Opportunistic scheduling for fixed-gain amplify-and-forward-based multiuser multirelay SWIPT cooperative networks

In this paper, we analyze the downlink outage performance of opportunistic scheduling in dual-hop fixed-gain amplify-and-forward (FG-AF) cooperative networks consisting of one source, multiple radio-frequency (RF) energy harvesting relays, and multiple destinations. To this end, a relay-destination selection scheme named direct links plus opportunistic channel state information (CSI)-based selection (DOS) scheme is proposed. The performance analysis in terms of outage probability (OP) is carried out for the proposed DOS scheme. In particular, an exact closed-form expression for the OP is provided. The developed analysis is corroborated through Monte-Carlo simulation. Numerical results show that the DOS scheme achieves full diversity gain, i.e., K + M, where K and M are the numbers of relays and destinations, respectively.