A Selective Physical Layer Network Coding for Wireless Two-Way Relaying

In this paper, we propose a selective physical layer network coding (SPNC) scheme in two-way relay channel (TWRC) for binary phase shift keying (BPSK) modulation over Rayleigh fading channels. Physical layer network coding (PNC) shows average throughput gain over traditional relaying in two-way relay systems, but not in all channel conditions PNC performs better than traditional relaying. The key idea of SPNC is to combine the advantage of PNC and traditional relaying in fading channels to improve throughput of the system. We show that in channel states when PNC fails to correctly detect XORed data from superimposed signal at the relay, it is still possible to detect one of the sources' data to retrieve up to half of the achievable throughput by a so called single node detection (SND) scheme. Also, we analyze error performance and throughput gain of SPNC. Simulation results show that SPNC achieves significant throughput gain over PNC in Rayleigh fading channels.