Power‐splitting relaying protocol for wireless energy harvesting and information processing in NOMA systems

Abstract

Non-orthogonal multiple access (NOMA) along with cooperative communications have been recognised as promising candidates for the fifth generation (5G) wireless networks and have attracted many researchers. Every networked device however has its own limited power supply. To this extent, this study investigates a power-splitting relaying (PSR) protocol for wireless energy harvesting (EH) and information processing in the NOMA systems to prolong the lifetime of the energy constrained relay nodes in wireless networks so as to avail the ambient radio-frequency (RF) signal as well as to simultaneously harvest the energy and process the information. Decode-and-forward relaying is employed at the relay node where the energy from the received RF signal is harvested and exploited to forward the information to the destination. Specifically, the outage probability and ergodic rate of the PSR protocol are derived to realise the impacts of EH time, EH efficiency, power splitting ratio, source data rate, and the distance between nodes. It is shown that an outperformance in terms of the energy efficiency is achieved with an increased EH efficiency and the employment of the NOMA when compared to the conventional orthogonal multiple access.