Relay Selection for Bi-directional Relay Systems with XOR-Phisical Layer Network Coding

Abstract

XOR-physical layer network coding is known to achieve superior performance in terms of an end-to-end throughput and frequency utilization efficiency. This paper proposes a novel relay selection technique to further improve transmission performance. We introduce a relay selection criteria that is defined as an end-to-end BER performance in the relay network. The proposed technique select a group of relays that maximizes the criteria. This paper applies lattice reduction-aided precoding in order to improve the transmission performance and to reduce computational complexity of the relay selection. The performance of the proposed relay selection is evaluated in a 2 × 2 MIMO bidirectional wireless relay system. The proposed selection attains a gain of about 13dB at the BER of 10 ^-4 .