Adaptive Iterative Water-Filling for Dynamic Spectrum Management in DSL Networks

Abstract

This paper considers an adaptive iterative water-filling (IWF) algorithm to deal with the near-far problem in Digital Subscriber Lines (DSL) networks. In order to protect the far-end users, the paper proposes a new power back-off strategy by a pro-active configuration of the spectral mask at the near-end users. Instead of reducing the total power of the near-end users as in IWF, the proposed algorithm allows the near-end users to only back off the power in certain frequency bands. Simulation shows a significant performance advantage of the proposed algorithm over the traditional IWF algorithm. Moreover, the performance of the proposed algorithm approaches the optimal performance obtained by centralized algorithm with full channel information requirement while retaining the low-complexity and distributed implementation of the IWF.