A MULTICARRIER E1-HDSL TRANSCEIVER SYSTEM WITH CODED MODULATION

In this paper, we present a trellis-coded multicarrier transceiver system, known as Discrete Multitone modulation, for the application of transmitting digital data at the E1 rate of 2.048 Mbit/s over existing copper telephone lines. The service of E1-HDSL (E1-rate High-speed Digital Subscriber Lines) is currently being studied by ETSI for future deployment in Europe. Because of severe crosstalk and additive white Gaussian noise (AWGN) encountered in E1-HDSL, the application of a powerful trellis code is highly desirable to ensure reliable system performance, with a required bit-error-rate (BER) of no more than 10(-7), at the desired E1 data rate. Detailed descriptions of the DMT transmitter and receiver structures are given, and projected performance results, both with and without the addition of a trellis code, are presented. Because of the different transmission environments encountered in the various countries in Europe, we have performed our computer simulation on both British and German (1) copper twisted-pairs. We find that with the addition of Wei's powerful 4-D 16-state trellis code: we can achieve the E1 rate with a positive margin over all loops tested using either one or two sets of twisted-pairs only, depending on the particular transmission scenario.