Wireless-powered cooperative multi-relay networks with relay selection

In this paper, we consider wireless information and power transfer in a cooperative multi-relay network (MRN) with relay selection. The off-grid relay terminals, which are randomly deployed within a certain cooperating area, help forward the source information to the destination following a decode-and-forward protocol. Adaptive power splitting is employed at each relay that attempts to decode the source information first and stores any remaining energy. Then according to different criteria, a single best relay is selected to forward the decoded source signal to the destination. Considering the spatial randomness of the intermediate relays and energy causality, the end-to-end outage probability of this wireless-powered MRN is analytically obtained under different relay selection schemes. Simulation results demonstrate that with more knowledge available for relay selection, a significantly better outage performance can be achieved, albeit at a higher implementation complexity.