Research On Radar Anti-jamming Algorithm Based On Blind Source Separation

Blind source separation(Blind Source Separation,BSS)refers to a method of recovering unknown source signals from mixed observation signals within certain constraints based on certain assumptions.Blind source separation technology has played an important role in the fields of voice signal,digital communication,biomedicine,radar array processing,and information security due to its powerful separation capabilities.This paper focuses on the application of blind source separation algorithm in radar signal anti-jamming.The main work and innovations of the thesis are as follows:1.The paper establishes the model of PD and LFM radar echo signals,analyzes and compares the characteristics of the signal’s ambiguity;constructs a mathematical model for suppressing interference of radio frequency noise,noise frequency modulation,function modulation,spectrum dispersion,slicing,and dense false targets.And distance deception,distance towing,speed deception,speed towing jamming models,and towing jamming are explained.2.The working process of Fast Independent Components Analysis(Fast ICA)algorithm and Joint Approximate Diagonalization of Eigen-matrices(JADE)algorithm is systematically studied.Aiming at the problem of uncertain output signal sequence of blind source separation algorithm,a signal screening scheme using similarity detection + threshold detection +parameter analysis is proposed.Solve the problem of target signal screening after blind separation.Blind source separation processing and signal screening are performed on the data collected by the actual radar platform,which verifies the feasibility of the method.3.Aiming at the anti-strong suppression interference of PD radar,a comprehensive solution of using interference type identification + passive tracking of the interference source+ blind source separation + adjustment of the center frequency of the narrowband filter is proposed.This method solves the problem of signal amplitude ambiguity after blind source separation,so that the blind source separation algorithm can be truly applied to radar antijamming.The simulation results verify that the scheme can effectively suppress suppressing interference.4.Perform in-depth and detailed simulation analysis on the five kinds of suppression interference capabilities of blind separation algorithm anti-noise frequency modulation,function modulation,spectrum dispersion,dense false targets,and slices,anti-distance deception and speed deception interference,and deception and suppression combined interference capabilities.The performance of Fast ICA and JADE algorithms are compared.5.The FPGA hardware implementation of the Fast ICA blind source separation algorithm has been studied in depth,and the specific implementation of the zero averaging,covariance matrix calculation module,whitening module and unmixing matrix module algorithm is decomposed in detail.Finally,on the FPGA hardware platform,The blind source separation effect of drag interference suppression with deception and suppression interference is tested,and the results show that the drag interference suppression ability of the algorithm on the actual platform is better than 15 dB.