Comparative Research Of Digital Television Terrestrial Transmission System

This article has mainly compared two kinds of Digital Television Terrestrial Broadcasting(DTTB)system's performance -- DTMB and DVB-T.First, the development of DTTB is presented, and standards of DTTB system in some countries are simply introduced. Then, this paper is separately introduces wireless channel's dissemination characteristic and the basic principle of Orthogonal Frequency Division Multiplexing system. At the same time, it describes the sub-carrier numbers selection and the signal frame's structure of the two kinds of system– DTMB and DVB-T, and it discusses the Pros and cons of the two kinds of system from the operating rate, efficiency and the channel capacity. Finally, the result of comparison focuses on the spectrum efficiency, transmission rate, anti-interference, mobile reception, single frequency network and shows that the DTMB system performance is more superior than in these aspects the DVB-T system.On the basis of the DTMB system, it briefly describes the ways to increase data transmission rate ways: it realizes increasing data transmission rate by increasing MQAM modulation, but the cost is to increase the transmission power of the base stations and cause electromagnetic wave pollution.