EURASIP Journal on Applied Signal Processing 
Volume 2006 (2006), Article ID 58380, 10 pages
doi:10.1155/ASP/2006/58380

Spectrally Compatible Iterative Water Filling

Jan Verlinden,1 Etienne Van den Bogaert,2 Tom Bostoen,1 Francesca Zanier,3 Marco Luise,4 Raphael Cendrillon,5 and Marc Moonen6

 1Access Networks Division, Alcatel, Francis Wellesplein 1, Antwerpen 2018, Belgium
2Research & Innovation Department, Alcatel, Francis Wellesplein 1, Antwerpen 2018, Belgium
3Department of Telecommunication Engineering, University of Pisa, Pisa 56122, Italy
4Department of Information Engineering, University of Pisa, 56122 Pisa, Italy
5School of Information Technology and Electrical Engineering, University of Queensland, Brisbane 4072, QLD, Australia
6Department of Electrical Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 10, Leuven-Heverlee 3001, Belgium
Received 2 December 2004; Revised 1 July 2005; Accepted 12 July 2005

Abstract

Until now static spectrum management has ensured that DSL lines in the same cable are spectrally compatible under worst-case crosstalk conditions. Recently dynamic spectrum management (DSM) has been proposed aiming at an increased capacity utilization by adaptation of the transmit spectra of DSL lines to the actual crosstalk interference. In this paper, a new DSM method for downstream ADSL is derived from the well-known iterative water-filling (IWF) algorithm. The amount of boosting of this new DSM method is limited, such that it is spectrally compatible with ADSL. Hence it is referred to as spectrally compatible iterative water filling (SC-IWF). This paper focuses on the performance gains of SC-IWF. This method is an autonomous DSM method (DSM level 1) and it will be investigated together with two other DSM level-1 algorithms, under various noise conditions, namely, iterative water-filling algorithm, and flat power back-off (flat PBO).