COORDINATED DIGITAL TRANSMISSION - THEORY AND EXAMPLES

New methods for the exploitation of noise correlations in multiple sig nal receivers are proposed. With dynamic coordination the entire corre lation can be exploited. Starting from the optimum receiver, structure s of receivers with reduced complexity are presented. Applying dynamic coordination, only correlations of simultaneous noise samples or a sp read of the signal-to-noise ratios remain. These effects can further b e exploited by static coordination if signal power and transmission ra te are alloted to the individual channels in an optimum way. Gains der ived by capacity arguments as well as by optimization of the signal co nstellation are given. It is shown that coordinated decision-feedback- equalization can achieve asymptotically capacity of the multi-channel. Finally, examples for HDSL transmission in the German Telekom network are given, derived from crosstalk transfer function measurements with in one binder group of a telephone line. For realistic situations gain s up to 3 dB due to coordination compared to the state of the art rece iver are possible.