Simultaneous Wireless Information and Power Transfer for Cooperative Relay Networks With Battery

In this paper, we investigate simultaneous wireless information and power transfer in a cooperative communication network consisting of one source, one battery-enabled relay, and one destination node. An amplify-and-forward relaying method is considered, where the relay node harvests energy from the received signal power to charge its battery, which is used to forward the received signal to the destination. We also consider a direct link between the source and the destination. The direct link signal can be combined with the relaying signal at the destination node using maximum ratio combining. Under the delay-limited transmission mode, closed form expressions for outage probability are derived for a battery-enabled relay. Our analytical results reveal the advantage of cooperative relay networks with a direct link. Also, we extend our design to a multiple-relay scenario, where the best relay is selected from the available number of relays, based on the information of relay locations. Finally, we demonstrate from simulation results based on outage probability that our proposed methods are efficient in comparison with Monte Carlo simulations.