非视线光散射通信的大气传输模型

Atmospheric Propagation Model in Non-Line-of-Sight Optical Scattering Communication

利用大气对光的散射作用可以实现非视线通信.在单次散射假定下,研究了非视线光散射通信系统的大气传输模型.利用该模型分析了光源发散角、接收视场和收发仰角等系统几何参数与接收散射光能量之间的关系;重点讨论了大气分子散射和气溶胶散射各自对接收散射光能量的贡献.结果表明当系统的收发仰角较大时,接收光能量主要来自大气分子散射;反之,气溶胶散射则成为接收光能量的主要部分.对于工作在日盲紫外光谱区的非视线通信系统,增加接收视场可以有效地增大系统的信噪比.发现在两种典型的收发仰角情况下,接收散射光能量随光源发散角的变化趋势是相反的,这说明光源发散角要根据实际的应用场合设计确定.

Based on the assumption of single-scattering, atmospheric propagation model of non-line-of-sight optical scattering communication system is studied. The model is used to analyze the correlations between received scattered energy and parameters of system, including source divergence angle, receiver field of view, and apex angles of transmitter and receiver in an optical scattering communication system. Contribution of atmospheric molecular scattering and aerosol scattering of received scattered energy is discussed. The results show that received scattered energy is attributed to molecular scattering at larger transmitter and receiver apex angles, but with the decrease of apex angles, aerosol scattering will be dominant in received scattered energy. Enhancing of the receiver field of view can effectively improve the signal noise ratio for communication systems operating in the solar-blind ultraviolet （UV） spectral region. In addition, the evolution tendency of received scattered energy versus the source divergence angle is inverse for two typical transmitter and receiver apex angles. This result suggests that divergence angle of source should be designed according to specified situation.