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