Performance Analysis of Zero Forcing Crosstalk Canceler in Vectored VDSL2

In this letter, we analyze the performance of a zero forcing (ZF) crosstalk canceler/precoder in vectored VDSL2. We show that there is gap between the theoretical capacity and the performance of the ZF canceler/precoder at higher frequencies and/or large number of vectored users. Unlike bounds developed to date, the tight rate approximations presented in this paper are valid over all frequency bands, even when the number of vectored users is large. Numerical results confirm the tightness of the derived approximations.