Systems Engineering and Electronics ›› 2025, Vol. 47 ›› Issue (11): 3635-3643.doi: 10.12305/j.issn.1001-506X.2025.11.12

• Sensors and Signal Processing • Previous Articles    

Interrupted-sampling repeater jamming suppression method based on non-optimal order FrFT

Zhenming WEN1,*, Guohong WANG1, Liang ZHANG2, Hongbo YU1   

  1. 1. Aviation Combat Service College,Naval Aviation University,Yantai 264001,China
    2. Unit 94326 of the PLA,Ji’nan 250000,China
  • Received:2024-02-01 Online:2025-11-25 Published:2025-12-08
  • Contact: Zhenming WEN

Abstract:

Interrupted-sampling repeater jamming, as a typical active spoofing jamming, can achieve the effect of single or multiple false target group by using radar coherence characteristics, which is difficult to be effectively suppressed by conventional signal processing means. In order to solve the above problem, the characteristics of interrupted-sampling repeater jamming and the fractional Fourier transform (FrFT) characteristics of linear frequency modulation (LFM) signal are analyzed. It is concluded that LFM signal affected by interrupted-sampling repeater jamming is processed by p?1 order FrFT, and the output is multiple sinusoidal signals with frequency difference. Based on this conclusion, the target echo and interrupted-sampling repeater jamming are transformed into sinusoidal signals of different frequencies, and then transformed into time-frequency domain to detect, mark and cover the frequency vector representing the jamming component to complete jamming suppression. Simulation results show that the proposed algorithm can suppress three types of interrupted-sampling repeater jamming, and is more advantageous when dealing with interrupted-sampling direct forwarding jamming (ISDJ) and interrupted-sampling loop forwarding jamming (ISLJ), which can generate multiple false target groups.

Key words: interrupted-sampling repeater jamming, fractional Fourier transform (FrFT), sinusoidal signal, frequency difference

CLC Number: 

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