Generalized iterative spectrum balancing and grouped vectoring for maximal throughput of digital subscriber lines

Loop loss and crosstalk are the main impairments in DSL. Recently, novel crosstalk rejection and reduction techniques have been proposed to achieve the maximum capacity of the DSL channel. The performance of these techniques depends strongly on the degree of coordination among the users. In this paper, we consider maximizing the throughput of DSL when the users are coordinated at different levels. Moreover, we propose a novel centralized power allocation algorithm by generalizing a recently proposed iterative spectrum balancing (ISB) algorithm. Our generalized ISB (GISB) algorithm provides a superior performance to the ISB with polynomial complexity in the number of users. This complexity is much lower than that of the optimal spectral balancing (OSB) algorithm. Moreover, it can be selected adaptively based on the available processing power