Reliability-based hybrid ARQ for partial-time jamming channels

In this paper, we consider the use of selective-retransmission ARQ protocols to improve communication performance on partial-time jamming channels. The schemes that we propose are based on reliability-based hybrid ARQ (RB-HARQ), in which the set of bits to be retransmitted is adaptively selected based on the estimated a posteriori probabilities at the output of a soft-input soft-output decoder. For channels with partial-time jamming, we can extend our measure of reliability to incorporate not only a posteriori probability information but also estimates of the probability that a bit was jammed. We compare the performance of the proposed scheme with that of a conventional approach in which a predetermined set of bits is retransmitted in response to a packet failure. The results show that RB-HARQ schemes can achieve better performance than the conventional approach.