A Hybrid Method for Interference Mitigation in GNSS Signals

A novel instantaneous frequency-based jamming interference suppression method for GNSS signals is developed. The spectrogram-based jammer instantaneous frequency estimation methods suffer from resolution limitation whereas the adaptive notch filter-based methods fail to track fast varying chirps with sudden jumps. We propose a novel jammer frequency estimation method based on the combination of these two approaches. The instantaneous frequency information is then exploited to remove the interference by applying zero-phase notch filtering that overcomes the problem of non-linear phase distortion common in notch filter-based methods. Experimental results indicate that the proposed hybrid approach achieves better interference suppression in GNSS signals as compared to other instantaneous frequency-based mitigation methods.