A Hierarchical Modulation and Network Coding-Assisted BICM System for Asymmetric Two Way Relay Channels

Asymmetry in average channel conditions is a challenging factor in two-way relay communication (TWRC) system in order to obtain a balanced performance at two end nodes. In this paper, for a coded TWRC system, we consider hierarchical modulation and network coding assisted bit interleaved coded modulation (HMNC-BICM) based system. The performance of the considered HMNC-BICM based system is compared with the bidirectional network coding assisted traditional bit-interleaved coded modulation (BNC-BICM) based system that uses regular signal constellations and a single interleaver. The presented simulation results show that the HMNC-BICM system not only provides the flexibility of having same reliability at both end nodes but also it has a superior performance in terms of average BER in an asymmetric TWRC system.