New results on soft-decision decoding of block codes

Generalized-minimum-distance (GMD) decoding is a soft-decision decoding algorithm that uses an acceptance criterion and a sequence of attempts at errors-and-ensures decoding in order to find the code work that is closest in generalized distance to the received vector. In the present work the authors develop a new acceptance criterion that gives better performance for GMD decoding that can be obtained with previous criteria. This acceptance criterion will lead to a decoding of many received vectors for which previous criteria will fail to find a code word. For M-ary signaling, the authors generalize the weights used in GMD decoding to permit each of the possible M symbol values to have a different weight