End-to-end rateless-coded physical layer network coding in two-way relay systems

In this paper, we propose a new physical layer network coding (PNC) scheme based on rateless coding for two-way relay systems which consist of two end nodes and one relay. The two-way relay channel is studied from a new perspective of end-to-end channel equivalence, and a novel end-to-end demodulator is proposed based on the resultant end-to-end equivalent channel. Unlike the conventional demodulator for the point-to-point channel, our proposed demodulator takes into account the potential error brought by the PNC mapping at the relay, thus improves the system reliability and throughput. The theoretical end-to-end achievable rate is further derived, which serves as an upper bound for the proposed demodulation scheme. Simulation results validate the high efficiency of the proposed scheme in terms of BER and system throughput.