Study Of Coded Modulation & Application Of TCM

Modern communication services require communication systems can provide high date rate with favorable communication quality. But this is a challenge for limited bandwidth channel with inter-symbol interference. In order to solve this problem, this thesis studied on two kinds of channel coded modulation schemes. The principles and applications of Trellis Coded Modulation (TCM) and Multilevel Coded Modulation (MLC) are investigated.This thesis introduced the concept of TCM, the principle of set partition and the method of computing coding gains. Soft decision Viterbi decoding is emphatically discussed and the performance of TCM is analyzed by computer simulation. This paper discussed the application of TCM in real modulation systems, proposed the schemes of TCM-8PSK and TCM-OFDM. According to the parameters of these two systems, the means to design encoder and decoder of TCM in FPGA are introduced.In terms of"channel capacity rule", this thesis discussed MLC system which chose punctured convolutional codes as component code. Multistage Decoding (MSD) and Parallel Decoding (PDL) are emphatically introduced. And the performance of comparison of MLC with different decoding methods over the Rayleigh channel is got by simulations.