Date Added: May 2012
Spectrum optimization is a promising means to tackle the crosstalk problem in DSL systems, and corresponds to a challenging non-convex optimization problem. Iterative Convex Approximation (ICA) methods have been proposed in the literature to deal with this optimization problem. These methods consist in solving a series of improving convex approximations and are typically implemented in a per-user iterative approach. In this paper, the authors develop a novel class of iterative methods that focus explicitly on per-user iterative implementations, and which consist of improved per-user approximations that are tighter and simpler to solve (in closed-form) than state-of-the-art ICA methods.