A novel statistical model for turbulence-induced fading in free-space optical systems

In this paper, we propose a new probability distribution function which accurately describes turbulence-induced fading under a wide range of turbulence conditions. The proposed model, termed Double GG distribution, is based on a doubly stochastic theory of scintillation and developed via the product of two Generalized Gamma (GG) distributions. The proposed Double GG distribution generalizes many existing turbulence channel models in a closed-form expression and provides an excellent fit to the published plane and spherical waves simulation data. We finally evaluate the performance of a free-space optical system over the Double GG turbulence channel and derive closed-form expressions for the bit error rate, assuming intensity modulation/ direct detection with on-off keying.