Uplink Performance Analysis of Wireless Energy Harvesting-Enabled NOMA-based Networks

This article presents a performance analysis of wireless energy harvesting (WEH)-enabled sensor networks that extract energy from ambient radio frequency (RF) signals prior to uplink transmission. A time-switching (TS)-based protocol is utilized to alternate sensor nodes between energy harvesting (EH) and data transmission modes. Implementing the non-orthogonal multiple access (NOMA) technique aims to boost the sensor network’s performance regarding uplink sum rate and outage probability. To optimize resource allocation, we propose an unequal operating time frame (OTF) scheme that determines data transmission and energy harvesting intervals based on channel gain quality. Simulation results affirm the superiority of NOMA over orthogonal multiple access (OMA), with NOMA enabling higher sum rates by accommodating more signals within the same frequency band, though at the expense of slightly degraded outage performance.