[信息与通信]基于GPON的FTTH系统中上行信道复用技术研究-陈可勇06003205.doc

基于GPON的FTTH系统中上行信道复用技术研究 摘要 吉比特无源光网络（GPON）是一种发展前景良好的接入网技术，具有带宽高，安全性、稳定性好，维护简单等优点。被认为是实现光纤到户（FTTH）最有前途的宽带接入方式。而上行接入技术是GPON中的关键技术。 本文根据ITU-T G.984协议，提出了GPON系统上行复用技术的简化思想——定时隙信道复用。首先，基于业界标准和实验情况,给出了GPON系统的TDM-WDM上行接入方案﹑工作参数和业务参数。其次，重点讨论了传输帧的结构，对帧的类型和位宽作了详细研究。再次，简化了GPON系统的工作流程，同时介绍了测距和同步的相关方法。最后，在理论的基础上，采用Verilog HDL硬件描述语言，并通过ModelSim实现了光线路终端（OLT）和光网络终端（ONU）功能的简单仿真，为进一步实现基于FPGA的千兆无源光网络MAC子层协议设计奠定了基础。 关键词：吉比特无源光网络；上行复用；传输帧；光线路终端；光网络终端；硬件描述语言 Abstract The Gigabit Passive Optical Network (GPON) is a kind of promising technology for optical fiber access. It is considered as the best broadband access method for its high bandwidth, strong security, good stability and easiness to maintain, etc. And upstream access is a key technology for GPON. According to the protocol of ITU-T G.984，this paper introduces a simplified idea of the upstream multiplexing technology of GPON: fixed timeslot and channel multiplexing. First, a TDM-WDM upstream access program as well as working and service parameters is presented based on industry standards and experimental situation. Second, the structure of transmission frame is mainly discussed through careful study in its type and bit width. Third, the workflow of GPON is simplified and methods of ranging and synchronization are introduced. And finally, on the basis of previous theories, functions of Optical Line Termination (OLT) and Optical Network Unit (ONU) are simulated by using ModelSim and Verilog Hardware Design Language (HDL), which contributes to the realizing of MAC sublayer protocol of GPON by Field Programmable Gate Array (FPGA). Keywords: gigabit passive optical networks; upstream multiplexing; transmission frame; optical line termination; optical network unit; hardware design language 目录 摘要 I Abstract II 目录 III 第一章 绪论 1 1.1吉比特无源光网络（GPON）简介 1 1.1.1 GPON相关概念 1 1.1.2 GPON优势凸显 1 1.1.3 GPON前景广阔 2 1.1.4 GPON协议简介 2 1.2吉比特无源光网络上行复用技术简介 5 1.2.1 波分复用（WDM）技术 5 1.2.2 时分复用（TDM）技术 5 1.3 光纤到户（FTTH）简介 6 1.4本文研究目的及TDM-WDM研究方案 7 第二章 定时隙信道复用GPON系