tailieunhanh - Báo cáo hóa học: " Research Article Selective Iterative Waterfilling for Digital Subscriber Lines"

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 Selective Iterative Waterfilling for Digital Subscriber Lines | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 59068 11 pages doi 2007 59068 Research Article Selective Iterative Waterfilling for Digital Subscriber Lines Yang Xu Tho Le-Ngoc and Saswat Panigrahi Department of Electrical and Computer Engineering McGill University 3480 University Street Montreal Quebec Canada H3A 2A7 Received 7 August 2006 Revised 15 December 2006 Accepted 5 March 2007 Recommended by H. Vincent Poor This paper presents a high-performance low-complexity quasi-distributed dynamic spectrum management DSM algorithm suitable for DSL systems. We analytically demonstrate that the rate degradation of the distributed iterative waterfilling IW algorithm in near-far scenarios is caused by the insufficient utilization of all available frequency and power resources due to its nature of noncooperative game theoretic formulation. Inspired by this observation we propose the selective IW SIW algorithm that can considerably alleviate the performance degradation of IW by applying IW selectively to different groups of users over different frequency bands so that all the available resources can be fully utilized. For N users the proposed SIW algorithm needs at most N times the complexity of the IW algorithm and is much simpler than the centralized optimal spectrum balancing OSB while it can offer a rate performance much better than that of the IW and close to the maximum possible rate region computed by the OSB in realistic near-far DSL scenarios. Furthermore its predominantly distributed structure makes it suitable for DSL implementation. Copyright 2007 Yang Xu 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 Crosstalk is the dominant source of performance degradation in digital subscriber lines DSLs systems where multiple