Modeling the Terminal Response of a Bundle of Twisted-Wire Pairs Excited by a Plane Wave

The proposal to use multiple-input multiple-output vectored transmission in digital subscriber line (DSL) systems has prompted a revision of the channel noise models used to characterize twisted-wire pairs (TWPs). In this context, a transmission-line model for predicting the terminal response of a bundle of TWPs to an illuminating plane-wave electromagnetic field is introduced. The corresponding nonuniform transmission-line equations for the multiconductor system are solved numerically. The goal of the model is to provide a tool for solving a wide variety of radio-frequency interference problems in DSL systems. Computed results for a variety of TWP structures are presented, and the issue of small random twisting nonuniformities is explored.