The Research On Digital Terrestrial Television Broadcasting Key Technology

DTTB(Digital Terrestrial Television Broadcasting)network is the basic infrastructure for information distribution in the country with the advantages of low cost and wide coverage.Transmitter's site planning,transmit diversity and receiving diversity algorithm are not only the key for the project,but also the necessary research for next generation of DTTB technology.For the above problems,this paper focuses on the planning of SFN transmission schedule,improved SFN transmit diversity method,and receive diversity equalization algorithm:1)In SFN transmit diversity technology,this paper focus on the eSFN(enhanced Single-Frequency Network)and TDCFS(Transmit Diversity Code Filter Sets)algorithms.Based on the TDCFS transmitter diversity technique,GDCA(Gradient Descent Cyclic Algorithm)is proposed to design the filter coefficients faster.A set of transmit diversity filter coefficients with better cross-correlation performance are designed and verified by system simulation;2)In the SFN receiving diversity algorithm,based on the overlapping equalizer structure which can keep performance advantage by the non-linear equalization of DFE(Decision Feedback Equalizer),a dual feed forward equalization architecture with high latency pre-match module is proposed in this paper.The simulation results show that the algorithm can fast the convergence process of the channel equalization and improve BER performance under the typical channel(Bad Urban);3)According to the characteristics of the DTTB national standard,this paper proposes a solution of "parameter matching principle" and "serial iterative optimization process" to guide the implementation of SFN project and was used in practice.