Performance evaluation of IRS-assisted FSO systems with RSMA: effects of atmospheric turbulence and misalignment errors

Abstract

This paper investigates the performance of an intelligent reflecting surface (IRS)-assisted free-space optical (FSO) communication system employing rate-splitting multiple access. The FSO channel is modeled using the Gamma–Gamma fading distribution while accounting for pointing errors and supporting both heterodyne detection and intensity modulation with direct detection. Closed-form expressions for critical performance metrics, including outage probability, average bit error rate, and average capacity, are derived and validated through numerical simulations. The analysis incorporates essential factors such as attenuation ( α), atmospheric turbulence ( β), and pointing error ( ζ), along with various power allocation strategies. The findings highlight the substantial impact of these parameters on system performance, offering valuable guidance for the optimization of IRS-assisted FSO networks.