Performance analysis for NOMA energy harvesting relaying networks with transmit antenna selection and maximal-ratio combining over Nakagami-m fading
Non-orthogonal multiple access (NOMA), which is an effective solution to improve spectral efficiency, has been considered as an emerging candidate for the fifth generation multiple access. In addition, simultaneous wireless information and power transfer, which aims to maximise energy efficiency, has received significant attention. In this study, the authors design NOMA for downlink energy harvesting (EH) multiple-antenna relaying networks. The base station communicates with multiple mobile users simultaneously via an EH relay node. In the first slot, the relay node harvests energy from the received signals; and in the second slot, the relay node uses the harvested energy to broadcast the received signals to all mobile users. Antenna selection is adopted at the base station while maximal-ratio combining is applied at the mobile users. The outage performance for the NOMA-EH relaying networks is studied over Nakagami-m fading and closed-form expressions for the outage probability are obtained. In addition, the presented simulation results demonstrate the correctness of the authors’ analysis and the advantage of NOMA over conventional orthogonal multiple access.