Key Techenology Of Synchronization And Equalization For Digital Terrestrial Television Broadcasting

With the digital era, digital television has developed rapidly in China. In 2006, China enacted a terrestrial digital TV transmission system of national standards. Compared with cable digital TV and satellite digital TV, channel to the environment of terrestrial digital TV transmission system is more complex. Due to reflection, diffraction and scattering from the pedestrians, vehicles and construction, the received terrestrial digital TV signal is a composed signal of several paths. Signals of different path with different phase and time delay superimpose on each other to form a rapid changing multipath fading. Besides, the movement of surrounding objects and receivers will change multi-path channel in time, frequency and space on the formation of the dispersion. In order to counter the terrestrial digital TV transmission system in the worst channel, it is necessary to do in-depth research for the receiver on the technology of synchronization and equalization. This article focuses on the research of key synchronization and equalization technologies, including the following:Propose a synchronization strategy based on PN training sequence,as well as a robust rapid PN phase detection algorithm.Propose an overlap structure equalization algorithm for the pre-echo channel, which can weaken the dependence on feedforward equalizer, enhance the performance and reduce the complexity.Propose an equalization algorithm combined with NR code, which prompt the receiver's performance and stability in the dynamic high-speed mobile channel.In the absence of NR code and the use of high-level constellation, this paper proposes a cyclic-training method algorithm to improve the conditions of high bit-rate equalizer against dynamic channel.