Asymptotic performance analysis of zero forcing DSL systems

In this paper, we present a novel approximation to the spectral efficiency at the output of a zero-forcing (ZF) receiver in a DSL upstream system. This approximation is extracted by a new asymptotic analysis, where we construct an alternative sequence of systems that includes the system of interest. Drawing on works in the field of large dimensional random matrices, we show that the user rate in this sequence converges to a non-zero rate. We also provide numerical simulations which show that this approximation is accurate even for relatively low dimensional systems.