METHOD AND APPARATUS FOR DECODING BLOCK CODES

A decoding system processes a received vector r to produce a soft symbol information vector output s including a reliability value for each received code symbol. From the reliability values, clusters of symbols within the received vector r having low reliability are identified and detected. Responsive thereto, the received vector r is permuted to scatter the low reliability symbols within each detected low reliability cluster throughout a given codeword. A decoding generator matrix G is also correspondingly permuted is response to the detection of low reliability clusters of symbols. Utilizing a trellis obtained from the permuted decoding generator matrix G', the permuted received vector r' is then sequentially or otherwise suboptimally decoded.