 31, 2011
    Assignee: Denso Corporation
    Inventor: Masahiro Sugiura
  • Patent number: 7948423
    Abstract: A system, apparatus and method for continuous synchronization of multiple ADC circuits is described. The ADC circuits can be arranged in a master-slave configuration within the system so that the converter clock is subdivided into slower speeds for the data output clock or for the control of de-multiplexing the outputs onto a wider bus, while maintaining ADC-to-ADC synchronization resilient to perturbations from noise and other upset sources. The configuration of the ADCs in the master-slave configuration can be varied according to overall system requirements in any one of a sequential configuration, a parallel configuration or a tree type of configuration, as well as others. Digital and/or analog timing adjustments can be made to each of the ADC circuits. The master clocking signals can be generated by a master clock generator circuit, which is either internally implemented in an ADC circuit, or externally implemented as a separate master clock generator circuit.
    Type: Grant
    Filed: April 15, 2010
    Date of Patent: May 24, 2011
    Assignee: National Semiconductor Corporation
    Inventors: Robert Callaghan Taft, Heinz Werker, Pier Francese, David Brian Barkin
  • Patent number: 7933769
    Abstract: In a method and device for low-frequency emphasis, where the spectrum of a sound signal is transformed in a frequency domain and comprises transform coefficients grouped in a number of blocks, a maximum energy for one block having a position index is calculated. Also, a factor having a position index smaller than the position index of the block with maximum energy is calculated for each block. For each block, an energy of the block is calculated, the factor is computed from the calculated maximum energy and the computed energy of the block, and a gain is determined from the factor and applied to the transform coefficients of the block.
    Type: Grant
    Filed: February 15, 2007
    Date of Patent: April 26, 2011
    Assignee: Voiceage Corporation
    Inventor: Bruno Bessette
  • Patent number: 7933317
    Abstract: A telecommunications transmitting device, including: an encoder configured to generate an initial signal formed by at least one reference sequence including an initial integer number of pulses dispatched over a same integer number of time windows; a transmitter configured to transmit the initial signal to a receiver; a demodulation device configured to determine that no acknowledgement from the receiver in response to the initial signal is received; and a processing unit configured to tune a second integer number of pulses constituting a second reference sequence, the second integer number being larger than the initial integer number, wherein the transmitter is configured to transmit a second signal formed by the second reference sequence including the second integer number of pulses dispatched over a same integer number of time windows.
    Type: Grant
    Filed: March 3, 2006
    Date of Patent: April 26, 2011
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Gwillerm Froc
  • 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: 7884744
    Abstract: Circuit arrangement, LIN comprising such circuit arrangement as well as method for processing input signals of the LIN In order to further develop a circuit arrangement (100)—for processing at least one input signal (12) from at least one data bus (10) of at least one LIN and—for providing the data bus (10) with at least one output signal (18), as well as a corresponding operating method in such way that EMI performance and/or EMI performance of the LIN (300) is improved, it is proposed to provide—at least one analog-digital converting circuit (ADC) for converting the analog input signal (12) into at least one digital signal (14) to be processed, and—at least one digital-analog converting circuit (DAC) for converting the processed digital signal (16) into the analog output signal (18).
    Type: Grant
    Filed: August 22, 2007
    Date of Patent: February 8, 2011
    Assignee: NXP B.V.
    Inventors: Clemens Gerhardus De Haas, Inesz Marycka Weijland, Gerrit Jan Bollen, Edwin Schapendonk
  • Patent number: 7880647
    Abstract: A Huffman decoding method for decoding codewords included in an encoded data transmitted via a stream includes: processing codewords of a codebook that is predefined or extracted from the stream to derive at least an auxiliary lookup table, and storing each derived auxiliary lookup table in a storage device; and searching a decoded value corresponding to a target codeword included in the encoded data according to at least the auxiliary lookup table stored in the storage device and the codebook.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: February 1, 2011
    Assignees: Silicon Motion Inc., Silicon Motion Inc.
    Inventor: Yiyuan Sun
  • Patent number: 7864868
    Abstract: An efficient method and system for detecting frame slip in an inband signalling block in pulse code modulation. The effect of frame slip on the inband signalling block is that the bits following the frame slip are transferred from the signalling block into an adjacent block. The octet slip is detected by searching an error bit in a signalling block by comparing it to a sample block. If an error bit is found, an error count for the adjacent block starting from the error bit is calculated. If the error count is more than one, a second error bit of the signalling block is searched (26) and bits of the adjacent block after second error bit are verified (27). If bits of the adjacent block after the second error bit are not correct, the octet slip cannot be assumed (29). Otherwise the octet slip can be assumed by analyzing error count and error bits.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: January 4, 2011
    Assignee: Nokia Siemens Networks Oy
    Inventor: Juha Sarmavuori
  • 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
  • Publication number: 20100239027
    Abstract: A method of encoding/decoding a digital signal using linear quantization by sections, and an apparatus for the same are provided. The method of encoding includes: converting a digital input signal, and removing redundant information from the digital signal; allocating a number of bits allocated to each predetermined quantized unit considering the importance of the digital signal; dividing the distribution of signal values into predetermined sections based on the predetermined quantized units, and linear quantizing data converted pin the operation of converting the digital input signal by sections; and generating a bit stream from the linear quantized data and predetermined side information. Therefore, a sound quality is improved compared to a sound quality produced by conventional linear quantizing devices and a complexity of a non-linear quantizing device is reduced.
    Type: Application
    Filed: June 2, 2010
    Publication date: September 23, 2010
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Junghoe KIM, Dohyung Kim, Shihwa Lee, Sangwook Kim
  • Patent number: 7801020
    Abstract: A mobile channel estimation algorithm is disclosed, for use in a DVB-H coded OFDM demodulator. The mobile channel estimation algorithm estimates the mobile channel transfer function, overcoming many of the delay spread limitations without using time filtering and without having to collect many OFDM symbols. Once the channel estimate has been found for each symbol, equalization and inter-carrier-interference cancellation may be carried out relatively easily using known methods. The mobile channel estimation algorithm may be used in DVB-H as well as in other areas of OFDM.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: September 21, 2010
    Assignee: Intel Corporation
    Inventors: Parveen K. Shukla, Thushara Hewavithana, Bernard Arambepola
  • Patent number: 7787543
    Abstract: A pulse pattern generator (11) has a pulse generating unit (12) and a lowpass filter (14), and the pulse generating unit (12) includes an amplitude-value setting unit (13, 13a). The pulse generating unit (12) generates a pulse signal formed in a step-like wave in which at least one of rise and fall of a signal is changed in a step-like manner. The lowpass filter (14) smoothes the pulse signal generated by the pulse generating unit (11), and outputs a smoothed pulse signal. The amplitude-value setting unit (13, 13a) adjusts an amplitude value of a step-like wave that forms the pulse signal in order to set a shape of an eye waveform based on a setting value when an eye pattern of the output from the lowpass filter (14) is formed. The pulse pattern generator (11) can output the pulse signal having a desired pulse pattern having the predetermined eye closure from the lowpass filter (14).
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: August 31, 2010
    Assignee: Anritsu Corporation
    Inventor: Kazuhiko Yamaguchi
  • Patent number: 7769099
    Abstract: The invention relates to techniques for implementing high-speed precoders, such as Tomlinson-Harashima (TH) precoders. In one aspect of the invention, look-ahead techniques are utilized to pipeline a TH precoder, resulting in a high-speed TH precoder. These techniques may be applied to pipeline various types of TH precoders, such as Finite Impulse Response (FIR) precoders and Infinite Impulse Response (IIR) precoders. In another aspect of the invention, parallel processing multiple non-pipelined TH precoders results in a high-speed parallel TH precoder design. Utilization of high-speed TH precoders may enable network providers to for example, operate 10 Gigabit Ethernet with copper cable rather than fiber optic cable.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: August 3, 2010
    Assignee: Leanics Corporation
    Inventors: Keshab K. Parhi, Yongru Gu
  • Patent number: 7746764
    Abstract: The present invention provides an approach for quadrature signal generation, which does not require orthogonal reference signals or nearly orthogonal reference signals as an input or given condition. The techniques provided herein can utilize a reference phase shift less than 90° but greater than 0°, along with an inversion to create orthogonal signals. The techniques provided here reduce the number of critical manipulations required from a hardware perspective.
    Type: Grant
    Filed: October 21, 2005
    Date of Patent: June 29, 2010
    Assignee: ParkerVision, Inc.
    Inventors: Gregory S. Rawlins, David Sorrells, Greg Milne, Mike Rawlins
  • Patent number: 7734465
    Abstract: Techniques and tools related to coding and decoding of audio information are described. For example, redundant coded information for decoding a current frame includes signal history information associated with only a portion of a previous frame. As another example, redundant coded information for decoding a coded unit includes parameters for a codebook stage to be used in decoding the current coded unit only if the previous coded unit is not available. As yet another example, coded audio units each include a field indicating whether the coded unit includes main encoded information representing a segment of an audio signal, and whether the coded unit includes redundant coded information for use in decoding main encoded information.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: June 8, 2010
    Assignee: Microsoft Corporation
    Inventors: Tian Wang, Kazuhito Koishida, Hosam A. Khalil, Xiaoqin Sun, Wei-Ge Chen
  • Patent number: 7728753
    Abstract: A system, apparatus and method for continuous synchronization of multiple ADC circuits is described. The ADC circuits can be arranged in a master-slave configuration within the system so that the converter clock is subdivided into slower speeds for the data output clock or for the control of de-multiplexing the outputs onto a wider bus, while maintaining ADC-to-ADC synchronization resilient to perturbations from noise and other upset sources. The configuration of the ADCs in the master-slave configuration can be varied according to overall system requirements in any one of a sequential configuration, a parallel configuration or a tree type of configuration, as well as others. Digital and/or analog timing adjustments can be made to each of the ADC circuits. The master clocking signals can be generated by a master clock generator circuit, which is either internally implemented in an ADC circuit, or externally implemented as a separate master clock generator circuit.
    Type: Grant
    Filed: October 13, 2008
    Date of Patent: June 1, 2010
    Assignee: National Semiconductor Corporation
    Inventors: Robert Callaghan Taft, Heinz Werker, Pier Francese, David Barkin
  • 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: 7684496
    Abstract: Methods and systems for transmitting a discrete information over a communication path comprising analogue communication lines and a pulse-code modulation (PCM) channel are considered, which methods and systems allow to increase the data transfer rate over the entire path up to the data transfer rate in the PCM channel irrespective of the quality of analogue communication lines really employed. In this case, the spectrum of signal being transmitted over the analogue communication line is selected such that the information transfer rate over this analogue communication line is equal to the information transfer rate over the PCM channel, and the number of quantization levels for samples being transmitted over the analogue communication line is the least possible for this analogue communication line.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: March 23, 2010
    Inventors: Igor Borisovich Dounaev, Leonid Alexeevich Letounov
  • Patent number: 7664203
    Abstract: Methods and systems for processing a single sub-channel that includes two or more combined channels. Using intermediate frequency sub-sampling, two or more channels from a broad band signal are combined into a single sub-channel for further analog and digital processing. Each of the two or more channels is down converted to an intermediate frequency, filtered to remove certain undesired channels, and combined such that the two or more channels are adjacent to each other. A digital representation of the sub-channel is produced from the combined intermediate frequency channels. Each channel within the digital representation is down converted to baseband, and the in-phase and quadrature components are separated from each other. Compared to one direct down conversion technique, intermediate frequency sub-sampling as described in the application may reduce the number of analog to digital converters and control amplifiers used in analog processing by a factor of four.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: February 16, 2010
    Assignee: Microsoft Corporation
    Inventors: Dan Q. Tu, Louis F. Coffin, III
  • Patent number: 7653127
    Abstract: Bit-Edge Zero Forcing Equalizer. A novel solution is presented by which a BE-ZFE (Bit-Edge Zero Forcing Equalizer) is employed to drive an error term within a data signal to an essentially zero value. This new BE-ZFE looks at values of data that occur at the bit edges of a data signal and drives the associated error term to zero. The new BE-ZFE is appropriately implemented within communication systems that are phase (or jitter) noise limited. Some examples of such communication systems include high-speed serial links one type of which serviced using a SERDES (Serializer/De-serializer) where data that is originally in a parallel format is serialized into a serial data stream and then subsequently de-serialized back into a parallel data stream.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: January 26, 2010
    Assignee: XILINX, Inc.
    Inventors: Brian T. Brunn, Stephen D. Anderson
  • 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
  • Patent number: 7636051
    Abstract: A statistical value update unit calculates the fluctuation of measurement data. A filtering processing unit extracts a normal white noise component from the fluctuation of the measurement data using an adaptive lattice filter. A statistical test unit determines whether or not the variance of the normal white noise component is out of a predetermined scope in reference distribution. A change decision unit detects a stationary change of the status of a target system based on a detection ratio of an outlier.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: December 22, 2009
    Assignee: Fujitsu Limited
    Inventors: Satoshi Imai, Akiko Yamada, Hitoshi Yamada, Hitoshi Ueno, Koji Nakamichi, Akira Chugo
  • Patent number: 7627469
    Abstract: Any disagreement of the power level before encoding an audio signal and the power level after encoding the audio signal is adjusted to improve the sound quality to the auditory sense.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: December 1, 2009
    Assignee: Sony Corporation
    Inventors: Benjamin Frederic Nettre, Keisuke Toyama, Shiro Suzuki
  • Publication number: 20090238287
    Abstract: A method of determining a variable quantization step size is disclosed. In the method of determining a variable quantization step size, a channel characteristic parameter is obtained in order to calculate a quantization step size (?) used in channel decoding. The quantization step size (?) is variably determined based on the channel characteristic parameter. Therefore, the method of determining a variable quantization step size may improve channel decoding.
    Type: Application
    Filed: May 17, 2007
    Publication date: September 24, 2009
    Inventor: Keun-Moo Lee
  • Patent number: 7580832
    Abstract: An apparatus for producing a fingerprint signal from an audio signal includes a means for calculating energy values for frequency bands of segments of the audio signal which are successive in time, so as to obtain, from the audio signal, a sequence of vectors of energy values, a means for scaling the energy values to obtain a sequence of scaled vectors, and a means for temporal filtering of the sequence of scaled vectors to obtain a filtered sequence which represents the fingerprint, or from which the fingerprint may be derived. Thus, a fingerprint is produced which is robust against disturbances due to problems associated with coding or with transmission channels, and which is especially suited for mobile radio applications.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: August 25, 2009
    Assignee: M2ANY GmbH
    Inventors: Eric Allamanche, Juergen Herre, Oliver Hellmuth, Thorsten Kastner, Markus Cremer
  • Patent number: 7532671
    Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.
    Type: Grant
    Filed: June 9, 2008
    Date of Patent: May 12, 2009
    Assignee: InterDigital Technology Corporation
    Inventors: Leonid Kazakevich, Rui Yang
  • Patent number: 7499509
    Abstract: An apparatus for compensating nonlinearly distorted multicarrier signals, a multicarrier signal receiver using the same, and a method therefor are provided, where the apparatus for compensating multicarrier signals and the multicarrier signal receiver using the apparatus extract parameter information on the HPA mode from the received signal so that nonlinear distortion of the received multicarrier signal is compensated for even though an accurate transfer function of a high power amplifier (HPA) is not known and side information or a special training signal is not transmitted when a signal is transmitted, such that nonlinearly distorted multicarrier signals such as OFDM signals transmitted by an HPA having a variety of transfer functions can be adaptively compensated and therefore a demodulated signal with an improved symbol error rate (SER) can be obtained.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: March 3, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sergey Zhidkov
  • Publication number: 20080240259
    Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.
    Type: Application
    Filed: June 9, 2008
    Publication date: October 2, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Leonid Kazakevich, Rui Yang
  • Patent number: 7406157
    Abstract: Embodiments of the invention provide methods for determining the characteristics of a local loop using the multi-carrier tones of a DSL activation process. For one embodiment, one or more sets of downstream multi-carrier tones of a digital subscriber line activation process are received at an extended voice-band modem and are capable of transmitting upstream multi-carrier tones of the digital subscriber line activation process over a local loop. The downstream carrier tones and the upstream carrier tones are folded into a first multi-tone signal and a second multi-tone signal, respectively, each having a plurality of component signals within the spectrum band of the extended voice-based modem. The total signal power of the first multi-tone signal is divided by the power of one of the plurality of component signals of the second multi-tone signal to determine a ratio value. The ratio value is used to determine a characteristic of the local loop.
    Type: Grant
    Filed: September 3, 2003
    Date of Patent: July 29, 2008
    Assignee: Intel Corporation
    Inventors: Sigang Qiu, Prashant Pratap Tawade, Vedavalli G. Krishnan, Wesley H. Smith, Mandayam Krishnan
  • 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: 7391814
    Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.
    Type: Grant
    Filed: May 3, 2007
    Date of Patent: June 24, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Leonid Kazakevich, Rui Yang
  • Publication number: 20080137758
    Abstract: A method and apparatus is disclosed herein for decoding data (e.g., video data) using transforms. In one embodiment, the decoding process comprises scaling a block of coefficients using a scaling factor determined for each coefficient by computing an index for said each coefficient and indexing a look-up table (LUT) using the index. The index is based on a quantization parameter, a size of the block of coefficients, and a position of said each coefficient within the block. The method also comprises applying a transform to the block of scaled coefficients.
    Type: Application
    Filed: February 15, 2008
    Publication date: June 12, 2008
    Inventor: Frank Jan Bossen
  • Publication number: 20080137757
    Abstract: A method and apparatus is disclosed herein for decoding data (e.g., video data) using transforms. In one embodiment, the decoding process comprises scaling a block of coefficients using a scaling factor determined for each coefficient by computing an index for said each coefficient and indexing a look-up table (LUT) using the index. The index is based on a quantization parameter, a size of the block of coefficients, and a position of said each coefficient within the block. The method also comprises applying a transform to the block of scaled coefficients.
    Type: Application
    Filed: February 15, 2008
    Publication date: June 12, 2008
    Inventor: Frank Jan Bossen
  • Patent number: 7376189
    Abstract: The subject invention provides a remote control signal reception circuit that carries out quantization of an input data signal 101 by sampling the signal with a first sampling frequency that is higher than a frequency of said input data signal, and stores a result of the quantization 105 in storing means; and then, the result of the quantization 105 stored in said storing means is corrected according to each result, and is outputted as quantization data 106. In this way, the present invention provides an infrared light reception unit that achieves highly-faithful reproduction of the original waveform, allowing multi-stages transmission in a simple manner.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: May 20, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hiroshi Tanaka
  • Patent number: 7346113
    Abstract: A system and method are provided for stopping a quantized signal from a noise-shaper with a significantly reduced inband transient, compared to a traditional random stop of a noise-shaped signal. The noise-shaped signal is stopped at a favorable time controlled by a detector that monitors the noise-shaped signal. The detector indicates the occurrence of a good time to stop the noise-shaper such that the transient due to the stop is minimized in a fashion that substantially reduces the inband disturbance.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: March 18, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Thomas H. Hansen, Lars Risbo
  • Patent number: 7330555
    Abstract: An L-channel signal and an R-channel signal are input into a subtractor in which the difference between the L-channel signal and the R-channel signal is determined. The resulting signal is input into first and second multipliers. In the first multiplier, a mixed output signal is generated by using the channel mixture ratio calculated in a previous frame. In the second multiplier, a mixed output signal is generated by using the channel mixture ratio calculated in a current frame. The mixed output signals from the first and second multipliers respectively undergo spectrum transform in first and second spectrum transformers, and quantized in first and second quantizers. A comparator compares a quantization error in the first quantizer with that in the second quantizer. If the quantization error in the second quantizer is greater than that in the first quantizer by a predetermined factor, the comparator controls a switch to select the output of the first quantizer.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: February 12, 2008
    Assignee: Sony Corporation
    Inventor: Shiro Suzuki
  • Patent number: 7324598
    Abstract: An apparatus includes a quantizer to generate a quantized signal from an input signal and a function unit may be included to generate an output signal by applying a predetermined function to the quantized signal. The apparatus further may include a correction unit to compensate for distortion in the output signal.
    Type: Grant
    Filed: July 15, 2002
    Date of Patent: January 29, 2008
    Assignee: Intel Corporation
    Inventors: Yoni Perets, Kobby Pick
  • Publication number: 20080008253
    Abstract: A vehicle communication system has a receiving unit on a vehicle side for inputting a demodulated analog signal to determination units based on a received radio signal from a key unit. Then, one of the two determination units outputs a high-check signal that takes a high value when the analog signal is greater than a high threshold and the other determination unit outputs a low-check signal that takes a low value when the analog signal is smaller than a low threshold. Then, a sync. signal generator successively defines a determination period based on the high and low check signals. Then, a binary level of the analog signal is determined by a level determination unit based on the check signals, along with an estimation and a correction of an indefinite signal when the signal level cannot be determined based on a coding rule and the determination by the determination units.
    Type: Application
    Filed: May 29, 2007
    Publication date: January 10, 2008
    Applicant: Denso Corporation
    Inventor: Masahiro Sugiura
  • Patent number: 7315264
    Abstract: Systems and methods implemented in a multi-bit digital noise shaper for reducing or eliminating undesirable transient response when the noise shaper exits a clipping state. In one embodiment, the noise shaper includes a quantizer, a filter, and a filter control unit that detects clipping in the quantizer and dynamically adjusts the allowable range of the internal state values of the filter. In one embodiment, a clipping mechanism is provided for each state value within the filter to clip the state value if it exceeds a corresponding clipping level. The clipping level for each state value is lower when the quantizer is clipping, and higher when the quantizer is not clipping. The clipping level for each state value may be transitioned either immediately or gradually from a current level to a target level (which is lower when the quantizer is clipping, and higher when the quantizer is not clipping.
    Type: Grant
    Filed: January 17, 2006
    Date of Patent: January 1, 2008
    Assignee: D2Audio Corporation
    Inventor: Jack B. Andersen
  • Patent number: 7292902
    Abstract: Methods for splicing PCM audio frames form modified frames by appending to each frame either a portion of the next preceding frame or the next following frame. According to a first approach, splices are obtained by fading up and fading down a frame end and a frame appendage only at a splice point, and overlapping and combining to provide a crossfade at the splice. Alternatively, every frame end and frame appendage is faded up and faded down, overlapped and combined. A subtractive method of providing complementary fade-up and fade-down reduces rounding errors.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: November 6, 2007
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Michael J. Smithers, Kenneth James Gundry
  • Patent number: 7281176
    Abstract: In one embodiment, a method may determine a number of data transitions occurring in a forbidden zone at each of a first and second slice levels and adjust a slice level offset for an amplifier based on the number of data transitions at the first and second slice levels. Furthermore, a phase window of the forbidden zone may be adjusted to attain a desired bit error rate for a receiver.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: October 9, 2007
    Assignee: Silicon Laboratories Inc.
    Inventor: Adam B. Eldredge
  • Patent number: 7266152
    Abstract: A device for performing predetermined processing on an input signal that may have a signal amplitude of more than one bit. The input signal is obtained by subjecting one-bit serial signals to predetermined signal processing, wherein the signal amplitude of more than one bit is converted to a one-bit serial signal by accumulating the signal amplitudes that exceed one bit, delaying the accumulated signal on the basis of the input signal, and outputting the accumulated signal.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: September 4, 2007
    Assignee: Sony Corporation
    Inventors: Masayoshi Noguchi, Gen Ichimura, Nobukazu Suzuki
  • Patent number: 7233624
    Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: June 19, 2007
    Assignee: InterDigital Technology Corporation
    Inventors: Leonid Kazakevich, Rui Yang
  • Patent number: 7227910
    Abstract: In up-to date communication devices an intermediate frequency signal is generated at first in a digital way and than is converted to an analogue signal by a digital-to-analogue converter (10). In order to offer a greater flexibility in choosing a particular digital-to-analogue converter (10) the invention proposes to use sigma-delta modulators (8), the output bit width (n) of which is arranged to be configurable. The advantage of providing sigma-delta modulators with a configurable output bit width is that by this the output bit width of the interpolation filters can be easily adapted to the input bit width of a chosen digital-to-analogue converter without the need to change the internal design of a baseband processing circuit.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: June 5, 2007
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Dietmar Lipka