Patents by Inventor Xiaoqiang Ma

Xiaoqiang Ma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8363536
    Abstract: A receiver for receiving an orthogonal frequency division multiplexed (OFDM) digital video broadcast (DVB) signal including OFDM symbol sets including data symbols and pilot symbols transmitted using a plurality of sub-carriers, the OFDM DVB signal being transmitted toward the receiver via a transmission channel, the receiver including an input module configured to receive the OFDM DVB signal via the transmission channel, and a channel estimation module coupled to the input module and configured to calculate channel estimates of the transmission channel by performing Fourier transforms on the OFDM symbol sets to produce transformed symbol sets in the frequency domain and by performing minimum mean square error (MMSE) equalization on the transformed symbol sets using a sub-set of the pilot symbols in the OFDM DVB signal.
    Type: Grant
    Filed: August 28, 2006
    Date of Patent: January 29, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Patent number: 8238479
    Abstract: A method for synchronizing a receiver to a received signal begins by down-converting the received signal to a first baseband signal. A coarse frequency offset (CFO) of the first baseband signal is determined and is applied to the down-converting of the received signal to a second baseband signal. A fine frequency offset (FFO) of the second baseband signal is determined. The receiver is synchronized to the received signal using the CFO and the FFO.
    Type: Grant
    Filed: March 13, 2009
    Date of Patent: August 7, 2012
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Gillyoung Jung, Azzedine Touzni, Xiaoqiang Ma
  • Patent number: 8081690
    Abstract: A receiver for receiving an orthogonal frequency division multiplexed (OFDM) digital video broadcast (DVB) signal including OFDM symbol sets including data symbols and pilot symbols transmitted using a plurality of sub-carriers, the OFDM DVB signal being transmitted toward the receiver via a transmission channel, the receiver including an input processor configured to receive the OFDM DVB signal via the transmission channel and to perform a Fourier transform on the OFDM DVB signal to provide a frequency-domain signal, a channel estimation processor coupled to the input processor and configured to calculate final channel estimates, the channel estimation processor being configured to perform time-domain prediction on the frequency-domain signal to provide established sub-carriers that each have corresponding initial channel estimates, and perform minimum mean square error (MMSE) equalization on the frequency-domain signal using the initial channel estimates that correspond to a sub-set of the established sub-c
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: December 20, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20100238358
    Abstract: A method and apparatus are disclosed for determining the presence of adjacent channel interference. Received digital signals are processed to detect the existence of strong channels adjacent to the channel of interest and control signals may be generated based on the detection of strong adjacent channels. The control signals are then used to adjust the signal power of the received signals.
    Type: Application
    Filed: March 20, 2009
    Publication date: September 23, 2010
    Applicant: ADVANCED MICRO DEVICES, INC.
    Inventors: Xiaoqiang Ma, Azzedine Touzni, Jason Adams, David Lewis, Louis Giannini, Feng Huang
  • Publication number: 20100232552
    Abstract: A method for synchronizing a receiver to a received signal begins by down-converting the received signal to a first baseband signal. A coarse frequency offset (CFO) of the first baseband signal is determined and is applied to the down-converting of the received signal to a second baseband signal. A fine frequency offset (FFO) of the second baseband signal is determined. The receiver is synchronized to the received signal using the CFO and the FFO.
    Type: Application
    Filed: March 13, 2009
    Publication date: September 16, 2010
    Applicant: ADVANCED MICRO DEVICES, INC.
    Inventors: Gillyoung Jung, Azzedine Touzni, Xiaoqiang Ma
  • Patent number: 7668269
    Abstract: A method of signal processing according to an embodiment includes estimating a response of a transmission channel during a symbol period. Based on an estimated response of the transmission channel, components of a model of a phase noise process during the symbol period are estimated. Based on the phase noise process model, an estimate of a symbol received during the symbol period is obtained.
    Type: Grant
    Filed: May 9, 2005
    Date of Patent: February 23, 2010
    Assignee: ATI Technologies, Inc.
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20090316053
    Abstract: Pilot processing logic, depending upon which modulation scheme of wireless digital mobile television signals is being received, produces both fractional frequency offset and fractional timing offset for symbols for a respective modulation scheme whether the modulation scheme employs pilot or non-pilot information. As such, in operation, the pilot processing logic will produce both fractional frequency offset and fractional timing offset for symbols from different modulation schemes that employ pilot or non-pilot information so that multiple different modulation schemes of wireless digital mobile television signals can be received by a mobile device, for example, that employs the mobile television demodulating circuit. A dual operation circuit selects the mode of operation, namely the modulation scheme (e.g., T-DMB or DVB-T) of the digital mobile television signal that is being received.
    Type: Application
    Filed: June 18, 2008
    Publication date: December 24, 2009
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Feng Huang, Azzedine Touzni, Xiaoqiang Ma
  • Patent number: 7583755
    Abstract: A method among the embodiments includes calculating a value of a parameter of a nonlinear model of a signal as transmitted into a transmission channel, and applying the calculated value to obtain an estimate of data values carried by the signal. Applications to multicarrier signals are described.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: September 1, 2009
    Assignee: ATI Technologies, Inc.
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20090180558
    Abstract: A receiver for receiving an orthogonal frequency division multiplexed (OFDM) digital video broadcast (DVB) signal including OFDM symbol sets including data symbols and pilot symbols transmitted using a plurality of sub-carriers, the OFDM DVB signal being transmitted toward the receiver via a transmission channel, the receiver including an input processor configured to receive the OFDM DVB signal via the transmission channel and to perform a Fourier transform on the OFDM DVB signal to provide a frequency-domain signal, a channel estimation processor coupled to the input processor and configured to calculate final channel estimates, the channel estimation processor being configured to perform time-domain prediction on the frequency-domain signal to provide established sub-carriers that each have corresponding initial channel estimates, and perform minimum mean square error (MMSE) equalization on the frequency-domain signal using the initial channel estimates that correspond to a sub-set of the established sub-c
    Type: Application
    Filed: January 11, 2008
    Publication date: July 16, 2009
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Patent number: 7558337
    Abstract: A method of signal processing according to one of several embodiments includes estimating a deterministic component of a received signal. The estimating is based on an estimated response of a transmission channel. Based on the estimated deterministic component, a non-deterministic component of the received signal is estimated. Based on corrupted portions of the estimated non-deterministic component, a noise estimate is obtained, and the received signal is compensated based on the noise estimate. A method according to another embodiment includes replacing received samples at corrupted locations with values from a calculated model.
    Type: Grant
    Filed: January 11, 2006
    Date of Patent: July 7, 2009
    Assignee: ATI Technologies, Inc.
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20080049598
    Abstract: A receiver for receiving an orthogonal frequency division multiplexed (OFDM) digital video broadcast (DVB) signal including OFDM symbol sets including data symbols and pilot symbols transmitted using a plurality of sub-carriers, the OFDM DVB signal being transmitted toward the receiver via a transmission channel, the receiver including an input module configured to receive the OFDM DVB signal via the transmission channel, and a channel estimation module coupled to the input module and configured to calculate channel estimates of the transmission channel by performing Fourier transforms on the OFDM symbol sets to produce transformed symbol sets in the frequency domain and by performing minimum mean square error (MMSE) equalization on the transformed symbol sets using a sub-set of the pilot symbols in the OFDM DVB signal.
    Type: Application
    Filed: August 28, 2006
    Publication date: February 28, 2008
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20070098090
    Abstract: A method among the embodiments includes calculating a value of a parameter of a nonlinear model of a signal as transmitted into a transmission channel, and applying the calculated value to obtain an estimate of data values carried by the signal. Applications to multicarrier signals are described.
    Type: Application
    Filed: October 31, 2005
    Publication date: May 3, 2007
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20070036239
    Abstract: A method of signal processing according to one of several embodiments includes estimating a deterministic component of a received signal. The estimating is based on an estimated response of a transmission channel. Based on the estimated deterministic component, a non-deterministic component of the received signal is estimated. Based on corrupted portions of the estimated non-deterministic component, a noise estimate is obtained, and the received signal is compensated based on the noise estimate. A method according to another embodiment includes replacing received samples at corrupted locations with values from a calculated model.
    Type: Application
    Filed: January 11, 2006
    Publication date: February 15, 2007
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Publication number: 20060251198
    Abstract: A method of signal processing according to an embodiment includes estimating a response of a transmission channel during a symbol period. Based on an estimated response of the transmission channel, components of a model of a phase noise process during the symbol period are estimated. Based on the phase noise process model, an estimate of a symbol received during the symbol period is obtained.
    Type: Application
    Filed: May 9, 2005
    Publication date: November 9, 2006
    Inventors: Xiaoqiang Ma, Azzedine Touzni
  • Patent number: 7092436
    Abstract: A system and method detect symbols of a modulated signal received via a plurality of channels of a wireless communications system. A symbol transmitted via the channels is initially estimated based on the channel estimate from either pilot symbol or previously estimated symbol, and then channel estimate is updated. The next estimate of the symbol is computed by using updated channel information and maximizing the expectation of the log likelihood function. The next estimate is then quantized according to the signal constellation. The quantized estimate of the symbol is compared with the previous estimate of the symbol to determine if the previous estimate of the symbol and the quantized next estimate of the symbol have converged. Otherwise, the quantized next estimate of the symbol is made as the input for the next iteration, and the updating, optimizing, quantizing, and comparing are repeated until the estimate converges.
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: August 15, 2006
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Xiaoqiang Ma, Hisashi Kobayashi, Stuart C. Schwartz, Daqing Gu, Jinyun Zhang
  • Publication number: 20030147476
    Abstract: A system and method detect symbols of a modulated signal received via a plurality of channels of a wireless communications system. A symbol transmitted via the channels is initially estimated based on the channel estimate from either pilot symbol or previously estimated symbol, and then channel estimate is updated. The next estimate of the symbol is computed by using updated channel information and maximizing the expectation of the log likelihood function. The next estimate is then quantized according to the signal constellation. The quantized estimate of the symbol is compared with the previous estimate of the symbol to determine if the previous estimate of the symbol and the quantized next estimate of the symbol have converged. Otherwise, the quantized next estimate of the symbol is made as the input for the next iteration, and the updating, optimizing, quantizing, and comparing are repeated until the estimate converges.
    Type: Application
    Filed: January 25, 2002
    Publication date: August 7, 2003
    Inventors: Xiaoqiang Ma, Hisashi Kobayashi, Stuart C. Schwartz, Daqing Gu, Jinyun Zhang