SEP analysis of FSO system employing SIM-MPSK with noisy phase reference

In this paper, novel analytical expression for the symbol error probability (SEP) of free-space optical (FSO) system employing subcarrier intensity modulation (SIM) with M-ary Phase-Shift Keying (MPSK) are derived, based on the Fourier series method (FSM). The irradiance fluctuations of the received signal are modeled by the K distribution convenient in strong atmospheric turbulence conditions. The hardware imperfections of PSK demodulator are taken into account, which are presented through the phase noise modeled by Tikhonov distribution. Numerical results are presented and confirmed by Monte Carlo simulations. The numerical results illustrate the effects of atmospheric turbulence strength and phase noise on SEP performance. The existence of hardware imperfections, presented through phase noise, degrades the FSO system performance to a large extent.