Study On Trellis-Coded Modulation And Viterbi Decoding Used In ADSL

This thesis firstly introduces technique character and application foreground of asymmetric digital subscriber line (ADSL), then studies the theories of trellis-coded modulation (1CM) and Viterbi decoding algorithm, the analysis of design method of multidimensional constellation by using sublattice division, the Viterbi decoding method of trellis-code modulation, and the emphasis is put on the calculating method of upper bound to error bit probability by using error-state diagram and generation function. Finally, an ADSL system using 4-dimensional TCM and that without using 4-dimensional TCM are simulated. It is concluded that the performance of system using 4-dimensional 1CM is improved efficiently.