Analytical performance assessment of FSO links over cascaded Snedecor’s [formula omitted] turbulence channels in the presence of pointing errors

Abstract

The performance of free-space optical (FSO) links over cascaded Snedecor’s F turbulence channels with pointing errors is investigated in this paper. To this end, we derive exact analytical expressions for the probability distribution function (PDF) and the cumulative distribution function (CDF) of the irradiance fluctuations in the presence of pointing errors. We also provide exact analytical expressions for the PDF, the CDF, the moment generating function (MGF), the moments, and the scintillation index (SI) of the received signal-to-noise ratio (SNR) assuming both intensity modulation/direct detection (IM/DD) and coherent heterodyne detection. The derived statistical expressions for the SNR are further utilized to derive exact analytical and asymptotic expressions for the outage probability, the average symbol error rate (SER) of various modulation techniques, and the average ergodic capacity. The derived asymptotic expressions give insights into the diversity gain of the system. The derived expressions are verified by Monte-Carlo simulations.