SIC aided physical-layer network coding for multi-way relay channels

In this paper, we investigate the physical-layer network coding (PNC) scheme based on successive interference cancellation (SIC) in multi-way relay channels (MWRC). We consider a scenario where all users simultaneously transmit signals to the relay in the up-link stage while the relay broadcasts a coded message in the down-link stage. In order to extract the network codes from superimposed signals and guarantee a low decoding complexity, we propose a novel SIC scheme at the relay node to iteratively estimate the signals from all users. A Max-Min strategy is introduced as an optimal solution to power allocation among users to ensure accurate estimation in the SIC process. In addition, to further improve the system performance, an optimal strategy that decides the coding rule is developed by considering the error probability of the SIC process. Simulation results demonstrate the performance improvement of the proposed SIC aided PNC technique when used in conjunction with the optimal power allocation and coding rule in multi-way relay channels.