Performance Analysis of an Energy‐Limited Multi‐User Mixed RF/FSO System

ABSTRACT This paper investigates an energy‐limited multi‐user mixed radio frequency/free space optical (RF/FSO) system, where the RF links and FSO link undergo Rayleigh fading and Gamma‐Gamma turbulence models incorporating the effect of pointing errors, respectively. Simultaneous wireless information and power transfer (SWIPT) based on the power splitting protocol is employed to maintain communication continuity of the system operating in an energy‐limited scenario. Moreover, an energy‐based user selection strategy is adopted to enhance the overall performance. Closed‐form expressions for outage probability (OP) and approximate bit error rate (BER) are provided by using Meijer‐G functions. The accuracy of theoretical derivations is validated by Monte‐Carlo simulations. Results demonstrate that, under the user selection strategy, merely increasing the number of users cannot significantly boost system performance. Furthermore, influenced by multiple factors, the prudent design of the power splitting proportion enables system performance optimization.