Research On Anti-jamming Signal Processing Method Of Chirp Continuous Wave Fuze

In the light of the fourth generation jammer which can cover millimeter wave and more and more complex electromagnetic environment,this paper takes LFMCW fuze as the platform,and studies the anti-jamming algorithm of typical suppression jamming and deception jamming from the aspect of signal processing.(1)Model noise AM interference and noise FM interference signal and build a simulation model of the FM fuze ranging system based on Simulink.The noise amplitude modulation jamming module and noise frequency modulation module are added to the basic frequency modulation fuze system model,respectively.Analyze the influence of interference on the output difference frequency signal and the system ranging accuracy under three factors of different system carrier frequency and interference frequency,different interference signal ratio and change of noise bandwidth.(2)In the light of the noise FM jamming and noise AM jamming,the anti-jamming algorithm based on fractional Fourier transform and adaptive filter are studied.Both algorithms can suppress the jamming signal.Aiming at the noise FM jamming,the time-frequency analysis is carried out,and a noise FM jamming suppression method based on instantaneous estimation signal reconstruction is proposed It is proved that this method can suppress noise FM interference well,and the complexity of this algorithm is low.(3)In the light of the active deceptive jamming,the deceptive jamming detection method based on amplitude distribution characteristics is adopted.The difference of amplitude distribution between deceptive jamming signal and real target is analyzed,and the Kolmogorov Smirnov test statistic based on cumulative distribution function is extracted.The multi scattering models of typical near ground target armored vehicles and wheeled vehicles are established,and the simulation results are compared with the experimental results Velocity estimation and compensation are used to preprocess the one-dimensional range profile;FEKO software is used to model the typical ground target,and the radar cross section data of target echo is derived.The obtained one-dimensional range profile uses Fréchet distance to match the spectrum of jamming signal and target signal,which proves that the one-dimensional range profile can distinguish the real target and jamming signal to a certain extent.