Performance Analyses of SWIPT-NOMA Enabled IoT Relay Networks

In this paper, the performance of Non-Orthogonal multiple access (NOMA) with Simultaneous Wireless Information and Power Transfer (SWIPT) for Internet of Things (IoT) relaying networks over Nalagami-m fading channel is investigated. Comparison with benchmark schemes using Time Division Multiple Access (TDMA) Orthogonal Multiple Access (OMA) with SWIPT is done. Closed-form expressions for the outage probability of all users, the system throughput, and the cooperative relaying between users are analytically derived and validated by Monte Carlo simulations in Nakagami-m fading channel. It is analytically proven that the SWIPT-NOMA outperforms the SWIPT-OMA schemes, reducing the outage probability and enhancing the overall system throughput with the appropriate choice of power allocation and user target rates. With cooperative communication from the near user and the relay to the far user, a reduction of the outage probability and an enhancement of the diversity gain for the far user of the SWIPT-NOMA were proven to be achieved even if one of these two links was in an outage.