Low-complexity Chase-like bounded-distance decoding algorithms

A soft-decision decoder for an error-correcting block code of Hamming distance d is said to achieve bounded-distance (BD) decoding if its error-correction radius is equal to that of a complete Euclidean distance decoder. The Chase decoding algorithms are reliability-based algorithms achieving BD decoding. The least complex version of the original Chase algorithms ("Chase-3") uses about d/2 trials of a conventional binary decoder. In this paper, we propose two Chase-like decoding algorithms which also achieve BD decoding: a static method requiring about d/6 trials, and a dynamic method requiring only about d/12 trials. Hence, the complexity is reduced by factors of three and six, respectively, compared to the Chase-3 algorithm.