Adaptive modulation and coding over network coded multiple access relay channel

In network coded multiple access relay channel (NC-MARC), it is not trivial to deploy adaptive modulation and coding, because the source nodes have two kinds of channel state information fed back from the relay and the destination respectively. So jointly choosing a proper modulation and coding scheme (MCS) for the two sources and the relay becomes a challenge to be solved. In this paper, we investigate the MCS selection for two sources and the relay jointly. The frame error rate and average throughput are analyzed from the system perspective, and then a low-complexity MCS selection scheme is proposed for NC-MARC. The proposed MCS selection scheme is less complicated compared with exhaustive method, so that it has better scalability for practical networks. Simulation results show that the performance of the proposed scheme is better than existed schemes and is very close to that of the optimal exhaustive method.