An adaptive notch filter for eliminating multiple sinusoids with reduced bias

In this paper we propose a new algorithm for an adaptive notch filter implemented using an allpass filter, for elimination of multiple sinusoids. The notch filter is implemented using cascades of second order notch filters, each of which has been realized using a second order direct form allpass filter. We also present an analysis which indicates that the proposed algorithm has a reduced bias in the estimation of the input sinusoids. Simulation results that have been provided confirm this analysis