Performance of SWIPT‐Assisted CNOMA System With P‐CSI User Selection Under Nakagami‐<i>m</i> Fading

ABSTRACT This paper focuses on the performance investigation of a cooperative non‐orthogonal multiple access (CNOMA) system consisting of a single base station (BS), multiple near users, and a single far user. The near users are energy‐constrained and harvest energy using the simultaneous wireless information and power transfer (SWIPT) technique. The BS uses a partial‐channel state information (P‐CSI) scheme to select a near user. The BS broadcasts the superimposed near users' and far user's signals. The selected near user performs successive interference cancellation (SIC) to detect the data. It uses the harvested energy to forward the far user data using the decode‐and‐forward protocol. The Nakagami‐ m fading environment is considered for the analysis of the system in terms of outage probability, throughput, and energy efficiency. We derive closed‐form expressions for the far and the selected near users. We validate the results obtained using these expressions with simulation results. Also, we compare different user selection schemes existing in the literature with P‐CSI. P‐CSI is observed to outperform some of these schemes.