Analysis of a sub-block recovery scheme for decoding a concatenated error control code

In this paper, theoretical analysis is presented for the sub-block recovery scheme that can be integrated into concatenated error control coding schemes used by communication systems employing hybrid-ARQ. Based on this analysis, we show that if the inner code is a turbo code and iterative sub-optimal decoding is used, the sub-block recovery scheme results in improved packet error rate performance. We also show that if the decoder uses the maximum likelihood decoding algorithm, the sub-block recovery scheme does not introduce performance improvement. We confirm our results by simulations of systems with SOVA and log-MAP algorithms.