A MULTICARRIER E1-HDSL TRANSCEIVER SYSTEM WITH CODED MODULATION

In this paper, we present a trellis-coded multicarrier transceiver sys tem, known as Discrete Multitone modulation, for the application of tr ansmitting digital data at the E1 rate of 2.048 Mbit/s over existing c opper telephone lines. The service of E1-HDSL (E1-rate High-speed Digi tal Subscriber Lines) is currently being studied by ETSI for future de ployment in Europe. Because of severe crosstalk and additive white Gau ssian noise (AWGN) encountered in E1-HDSL, the application of a powerf ul trellis code is highly desirable to ensure reliable system performa nce, with a required bit-error-rate (BER) of no more than 10(-7), at t he 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. B ecause of the different transmission environments encountered in the v arious 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 achi eve the E1 rate with a positive margin over all loops tested using eit her one or two sets of twisted-pairs only, depending on the particular transmission scenario.