Throughput analysis of wireless-powered decode-and-forward relay systems with interference

This paper investigates the throughput of a wireless-powered dual-hop relaying system with the presence of co-channel interference. Specifically, an energy-constrained source node communicates with a destination node through an energy-constrained decode-and-forward relay node. Considering a time-splitting approach, both source and relay are first powered by a dedicated power beacon (PB), whereas the relay further exploit the benefit from the interfering signals as a plentiful power supply. Then, source transmits information to the destination with the help of the relay. The instantaneous throughput of the system is maximized by optimizing the time-split parameter. In order to determine the average throughput of the system in delay-limited transmission mode, analytical expressions for the outage probability are derived. In addition, we present asymptotic outage expressions under strong interference conditions. Our results, reveal that by energy harvesting from the interfering signals at the relay, the instantaneous throughput is increased compared with the case where the relay is only powered by the PB. Moreover, under strong interference conditions the optimal time-split that maximize the throughput of the the delay-limited transmission mode is much higher than that for weak interference condition.