Mitigation of radio interference in xDSL transmission

The twisted pair copper access network was originally intended as a transmi ssion medium for low-bandwidth analog voice signals. Unlike voiceband modem s that operate in this frequency band, emerging high-speed digital transmis sion systems like ADSL and VDSL use a much larger spectrum. Because VDSL si gnals contain frequencies up to several megahertz, these broadband signals are susceptible to more hostile noise conditions. This article identifies t he different noise impairments and shows how their effect can be mitigated in multicarrier-based VDSL systems.