数字电视传输网络技术与标准（Digital TV transmission network technology and standard）.doc

数字电视传输网络技术与标准（Digital TV transmission network technology and standard） - digital television transmission network technology and standards - Source: broadcast television information 2004-01-05 15:29:04. 0 Author: professor Yang zhixing, director of digital TV transmission technology rd center of tsinghua university Key words: digital TV, transmission network, analog TV, broadcast TV, coverage, analog TV, signal, coaxial cable Three transmission networks, three transmission standard systems, constitute a digital television grid. Different digital TV systems occupy a grid. China is nurturing its own digital TV transmission standards, which are expected to have greater autonomy in setting up a digital TV grid. Digital TV has three transmission networks Digital TV transmission network mainly refers to terrestrial, cable and satellite radio transmission network. The terrestrial digital television broadcast network, which broadcasts radio waves through the TV stations commanding high antenna, overrides TV users, who watch TV programs by receiving antennas and television sets. This is the most basic digital television broadcast transmission network form, in addition to entertainment, study and other public welfare function, its universality, controllable and anti-destroying ability was seen as a national security facilities, making it the case of an emergency mobilization of the national most directly and reliable government mouthpiece. Due to the inability of analog TV transmission network to deal with noise accumulation and multipath interference, the antenna is forced out of the room, resulting in the development of the public antenna system in the cluster. As the whole channel analog TV broadcasting signal optical fiber broadband transmission technology breakthrough, a dry for optical fiber, coaxial cable for the tree hybrid fiber/coaxial (HFC) net in common use of the city, gradually evolving into independence from the ground broadcast system of cable TV network, with