Patents by Inventor Richard John Gammack

Richard John Gammack 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).

  • Error detection and correction system for a stream of encoded data
    Patent number: 6154871
    Abstract: The invention provides a decoder of symbols of received data, the data being encoded according to a convolutional encoding scheme and transmitted through a communications channel. The data is punctuated according to a puncturing matrix, and has a plurality of state values which describe a sequence of state transitions. The decoder has a generation unit that accepts the received data for calculating metrics of the transitions thereof. A selector responsive to the generation unit selects a path of transitions corresponding to the path produced by a transmitter of the data stream. A traceback unit maintains historical information representative of sequential decision operations of the selector. A counter is provided for counting illegal state transitions of the path selected by the selector, and a control unit, responsive to the counter, determines a puncture rate and adjusts a puncture phase of the received data.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: November 28, 2000
    Assignee: Discovision Associates
    Inventors: Anthony Peter John Claydon, Richard John Gammack, William Philip Robbins, Charles Dunlop MacFarlane, Thomas Foxcroft, Andrew Peter Kuligowski, Richard James Thomas
  • Error detection and correction system for a stream of encoded data
    Patent number: 5742622
    Abstract: The invention provides a decoder of symbols of received data, the data being encoded according to a convolutional encoding scheme and transmitted through a communications channel. The data is punctuated according to a puncturing matrix, and has a plurality of state values which describe a sequence of state transitions. The decoder has a generation unit that accepts the received data for calculating metrics of the transitions thereof. A selector responsive to the generation unit selects a path of transitions corresponding to the path produced by a transmitter of the data stream. A traceback unit maintains historical information representative of sequential decision operations of the selector. A counter is provided for counting illegal state transitions of the path selected by the selector, and a control unit, responsive to the counter, determines a puncture rate and adjusts a puncture phase of the received data.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: April 21, 1998
    Assignee: Discovision Associates
    Inventors: Anthony Peter John Claydon, Richard John Gammack, William Philip Robbins, Charles Dunlop MacFarlane, Thomas Foxcroft, Andrew Peter Kuligowski, Richard James Thomas