Adaptive sinusoid detection using IIR notch filters and multirate techniques

In this paper, a new structure for the detection of sinusoids using adaptive IIR notch filters and multirate techniques is presented. By using the frequency enhancement property of the decimation in time process, the proposed structure avoids the use of almost unity radius notch filters. A stochastic analysis of the convergence properties of the proposed multirate IIR notch filter structure is discussed. The analysis verifies the low adaptation coefficient variance of the proposed structure, and the small bias in the frequency estimates of multiple sinusoidal signal. Computer simulations show the superior performance of the proposed structure for the detection of closely-spaced sinusoids and tracking of nonstationary sinusoidal signals