Performance of hybrid ARQ scheme based on bit-to-symbol mapping

This paper considers coded packet retransmission diversity scheme that reduce the probability of error. The proposed retransmission diversity scheme employs bit-interleaved coded modulation (BICM) and varies the bit-to-symbol mapping among multiple transmissions of the same packet (e.g., ARQ). The obtained mappings for forthcoming transmissions is chosen such that the sum of the magnitudes of the LLR of the bits forming the symbols in different (re)transmissions is maximized. Our performance results show that the proposed scheme performs better (in terms of BER) than a retransmission scheme transmitting same mappings all the time (e.g., Chase combining).