State-space Kalman adaptive IIR notch filter

A second-order adaptive IIR notch filter based on state-space structure and discrete Kalman filtering (SKANF) is represented in this paper. It is well known that the state-space description not only provides a more detail explanation of the system characteristic compared to the input-output description but also has robustness to finite word-length effects. In addition, by using the discrete Kalman filtering, the fluctuation of an estimated parameter of the filter is reduced. Additonally, sinusoidal signal detection and FM signal demodulation are employed to evaluate the performance of the proposed filter compared to the conventional structure, the adaptive IIR notch filter (ANF) and state-space adaptive IIR notch filter (SANF) Based on the proposed structure, the computer simulation results confirm that the performance of the proposed filter has been improved over ANF and also is superior to SANF.