tailieunhanh - Báo cáo hóa học: " Research Article A Dual Decomposition Approach to Partial Crosstalk Cancelation in a Multiuser DMT-xDSL Environment"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article A Dual Decomposition Approach to Partial Crosstalk Cancelation in a Multiuser DMT-xDSL Environment | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 37963 11 pages doi 2007 37963 Research Article A Dual Decomposition Approach to Partial Crosstalk Cancelation in a Multiuser DMT-xDSL Environment JanVangorp 1 PaschalisTsiaflakis 1 MarcMoonen 1 Jan Verlinden 2 and Geert Ysebaert2 1 Department of Electrical Engineering Katholieke Universiteit Leuven 3001 Leuven Belgium 2 DSL Experts Team Alcatel-Lucent 2018 Antwerpen Belgium Received 21 September 2006 Accepted 14 May 2007 Recommended by Sudharman Jayaweera In modern DSL systems far-end crosstalk is a major source of performance degradation. Crosstalk cancelation schemes have been proposed to mitigate the effect of crosstalk. However the complexity of crosstalk cancelation grows with the square of the number of lines in the binder. Fortunately most of the crosstalk originates from a limited number of lines and for DMT-based xDSL systems on a limited number of tones. As a result a fraction of the complexity of full crosstalk cancelation suffices to cancel most of the crosstalk. The challenge is then to determine which crosstalk to cancel on which tones given a complexity constraint. This paper presents an algorithm based on a dual decomposition to optimally solve this problem. The proposed algorithm naturally incorporates rate constraints and the complexity of the algorithm compares favorably to a known resource allocation algorithm where a multiuser extension is made to incorporate the rate constraints. Copyright 2007 Jan Vangorp et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Far-end crosstalk FEXT which is typically 10-15 dB larger than the background noise is a major source of performance degradation in xDSL systems. One strategy for dealing with this crosstalk is .