大气湍流下激光斜程通信误码率分析

摘要

自由空间激光通信系统的性能容易受大气湍流效应影响而下降。针对地空激光通信的实际情况，将修正Rytov方法应用于大气湍流条件下的光波斜程传输研究。基于ITU－R大气结构常数模型，建立了湍流条件下系统误码率的数学计算模型，对不同强度湍流信道的系统误码率进行了数值计算，讨论了误码率受通信高度、天顶角、工作波长及近地面风速等系统参数影响程度及变化规律。结果表明：大气湍流强度是影响系统性能的决定性因素；在相同强度湍流条件下，系统的误码率随通信高度、天顶角、风速的增大而增大，随工作波长的增大而减小。%The performance of free-space laser communication system is easy to be affected by the atmospheric turbu-lence. Considering the practical situation of air-to-ground laser communication,the modified Rytov method is applied in the optical wave propagation in the slant path under atmospheric turbulence. Based on the ITU-R turbulence struc-ture constant model,a mathematical calculation model of bit error rate under atmospheric turbulence conditions is es-tablished;Through the bit error rate calculation under turbulence channel of different intensities,effects of system pa-rameters,like communication height,zenith angle,wavelength,the near surface wind speed etc. on the bit error rate are discussed. The results show that the intensity of atmospheric turbulence is the decisive factor affecting the system performance.Under the same intensity of turbulent,the system′s bit error rate increases with the increase of communi-cation height,zenith angle,wind speed near surface,and decreases with the increase of the wavelength.