New Technique for Attenuation of Narrow-Band Interference with Applications in Control and Communications Systems

Powerful adaptive filters for attenuation of multiple narrow-band interference in control and communications systems are implemented using a combination of multi-rate and heterodyne systems made adaptive by varying the sample rates and use of tunable heterodyne filters. A modified Kwan-Martin array of second- order FIR filters robustly identifies up to ten narrow-band interference signals. The new adaptive multi-rate heterodyne system translates and scales the entire signal spectrum to a series of fixed notch filters that provide the attenuation. The resulting system allows for robust adaptation while attenuating the interference with minimum effect on the desired signal.