【作者】 万玲玉；

【导师】 李庄； 韦文楼； 蒋丽娟；

【作者基本信息】 广西大学 ， 理论物理， 2002， 硕士

【摘要】 本文对建立于3．4km的近地视距光通信链路在不同气象条件下的工作情况进行了详细分析和理论探讨，给出了霾、雾、雨、大气湍流对光通信链路的影响结果，并就大气衰减信道和大气湍流信道进行了理论分析。本文的第一章对激光通信及大气激光通信的发展作了一简要概括。第二章简要介绍了大气对光束传输和大气激光通信的影响，它是我具体工作(第四—第六章)的基础。 第三章介绍了实验所建立的大气光通信链路及所用设备，给出了总体实验结果和不同天气情况下的系统误码率。 第四章给出了霾、雾、雨对光通信链路的具体影响结果，分别就它们的衰减系数进行了计算，分析了它们造成系统误码的原因。 第五章给出了晴好天气下实验中记录的光强闪烁，观察到了和理论结果相一致的大气闪烁日变化，根据弱湍流理论估算了大气湍流的强弱程度，给出了光强闪烁和系统误码率变化曲线，分析了大气湍流条件下的误码原因并就其特点和第四章的结果进行了比较。 第六章给出了大气衰减信道中衰减系数和系统误码率的数值计算图，得到了和雾、霾影响结果基本一致的变化曲线。计算了不同湍流强度下系统的探测概率并就实验结果进行了分析。最后比较了桂林、北京 广西大学硕士论文 两地的气象条件和通信惰况。更多还原

【Abstract】 This paper researched the performance of 3 . 4km line-of-sight laser link under different weather conditions. Effects of haze, fog, rain and atmosphere turbulence on the BER of experimental link are given and theoretical analysis is taken through two communication channel models梐ttenuation channel and turbulence channel. In chapter l,we give a summary of laser communication and the development of atmosphere laser communication. In chapter 2,we introduce roughly effects of atmosphere on the propagationof laser beams and the laser communication system. They are the general bases of my concrete work (chapter4 to chapter 6).Chapter 3 introduces the experimental link and its instruments. The overall experimental results and the BER of communication system under different weather conditions are given.Chapter 4 gives the effects of haze, fog and rain on the BER of optical communication link and calculates their extinction coefficient. The major reasons of cause to the experimental link’s BER are discussed.In chapter 5, experimental results of intensity fluctuation in fine day are given and expected variations in the scintillation over the course of a day are observed. In there, we calculate the turbulent intensity through weak turbulent theory, report the overall BER of link in the presence of strong scintillation, and analyze why cause to the BER. Besides, the characters of BER are comparied with the results of chapter 4.Chapter 6 obtains the BER as function of extinction coefficient by attenuation channel model, which fit for experimental link when thick haze and fog presented. And then we calculate the detection probability of communication system under different turbulent intensity and analyze the relation to BER. In the end, we compare the overall experimental results between Guilin and Beijing.更多还原