自由空间光通信系统中占空比复用的改进  

Improvement on DCDM-based FSO transmission system

作　　者：柴佳[1] 陈新桥[1] 张薇[1] 黄亚楠[1] CHAI Jia;CHEN Xinqiao;ZHANG Wei;HUANG Yanan(College of Information Engineering, Communication University of China, Beijing 100024 ,China)

机构地区：[1]中国传媒大学信息工程学院

出　　处：《激光杂志》2018年第4期102-105,共4页Laser Journal

基　　金：ARM平台升学处理软件开发项目(No.HG170)

摘　　要：针对自由空间光通信（FSO）系统中,信号的信息容量随着用户数量增加而受到限制的问题,提出了对占空比复用（DCDM）的改进,研究了改进的工作原理及实现方法,用Matlab软件编写了改进后系统的调制器和解调器,用Optisystem软件搭建了该系统的实验仿真平台。利用替换信号对复用信号移除替换,实现了替换信号的占空比数值可调,对比分析了系统误码率和每比特复用信号的平均能量。仿真结果表明：改进后四路通信系统的幅值阶数降低1阶,每比特复用信号的平均能量最大降低16.25%,在系统误码率是时,改进后系统信息容量增加23Gbit/s。In the free space optical communication（ FSO） system,the channel capacity is limited by the increasing of users,so an improvement on duty cycle division multiplexing（ DCDM） was proposed. The principle and the method of realizing have been analyzed; the module of modulation,demodulation and block diagram of improved-DCDM（ I-DCDM） were established by jointing Matlab and Optisystem. By replacing some multiplexed signals using replacing signals,the different duty cycle of replacing signals were achieved in a system. The BER and average energy per bit were analyzed. Simulation results verified that the level amplitude of multiplexed signals was reduced by 1 and the power of transmitted signal was reduced by 16. 25% in a 4-channel system. When the BER is,the improved system increase in the channel capacity is about 23 Gbit/s.

关 键 词：信号替换 自由空间光通信 占空比复用 信息容量 

分 类 号：TN919[电子电信—通信与信息系统]