A single-parameter adaptive comb filter

Abstract

The study is concerned with a single-parameter adaptive comb filter (ACF), a multi-notch filter with periodically located nulls. The filter is suggested to retrieve a waveform modeled by superposition of harmonics, in particular, periodic non-sinusoidal signal. Using trigonometric constraints between the signal fundamental frequency and over tones results in a non-linear estimation problem. In the present study, the parameter adjustment relies on the extended Kalman filter scheme. Particularly, the 2, 3 and 4 notch ACF are derived and tested under different conditions. Given a multi-tone scenario, the ACF significantly outperforms common adaptive multi-notch filter.