Design and evaluation of DSL systems with common mode signal exploitation.

DSL technology ('digital subscriber line') provides broadband service over 'twisted pair' copper wires of the existing telephone network. Unfortunately, electromagnetic coupling between twisted pairs in the same bundle leads to (especially in new systems that make use of high frequencies) crosstalk and therefore a degradation in performance, and possibly complete loss of service. Dynamic spectrum management and crosstalk cancellation techniques can partially compensate for this effect. This project will perform a theoretical investigation into how the exploitation of 'commonmode' signals could comate sustantially for the performance reduction and even lead to a significant incraese in capacity. Specifically, the main focus of the project will be on transmission channel charachteristics, physical line and crosstalks modelling, and the development of theoretical concepts for an improved dynamic spectrum management that makes explicit use of 'common-mode' signal and even 'common-mode' signalization.