DMT MIMO-IC Rate Maximization in DSL with Combined Signal and Spectrum Coordination

Theoretical research has demonstrated that the achievable gains in data rate with dynamic spectrum management, i.e. signal coordination or spectrum coordination, are substantial for digital subscriber line (DSL) networks. Work on these two fronts has progressed steadily and, more often than not, independently. In this paper, we combine the two types of coordination for a mixed DSL scenario, in which some of the infrastructure required for full two-sided signal coordination is available, but not all. This scenario, which is referred to as the discrete multitone multiple-input, multiple-output interference channel (DMT MIMO-IC), consists of multiple interfering users, each operating a distinct subset of DSL lines as a MIMO system. Coordination is done both on the signal level (with per user MIMO techniques) and on the spectrum level (with multiuser power allocation). We propose two algorithms for the DMT MIMO-IC weighted rate maximization problem. In the first algorithm, we profit from recent A preliminary version of this paper was presented at the European Signal Processing Conference (EUSIPCO), Barcelona, Spain, in September 2011. This research work was carried out at the ESAT Laboratory of the KU Leuven, in the frame of KU Leuven Research Council CoE EF/05/006 Optimization in Engineering (OPTEC) and PFV/10/002 (OPTEC), Concerted Research Action GOAMaNet, the Belgian Programme on Interuniversity Attraction Poles initiated by the Belgian Federal Science Policy Office IUAP P6/04 (DYSCO, Dynamical systems, control and optimization, 2007-2011), Research Project FWO nr.G.0235.07(Design and evaluation of DSL systems with common mode signal exploitation) and IWT Project PHANTER: PHysical layer and Access Node TEchnology Revolutions: enabling the next generation broadband network.