INSURING SPECTRAL COMPATIBILITY OF ITERATIVE WATER-FILLING (ThuAmSS1)

Author(s) : Radu Suciu (Alcatel, Belgium) Etienne Van den Bogaert (Alcatel, Belgium) Jan Verlinde (Alcatel, Belgium) Tom Bostoen (Alcatel, Belgium)

Abstract : DSM (Dynamic Spectrum Management) consists of a set of techniques that basically allow a DSL modem to adapt its transmit spectra according to the noise on the line, instead of using a fixed mask. There are several algorithms that per-form DSM, and this contribution will refer to the well-known “Iterative Water-Filling” (IWF) [1]. The T1E1.4 group (ANSI) specifies several methods to en-sure spectral compatibility [2]: Method A (fixed mask) and Method B (a set of tests that the new service’s transmit power spectral density (PSD) must pass. Since simulations have shown that Method A is too restrictive for Iterative Water-Filling, a new set of masks is proposed in the present contribution (satisfying Method B). Simulation results are presented as well, showing the gains of Iterative Water-filling under these conditions.

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