Probability of fade estimation for FSO links with time dispersion and turbulence modeled with the gamma-gamma or the I-K distribution

In this work, we study the influence of the time dispersion and atmospheric turbulence effects on the performance of a free space optical communication system, which is using longitudinal Gaussian pulses as information bit carriers. The scintillation effect, is modeled with the gamma-gamma or the I-K distribution, which, both, are suitable to emulate irradiance fluctuations due to weak to strong atmospheric turbulence conditions. Additionally, we estimate the influence of the time dispersion effect on chirped pulse's propagation. Taking into account these effects, closed form mathematical expressions for the evaluation of fade's probability of the wireless optical link, are derived. Additionally, the possibility of improving the availability results by choosing the appropriate link and pulse's parameter values is further investigated. Finally the numerical results from the derived mathematical expressions are presented.