Improving network performance by using multiple power-constrained amplify-and-forward relays

In this paper, the performance of radio frequency energy harvesting system with multiple power-constrained relays over Rician/Rayleigh fading channels is studied. This considered system consists of one power and information source, multiple power-constrained relays and one destination. In order to exploit the diversity advantage of cooperative network with low computational complexity, the relays apply the amplify-and-forward (AF) scheme to forward the received signal and the destination uses the selection combining (SC) scheme to receive the information. We derive the exact closed-form expressions of outage probability, throughput and average symbol error probability by using statistical characteristics of signal-to-noise ratio (SNR). Moreover, in order to understand the behavior of this system, we investigate the performance in various system parameters, such as energy harvesting time, relay number, and relay location. Finally, the correctness of the analytical results is confirmed by Monte-Carlo simulation.