Patents by Inventor Chun C. Lu

Chun C. Lu 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: 4652703
    Abstract: A digital voice communication apparatus having improved echo suppression includes a transmission gain detection circuit for detecting a near talker signal and a receiver gain detection circuit for detecting a far talker signal. An echo detecting circuit detects which of the near talker and far talker signals has a lesser value and suppresses the gain of the one detected to have the lesser value. A far talker suppressing circuit detects whether the most recent peak gain in this near talker signal is greater than a threshold and is greater than the gain of the far talker signal. If this condition exists the far talker signal is suppressed. A near talker signal suppressing circuit detects whether the most recent gain of the far talker signal is greater than a threshold and is greater than the gain of the near talker signal. If so, the gain of the near talker signal is suppressed.
    Type: Grant
    Filed: March 1, 1983
    Date of Patent: March 24, 1987
    Assignee: Racal Data Communications Inc.
    Inventors: Chun C. Lu, William J. Miller, Jack E. Stephenson, Jay P. Jayapalan
  • Patent number: 4609788
    Abstract: A digital communication apparatus with improved echo suppression includes a circuit for detecting the gain of a far talker signal and a circuit for detecting the gain of a near talker signal. These gains are compared and echo suppression is accomplished by suppressing the lesser of the two gains.
    Type: Grant
    Filed: March 1, 1983
    Date of Patent: September 2, 1986
    Assignee: Racal Data Communications Inc.
    Inventors: William J. Miller, Chun C. Lu