Performance Analysis of Amplify-and-Forward Best-Relay System Based on SWIPT

In this paper, an amplify-and-forward (AF) best-relay system based on simultaneous wireless information and power transfer (SWIPT) is proposed and analyzed. Its working principle is as follows: the source node sends signals to M relays and the destination. In the M relays, the relay that has the highest harvested energy level is considered as the best one and forwards the received signal to the destination. The maximal ratio combining (MRC) technology was subsequently used to combine the two signals at the destination. A direct link between the source node and the destination was added to the traditional non-direct links. The performance of the system was studied in Rayleigh fading channel. The expression of the system outage probability was derived and simulated using the Monte Carlo method. The simulation results validate the proposed analysis method. It also demonstrates that the performance of the proposed system is significantly improved compared with the traditional non-direct links.