Suboptimum weighted-output symbol-by-symbol decoding of block codes

Performance of concatenated coding systems is improved by the use of weighted-output intermediate decodings. However, this use implies a generally prohibitive complexity, especially for long codes. This paper is intended to study a suboptimum symbol-by-symbol weighted-output decoding process of block codes derived from the optimum one. Some variability of the computation effort being allowed, it is shown that the average decoding complexity can be reduced without too much impairing the performance.