Patents by Inventor David S. Farrell

David S. Farrell 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).

  • Publication number: 20240091417
    Abstract: Anti-staining hydration mediums for medical products and packaged medical products containing the same.
    Type: Application
    Filed: October 13, 2020
    Publication date: March 21, 2024
    Inventors: Satwinder S. Panesar, David J. Farrell
  • Patent number: 7450714
    Abstract: A non-linear processor for use in an echo canceller is set forth. The non-linear processor includes a center clipping digital filter receiving an echo compensated signal. The non-linear processor provides a center clipped output signal having non-linear thresholds at values of +TNLP and ?TNLP. The value of TNLP is dynamically dependent, at least in part, on echo return loss measurements. To limit the processor's susceptibility to corruption from double-talk conditions, the non-linear processor inhibits the dynamic setting of the TNLP value when a double-talk condition is present. Additionally, or in the alternative, the non-linear processor locks the value of the echo return loss measurement after a predetermined number of consecutive echo return loss measurements have values falling within a predetermined range of one another. Such locking further reduces the susceptibility of the non-linear processor to corruption from double-talk conditions.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: November 11, 2008
    Assignee: Tellabs Operations, Inc.
    Inventors: David S. Farrell, Tianfang Liu
  • Patent number: 7200222
    Abstract: An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive double-talk detection. The echo canceller circuit comprises a second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call. The adaptive tap coefficients of the second digital filter are updated over the duration of the call using a Least Mean Squares process having an adaptive gain a. A channel condition detector is used to detect channel conditions during the call. The channel condition detector is responsive to detected channel conditions for changing the adaptive gain a during the call. For example, the channel condition detector may detect the presence of a double-talk condition and set the adaptive gain a to zero. Similarly, the channel condition detector may detect the occurrence of a high background noise condition and set the adaptive gain a to a level less than 1 that is dependent on the detected level of the background noise.
    Type: Grant
    Filed: June 23, 2003
    Date of Patent: April 3, 2007
    Assignee: Tellabs Operations, Inc.
    Inventors: Kenneth P. Laberteaux, Richard C. Younce, Bruce E. Dunne, David S. Farrell
  • Patent number: 7020278
    Abstract: A non-linear processor for use in an echo canceller is set forth. The non-linear processor includes a center clipping digital filter receiving an echo compensated signal. The non-linear processor provides a center clipped output signal having non-linear thresholds at values of +TNLP and ?TNLP. The value of TNLP is dynamically dependent, at least in part, on echo return loss measurements. To limit the processor's susceptibility to corruption from double-talk conditions, the non-linear processor inhibits the dynamic setting of the TNLP value when a double-talk condition is present. Additionally, or in the alternative, the non-linear processor locks the value of the echo return loss measurement after a predetermined number of consecutive echo return loss measurements have values falling within a predetermined range of one another. Such locking further reduces the susceptibility of the non-linear processor to corruption from double-talk conditions.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: March 28, 2006
    Assignee: Tellabs Operations, Inc.
    Inventors: David S. Farrell, Tianfang Liu
  • Publication number: 20040086108
    Abstract: An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive double-talk detection. The echo canceller circuit comprises a second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call. The adaptive tap coefficients of the second digital filter are updated over the duration of the call using a Least Mean Squares process having an adaptive gain a. A channel condition detector is used to detect channel conditions during the call. The channel condition detector is responsive to detected channel conditions for changing the adaptive gain a during the call. For example, the channel condition detector may detect the presence of a double-talk condition and set the adaptive gain a to zero. Similarly, the channel condition detector may detect the occurrence of a high background noise condition and set the adaptive gain a to a level less than 1 that is dependent on the detected level of the background noise.
    Type: Application
    Filed: June 23, 2003
    Publication date: May 6, 2004
    Inventors: Kenneth P. Laberteaux, Richard C. Younce, Bruce E. Dunne, David S. Farrell
  • Patent number: 6614907
    Abstract: An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive double-talk detection. The echo canceller circuit comprises a second digital filter having adaptive tap coefficients to stimulate an echo response occurring during the call. The adaptive tap coefficients of the second digital filter are updated over the duration of the call using a Least Mean Squares process having an adaptive gain a. A channel condition detector is used to detect channel conditions during the call. The channel condition detector is responsive to detected channel conditions for changing the adaptive gain a during the call. For example, the channel condition detector may detect the presence of a double-talk condition and set the adaptive gain a to zero. Similarly, the channel condition detector may detect the occurrence of a high background noise condition and set the adaptive gain a to a level less than 1 that is dependent on the detected level of the background noise.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: September 2, 2003
    Assignee: Tellabs Operations, Inc.
    Inventors: Kenneth P. Laberteaux, Richard C. Younce, Bruce E. Dunne, David S. Farrell
  • Publication number: 20030043999
    Abstract: A non-linear processor for use in an echo canceller is set forth. The non-linear processor includes a center clipping digital filter receiving an echo compensated signal. The non-linear processor provides a center clipped output signal having non-linear thresholds at values of +TNLP and −TNLP. The value of TNLP is dynamically dependent, at least in part, on echo return loss measurements. To limit the processor's susceptibility to corruption from double-talk conditions, the non-linear processor inhibits the dynamic setting of the TNLP value when a double-talk condition is present. Additionally, or in the alternative, the non-linear processor locks the value of the echo return loss measurement after a predetermined number of consecutive echo return loss measurements have values falling within a predetermined range of one another. Such locking further reduces the susceptibility of the non-linear processor to corruption from double-talk conditions.
    Type: Application
    Filed: October 15, 2002
    Publication date: March 6, 2003
    Inventors: David S. Farrell, Tianfang Liu
  • Patent number: 6516063
    Abstract: A non-linear processor for use in an echo canceller is set forth. The non-linear processor includes a center clipping digital filter receiving an echo compensated signal. The non-linear processor provides a center clipped output signal having non-linear thresholds at values of +TNLP and −TNLP. The value of TNLP is dynamically dependent, at least in part, on echo return loss measurements. To limit the processor's susceptibility to corruption from double-talk conditions, the non-linear processor inhibits the dynamic setting of the TNLP value when a double-talk condition is present. Additionally, or in the alternative, the non-linear processor locks the value of the echo return loss measurement after a predetermined number of consecutive echo return loss measurements have values falling within a predetermined range of one another. Such locking further reduces the susceptibility of the non-linear processor to corruption from double-talk conditions.
    Type: Grant
    Filed: March 24, 2000
    Date of Patent: February 4, 2003
    Assignee: Tellabs Operations, Inc.
    Inventors: David S. Farrell, Tianfang Liu
  • Patent number: 6198819
    Abstract: A non-linear processor for use in an echo canceller is set forth. The non-linear processor includes a center clipping digital filter receiving an echo compensated signal. The non-linear processor provides a center clipped output signal having non-linear thresholds at values of +TNLP and −TNLP. The value of TNLP is dynamically dependent, at least in part, on echo return loss measurements. To limit the processor's susceptibility to corruption from double-talk conditions, the non-linear processor inhibits the dynamic setting of the TNLP value when a double-talk condition is present. Additionally, or in the alternative, the non-linear processor locks the value of the echo return loss measurement after a predetermined number of consecutive echo return loss measurements have values falling within a predetermined range of one another. Such locking further reduces the susceptibility of the non-linear processor to corruption from double-talk conditions.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: March 6, 2001
    Assignee: Tellabs Operations, Inc.
    Inventors: David S. Farrell, Tianfang Liu
  • Patent number: 6031908
    Abstract: An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive double-talk detection. The echo canceller circuit comprises a second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call. The adaptive tap coefficients of the second digital filter are updated over the duration of the call using a Least Mean Squares process having an adaptive gain a. A channel condition detector is used to detect channel conditions during the call. The channel condition detector is responsive to detected channel conditions for changing the adaptive gain a during the call. For example, the channel condition detector may detect the presence of a double-talk condition and set the adaptive gain a to zero. Similarly, the channel condition detector may detect the occurrence of a high background noise condition and set the adaptive gain a to a level less than 1 that is dependent on the detected level of the background noise.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: February 29, 2000
    Assignee: Tellabs Operations, Inc.
    Inventors: Kenneth P. Laberteaux, Richard C. Younce, Bruce E. Dunne, David S. Farrell