Feasibility Analysis And Channel Estimation Of Cable Bridge System

HFC is developed on the base of CATV network. HFC technology is suitable for the district which has been installed with a large number of cables. Because most of houses have been installed with CATV cable. Broadcast TV operator combines cable TV network with FTTB to effectively lower the cost of construction. This makes HFC a flexible and cheap access method, which can compete with ADSL of China Telecom.To achieve high-speed data access, we modulate high-speed data onto the out-of-band frequency of CATV cable through CB Switch and CB Modem and make telecom network, CATV network and Internet coexist on CATV cable. At present, the components of CATV network including distributor, splitter and cable are made in accordance with "The People's Republic of China Radio, Film and Television Industry Standard" which was drafted by Administration of Radio Film and Television. But this standard only covers 5～1000MHz and there is no standard that gives parameter over 1GHz.Different manufactures' components have different parameters on out-of-band frequency. There is no standard to be used as a reference. Because out-of-band CB technology will transfer signal over 1000MHz. Many problems will appear. Because the transmission attenuation is large, present contributor and splitter's insertion loss, reflection loss and frequency response can not meet the need of signal transmission. Thinking of channel test, we should do complete and suitable experiment through massive and extensive work about simulation, field test and building channel model.The project is a sub-project of Shanghai Science and Technology Commission project'High Reliable Communication Network Technology Research and Application'. Innovation of the thesis is building a complete mathematical estimation model through analyzing feasibility of access solution, which guides development of Cable Bridge and establishment of CB standard.My work is specified as following:first of all, I field tested the channel and systematically analyzed the mutual interference of CATV and Cable Bridge signal to verify the feasibility of Cable Bridge access solution. On this basis, I built distributor and splitter model as well as cable multi-path reflection model by means of test-based mathematical modeling. To simulation and fitting result, these models can reflect coaxial cable network's basic characteristic well. At last, I determine the most suitable working frequency band of Cable Bridge access system. The research is meaningful and valuable for CATV network to work in a high-speed, high-quality and multi-service way.