On Power Optimization in DSL Systems

Traditionally, dynamic spectrum management (DSM) deals with the rate maximization of digital subscriber lines subject to a per modem total transmit power constraint. Motivated by the desirability of reducing total power consumption, we reformulate the problem as one of minimizing the transmit power subject to minimum target rates. Both versions of the problem are special cases of a unified framework in which both rate maximization and power minimization are objectives. We also consider less complex formulation where a flat power backoff is applied relative to a fixed power profile.