Detection method and performance analysis for physical network coding in bidirectional relay networks with multiple antennas at relay

In terms of the bidirectional relay networks with relay consisting of multiple antennas, we proposed the PNC detecting method at the relay node, which could generate the Likelihood Ratio (LLR) soft information directly for the XORed bit related to two access users. Following which the upper bound of the bit error performance is provided in a closed form. Simulation results demonstrate that the proposed closed-form expression could properly evaluate the system performance. Furthermore, the novel method could provide superior performance compared with the traditional network coding schemes based on MIMO detection, such as ZF or MMSE, and hereby the improved throughput could be achieved.