Performance analysis for non-orthogonal multiple access in energy harvesting relaying networks

Non-orthogonal multiple access (NOMA), which uses the power domain for multiple users, has been considered as an emerging candidate for fifth generation downlink transmission. Energy harvesting (EH), a promising technology to prolong the lifetime of energy-constrained wireless networks, has attracted significant attention. In this study, the authors first combine NOMA with EH (NOMA-EH) to enhance system spectral efficiency and user fairness. An NOMA-based relaying network is analysed, where the relay node is equipped with EH device, and functions as the bridge between the base station and the multiple users. The outage performance of the NOMA-EH scheme-based relaying network is studied, where the transmitting antenna selection is applied at the base station and maximal ratio combining is applied at the multiple users. Furthermore, closed-form expression for the system outage probability is also derived. On the basis of the computer simulations, they show the correctness of the numerical analysis and confirm the superiority of the proposed NOMA-EH scheme.