Reduced search soft-decision minimum-distance decoding for binary block codes

A reduced search soft-decision decoding algorithm for binary block codes is presented. It is based on the weight distribution of the code and the transition probabilities of a binary input Q-ary output channel in sequencing the codeword classes during a table look-up operation. An upper bound is presented for the decoding time improvement factor of the reduced search algorithm compared to exhaustive table look-up decoding.