High-order center-frequency adaptive filters using block-diagram-based frequency transformation

This paper proposes a simple method of realization of center frequency adaptive filters for high-accuracy detection of band-pass signals immersed in a broadband signal. Our method extends the conventional method proposed by Kumar and Pal. While the conventional center-frequency adaptive filters were mathematically difficult to describe in the case of high filter order, our method provides a simple procedure to construct any kind of high-order center-frequency adaptive filter. We achieve this goal with the help of the frequency transformation and its block diagram representation. Simulation results show that our high-order center-frequency adaptive filters achieve higher signal-to-noise ratio (SNR) improvement than the conventional low-order filters including the adaptive notch filters.