On the Availability of Negative Exponential Turbulent FSO Links with Time Dispersion

Abstract

In this work, we investigate the influence of the group velocity dispersion effect along with the atmospheric turbulence on the performance of a terrestrial free space optical communication system which is using the atmosphere as propagation path. We assume that the examined wireless optical link employs longitudinal Gaussian pulses in order to transmit the information signal from the nonlinear laser diode of the transmitter to receiver’s photo detector. The atmospheric conditions are modelled through the negative exponential distribution model, which is a very accurate model for the signal’s irradiance estimation over strong turbulence conditions. Thus, taking into account these effects we obtain closed form mathematical expressions of the probability of fade of the link. Additionally, we evaluate specific parameters, such as the chirp, which can reduce the probability of fade and as a result they can improve the optical system’s characteristics. The influence of the time dispersion effect on chirped pulse’s propagation is further investigated. Finally, by using the derived mathematical expressions, we present several numerical results which demonstrate our suggestions for the improvement of the system’s performance