FSO system performance analysis based on novel Gamma–Chi-square irradiance PDF model

Abstract

In order to provide a novel analytically traceable free space optics (FSO) channel model for describing turbulence based irradiance fluctuations, following basic scintillation theory principles, we have derived closed-form expression for probability density function (PDF) of a new statistical Gamma–Chi-square model. Further, capitalizing on provided model, error performances of FSO system over on–off keying (OOK) transmission scheme both in the presence of atmospheric turbulence and misalignment fading (pointing error) is investigated. For both cases, the average bit error rate (ABER) at the receiving side of the system is determined in an analytically closed form. The results are graphically presented in order to analyze the impact of different levels of turbulence, as well as other relevant parameters, on the quality of the received signal in the OOK modulated FSO system.

Performance analysis of WSN–FSO system modeled by Gamma–Chi-square channel distribution

“…where k B is the Boltzmann constant and T is the absolute temperature. Distribution used to describe h and g channels, i.e., atmospheric turbulence channel between transmitter and CCR, as well as between CCR and receiver is the novel Gamma-Chi-square irradiance PDF (probability density function) model given as [24]:…”

“…The parameter α is the atmospheric turbulence parameter that represents the effective number of small-scale eddies of the scattering environment. This is the parameter of atmospheric turbulence that for propagation of plane waves and zero inner scale can be expressed as [24]: where σ 2 R represents the Rytov variance used to determine the intensity of the optical signal due to atmospheric turbulence, and is defined as:…”