中国激光, 2016, 43 (8): 0806003, 网络出版: 2016-08-10
星地相干光通信中的自适应光学系统带宽研究 下载: 709次
Bandwidth of Adaptive Optics System in Satellite-Ground Coherent Laser Communication
光通信 自适应光学 大气湍流 控制带宽 混频效率 optics communications adaptive optics atmospheric turbulence servo bandwidth mixing efficiency
摘要
针对星地相干激光通信,研究了自适应光学的系统带宽对通信性能的影响。对于特定校正阶数的自适应光学系统,得到了系统需求的控制带宽,并对比了同步轨道(GEO)卫星对地链路和低地轨道(LEO)卫星对地链路。结果显示低轨卫星链路所需的控制带宽远大于同步卫星链路,原因来自于低轨卫星和地面站的高速相对运动产生的垂直链路风速,同时低轨卫星对地链路对自适应光学的带宽需求和天顶角是成反比关系的。分析了低轨卫星对地相干激光通信链路混频效率和自适应系统带宽以及校正阶数的关系,结果表明,200 Hz的闭环带宽完全可以满足需求,当达到100 Hz带宽之后,增加变形镜单元数对混频效率的提升更为有效。
Abstract
The influence of system bandwidth of adaptive optics system to communication performance is investigated for satellite-ground coherent opticscommunication. For a certain modes corrected by adaptive optics, the required servo bandwidth is obtained and the low earth orbit (LEO) satellite-ground laser links are compared with the geosynchronous (GEO) satellite-ground laser links. The results show that the LEO links require larger servo bandwidth than the GEO links. This is due to the high speed relative movement between the LEO and the ground station can generate vertical wind speed link. And the bandwidth requirement of adaptive optics system for LEO-ground link and zenith angle are inversely related. The relationship between the mixing efficiency LEO-ground coherent laser communication link, the adaptive optics system servo bandwidth and corrected modes is also studied. The results show that 200 Hz of close-loop bandwidth can meet the requirement, and increasing the number of actuators on deformable mirror is a more effective way to improve the mixing efficiency when the bandwidth reaches 100 Hz.
李佳蔚, 陈卫标. 星地相干光通信中的自适应光学系统带宽研究[J]. 中国激光, 2016, 43(8): 0806003. Li Jiawei, Chen Weibiao. Bandwidth of Adaptive Optics System in Satellite-Ground Coherent Laser Communication[J]. Chinese Journal of Lasers, 2016, 43(8): 0806003.