空地光通信系统空间链路的建模与仿真.docVIP

系 统 仿 真 学 报? Journal of System Simulation 第 19 卷第 12 期 2007 年 6 月 Vol. 19 No. 12 Jun., 2007 空地光通信系统空间链路的建模与仿真 陈纯毅 1，杨华民 1，佟首峰 2，蒋振刚 1，姜会林 2，韩 成 1 (1.长春理工大学计算机科学技术学院, 长春 130022；2.长春理工大学光电工程学院, 长春 130022) 摘 要：用拟合方法得出大气消光系数随高度的变化关系，进而建立激光大气传输衰减模型；以 无湍流影响时到达接收机的光强为均值，根据对数振幅起伏方差求出光强闪烁方差，用高斯随机数 模拟光强闪烁；建立了光扩束和视轴失配所引起的光损耗模型。在 Matlab/Simulink 平台上开发了 仿真程序，其可作为完整的空间链路模块，在空地光通信仿真中直接使用。仿真结果与理论分析 具有一致性。 关键词：光通信; 建模; 仿真; 闪烁; 大气衰减 中图分类号：TP391.9 文献标识码：A 文章编号：1004-731X (2007) 12-2706-04 Modeling and Simulation of Space Link in Space-to-Land Optical Communication System CHEN Chun-yi1, YANG Hua-min1, TONG Shou-feng2, JIANG Zhen-gang1, JIANG Hui-lin2, HAN Cheng1 (1.Computer School, Changchun University of Science and Technology, Changchun 130022, China; 2.Optoelectronic Engineering School, Changchun University of Science and Technology; Changchun 130022, China) Abstract: Curve fitting method was applied to found the relationship between atmospheric extinction coefficient and altitude, and then the atmospheric attenuation model of laser propagation was established. The received optical intensity uninfluenced by atmospheric turbulence was used as the average intensity and the optical intensity scintillation variance was computed according to log-amplitude variance, then Gaussian stochastic number was used to simulate the scintillation. In addition, the optical loss model of beam spreading and mismatch of sight axis between transmitter and receiver was proposed. Based on Matlab/Simulink platform, the simulation program was developed, and it can be used directly as a space link module in a space-to-land optical communication simulation system. The simulation results show consistency with theory analysis. Key words: optical communication; modeling; simulation; scintillation; atmospheric attenuation 折射率不均匀，从而引起激光光斑的闪烁和漂移，产生所谓 的湍流效应[2-3]。空间对地面大气随机信道与普通的大气信 道不同，大气衰减特性和湍流特性都随高度而变化，使得激 光的传输特性变得更加复杂。 本文针对空地光通信系统的空间信道进行仿真建模，即 建立激光信号在整个空间链路的传输过程中所受的损耗和 噪声干扰的仿真模型，并在所建仿真模型的基础上开发了仿 真程序，