A Weighted-Output Symbol-by-Symbol Decoding Algorithm of Binary Convolutional Codes

A weighted-output symbol-by-symbol soft-decision decoding algorithm for convolutional codes is described. Its main intended use concerns concatenation schemes. If a convolutional code is used as inner code, it makes soft-decision decoding of the outer code possible, which improves the overall error rate. This algorithm relies on Bayesian estimation. Its comparison with Battail algorithm using cross-entropy minimisation shows that the latter is a special case of the former.