Wireless-powered NOMA relays for out-of-coverage devices

Abstract

<p>In a conventional Cooperative Non Orthogonal Multiple Access (NOMA) scheme, only one user from the NOMA pair acts as a relay and forwards information to the other user. In this paper, we aim to introduce NOMA-based relaying to extend the coverage of the source and serve the remote devices in out-of-coverage area. This extension in coverage is supported by powering the relays wirelessly with the help of simultaneous energy transfer so that the relays can self-sustain within the network without utilising their individual power. The closed-form expressions for outage probabilities of the downlink messages from source to the remote users and downlink throughput are derived. The proposed results confirm that this scheme successfully utilises wireless-powered NOMA relays in delivering the information of the source to remotely located users.</p>