湍流大气FSOC信道互易性及对发射自适应的影响机制研究

项目名称： 湍流大气FSOC信道互易性及对发射自适应的影响机制研究

项目编号： No.61475025

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 陈纯毅

作者单位： 长春理工大学

项目金额： 83万元

中文摘要： 利用信道互易，双向FSOC系统无需反馈链路即可实现发射自适应模式，以补偿湍流大气影响；但前提是对信道互易性保持和退化机理有深入认识，以便优化设计系统参数。Helmholtz电磁互易定理解决的是点互易问题，未考虑收发器尺度效应；目前缺乏将光学收发模式、收发光学参数、湍流路径分布模式、指向误差等纳入统一数学框架的湍流大气FSOC信道互易理论模型。首先建立互反信道状态间的统计相关解析模型,研究不同链路参数对信道互易的影响；然后利用数值模拟，从不同角度揭示湍流大气FSOC信道互易特性，以检验解析模型；接着阐明湍流大气FSOC信道互易性保持和退化的机理，导出保持良好信道互易性的链路条件，并通过实验测量进行验证；最后定义新的带CSIT估计误差和时延约束的平均容量指标，以此为基础分析不同信道互易性对发射自适应FSOC系统性能的影响。本项目可为基于信道互易的发射自适应FSOC系统的优化设计提供理论依据。

中文关键词： 自由空间光通信；湍流大气；信道互易；发射自适应；信道容量

英文摘要： By making use of channel reciprocity, transmission adaptation without the aid of a feedback link in bidirectional free-space optical communication (FSOC) systems can be realized to compensate the effects caused by turbulent atmosphere if the mechanism of persistence and degradation of channel reciprocity is deeply understood and hence the optimization of link parameters can be performed. The Helmholtz reciprocity principle solves the problem of point-to-point reciprocity, whereas it does not consider the scaling effect of transceivers. Up to now, there have been no theoretical models for the reciprocity of turbulent-atmosphere FSOC channels which consider the effects of the optical transceiving mode, transceiver parameters, turbulence path distribution mode and pointing error in a unified mathematical framework. First, analytical correlation models for the two reciprocal channel states will be derived. Second, numerical simulation will be performed to reveal the reciprocity of turbulent-atmosphere FSOC channels from a different viewpoint, and thus to verify the analytical models. Third, the mechanism of persistence and degradation of channel reciprocity will be formulated; the condition of keeping good channel reciprocity will be presented; experimental measurement will be carried out to verify this condition. Finally, a new metric for average capacity with constraints of both the prediction error of channel state information at the transmitter (CSIT) and time delay will be defined, and be used to analyze the effects that different degree of channel reciprocity has on the performance of FSOC systems using transmission adaptation. The results that will be obtained by this project can provide a theoretical basis for optimizing the design of FSOC systems using transmission adaptation based on channel reciprocity.

英文关键词： free-space optical communication;turbulent atmosphere;channel reciprocity;transmission adaptation;channel capacity