Suppression of turbulence noise in optical wireless communication system

Optical wireless communication (OWC) systems use the atmosphere as a propagation medium. In optical wireless communication links, atmospheric turbulence causes distortions in the laser beam wavefront, leading to fluctuations in both the intensity and the phase of the received light signal performance, i.e. signal fading. This paper presents a suppression method of turbulence noise on the basis of analyzing the optical signal effect of turbulence.In this paper, according to probability distributions of turbulence-induced intensity, we describe a BEP model. From the model, we develop an adaptive threshold detector technique to decrease the BEP. The BEP increases from 10^-11 to 10^-7 for a linear increase of normalized standard deviation σ_x of the log-amplitude from 0 to 0.5 which is shown in fig.1 at a stationary threshold. Finally, we describe the matched receiver to maximize the output signal-to-noise ratio (SNR). We also numerically compute the average bit-error probabilities for the filter case.