Abstract:To enhance transmission performance of multi-antenna source and multiple single-antenna two-way relay communication systems with decreased signal processing complexity, an optimal relay selection combined with beamforming scheme was proposed. The relay selection was performed by only local channel state information in a distributed way, and the transmitting and receiving beamforming vectors were realized according to two sources by maximum-ratiotransmission (MRT) and maximum-ratio-combining (MRC) rules. Based on the channel statistical property, the outage probability performance of the new scheme was analyzed in Rayleigh fading channels to deduce the closed expression of the system outage probability. The new scheme was simulated to compare with other five schemes. The results show that outage probability of the new transmission scheme is obviously better than those based on the path, sum rate, symbol error ratio, opportunistic single relay selection and equalpower multiple relays transmission. The system outage probability of the new scheme is improved with the increase of relay and antenna number, since the multirelay and multiantenna diversities can be fully utilized.