RFI suppression in multicarrier transmission systems

Mutual radio frequency interference with amateur radio transceivers may be a very serious problem for VDSL systems that use a frequency band up to about 12 MHz. Discrete multitone (DMT) is a strong candidate for the very high-speed digital subscriber loop (VDSL) standard, but it has previously been thought that it is overly sensitive to RFI (both egress and ingress). This paper defines the problems and is a preliminary report on a combination of methods applicable to DMT that solves them.