Ser-minimization Relay Selection for Two-way Relay Channels with Physical Layer Network Coding

This paper explores the relay selection scheme for two-way relay channels with physical layer network coding (PNC), where two end nodes exchange information via a selected relay node with the minimal symbol error rate (SER) performance among multiple candidate relay nodes. To reduce the computational complexity, we also propose a suboptimal minimal SER-based relay selection. The end-to-end SER performance of the proposed suboptimal scheme is analyzed. It is proved that full diversity order can be achieved by the suboptimal scheme if the set of candidate relays includes all relay nodes in the system. Extensive simulation results show that the proposed relay selection scheme can considerably improve the SER performance of two-way relay networks with PNC.