Distributed relay selection for energy harvesting systems in the presence of Nakagami and Rayleigh fading channels

Abstract

In this paper, we suggest a distributed relay selection (DRS) technique for cooperative systems with energy harvesting. Relay nodes harvest energy from radio frequency (RF) signal received from the source. Each relay is allowed to transmit only when its signal-to-noise ratio (SNR) is greater than a predefined threshold $$\varGamma _{\mathrm{th}}$$ . The SNR threshold $$\varGamma _{\mathrm{th}}$$ and harvesting duration are optimized to maximize the throughput. The throughput of DRS is compared to best relay selection (BRS) as well as Random relay selection (RRS) that does not use the SNR in the relay selection process. We derive the throughput at the packet level of DRS, BRS and RRS. The proposed DRS does not require any signalization to activate the relay. Our theoretical derivations are confirmed with computer simulations for Nakagami fading channels.