An Efficient Time Switching Protocol with Adaptive Power Splitting for Wireless Energy Harvesting Relay Networks

A new time switching protocol referred to as TSAPS is proposed for the energy harvesting (EH) relay networks based on the combination of conventional time switching (TS) protocol and adaptive power splitting (APS). In the framework of the decode and forward (DF) relaying with multiple relays, we derive the closed form expression for the outage probability of the proposed scheme and discuss its effective transmission rate considering the random relay selection (RRS) and opportunistic relay selection (ORS) scenarios. Through numerical analysis, we show that the proposed scheme can achieve better outage performance and the effective transmission rate as compared to the conventional TS and power splitting (PS) schemes proposed in the literature, irrespective of relay selection scenarios. By properly selecting time switching (TS) ratio, we demonstrate that the effective transmission rate of the proposed protocol can be optimized only with partial knowledge of channel gains in the network, which makes the proposed approach suitable for the distributed relay selection scenarios.