Punctured Trellis-Coded Modulation

THIS PAPER IS ELIGIBLE FOR THE STUDENT PAPER AWARD In classic trellis-coded modulation (TCM) signal constellations of twice the cardinality are applied when compared to an uncoded transmission enabling transmission of one bit of redundancy per PAM-symbol, i.e., rates of K K+1 when 2 denotes the cardinality of the signal constellation. In order to support different rates, multi-dimensional (i.e., D-dimensional) constellations had been proposed by means of combining subsequent oneor twodimensional modulation steps, resulting in TCM-schemes with 1 D bit redundancy per real dimension. In contrast, in this paper we propose to perform rate adjustment for TCM by means of puncturing the convolutional code (CC) on which a TCM-scheme is based on. It is shown, that due to the nontrivial mapping of the output symbols of the CC to signal points in the case of puncturing, a modification of the corresponding Viterbi-decoder algorithm and an optimization of the CC and the puncturing scheme are necessary.