The Applied Research Of The Dispersion Compensation Technology In The Cable Television Signal Transmission Over Long Distances

The cable television in China has developed rapidly in recent years. Cable TV network spreads the counties and towns all over the country, which composes national broadcasting TV transmission network with other transmission methods such as satellites and microwaves. The broadcasting TV transmission network which takes an important role in the national economy and the telecommunication network become the important elementary facilities of our national Informantion Industry. The emergence of digital television in the world sets off an unprecedented revolution in industrial technology, it brings not only high-capacity program transmission, a strong anti-interference ability, high-quality image and voice, more importantly is that it makes TV become active access to information, mutual communication, entertainment and leisure tools. As an important component part of the broadcasting television network, the cable television network gets more attention because of its special characteristics such as its wide transmission band, its extensive consumer range. The wide transmission band of the cable television network not only makes it transmit more broadcasting programs but also develops other network service using the network's abundant capacity.The construction of cable TV network has entered into the fast lane. Especially the strategic plan of the convergence of three networks has already come to consensus and implemented at "speeding up the upgrading of cable TV network, strengthenning multi-functional development and application in the network, striving for the new points for economic growth". So far, most of the cable television networks in the big or medium cities has mainly finished HFC local network(750 MHz or 860 MHz)'s renovation and upgrading. But the problems in the network transportation between the small and medium cities, especially the problem of the descent of the system target because of the dispersion of the light in the long-distance light transmit always assails the development of the network business in the cities and counties.The thesis first comments on the construction, structure of the CATV network which bases on the technology in the light dispersion and compensation, it also comments on the methods of the signal modulation. Then it introduces a series of the network reforming projects about the dispersion and compensation of light. In the network reforming projects, the writer has the thorough consideration of the technology and other businesses'development in the present and future, and reserves the index opulent amount. The article analyses the application of the light dispersion and compensation in the cities and counties'cable television network and proposes some solutions to some practical problems in the process of design, installment and modulation.The technological reform of the light dispersion and compensation in the cities and counties'cable television network not only promotes the reliability and service qualities of the network, but also can achieve a number of appreciation business on the network, which fully develop the network economic benefits and improve the network competitive ability.