The Research Of Coded Modulation Technology Based On Turbo Code

Turbo code represents the most advanced channel coding technology in the world nowadays.Because its error-correcting performance is very closely to the Shannon limit,Turbo code attracting concern and study of countless experts and scholars in communication domain once it appears.The goal of this paper is to study the application of coded modulation technology in communication system based on turbo code. Firstly, the encoder and decoder basic structures and theory of turbo code are introduced. Secondly ,introduced the basic principle and composition method of TCM, and turbo code combined with TCM so formed T-TCM technology,then put forward a new signal mapping method for 16QAM constellation of nonuniform sources.we combined it with T-TCM and apply to satellite communication in order to improve its performance further. Then introduced the fundamentals of OFDM modulation technology. Multipath fading is the main characteristic of mobile communication channel, and OFDM technology can well resist multipath fading ,so it can solve the problem of anti-interference when high speed data transmission in wireless communication . Finally we combine turbo code with OFDM technology ,then make some emulations under several kinds of channel fading types in the mobile communication ,it has offered new choice for turbo code applying in fading channel.Turbo code combined with high-efficient modulation technology is the focus in recent years, but how to choose the structure parameters,the interleaving and the structures of encoder and decoder according to different modulation technology can make the whole performance better are await further research.