Reed-Solomon (RS) code and multidimensional trellis-coded modulation (MTCM) can be concatenated to improve the performance of Discrete Multitone (DMT) modulated digital subscriber line (DSL) systems. The criteria to design an effective coding scheme with MTCM and RS code including an efficient interleaver are described in this paper. The results of simulation to evaluate the performance of the proposed coding scheme are presented. The performance is compared with the earlier designs and some useful findings are observed. In addition, a novel iterative decoding scheme is also proposed for ADSL channel.