The Link Attenuation Model Based on Monte Carlo Simulation for Laser Transmission in Fog Channel

Free space optical (FSO) systems were usually designed according to the link budget analysis. However, the previous link attenuation estimations for fog channel were not precise. The link budget would be distorted, and resulting in the robustness degeneration of FSO system. Therefore, it is necessary to establish an accurate link attenuation model of fog channel. The previous models were mainly adopted by the Beer-Lambert law, or by classical Monte Carlo simulation combined with the fog drop size distribution. Unfortunately, the estimation deviation was eventually not fall within the acceptable range for FSO link budget analysis. We established a link attenuation model based on Monte Carlo simulation and Kim formula. Our model took the influence of multiple scattering and receiving parameters into consideration, and without the measurement of the fog drop size distribution and scattering cross-sections. The fog experiment was set up to verify the analysis results. And the experiment results revealed that the estimation deviation RMSE (root mean square error)
$<\!1$
, which validated the accuracy of link attenuation model. The link attenuation model can be used to strengthen the link budget analysis of FSO system and guide the parameter design of future FSO communication system under fog channel.