Turbo Codes In Digital Video Broadcasting Applications

DTTB(Digital Television Terrestrial Broadcasting) is one of the present digital television broadcasting modes, whose transmission media is earth. After a decade of intense research and development, the standards of Digital Television Satellite Broadcasting and Digital Television Cable Broadcasting have been confirmed. But the standard of Digital Television Terrestrial Broadcasting is still in disputation, for its transmission environment is rather awful, its spectrum resource is very limited and its service required is disperse, so it is potential to be improved in many aspects.DVB-T (Digital Video Broadcasting) specification is one of the DTTB standards. It has better results in digital television program terrestrial reception test and has good appraisement in digital television broadcasting industry. This paper based on COFDM transmission scheme, expround the encode/decode technology in channel of DVB-T COFDM transmission system,it is very important in DVB-T COFDM transmission system. The performance of encode/decode will have a tremendous influence to the whole transmission system, we can improve performance through the choice to every module circuit parameter, and we can use other outstanding encode/decode schemes too, it will improve the performance of the whole system greater. This paper gives the COFDM transmission principle and DVB-T COFDM scheme. On the basis of theory about channel coding, simulation of the performance on SCCC based with Matlab has been done. Turbo codes have been the hot research area in communication since it was proposed in 1993. Turbo decoding has been paid more attention. The principle of Turbo codes is introduced in the following aspects: encoder, decoder structure and trellis termination. Some performance effect factors are simulated based on the performance analysis. And then, this paper analyses the turbo decoding algorithms from the aspects of performance and complexity. Finally, Turbo coding applied in COFDM is discussed, and its feasibility also tested by lots of performance analysis.