Performance analysis of an earth-satellite intensity modulated FSO link in the presence of turbulence and varying path loss

Using Gamma-Gamma distribution to describe the atmospheric turbulences, we present a wireless optical communication model incorporating intensity modulation/direct detection (IM/DD) technique. Specifically, we have derived the closed form expressions for the cumulative distribution function (CDF) and the probability distribution function (PDF) for an FSO transmission system. Accounting for the atmospheric path losses and Mie scattering, we offer the closed form expressions for different performance parameters of wireless optical transmission system such as, outage probability, bit error rate for different binary modulation schemes and ergodic capacity, all in terms of Meijer's G function. Moreover, utilizing the asymptotic approximation of Meijer's G function, the outage probability and bit error rate are presented in the form of simple elementary functions at higher values of signal-to-noise ratio (SNR).