Novel Distributed Turbo Coding Scheme in Two-Hop Relay Networks

The distributed turbo coding (DTC) with the combined diversity and coding gain has been proven to be an effective coding strategy to approach the capacity of relay networks. In this paper, a novel DTC scheme is proposed to further improve the diversity and coding gain, which can be applied to two-hop relay networks. At the relay, this scheme first computes the log-likelihood ratios (LLRs) of bits punctured at the source. Then, the relay forwards the hard-decided bits (-1 or 1) with the reliability larger than a threshold to the destination, otherwise it forwards the analog values between-1 and 1. Moreover, by using union bound techniques, we derive the upper bound on the end-to-end bit error rate (BER) of proposed DTC scheme under the quasi-static scenario. Finally, simulation results show the performance improvement of our scheme.