Adaptive estimation and compensation technique of channel nulls over VDSL systems

Abstract

A simple compensation technique for channel nulls induced by bridged taps is proposed over very high-speed digital subscriber line (VDSL) systems. The lost signal components caused by bridged taps are compensated for by an adaptive filter the transfer function of which has poles at the null frequencies. Null frequencies are adaptively estimated using the minimum power criterion of the filter output. The decision-feedback equaliser (DFE) with the proposed filter showed a 4-5 dB mean square error improvement compared with the conventional DFE.