A FrFT-notch filtering based GNSS anti-interference method

Interference detection and suppression is very important to improve the performance of global navigation satellite system (GNSS) receivers. In this paper, a novel GNSS interference mitigation algorithm using a Notch Filter is proposed supported by fractional domain analysis. Compared with the existing anti-interference techniques such as spectral line cutting method, the proposed technique applies notch filter for the sweep jamming signal estimation, using the instantaneous frequency and chirp rate estimates obtained by the Fractional Fourier Transform (FrFT). Meanwhile, the proposed method in this paper has been experimentally verified using the interfered GPS-L1 C/A signal. The analysis results demonstrates that the FrFT-supported notch filter effectively detect and suppress GNSS interference in challenging scenarios.