大气湍流对基于轨道角动量的自由空间光通信影响及解决方案综述

BU Yang1, YANG Zhi1, ZHAO Lijuan1,2, XU Zhiniu1

摘要:

基于轨道角动量(orbital angular momentum, OAM)的自由空间光通信（Free Space Optical Communication, FSOC）具有通信容量大、信息传输快等优点，FSOC系统以大气作为传输媒介，会受大气吸收、散射等影响，使OAM光束传输质量严重下降，进而影响FSOC系统的稳定性和可靠性。文中从OAM复用技术和大气湍流模型理论知识出发，分析不同湍流强度对OAM光束传输误码率和信道容量的影响，并且分析将多入多出（Multiple-Input Multiple-Output, MIMO）均衡技术及自适应光学（Adaptive Optics, AO）技术分别引入FSOC系统对大气湍流影响的缓解效果，比较分析两种技术中不同算法的优缺点，对技术发展现状进行综述及展望。

Abstract:

Free Space Optical Communication (FSOC) based on orbital angular momentum (OAM) has the advantages of large communication capacity and fast information transmission. The FSOC system uses the atmosphere as the transmission medium, which will be absorbed and scattered by the atmosphere. As a result, the transmission quality of the OAM beam is seriously degraded, which in turn affects the stability and reliability of the FSOC system. Based on the theoretical knowledge of OAM multiplexing technology and atmospheric turbulence model, this paper analyzes the influence of different turbulence intensities on the bit error rate and channel capacity of OAM beam transmission, and analyzes the multiple-input multiple-output (MIMO) equalization technology. And adaptive optics (Adaptive Optics, AO) technology respectively introduces the mitigation effect of FSOC system on atmospheric turbulence, compares and analyzes the advantages and disadvantages of different algorithms in the two technologies, and summarizes and prospects the technology development status.