Research On Adaptive Coded Modulation Based On CT-TCM

Adaptive coded modulation (ACM) is a powerful technique to achieve high throughput on flat fading channel. As one of the key techniques in 3G, adaptive coded modulation attracts more and more researchers' eyes in recent years.In this dissertation, the basic idea and the classification of ACM are systematically introduced, and the ACM based on channel state information is analyzed in detail. The paper analyzes some coded-design problems of Concatenated Two-State Trellis Coded Modulation (CT-TCM) in detail, such as the design of the underlying binary code, the design of symbol-interleavers, mapping rules and the asymmetrical and time-varying trellis structures of CT-TCM. Compared with the existing turbo-type bandwidth-efficient coded modulation schemes, CT-TCM has significantly reduced complexity without sacrificing performance.Finally, the paper introduces CT-TCM to ACM system based on channel state information. We present the general principles of combining CT-TCM with ACM techniques designed for flat fading channels. We then apply these techniques to a spectrally efficient adaptive coded modulation to obtain the CT-TCM adaptive coded modulation system. In our ACM system, we give two kinds of receiver structure corresponding to the two methods of channel estimation. These two methods are compared with each other, and we choose the better one for our adaptive CT-TCM system.