The Study On Time Service Technology Based On Digital Broadcasting Tv Signal

With the rapid development of DSP and GSI (Grand super Scale Integrated circuit) and the communication technology ,DBTV (digital broadcasting TV) technology has taken the place of analogy TV technology, and walking forward to the mature. DBTV system has been the mainstream gradually at the same time with its higher quality, multifunction, characteristic video program service.This paper is the subject as the center item of National Time Service Center which is digital satellite TV time frequency transmit research, it is mainly researched on how to use the international standard DTMB digital TV signal to carry out the time service, and this is a completely new time service which can be a supplement for the current time service, it is also made a good use of digital TV source.The article proposals a scheme for system time service after the introduction about the principle and concept of the time service, and national standard DTMB system structure and frame structure. The major work of this article refers to three points as following: First, make sure the operation principle of the time service system, coding to the standard time signal; second, identify the PN mode and carrier mode of DBTV signal in Xi'an area , then synchronize the bit and frame to the signal to make sure the fluent transmit of the data flow; at last ,it identifies the original phase of the current signal frame and measures the transmit pseudotime according to the simulation result of signal frame synchronization, and it acquires the clock error by calculating the delay of transmit according to the distance to infer the precision of system timing, and then make a correction to the clock, finally it proposals an improvable to the scheme after analyzing the error.