| Ultraviolet (UV) communication is a new type of free space opticalcommunication mode, which based on the process of scattering between the UVphotons and the particles in the air. Due to its excellent performances includenon-line-of-sight, anti-interference, low wiretapping and electromagnetic silent, UVcommunication adapts the environment of all-weather, Omni-bearing, securecommunication in complex terrain, therefore，It has great application prospect inmilitary and civilian. UV atmosphere characteristic path loss model and Propertyverification platform are the mainly contents of this paper, including the followingaspects:(1) Ultraviolet communication channel characteristic modeling:Single scattering model based on Rayleigh scattering and Mie scattering theoryis introduced to study the influences of operating range and the geometry to thesignal attenuation and pulse broadening effect. The model is also improved toadapting the non-coplanar geometry in this paper, which makes the model morepractical.Monte-Carlo model is designed and carried out in this paper, which overcomesthe distance limitation of single scattering model. And a method for photon motiondescription is put forward in3-D system of Coordinates, including photonsmovement sampling, tracking and route records. The convergence rate ofMonte-Carlo model is improved by Combining with single scattering modelingmethod. The simulation results of Monte-Carlo model can be used as a reference tocorrect the error of single scattering model to get more accurate parameters ofchannel characteristic, which are the important reference for platform building.(2) Ultraviolet communication platform building:The scheme design is fininshed based on the analysis of atmospherecharacteristic model. And the hardware and software design of the transmitter andreceiver modules are presented in detail, including the voice signal processing, theselection and implementation of modulation and demodulation, Light source driver,the detector signal processing.etc. Ultraviolet voice communication platform isfinished based on the devices which are selected by the results of models.The feasibility and performance of UV communication is confirmed by the field experiment. And model results are partly verified in chapter6. The experimentalresults shows that voice communication scheme based on UV communication isfeasible, LED source can support several meters of speech transmission, and arelatively better performance are achieved under smaller pitch angle and Largerdivergence angle. |
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