Digital RFI canceller for DMT based VDSL

Radio frequency interference (RFI) can severely degrade the performance of very high-speed digital subscriber lines (VDSLs). In the discrete multi-tone (DMT) based VDSL, some of the subchannels which are vulnerable to RFI penetration are not used, to alleviate the influence of the RFI. However, the sidelobes caused by the finite-point fast Fourier transform (FFT) are still serious. An efficient RFI cancelling method based on parameter estimation is proposed. The RFI signal after FFT looks like a sine function because it is a very narrowband signal. Therefore, it is possible to estimate the RFI components at each subchannel if we know the parameters that determine the shape of the RFI signal