Near-optimal joint antenna selection for amplify-and-forward relay networks

This paper considers a joint antenna selection method in amplify-and-forward (AF) relay networks where the source, relay and destination are all equipped with multiple antennas. Since the exhaustive search for antenna subset selection is computationally prohibitive, a low-complexity near-optimal joint antenna selection algorithm based on a constrained cross entropy optimization (CCEO) method is proposed to maximize the achievable rate. Simulation results reveal both the effectiveness and the efficiency of the proposed algorithm and the significant performance improvement over other benchmark selection techniques. Finally, it is demonstrated that the proposed algorithm can achieve near-optimal results regardless of the number of selected antennas, outage probabilities and the signal-to-noise ratios (SNRs) at the terminals.