Patents by Inventor Guangcai Zhou
Guangcai Zhou 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: 8134512Abstract: Methods, apparatuses and systems for aligning an antenna reflector with satellites in a satellite configuration.Type: GrantFiled: November 12, 2008Date of Patent: March 13, 2012Assignee: The DIRECTV Group, Inc.Inventors: Ernest C. Chen, Gustave R. Stroes, Yang-Yang Shi, Guangcai Zhou
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Patent number: 8023888Abstract: Methods and apparatuses for acquiring and demodulating a data stream transmitted in a communication system. A method in accordance with the present invention comprises finding a boundary of a physical layer frame (PLFrame) in the data stream, finding a first 26 bits of a Unique Word (UW) associated with the data stream, finding a scrambling code utilizing the UW, and using a decoding procedure to determine a modulation type and code rate used for desired signals within the data stream.Type: GrantFiled: March 8, 2010Date of Patent: September 20, 2011Assignee: The DIRECTV Group, Inc.Inventors: Joseph Santoru, Guangcai Zhou, Ernest C. Chen, Dennis Lai, Shamik Maitra
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Patent number: 7961880Abstract: Methods and apparatuses for determining scrambling codes for minimizing co-channel interference in a communication system. A method in accordance with the present invention comprises defining at least one initial default sequence, generating a scrambling code, scrambling a signal using the generated scrambling code, comparing the scrambled signal with all other scrambled signals meeting a specified criterion, and saving the scrambling code word if the comparison determines that the signal scrambled with the scrambling code also meets the specified criterion. The scrambling codes can be compared with each other for cross-correlation purposes to determine whether they meet the specified criterion based on laboratory testing.Type: GrantFiled: August 25, 2006Date of Patent: June 14, 2011Assignee: The DIRECTV Group, Inc.Inventors: Judith Wang, Guangcai Zhou, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Dennis Lai, Tung-Sheng Lin
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Publication number: 20110080517Abstract: Systems and methods for demodulating signals are disclosed. A system in accordance with the present invention comprises a frequency estimator, a tuner, coupled to the frequency estimator, for tuning to a frequency based on an estimate from the frequency estimator, a phase offset estimator for determining an average phase offset, and a demodulator, coupled to the tuner and the phase offset estimator, for demodulating the plurality of symbols, wherein the demodulator corrects a phase offset for a given symbol in the plurality of the symbols based on the average phase offset of symbols prior to the given symbol.Type: ApplicationFiled: October 1, 2009Publication date: April 7, 2011Applicant: The DIRECTV Group, Inc.Inventor: Guangcai Zhou
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Patent number: 7859330Abstract: Systems and methods for characterizing amplifiers. A system for characterizing an amplifier in accordance with the present invention comprises a Gaussian signal source for generating a signal in the frequency domain, a notch filter, coupled to the Gaussian Noise source, wherein the notch filter has a notch at a specified frequency and a frequency bandwidth, the frequency bandwidth encompassing the specified frequency, an Inverse Fast Fourier Transform device, coupled to an output of the notch filter, a normalization device, coupled to the Inverse Fast Fourier Transform device, an amplifier under test, coupled to the normalization device, for amplifying the signal generated by the Gaussian signal source, and a measurement device, coupled to an output of the amplifier, for measuring a power output of the amplifier in the frequency bandwidth and a noise output at the specified notch frequency, and for calculating the ratio between the power output and the noise output.Type: GrantFiled: April 9, 2009Date of Patent: December 28, 2010Assignee: The DIRECTV Group, Inc.Inventors: Guangcai Zhou, Tung-Sheng Lin, Dennis Lai, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Cecilia Comeaux
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Patent number: 7844213Abstract: Systems for delivering a plurality of broadcast programs where the transmitter and receiver roll-off factors are mismatched. A system in accordance with the present invention comprises a transmitter comprising a modulator, and a plurality of receivers, each receiver in the plurality of receivers receiving the plurality of broadcast programs, each receiver in the plurality of receivers further comprising a demodulator; wherein the modulator has a first root-raised cosine filter having a first roll-off factor and each receiver has a second root-raised cosine filter having a second roll-off factor, the first roll-off factor being smaller than the second roll-off factor.Type: GrantFiled: July 31, 2007Date of Patent: November 30, 2010Assignee: The DIRECTV Group, Inc.Inventors: Ernest C. Chen, Joseph Santoru, Shamik Maitra, Dennis Lai, Tung-Sheng Lin, Guangcai Zhou
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Publication number: 20100157881Abstract: Methods and apparatuses for acquiring and demodulating a data stream transmitted in a communication system. A method in accordance with the present invention comprises finding a boundary of a physical layer frame (PLFrame) in the data stream, finding a first 26 bits of a Unique Word (UW) associated with the data stream, finding a scrambling code utilizing the UW, and using a decoding procedure to determine a modulation type and code rate used for desired signals within the data stream.Type: ApplicationFiled: March 8, 2010Publication date: June 24, 2010Applicant: The DIRECTV Group, Inc.Inventors: Joseph Santoru, Guangcai Zhou, Ernest C. Chen, Dennis Lai, Shamik Maitra
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Patent number: 7715786Abstract: Methods and apparatuses for acquiring and demodulating a data stream transmitted in a communication system. A method in accordance with the present invention comprises finding a boundary of a physical layer frame (PLFrame) in the data stream, finding a first 26 bits of a Unique Word (UW) associated with the data stream, finding a scrambling code utilizing the UW, and using a decoding procedure to determine a modulation type and code rate used for desired signals within the data stream.Type: GrantFiled: February 7, 2007Date of Patent: May 11, 2010Assignee: The DIRECTV Group, Inc.Inventors: Joseph Santoru, Guangcai Zhou, Ernest C. Chen, Dennis Lai, Shamik Maitra
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Patent number: 7706466Abstract: A method and apparatus for transmitting and receiving a coded signal having an upper layer signal and a lower layer signal is disclosed. The method comprises the steps of combining the upper layer signal and the lower layer signal, encoding the combined upper layer signal and lower layer signal, delaying the upper layer signal, modulating the delayed upper layer signal, modulating the lower layer signal, transmitting the delayed upper layer signal and transmitting the lower layer signal. The apparatus comprises an encoder, for encoding a combined upper layer signal and lower layer signal, a delay, communicatively coupled to the encoder, for delaying the upper layer signal, a first modulator, for modulating the delayed upper layer signal, a second modulator, for modulating the lower layer signal, a transmitter, communicatively coupled to the first modulator, for transmitting the delayed upper layer signal, and a second transmitter, communicatively coupled to the second modulator.Type: GrantFiled: December 5, 2008Date of Patent: April 27, 2010Assignee: The DIRECTV Group, Inc.Inventors: Ernest C. Chen, Weizheng W. Wang, Guangcai Zhou, Tung-Sheng Lin, Joseph Santoru
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Publication number: 20090224824Abstract: Systems and methods for characterizing amplifiers. A system for characterizing an amplifier in accordance with the present invention comprises a Gaussian signal source for generating a signal in the frequency domain, a notch filter, coupled to the Gaussian Noise source, wherein the notch filter has a notch at a specified frequency and a frequency bandwidth, the frequency bandwidth encompassing the specified frequency, an Inverse Fast Fourier Transform device, coupled to an output of the notch filter, a normalization device, coupled to the Inverse Fast Fourier Transform device, an amplifier under test, coupled to the normalization device, for amplifying the signal generated by the Gaussian signal source, and a measurement device, coupled to an output of the amplifier, for measuring a power output of the amplifier in the frequency bandwidth and a noise output at the specified notch frequency, and for calculating the ratio between the power output and the noise output.Type: ApplicationFiled: April 9, 2009Publication date: September 10, 2009Applicant: The DIRECTV Group, Inc.Inventors: Guangcai Zhou, Tung-Sheng Lin, Dennis Lai, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Cecilia Comeaux
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Patent number: 7551736Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises scrambling a first header of the first signal using a first scrambling code, scrambling a second header of the second signal using a second scrambling code, and transmitting the first signal and the second signal with the scrambled first header and the scrambled second header over different channels of the communication system.Type: GrantFiled: April 11, 2005Date of Patent: June 23, 2009Assignee: The DIRECTV Group, Inc.Inventors: Lin-Nan Lee, Feng-Wen Sun, Adam Von Ancken, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Dennis Lai, Guangcai Zhou, Tung-Sheng Lin
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Patent number: 7535292Abstract: Systems and methods for characterizing amplifiers. A system for characterizing an amplifier in accordance with the present invention comprises a Gaussian signal source for generating a signal in the frequency domain, a notch filter, coupled to the Gaussian Noise source, wherein the notch filter has a notch at a specified frequency and a frequency bandwidth, the frequency bandwidth encompassing the specified frequency, an Inverse Fast Fourier Transform device, coupled to an output of the notch filter, a normalization device, coupled to the Inverse Fast Fourier Transform device, an amplifier under test, coupled to the normalization device, for amplifying the signal generated by the Gaussian signal source, and a measurement device, coupled to an output of the amplifier, for measuring a power output of the amplifier in the frequency bandwidth and a noise output at the specified notch frequency, and for calculating the ratio between the power output and the noise output.Type: GrantFiled: October 11, 2007Date of Patent: May 19, 2009Assignee: The DIRECTV Group, Inc.Inventors: Guangcai Zhou, Tung-Sheng Lin, Dennis Lai, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Cecilia Comeaux
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Publication number: 20090097589Abstract: A method and apparatus for transmitting and receiving a coded signal having an upper layer signal and a lower layer signal is disclosed. The method comprises the steps of combining the upper layer signal and the lower layer signal, encoding the combined upper layer signal and lower layer signal, delaying the upper layer signal, modulating the delayed upper layer signal, modulating the lower layer signal, transmitting the delayed upper layer signal and transmitting the lower layer signal. The apparatus comprises an encoder, for encoding a combined upper layer signal and lower layer signal, a delay, communicatively coupled to the encoder, for delaying the upper layer signal, a first modulator, for modulating the delayed upper layer signal, a second modulator, for modulating the lower layer signal, a transmitter, communicatively coupled to the first modulator, for transmitting the delayed upper layer signal, and a second transmitter, communicatively coupled to the second modulator.Type: ApplicationFiled: December 5, 2008Publication date: April 16, 2009Applicant: THE DIRECTV GROUP, INC.Inventors: ERNEST C. CHEN, Weizheng W. Wang, Guangcai Zhou, Tung-Sheng Lin, Joseph Santoru
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Patent number: 7512189Abstract: A method and apparatus for transmitting and receiving a coded signal having an upper layer signal and a lower layer signal is disclosed. The method comprises the steps of combining the upper layer signal and the lower layer signal, encoding the combined upper layer signal and lower layer signal, delaying the upper layer signal, modulating the delayed upper layer signal, modulating the lower layer signal, transmitting the delayed upper layer signal and transmitting the lower layer signal. The apparatus comprises an encoder, for encoding a combined upper layer signal and lower layer signal, a delay, communicatively coupled to the encoder, for delaying the upper layer signal, a first modulator, for modulating the delayed upper layer signal, a second modulator, for modulating the lower layer signal, a transmitter, communicatively coupled to the first modulator, for transmitting the delayed upper layer signal, and a second transmitter, communicatively coupled to the second modulator.Type: GrantFiled: October 10, 2003Date of Patent: March 31, 2009Assignee: The DIRECTV Group, Inc.Inventors: Ernest C. Chen, Weizheng W. Wang, Guangcai Zhou, Tung-Sheng Lin, Joseph Santoru
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Publication number: 20090068953Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises scrambling a first frame using a first scrambling code, attaching a first header to the first frame to create the first signal, scrambling a second frame using a second scrambling code, attaching a second header to the second frame to create the second signal, and transmitting the first signal and the second signal over different channels of the communication system.Type: ApplicationFiled: October 30, 2008Publication date: March 12, 2009Applicant: The DIRECTV Group, Inc.Inventors: Lin-Nan Lee, Feng-Wen Sun, Adam Von Ancken, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Dennis Lai, Guangcai Zhou, Tung-Sheng Lin
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Publication number: 20090052503Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises shifting a characteristic of the first signal with respect to a like characteristic of the second signal to mitigate co-channel interference, and transmitting the first signal and the second signal over different channels of the communication system.Type: ApplicationFiled: April 14, 2008Publication date: February 26, 2009Applicant: THE DIRECTV GROUP, INC.Inventors: Joseph Santoru, Ernest C. Chen, Shamik Maitra, Dennis Lai, Guangcai Zhou, Tung-Sheng Lin
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Publication number: 20090036086Abstract: Systems for delivering a plurality of broadcast programs where the transmitter and receiver roll-off factors are mismatched. A system in accordance with the present invention comprises a transmitter comprising a modulator, and a plurality of receivers, each receiver in the plurality of receivers receiving the plurality of broadcast programs, each receiver in the plurality of receivers further comprising a demodulator; wherein the modulator has a first root-raised cosine filter having a first roll-off factor and each receiver has a second root-raised cosine filter having a second roll-off factor, the first roll-off factor being smaller than the second roll-off factor.Type: ApplicationFiled: July 31, 2007Publication date: February 5, 2009Applicant: THE DIRECTV GROUP, INC.Inventors: ERNEST C. CHEN, JOSEPH SANTORU, Shamik MAITRA, DENNIS LAI, TUNG-SHENG LIN, GUANGCAI ZHOU
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Patent number: 7469019Abstract: A method and apparatus for optimizing a system for transmitting a layered modulated signal is disclosed. The method comprises the steps of defining the system in terms of a set of system parameters, including an optimal power separation S between a power of a first modulation layer and a power of a second modulation layer and a required system carrier-to-noise ratio (CNRS), determining an optimal power separation S to minimize the error rate of a lower layer modulated signal BERL, and selecting the remaining system parameters in the set of system parameters using the determined optimal power separation S.Type: GrantFiled: January 18, 2007Date of Patent: December 23, 2008Assignee: The DIRECTV Group, Inc.Inventors: Weizheng Wang, Guangcai Zhou, Tung-Sheng Lin, Ernest C. Chen, Joseph Santoru, William C. Lindsey
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Patent number: 7460832Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises scrambling a first frame using a first scrambling code, attaching a first header to the first frame to create the first signal, scrambling a second frame using a second scrambling code, attaching a second header to the second frame to create the second signal, and transmitting the first signal and the second signal over different channels of the communication system.Type: GrantFiled: April 11, 2005Date of Patent: December 2, 2008Assignee: The DIRECTV Group, Inc.Inventors: Lin-Nan Lee, Feng-Wen Sun, Adam Von Ancken, Joseph Santoru, Ernest C. Chen, Shamik Maitra, Dennis Lai, Guangcai Zhou, Tung-Sheng Lin
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Patent number: 7412209Abstract: Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises shifting a characteristic of the first signal with respect to a like characteristic of the second signal to mitigate co-channel interference, and transmitting the first signal and the second signal over different channels of the communication system.Type: GrantFiled: April 11, 2005Date of Patent: August 12, 2008Assignee: The DIRECTV Group, Inc.Inventors: Joseph Santoru, Ernest C. Chen, Shamik Maitra, Dennis Lai, Guangcai Zhou, Tung-Sheng Lin