Patent ID: 7376208

Claim:
A decoding method carried out in a receiver configured to accept format information relating to sequences of input data, and to use format information in the attempted decoding of each input sequence, and to issue a positive acknowledgement signal in the event that an input sequence expected in a given timeslot is received and successfully decoded, or to issue a negative acknowledgement signal in the event of failure to decode an expected sequence, or to issue acknowledgement signals of both said types, the method comprising: receiving previous acknowledgement signals issued in response to decoding or attempted decoding of recent expected input sequences; receiving a current format message which pertains to a current input sequence; searching a search set of candidate format indices for an index which best matches the format message according to a matching criterion, and selecting said index; before the searching step, reading the previous acknowledgement signals that were issued in response to the decoding or attempted decoding of the most recent two or more expected input sequences, and when said previous acknowledgement signals satisfy an appropriate condition, determining a level of redundancy of the current input sequence based on the acknowledgment signals of last two or more input sequences, and limiting the search to fewer than all the indices in the candidate set, based on the determined level of redundancy; and decoding the current input sequence using the format information that corresponds to the selected index.