节点文献
分布接入的视频光纤传输系统
Distributed Access Video Optical Fiber Transmission System
【作者】 汤广强；
【导师】 于晋龙；
【作者基本信息】 天津大学 ， 通信与信息系统， 2007， 硕士
【摘要】 视频光纤传输技术是远程监控和有线电视系统中常用的重要技术,具有传输频带宽、传输信息量大、传输损耗低、传输质量高、传输距离远以及抗电磁干扰性能好等优点。本文采用一种新的结构的分布接入的视频光纤传输系统,并且设计了一种与分布接入的视频光纤传输系统相适应的视频传输节点,实现了多路视频信号的光纤传输。这种新的系统结构和视频传输节点的设计已申报国家发明专利。本论文主要包括以下几项工作:1.本文首先根据分布接入的视频光纤传输的原理构建了分布接入的视频光纤传输系统的总体方案。本系统采用多路调频信号频分复用(FDM)和光波分复用(WDM)相结合的技术方案实现分布接入的视频信号的光纤传输。2.根据分布接入的视频光纤传输系统的总体方案,建立了三路视频调频信号频分复用和四路光信号波分复用的实验系统。系统中包括十二个视频传输节点和一个接收节点。针对实验系统的构成和特点,进行了器件的选择和参数的确定。同时,对系统的光功率、载噪比、复合二次差拍失真CSO、复合三次差拍失真CTB等参数进行了理论分析和计算。3.根据实验系统方案,对视频传输节点的光路和电路进行设计,其中电路部分设计包括:光电检测处理电路的设计、频分复用电路设计、激光器驱动和调制发射电路设计以及系统电源电路设计。4.实验系统设计中,高频电路的PCB设计、高频信号的辐射和干扰以及阻抗匹配等关键问题通过仿真优化、系统实验调试等措施得到了较好的解决。
【Abstract】 Video optical fiber transmitting technology is a important technology frequently adopted in Long Distance Video Supervisory System and CATV transmitting system, which has many advantages, such as a wide transmission bandwidth、a large quantity of information、low transmission loss、high transmission quality、long transmission distance and high interference free quality. A new structure distributed access video optical fiber transmission system is adopted and a video transmission node is designed for the system to realize multi-video-signal optical fiber transmission in the paper. The structure of the system and the design of the node are applied for national patent of invention.The methods and experiments in the paper are mainly as follows:1. Firstly a distributed access video optical fiber system is designed according to the distributed access video optical fiber transmission theory presented in the paper. The system adopts a combination of frequency division multiplexing and wavelength division multiplexing technique to transmit distributed access video signals in optical fiber.2. A experiment system is designed with three channels frequency modulated video signals multiplexed by frequency division and four channels wavelength division multiplexing according to the system presented above.There are twelve video transmission nodes and one receiving node in the system. Devices are selected and parameters are fixed according to the structure and the features of the system. Parameters such as optical power、carrier-to-noise ratio、composite second order (CSO) and composite triple beat (CTB) distortions are analyzed and calculated.3. According to the experiment system, the optical link and circuits are designed for the video transmission node, in which the circuits design includes photoelectric processing circuits design、frequency division multiplexing circuit design、the drive、modulating and transmitting circuits of the laser design and the system power circuits design.4. In the process of the system design, some key points such as PCB design for the high frequency circuits、the radiated interference of the high frequency signal and impedance matching are solved by emulation、optimization and system debugging.