MER: Mixed Error Reduction Approach for Soft-Decision Decoding of Product Block Codes

A Mixed Error Reduction (MER) scheme is presented for soft-decision decoding of binary product block codes. The MER scheme is realized by combining two algorithms having different performance objectives: bit-error-rate (BER) reduction followed by word-error-rate (WER) reduction. BER reduction is achieved by employing soft-in soft-out, possibly iterative, algorithm whose aim here is to improve the residual signal-to-noise ratio with each iteration. For WER reduction a two-step, soft-in hard-out, sub-optimal algorithm for decoding product codes is presented. This decoding algorithm guarantees correct decoding (at least) up to half the minimum Euclidean distance of the product code. The MER scheme exhibits good WER, as well as BER performance, with low computational burden.