Simple Generation of Gamma, Gamma–Gamma, and K Distributions With Exponential Autocorrelation Function

The simulation of a free-space optical (FSO) communication channel in the presence of strong turbulence typically requires the generation of channel states with a K or gamma–gamma distribution and a predefined autocorrelation function. In this paper, we propose a simple and effective simulator of the strong-turbulence FSO channel that addresses the influence of the temporal covariance effect. Specifically, the proposed simulator provides K and gamma–gamma distributed values with the exponential autocorrelation function and a prescribed correlation time. This simulator is based on the numerical solution of the first-order stochastic differential equation. The simulated channel states are generated by a simple discrete-time differential equation and the simulator performance is analyzed in the paper.

I. Introduction

The issue of the generation of time-correlated non-Gaussian processes has long been a subject of interest in diverse fields of application, such as radars [1], [2], RF communication channel modeling [3]– [5], optical channel modeling [6] –[9] and signal processing [10] .