Simulations of Far-end Crosstalk based on Modified Matrices of Transmission Line

Abstract

Far-end crosstalk (FEXT) is the dominant source of disturbance in digital subscriber lines. One of the most promising solutions for FEXT cancellation is Vectored Discrete Multi-tone modulation (VDMT). However, this process of elimination by VDMT is mathematically very complex and it causes high computational demands in multiplexors and terminals. The promising solution would be performing VDMT only for a limited number of the most disturbing pairs in a cable. However, this method would require very accurate and realistic simulations of FEXT and its individual prediction for each pair in a metallic cable. The standard simple FEXT model is not very accurate and does not provide realistic results. That’s why a new advanced method for modeling of FEXT was developed and is presented here. This advanced FEXT model is based on the modified transmission matrices together with calculation of capacitive and inductive unbalances between pairs in a cable and it also respects cable’s internal structure. This paper includes mathematical derivation of the advanced FEXT model as well as examples of obtained results, which are also compared with standard FEXT model and with measured characteristics. Ill. 4, bibl. 8, tabl. 1 (in English; abstracts in English and Lithuanian).

http://dx.doi.org/10.5755/j01.eee.116.10.876