Turbo Coding for Transmission over ADSL

摘要

A multidimensional 16-state Trellis Coded Modulation (MTCM) is given as an option in Asymmetric Digital Subscriber Lines (ADSL) standard based on discrete multitone (DMT) techniques. To further improve the transmission performance, instead of this MTCM, we propose to use bandwidth efficient turbo trellis coded modulation (TTCM) in ADSL DMT systems. In this paper, we show that by using turbo codes, we can obtain 6 dB coding gain for a bit error rate (BER) of 10~(-6) in AWGN channels and more than 6.8 dB coding gain for a BER of 10~(-7) using a concatenated conding scheme.