Abstract
In this paper, we examine the performance of a free-space optical (FSO) communication system under imperfect Fisher-Snedecor atmospheric turbulence channels. Taking into consideration the atmospheric turbulence, channel estimation errors, and pointing errors, simple and accurate analytical expressions for the probability density function and cumulative density function under intensity modulation direct detection (IM/DD) and heterodyne detection techniques are derived. Consequently, new analytical expressions for useful performance metrics such as outage probability, average bit error rate, and ergodic capacity are derived. To get more insight into the system diversity gain, asymptotic analytical expressions, in the high signal-to-noise ratio regime, for the outage probability and average BER are obtained. Our analysis is validated by means of numerically and Monte-Carlo simulations under various