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HFC网络论文:数字电视信号的 HFC网络传输研究【中文摘要】目前,中国有线电视数字化工程正在各个城市轰轰 烈烈地开展当中。对于中国的广电技术人员来说,将面临从模拟有线 电视的维护工作向维护数字电视的转变。当前中国的有线电视网络结 构形式基本上都是HFC光纤同轴混合),从模拟电视向数字电视的转 变需要的仅仅是在网络的前端机房增加数字电视信号编码和调制设 备和用户终端增加数字电视信号解调和解码设备(数字电视机顶盒),然后将HFC网络中传输的模拟电视信号变为数字电视信号就可以完 成。但是,由于数字电视信号和模拟电视信号采用了不同的编码和调 制方式,数字电视信号在原来传送模拟电视信号的HFC网络中会不会发生新的问题,仅仅从理论分析上是无法预测的。因此,结合南京广电 网络公司数字电视整体转换工程开展 4个月以来的数字电视业务维 护工作,对HFC网络状态和数字电视(QAM信号传输的影响进行了理 论分析和实验探究。在文章中,主要模拟了 HFC网络系统内部常见问 题引起的数字电视信号故障,分析了典型的HFC网络系统受外界干扰 引起的数字电视信号故障,并根据这两类故障的特点讨论了数字电视 信号非中断故障的排查流程。【英文摘要】Nowadays, the digital TV broadcasting service is developing quickly in manycities in China. The changing of TV broadcasti ng from an alog to digital will be a challe nge to most of our televisi on tech ni cia ns. The main structure ofChina s present Community Antenna Television Network is HFC (Hybrid Fiber Coax).What we need to do to complete the changeis add ing coders and modulators in Head-e nd and decoders and demodulators in Set-Top-Box, the consumers digital television receiver, then change the signals transmitting in HFC network from analog to digital. However, as an analog signal and a digital sig nal are coded and modulated in differe nt ways, its difficult to predict if there will be new problems when digital signal travels in the HFC network which is used for transmitting analog one only in theory. As the result, synthesizing the servicing work of digital television in four mon ths since digital televisi on gen eralizati on project bega n in Nanjing, here are some an alyses in theory and experimentationsin real situationto study whether the statusof HFC n etwork will in flue nce the QAM sig nal traveli ng in it.In this thesis, somecommoidefects in HFCnetwork system likely to in flue nce the digital televisi onsig nal were simulated, andsome typical exter nal in terfere nce which will in flue nce the digital sig nals was discussed. At the end of this thesis, con sideri ng the characteristics of the two ki nd malfu ncti ons which will in flue nce the digitalsig nals tran smissi on,how to elim in ate them was discussed.【关键词】HFC网络 数字电视信号QAM数字电视业务维护 常 见故障【英文关键词】HFC(Hybrid Fiber Coax) networkdigital televisi on sig nalQAM(Quadrature AmplitudeModulatio n)servic ing work of digital televisi oncom mon defects【备注】索购全文在线加好友自:1.39938848同时提供论文写作一对一指导和论文发表委托服务【目录】数字电视信号的 HFC网络传输研究 摘要4-5 Abstract 5 第一章 绪论8-131.1本文主要研究目的、意义和内容8-101.1.1研究目的和意义 8-91.1.2研究内容9- 101.2课题背景10-121.2.1 HFC网络发展现状10- 111.2.2数字电视的发展历程11-121.3本课题的研究手段和章节安排12-13 第二章 文献综述13-192.1关于HFC网络的研究发展13-152.2关于数字电视信号的研究发展15-19第三章 理论概要19-413.1 HFC网络结构19-243.1.1 HFC网络结构概述19-203.1.2光缆干线网络结构 20-233.1.3 分配电缆网络结构23-243.1.4用户室内网络结构 243.2数字电视系统与数字电视信号 24-303.2.1数字电视系统组成24-25 3.2.2 数字电视信号的传输方式 25-26 3.2.3 数字电视 信号的调制与解调26-303.3数字电视信号在HFC网络中的传输
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