Performance of MPSK With Gaussian Phase Errors in Mixed FSO/RF Systems

This letter investigates the average bit error rate (BER) performance of M-ary phase-shift keying (MPSK) in mixed free-space optical/radio frequency (FSO/RF) transmission systems employing amplify-and-forward relaying under the influence of Gaussian phase errors. The FSO link is characterized by Málaga distribution with pointing errors under heterodyne detection, while the RF link undergoes Nakagami-m fading. We derive new analytical expressions for the average BER of binary phase-shift keying, quadrature phase-shift keying, and MPSK using the H-function of two variables. Monte Carlo simulations are performed to verify the accuracy of these derived expressions.