Derivative Based Real-Time Spectrum Coordination for DSL

In digital subscriber line systems, spectrum coordination is a powerful technique to improve performance. A typical spectrum coordination algorithm employs an iterative procedure to solve the rate adaptive spectrum management problem. These iterative procedures deliver a feasible result only after convergence, and are therefore mostly unable to deal with real-time computational constraints. Recently, the new paradigm of so-called real-time dynamic spectrum management has been defined. This paper presents a simple and powerful framework for real-time spectrum coordination based on bi-coordinate ascent methods. This framework is then used to define a novel derivative based real-time spectrum coordination algorithm with provable convergence properties, referred to as fast derivative based iterative power difference balancing (F-DB-IPDB). Simulation results show a significant improvement in performance compared to the state of the art.