激光脉冲湍流大气瞬态传输机理及对FSO通信的影响研究

项目名称： 激光脉冲湍流大气瞬态传输机理及对FSO通信的影响研究

项目编号： No.61275080

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 杨华民

作者单位： 长春理工大学

项目金额： 75万元

中文摘要： 激光脉冲属于瞬态光场，其光场统计特性依赖于具体时间位置。湍流大气传输使激光脉冲发生形状畸变、时间扩展、到达时间起伏、时变光强闪烁等瞬态特性变化。与低速率IM/DD模式FSO通信系统不同，当速率达到几十Gbps以上时，传统的基于连续光波传播理论的FSO通信湍流大气影响模型不再可靠，在模型中必须考虑激光脉冲瞬态特性变化的影响。首先研究激光脉冲湍流大气传输的瞬态特性变化机理，建立激光脉冲的瞬态特性解析理论模型；然后开展激光脉冲湍流大气传输的数值模拟研究，从不同的物理角度来检验和修正解析理论模型；接着研究湍流大气导致的激光脉冲瞬态特性变化与FSO通信判决信噪比的模型关系，以便可靠地评估和分析FSO通信中的湍流大气影响；最后开展激光脉冲湍流大气传输瞬态特性及FSO通信误码率测量实验研究，通过分析和比较实现对理论模型的检验和修正。本项目研究可为湍流大气信道FSO通信系统的性能评估与优化设计提供支持。

中文关键词： 自由空间光通信；湍流；脉冲；传输；展宽

英文摘要： Laser pulses belong to transient optical fields whose statistics is dependent on the time. The propagation of a laser pulse in turbulent atmosphere causes the changes of its transient characteristics, such as the shape distortion, temporal broadening, arrival-time fluctuations, time-varying intensity scintillations, and so on. Different from the low-speed FSO communication system using IM/DD scheme, if the speed increases beyond several Gbps, the traditional models for evaluating the effects of turbulent atmosphere on the FSO communication performance becomes invalid, in which the changes of transient characteristics of laser pulses need to be considered. First, the change mechanism of the transient characteristics of laser pulses will be investigated and the theoretical models will be derived. Second, numerical simulations of laser pulses propagating in turbulent atmosphere will be studied, and the results can be used to validate and correct the theoretical models from a different physical perspective. Third, the models with respect to the relationship between the decision signal-to-noise ratio (SNR) of FSO communication receiver and the turbulence-induced changes of transient characteristics of laser pulses will be proposed to evaluate and analyze the turbulence-induced effects on the FSO communication perform

英文关键词： free-space optical communication；turbulence；pulse；propagation；broadening