Tracking characteristics of an adaptive IIR notch filter for sinusoidal frequency variation

Abstract

Tracking behavior of a gradient-based simplified algorithm for an adaptive infinite impulse response (IIR) notch filter with a sinusoidally-varying input signal frequency is presented in this paper. A first-order difference equation with respect to a steady-state instantaneous frequency tracking error is derived. The difference equation is used to derive tracking error and tracking mean square error (MSE) expressions based on the power spectral density (PSD) method. Extensive computer simulations are included to substantiate the analysis and show its limits.