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).
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Patent number: 8363536Abstract: 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: GrantFiled: August 28, 2006Date of Patent: January 29, 2013Assignee: QUALCOMM IncorporatedInventors: Xiaoqiang Ma, Azzedine Touzni
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Patent number: 8238479Abstract: 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: GrantFiled: March 13, 2009Date of Patent: August 7, 2012Assignee: Advanced Micro Devices, Inc.Inventors: Gillyoung Jung, Azzedine Touzni, Xiaoqiang Ma
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Patent number: 8081690Abstract: 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-cType: GrantFiled: January 11, 2008Date of Patent: December 20, 2011Assignee: QUALCOMM IncorporatedInventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20100238358Abstract: 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: ApplicationFiled: March 20, 2009Publication date: September 23, 2010Applicant: ADVANCED MICRO DEVICES, INC.Inventors: Xiaoqiang Ma, Azzedine Touzni, Jason Adams, David Lewis, Louis Giannini, Feng Huang
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Publication number: 20100232552Abstract: 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: ApplicationFiled: March 13, 2009Publication date: September 16, 2010Applicant: ADVANCED MICRO DEVICES, INC.Inventors: Gillyoung Jung, Azzedine Touzni, Xiaoqiang Ma
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Patent number: 7668269Abstract: 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: GrantFiled: May 9, 2005Date of Patent: February 23, 2010Assignee: ATI Technologies, Inc.Inventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20090316053Abstract: 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: ApplicationFiled: June 18, 2008Publication date: December 24, 2009Applicant: Advanced Micro Devices, Inc.Inventors: Feng Huang, Azzedine Touzni, Xiaoqiang Ma
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Patent number: 7583755Abstract: 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: GrantFiled: October 31, 2005Date of Patent: September 1, 2009Assignee: ATI Technologies, Inc.Inventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20090180558Abstract: 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-cType: ApplicationFiled: January 11, 2008Publication date: July 16, 2009Inventors: Xiaoqiang Ma, Azzedine Touzni
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Patent number: 7558337Abstract: 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: GrantFiled: January 11, 2006Date of Patent: July 7, 2009Assignee: ATI Technologies, Inc.Inventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20080049598Abstract: 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: ApplicationFiled: August 28, 2006Publication date: February 28, 2008Inventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20070098090Abstract: 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: ApplicationFiled: October 31, 2005Publication date: May 3, 2007Inventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20070036239Abstract: 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: ApplicationFiled: January 11, 2006Publication date: February 15, 2007Inventors: Xiaoqiang Ma, Azzedine Touzni
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Publication number: 20060251198Abstract: 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: ApplicationFiled: May 9, 2005Publication date: November 9, 2006Inventors: Xiaoqiang Ma, Azzedine Touzni
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Patent number: 7092436Abstract: 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: GrantFiled: January 25, 2002Date of Patent: August 15, 2006Assignee: Mitsubishi Electric Research Laboratories, Inc.Inventors: Xiaoqiang Ma, Hisashi Kobayashi, Stuart C. Schwartz, Daqing Gu, Jinyun Zhang
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Publication number: 20030147476Abstract: 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: ApplicationFiled: January 25, 2002Publication date: August 7, 2003Inventors: Xiaoqiang Ma, Hisashi Kobayashi, Stuart C. Schwartz, Daqing Gu, Jinyun Zhang