In this paper we describe a method for supressing Radio Frequency Interference (RFI) in Discrete Multitone (DMT) based Very High bit rate Digital Subscriber Line systems. The method operates in the frequency domain of a DMT-system. It is based on a Taylor-expanded transfer function which maps the disturbance from the RF-signal onto the DMT-carriers. By measuring the RF-disturbance on a few unmodulated DMT-carriers we are able to subtract estimates of the disturbance from every modulated DMT-carrier. The RF-signal is assumed to be an unknown narrowband signal. Simulation results show that this method, applied to an RFI-signal with the same average power as the VDSL-signal, reduces the SNR-loss from about 20 dB to less than 1 dB.
Godkänd; 1998; 20080220 (ysko)