Patents by Inventor Christopher J. Pladdy

Christopher J. Pladdy 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: 7532688
    Abstract: An impulse response is estimated for a channel by estimating an intermediate impulse response of the channel. The intermediate impulse response comprises at least one multipath spike and one or more non-deterministic noise components at locations throughout the channel Then, a threshold function is applied to the estimated intermediate impulse response across at least a portion of the channel in order to provide an estimated final impulse response of the channel. The threshold function has the effect of nulling the noise components of the channel having values less than the threshold function at the location within the channel of the respective noise component, and the threshold function is characterized by a level that varies across the portion of the channel from a minimum value to a maximum value in a manner determined by the location of the at least one multipath spike within the channel.
    Type: Grant
    Filed: March 23, 2007
    Date of Patent: May 12, 2009
    Assignee: Zenith Electronics LLC
    Inventors: Mark Fimoff, Sreenivasa M. Nerayanuru, Christopher J. Pladdy
  • Patent number: 7289580
    Abstract: An impulse response of a channel is estimated by correlating a received signal with a stored vector. The received signal contains a training sequence having a length Ltr, the stored vector has a length Lsv, Ltr/n=Lsv, and n is greater than two. The signal is received by a device. The vector is determined based on the training sequence and an ideal channel. The ideal channel is an idealized form of a channel through which the device receives the signal. A plurality of correlations may be performed where each correlation provides a substantially noise-free estimate of the impulse response of a different portion of the channel. The correlations are combined to provide an estimate of the impulse response of the channel.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: October 30, 2007
    Assignee: Zenith Electronics Corporation
    Inventors: Christopher J. Pladdy, Mark Fimoff, Sreenivasa M. Nerayanuru, Serdar Ozen, Michael D. Zoltowski
  • Patent number: 7239679
    Abstract: An impulse response is estimated for a channel by estimating an intermediate impulse response of the channel. The intermediate impulse response comprises at least one multipath spike and one or more non-deterministic noise components at locations throughout the channel. Then, a threshold function is applied to the estimated intermediate impulse response across at least a portion of the channel in order to provide an estimated final impulse response of the channel. The threshold function has the effect of nulling the noise components of the channel having values less than the threshold function at the location within the channel of the respective noise component, and the threshold function is characterized by a level that varies across the portion of the channel from a minimum value to a maximum value in a manner determined by the location of the at least one multipath spike within the channel.
    Type: Grant
    Filed: August 26, 2002
    Date of Patent: July 3, 2007
    Assignee: Zenith Electronics Corporation
    Inventors: Mark Fimoff, Sreenivasa M. Nerayanuru, Christopher J. Pladdy
  • Patent number: 7203257
    Abstract: A channel impulse response for a channel is determined by determining an initial channel impulse response estimate based upon a stored training sequence and a received signal, by thresholding the initial channel impulse response estimate, by estimating a noise variance for the channel based upon the stored training sequence, the thresholded initial channel impulse response estimate, and the received signal, by determining an inverse of a covariance matrix based on the estimated noise variance and the thresholded initial channel impulse response estimate, by updating the channel impulse response based on the inverse covariance matrix, the stored training sequence, and the received signal, and by thresholding the updated channel impulse response estimate.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: April 10, 2007
    Assignee: Zenith Electronics Corporation
    Inventors: Mark Fimoff, Sreenivasa M. Nerayanuru, Serdar Ozen, Christopher J. Pladdy, Michael D. Zoltowski
  • Patent number: 7177354
    Abstract: The tap weights of an equalizer are initialized in response to a received relatively short training sequence, and new tap weights for the equalizer are thereafter successively calculated in response to relatively long sequences of received symbols and corresponding sequences of decoded symbols. These new tap weights are successively applied to the equalizer.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: February 13, 2007
    Assignee: Zenith Electronics Corporation
    Inventors: Mark Fimoff, William Hillery, Sreenivasa M. Nerayanuru, Serdar Ozen, Christopher J. Pladdy, Michael D. Zoltowski
  • Publication number: 20040234009
    Abstract: A channel impulse response for a channel is determined by determining an initial channel impulse response estimate based upon a stored training sequence and a received signal, by thresholding the initial channel impulse response estimate, by estimating a noise variance for the channel based upon the stored training sequence, the thresholded initial channel impulse response estimate, and the received signal, by determining an inverse of a covariance matrix based on the estimated noise variance and the thresholded initial channel impulse response estimate, by updating the channel impulse response based on the inverse covariance matrix, the stored training sequence, and the received signal, and by thresholding the updated channel impulse response estimate.
    Type: Application
    Filed: May 23, 2003
    Publication date: November 25, 2004
    Inventors: Mark Fimoff, Sreenivasa M. Nerayanuru, Serdar Ozen, Christopher J. Pladdy, Michael D. Zoltowski
  • Publication number: 20040213341
    Abstract: The tap weights of an equalizer are initialized in response to a received relatively short training sequence, and new tap weights for the equalizer are thereafter successively calculated in response to relatively long sequences of received symbols and corresponding sequences of decoded symbols. These new tap weights are successively applied to the equalizer.
    Type: Application
    Filed: April 22, 2003
    Publication date: October 28, 2004
    Inventors: Mark Fimoff, William Hillery, Sreenivasa M. Nerayanuru, Serdar Ozen, Christopher J. Pladdy, Michael D. Zoltowski
  • Publication number: 20030223517
    Abstract: An impulse response is estimated for a channel by estimating an intermediate impulse response of the channel. The intermediate impulse response comprises at least one multipath spike and one or more non-deterministic noise components at locations throughout the channel. Then, a threshold function is applied to the estimated intermediate impulse response across at least a portion of the channel in order to provide an estimated final impulse response of the channel. The threshold function has the effect of nulling the noise components of the channel having values less than the threshold function at the location within the channel of the respective noise component, and the threshold function is characterized by a level that varies across the portion of the channel from a minimum value to a maximum value in a manner determined by the location of the at least one multipath spike within the channel.
    Type: Application
    Filed: August 26, 2002
    Publication date: December 4, 2003
    Inventors: Mark Fimoff, Sreenivasa M. Nerayanuru, Christopher J. Pladdy
  • Publication number: 20030223514
    Abstract: An impulse response of a channel is estimated by correlating a received signal with a stored vector. The received signal contains a training sequence having a length Ltr, the stored vector has a length Lsv, Ltr/n=Lsv, and n is greater than two. The signal is received by a device. The vector is determined based on the training sequence and an ideal channel. The ideal channel is an idealized form of a channel through which the device receives the signal. A plurality of correlations may be performed where each correlation provides a substantially noise-free estimate of the impulse response of a different portion of the channel. The correlations are combined to provide an estimate of the impulse response of the channel.
    Type: Application
    Filed: October 9, 2002
    Publication date: December 4, 2003
    Inventors: Christopher J. Pladdy, Mark Fimoff, Sreenivasa M. Nerayanuru, Serdar Ozen, Michael D. Zoltowski