Multiple NEXT interference cancelation in VDSL

F. GREGORIO; J. E. COUSSEAU; P.D. DOÑATE

San Nicolás

Congreso; X Reunión de Procesamiento de la Información y Control; 2003

RPIC

Sorne of the rnost irnportant dis-turbing sources that affect VDSL systerns are crosstalk frorn different DSL services and the near-far problern. A rnethodology to reduce NEXT interferences produced by rnultiple sim-ilar services that have srnaller bandwidth than VDSL, as are the case of rnultiple local area networks (LAN), is introduced in this work. There are different techniques that can be applied to cancel Next LAN interferences, but rnost of thern only work correctly when a dorn-inant LAN interference exists. If there is not a dorninant interference these rnethods fail to reduce the crosstalk or becorne very cornplex to irnplernent considering the requirernents of big cornputational recurses. In this work, a new cancelling technique ap-plied to reduce NEXT interference frorn rnul-tiple passband CAP systerns which have differ-ent carrier frequencies is presented. Multiple passband CAP systerns can be regarded as an alternative LAN service not olny for resourses distribution but also because they can coexist with VDSL services in a more efficient way in terrns of crosstalk cancelation. Cornputer sirnulations using standard LAN rnodels, HPN A systerns and CAP systerns are included to verify the cancellation results.