Simplified relay antenna selection with source beamforming for MIMO two-way relaying networks

A simplified relay antenna selection with source beamforming（RAS-BF） scheme is advocated for multiple-input multiple-output（MIMO） two-way relaying networks（TWRNs） employing amplify-and-forward（AF） protocol, which does not require channel estimation at the relay node and the optimal relay antenna can be simply determined by comparing the minimum received pilot signaling powers pertaining to each antenna.The theoretical analysis of system outage probability and average symbol error rate（SER） shows that full diversity order can also be achieved by the simplified scheme. Simulation results are provided to verify our theoretical results and further illustrate that the simplified scheme outperforms the outage-optimal counterpart in the presence of channel state information（CSI） imperfections.