LFM Interference Suppression Algorithm Based on FrFT

Abstract

Differential frequency hopping (DFH) communication system is widely used in the field of confidential communication with strong anti-jamming ability. Linear frequency modulation (LFM) signal with a broadband non-stationary characteristic can cause a great influence on the DFH communication system. In order to solve the problem of anti LFM interference in DFH system, this paper proposal a LFM interference suppression algorithm which is based on FrFT(Fractional Fourier Transform). By combining different order in FrFT, the optimal order is extracted and the LFM interference signal is identified. Further LFM interference suppression is realized. The simulation results show that the algorithm can effectively mitigate LFM interference in DFH communication system to improve the SNR.