Intertwined With The Space-time Coding Scheme Performance. Of Turbo Codes

On the basis of channel capacity and shannon limit of information theory, we introduce the Turbo codes which obtain the near capacity performance. Methods of theory analysis and computer simulation are used to research the structure and performance of Turbo codes, especially the interleaver in the Turbo codes which is the emphasis of the author. There are seven chapters in this paper altogether. In the second chapter we give the structure of Turbo codes encoding and the algorithm of decoding, the optimization design of the Turbo codes. Subsequently in the third chapter we emphasis our research point on the interleaver of the Turbo codes. From the point of Shannon theory interleaver is the important factor which make Turbo codes have the nature of long random codes. we present 14 kinds of interleaver and each of them has the different effect on the Turbo codes, especially the Code-Matched interleaver. The deep analysis of Turbo codes show that the codewords weight is one reason of Turbo codes excellent performance.The code-Matched interleaver affect the codewords weight and eventually make Turbo codes present the optimal performance. we make out the complete design rule of code-Matched interleaver in the paper. We develop the parallel decoding algorithm which decrease the decoding delay and the permutation mapping law in the fourth chapter, on the basis of which we bring forward the S-random interleaver design in the parallel decoding. The fifth chapter is about the scheme of Turbo code combined ARQ and some results are concluded.Diverdity is the technique in wireless communications that resist the multipath effect and enhance the capacity. In the sixth chapter we introduce the transmit diversity schemes including V-BLAST, D-BLAST, space-time trellis coding and space-time block coding. And we combine the Turbo codes and space-time block coding scheme to obtain the coding gain and the diversity gain of communication system.