Performance Evaluation of Power-Beacon-Assisted Wireless-Powered NOMA IoT-Based Systems

Abstract

In this article, we investigate power beacon (PB)-assisted wireless-powered nonorthogonal multiple access (NOMA) Internet-of-Things (IoT)-based systems, where all transmitters harvest energy from a PB to transmit their signals to a destination by employing a time-splitting mechanism. In order to utilize spectral efficiency and enhance the quality of service of an edge user (EU), a cellular base station can communicate with the EU thank to the help of one IoT node in a cellular network by employing the NOMA protocol. To characterize the performance of the proposed systems, we derive the exact closed-form expression for the outage probability, throughput, energy efficiency, and the approximate closed-form expression for the ergodic capacity. To further improving the system performance, we present two algorithms that are to minimize the outage performance of users by optimizing the time-splitting factor and to maximize sum throughput via jointly optimal power allocation and time-spitting factor. Our numerical results show that the proposed system has outstanding performance in comparison with simultaneous wireless information and power transfer NOMA systems under time switching mechanism based on the IoT relay.