Blue-green Laser Communication Downlink Channel Monte Carlo Simulation And Modeling

Blue-green laser communication downlink channel consist of atmosphere , atmosphere-ocean interface and ocean is a random channel, the equivalent math model has important theoretical guidance and practical significance for the entire communications system analysis and design. Blue-green laser communication downlink channel under different scenarios have very different characteristics ,this article focus on the characteristics of distribution, scattering and absorption properties of the multi-layer laser transmission medium, and the method of Monte Carlo simulation and theoretical analysis is adopted for modeling the atmosphere-ocean laser communication channel.Firstly, the optical properties of molecules and aerosol in vertical atmospheric channel and the characteristics of laser pulse through different channel mediums are analyzed in detail. According to the actual composition of the atmosphere over the sea ,the atmospheric laser transmission channel is divided into the three-layer media ,and The atmospheric aerosol scattering below Cloud has been detailed analyzed and research.Secondly , the scattering and absorption properties of water molecules and suspended particles on the vertical direction are analyzed in detail. According to the characteristics of distribution of hydrological element,the third category seawater is divided into the two-layer media.Finally,the theory of the tap time delay filter has been researched, through the time-domain signal waveforms from simulation, we set up the channel equivalent models in ten typical scenes with the tap time delay filter.Theoretical analyses prove that the equivalent channel model under different scenarios is accurate. This equivalent channel model has laid a good foundation for the subsequent research of the link-layer performance of the blue-green laser communication system.