dqpsk调制光纤通信系统的设计与仿真.doc

DQPSK调制光纤通信系统的设计与仿 摘 要 在高速光纤通信系统中，DPSK和 DQPSK是两种具有很好的色散容忍性的 调制传输格式，本文在分析光信号传输理论的基础上，特别研究了四项相对相 移键控（DQPSK）调制格式并对其进行了软件仿真，实验得出其具有更好的色 散容忍性，论文所做工作如下： 1.分析了 DQPSK调制格式中关键器件马赫曾德尔调制器工作原理，并介绍其中 的关键技术：预编码，预编码对 DQPSK调制的影响很大，并且着重分析了两种 调制方式：串联和并联调制，最终可以得到两种调制码型： NRZ-DQPSK， RZ-DQPSK。 2.利用 optisystem软件实现了 DQPSK调制格式的仿真模型，此处马赫曾德尔调 制器采用并联模式，最终得出 NRZ-DQPSK和 RZ-DQPSK两种调制码型，改变 光纤传输距离，得到不同传输距离情况下的眼图，并对眼图进行比较分析。仿 真发现 RZ-DQPSK码型具有更好的色散容忍性。 关键词：光纤通信 新型调制格式 DQPSK Design and simulation of optical fiber communication system based on DQPSK modulation ABSTRACT In high-speed optical fiber communication systems, DPSK and DQPSK two having good dispersion tolerance modulated transmission format, the theory on the basis of the analysis of the optical signal transmission, in particular studied four relative phase shift keying (DQPSK) modulationformat and software simulation experiment has better dispersion tolerance, paper works as follows: 1.An analysis of the working principle of the key components in the DQPSK modulation format Mach-Zehnder modulator, and one of the key technology: pre-coded, pre-coded DQPSK modulation, and analyzed two modulation methods: 1  series and parallel modulation, can eventually be two types of modulation formats: NRZ-DQPSK, RZ-DQPSK. 2. Realized using optisystem software simulation model of the DQPSK modulation format, and here for the Mach-Zehnder modulator in parallel mode, and ultimately the NRZ-DQPSK and the RZ-DQPSK modulation pattern, the to change optical fiber transmission distance, to obtain different transmission distances casethe eye diagram and eye diagram for comparative analysis. Simulation RZ-DQPSK pattern has better dispersion tolerance. Keywords: Optical fiber communication New modulation formats DQPSK 2  目 录 第一章绪论..............................................................................................................1 1.1概述........