RLS based MIMO channel identification for FEXT compensation in vectored xDSL system

Far-end Crosstalk (FEXT) is the major limiting factor in further increase of data rate in xDSL systems. Having the knowledge of the MIMO channel transmittance one can design appropriate precoder, which by the introduction of appropriate pre-distortion into transmitted signals results in FEXT compensation. As is shown in the paper identification of MIMO downstream channel in xDSL systems can be performed in frequency domain with a recursive least-squares method (RLS). Such an approach decreases computational complexity as well as memory requirement and enables tracking of individual subchannels variation.