Performance analysis of joint decode-and-forward scheme for two-way relay channels

This paper addresses the performance of the joint decode-and-forward (JDF) strategy for two-way relay systems over Rayleigh fading channels. We show that the JDF enjoys a lower bit error rate (BER) in the first time slot, which translates into higher capacity for broadcast in the second time slot. Specifically, we present the optimal decision rules for JDF and partial decoding-and-forward (PDF) and derive their corresponding BER union bounds for BPSK signals. Furthermore, we propose a novel scheme, termed JDF-JM, to re-encode the messages at the relay node for unmatched data rates from the two sources. The achievable rates of JDF and PDF for the second time slot are then analyzed. Simulation results are provided to illustrate the performance of JDF over DF-XOR under different channel coding and modulation settings.