Spectrum Optimization in Multi-User DSL Systems

Paschalis Tsiaflakis
Katholieke Universiteit Leuven, Belgium

Wednesday, October 6, 2010 at 4:00pm
Engr IV Maxwell Room 57-124

Abstract
Crosstalk interference among different DSL lines within the same cable bundle is the dominant source of performance degradation in current DSL systems. The presence of crosstalk transforms DSL systems into a very challenging multi-user multi-carrier interference environment, where different DSL users can significantly impact each other's data transmission. Multi-user spectrum optimization is a powerful technique to tackle this crosstalk problem by coordinating the transmit spectra of the different users. This type of coordination can lead to spectacular improvements in data rates as well as large energy savings, which is recently also referred to as Green DSL. The corresponding problem formulations however correspond to challenging nonconvex optimization problems. In this seminar, it will be shown that the usage of recent advances in optimization theory together with a customized optimization approach can result in very efficient and practical spectrum optimization algorithms.

Biography
Dr. Paschalis Tsiaflakis is currently a Postdoctoral Research Associate in the Department of Electrical Engineering at the Katholieke Universiteit Leuven (K.U.Leuven), Belgium, with Prof. Marc Moonen. He received the M.Eng. degree in information and communication technology from the Katholieke Hogeschool Limburg, Belgium, in 2001 and the Master's degree and the Ph.D. degree, both in electrical engineering, from the K.U.Leuven, Belgium, in 2004 and 2009, respectively. In 2007, he was a Visiting Researcher at Princeton University, NJ, USA, with Prof. Mung Chiang. Since 2004, he has been involved in several industrial research projects in collaboration with Alcatel-Lucent, Belgium. His research interests include signal processing and optimization of digital communication systems. He received the "Belgian Young ICT Personality 2010" award by FITCE.be in 2010, the "Best Multimedia Master Thesis" award by PIMC in 2001, an FWO Aspirant Grant for the period 2004-2008, a PDMK postdoc grant in 2009 and a Francqui Intercommunity Postdoc Grant in 2010.