A Null Reshaping Scheme of Adaptive Notch Filter for RFI Reduction over CAP-Based VDSL Systems(Transmission Systems and Transmission Equipment)

概要

論文の詳細を見る
In this paper, a simple adaptive notch filter (ANF) scheme for reducing RFI over CAP/QAM-based VDSL systems is proposed. To alleviate the spectral null caused by notch filtering, a null reshaping scheme is introduced between the normal ANF and the decision feedback equalizer (DFE). The proposed filter scheme can control the width and depth of the null. The shallow and narrow null obtained by null reshaping reduces the loss of signal components and consequently improves the mean square error (MSE) at the output of the equalizer. The proposed null reshaping scheme also enables the infinite impulse response (IIR) type constrained ANF to have a smaller pole con- traction factor α. This results in a fast convergence property in RFI frequency estimation with a recursive prediction error (RPE) algorithm. The performance variations of the proposed null re-shaping are investigated with varying filter parameters. Compared to the conventional ANF, simulation results show that, at the expense of small system complexity, the proposed structure yields a 2-3 dB MSE gain and a fast convergence property for RFI estimation.
社団法人電子情報通信学会の論文
2003-10-01