New results on turbulence modeling for free-space optical systems

In this paper, we propose a statistical channel model, named as Double-Weibull, to describe the irradiance fluctuations in moderate and strong turbulence for free-space optical (FSO) systems. The proposed stochastic model is based on the scintillation theory and derived via the product of two Weibull random variables. Closed-form expressions of probability and cumulative density functions are provided in terms of Meijer´s G-function. We also compare the new model with the classical gamma-gamma model and assess their accuracy via a set of simulations when both plane and spherical waves are considered. We finally evaluate the performance of an FSO system over the Double-Weibull turbulence channel and derive closed-form expressions for the bit-error rate, assuming intensity-modulation/direct detection with On-Off keying, and the outage probability.