Wideband LFM Interference Suppression of GNSS Receiver Based on Fractional Fourier Transform and Power Inversion

In order to improve the anti-jamming ability of global navigation satellite system (GNSS) receiver against wideband LFM jamming signal, a novel wideband LFM interference suppression method based on fractional Fourier transform (FRFT) and power inversion (PI) algorithm is proposed. Firstly, the fractional Fourier (FRF) domain correlation matrix of array received signal with wideband LFM interference is derived to replace the traditional correlation matrix. Then, the PI algorithm is used to suppress the wideband LFM interference in the FRF domain. Finally, the inverse FRFT is taken to get the signal with the LFM interference being mitigated. Simulation results demonstrate that the proposed method can effectively suppress the wideband LFM interference. Even though the direction-of-arrival(DOA) of the GNSS signal is similar to or even the same as that of the wideband LFM interference, it can also effectively suppress the interference signal without causing significant GNSS signal loss, and it can provide correctly acquisition.