Patents by Inventor Phillip F. Chang

Phillip F. Chang 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: 10187397
    Abstract: An apparatus, method, computer readable medium, and system are provided to determine whether a non-linear signal impairment is present in a network communication channel. For instance, a computing device may transmit equalization coefficients to a user device to modify future signals generated by the user device. If the equalization coefficients are unable to reduce a signal impairment, the signal impairment may be a non-linear signal impairment. The computing device may generate symbol placements based on signals received from the user device and transmit status messages.
    Type: Grant
    Filed: February 7, 2017
    Date of Patent: January 22, 2019
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Publication number: 20180198798
    Abstract: An apparatus, method, computer readable medium, and system are provided to determine whether a non-linear signal impairment is present in a network communication channel. For instance, a computing device may transmit equalization coefficients to a user device to modify future signals generated by the user device. If the equalization coefficients are unable to reduce a signal impairment, the signal impairment may be a non-linear signal impairment. The computing device may generate symbol placements based on signals received from the user device and transmit status messages.
    Type: Application
    Filed: February 7, 2017
    Publication date: July 12, 2018
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Patent number: 9602518
    Abstract: An apparatus, method, computer readable medium, and system are provided to generate a symbol placement associated with a transmission scheme by transforming a retrieved set of equalization coefficients. Symbols included in the symbol placement may be analyzed and quantified in terms of their distance from a decision boundary. Symbols may be synthesized on an iterative basis in order to obtain visibility into the underlying performance of the transmission scheme over time. If equalization is unable to reduce a signal impairment below a threshold value within a predetermined amount of time, then a determination may be made that a non-linear distortion source is present in a network or communication system. Signals received from a plurality of user terminals may be compared with one another in order to determine a probable location or cause of the non-linear distortion.
    Type: Grant
    Filed: February 24, 2014
    Date of Patent: March 21, 2017
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Patent number: 9537680
    Abstract: Methods and systems are provided in which a network induces different distortions in signals traversing different segments of the network. The distortions may be used to identify locations on the network of devices that transmit and receive the signals. The distortions may be reflected in equalization coefficients programmed into transmitting or receiving devices, which may be used to pre or post filter the signals to compensate for the distortions.
    Type: Grant
    Filed: January 7, 2015
    Date of Patent: January 3, 2017
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang, Bryan Scott Johnston
  • Patent number: 9438605
    Abstract: An analyzer can obtain data regarding signal characteristics in each of multiple communication channels within an access network. The analyzer can use that data to create signatures corresponding to each of the multiple channels. Based on similarities between signatures, the analyzer may then identify clusters of signatures associated with devices that share channels or portions of channels.
    Type: Grant
    Filed: August 26, 2014
    Date of Patent: September 6, 2016
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Patent number: 9386025
    Abstract: An apparatus, method, computer readable medium, and system are provided to generate a symbol placement associated with a transmission scheme by transforming a retrieved set of equalization coefficients. Symbols included in the symbol placement may be analyzed and quantified in terms of their distance from a decision boundary. Symbols may be synthesized on an iterative basis in order to obtain visibility into the underlying performance of the transmission scheme over time. If equalization is unable to reduce a signal impairment below a threshold value within a predetermined amount of time, then a determination may be made that a non-linear distortion source is present in a network or communication system. Signals received from a plurality of user terminals may be compared with one another in order to determine a probable location or cause of the non-linear distortion.
    Type: Grant
    Filed: February 24, 2014
    Date of Patent: July 5, 2016
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Publication number: 20150256430
    Abstract: Methods and systems are provided in which a network induces different distortions in signals traversing different segments of the network. The distortions may be used to identify locations on the network of devices that transmit and receive the signals. The distortions may be reflected in equalization coefficients programmed into transmitting or receiving devices, which may be used to pre or post filter the signals to compensate for the distortions.
    Type: Application
    Filed: January 7, 2015
    Publication date: September 10, 2015
    Inventors: Lawrence D. Wolcott, Phillip F. Chang, Bryan Scott Johnston
  • Patent number: 8971394
    Abstract: Methods and systems are provided in which a network induces different distortions in signals traversing different segments of the network. The distortions may be used to identify locations on the network of devices that transmit and receive the signals. The distortions may be reflected in equalization coefficients programmed into transmitting or receiving devices, which may be used to pre or post filter the signals to compensate for the distortions.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: March 3, 2015
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang, Bryan Scott Johnston
  • Publication number: 20150046982
    Abstract: An analyzer can obtain data regarding signal characteristics in each of multiple communication channels within an access network. The analyzer can use that data to create signatures corresponding to each of the multiple channels. Based on similarities between signatures, the analyzer may then identify clusters of signatures associated with devices that share channels or portions of channels.
    Type: Application
    Filed: August 26, 2014
    Publication date: February 12, 2015
    Applicant: COMCAST CABLE COMMUNICATIONS, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Patent number: 8856535
    Abstract: An analyzer can obtain data regarding signal characteristics in each of multiple communication channels within an access network. The analyzer can use that data to create signatures corresponding to each of the multiple channels. Based on similarities between signatures, the analyzer may then identify clusters of signatures associated with devices that share channels or portions of channels.
    Type: Grant
    Filed: November 1, 2010
    Date of Patent: October 7, 2014
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Publication number: 20140241409
    Abstract: An apparatus, method, computer readable medium, and system are provided to generate a symbol placement associated with a transmission scheme by transforming a retrieved set of equalization coefficients. Symbols included in the symbol placement may be analyzed and quantified in terms of their distance from a decision boundary. Symbols may be synthesized on an iterative basis in order to obtain visibility into the underlying performance of the transmission scheme over time. If equalization is unable to reduce a signal impairment below a threshold value within a predetermined amount of time, then a determination may be made that a non-linear distortion source is present in a network or communication system. Signals received from a plurality of user terminals may be compared with one another in order to determine a probable location or cause of the non-linear distortion.
    Type: Application
    Filed: February 24, 2014
    Publication date: August 28, 2014
    Applicant: COMCAST CABLE COMMUNICATIONS, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Patent number: 8693530
    Abstract: An apparatus, method, computer readable medium, and system are provided to generate a symbol placement associated with a transmission scheme by transforming a retrieved set of equalization coefficients. Symbols included in the symbol placement may be analyzed and quantified in terms of their distance from a decision boundary. Symbols may be synthesized on an iterative basis in order to obtain visibility into the underlying performance of the transmission scheme over time. If equalization is unable to reduce a signal impairment below a threshold value within a predetermined amount of time, then a determination may be made that a non-linear distortion source is present in a network or communication system. Signals received from a plurality of user terminals may be compared with one another in order to determine a probable location or cause of the non-linear distortion.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: April 8, 2014
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Patent number: 8416697
    Abstract: An apparatus, method, and system are provided for determining a location of an error source. Equalization coefficients may be retrieved and an average period of time between localized peak amplitudes may be determined. The average period of time may be multiplied by a velocity of propagation associated with a communication channel to determine an approximate location of the error source. The equalization coefficients may correspond to the inverse of the frequency response associated with the communication channel and may be updated over time using replacement or combination (e.g., convolution) techniques.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: April 9, 2013
    Assignee: Comcast Cable Communications, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Publication number: 20110243214
    Abstract: Methods and systems are provided in which a network induces different distortions in signals traversing different segments of the network. The distortions may be used to identify locations on the network of devices that transmit and receive the signals. The distortions may be reflected in equalization coefficients programmed into transmitting or receiving devices, which may be used to pre or post filter the signals to compensate for the distortions.
    Type: Application
    Filed: June 8, 2011
    Publication date: October 6, 2011
    Applicant: COMCAST CABLE COMMUNICATIONS, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang, Bryan Scott Johnston
  • Publication number: 20110197071
    Abstract: An analyzer can obtain data regarding signal characteristics in each of multiple communication channels within an access network. The analyzer can use that data to create signatures corresponding to each of the multiple channels. Based on similarities between signatures, the analyzer may then identify clusters of signatures associated with devices that share channels or portions of channels.
    Type: Application
    Filed: November 1, 2010
    Publication date: August 11, 2011
    Applicant: COMCAST CABLE COMMUNICATIONS, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Publication number: 20110194597
    Abstract: An apparatus, method, computer readable medium, and system are provided to generate a symbol placement associated with a transmission scheme by transforming a retrieved set of equalization coefficients. Symbols included in the symbol placement may be analyzed and quantified in terms of their distance from a decision boundary. Symbols may be synthesized on an iterative basis in order to obtain visibility into the underlying performance of the transmission scheme over time. If equalization is unable to reduce a signal impairment below a threshold value within a predetermined amount of time, then a determination may be made that a non-linear distortion source is present in a network or communication system. Signals received from a plurality of user terminals may be compared with one another in order to determine a probable location or cause of the non-linear distortion.
    Type: Application
    Filed: August 2, 2010
    Publication date: August 11, 2011
    Applicant: COMCAST CABLE COMMUNICATIONS, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang
  • Publication number: 20110194418
    Abstract: An apparatus, method, and system are provided for determining a location of an error source. Equalization coefficients may be retrieved and an average period of time between localized peak amplitudes may be determined. The average period of time may be multiplied by a velocity of propagation associated with a communication channel to determine an approximate location of the error source. The equalization coefficients may correspond to the inverse of the frequency response associated with the communication channel and may be updated over time using replacement or combination (e.g., convolution) techniques.
    Type: Application
    Filed: August 2, 2010
    Publication date: August 11, 2011
    Applicant: COMCAST CABLE COMMUNICATIONS, LLC
    Inventors: Lawrence D. Wolcott, Phillip F. Chang