影响激光大气通信距离的诸因素分析

Analysis of the parameters influencing the distance of free-space laser communication

激光大气通信技术由于具有宽带大容量、低成本、无需频率许可等优点 ,近几年来作为一种新的宽带无线接入方式受到人们的广泛关注。激光大气通信距离受多种因素的制约 ,通常仅数公里。本文在建立激光大气通信系统数学模型的基础上 ,分析了激光束发散角、大气衰减、激光发射功率以及探测器灵敏度对通信距离的影响 ,结果显示较窄的光束发散角、较高的探测器灵敏度有利于通信距离的延长 ,而通过提高激光发射功率来延长通信距离的办法不可取 ,从而为系统设计提供参考依据。

Free-space laser communication is becoming attractive as a new wideband wireless access technology in recent years by virtue of its many advantages, such as high-bandwidth, low cost and being license-free. Laser beam can only travel a few kilometers through the atmosphere because of some limiting factors. Based on the mathematical model of free-space laser communication, this article analyses the effects of beam divergence, atmospheric attenuation, laser power and detector sensitivity on the link range. The results show that it is effective to extend the range by narrower beam divergence and higher detector sensitivity, and higher laser power is unadvisable. The analyses in this paper are helpful for system design.