Fuze Signal Processing And Anti-chaff Interference Research

The millimeter-wave fuze has the advantages of strong detection ability,accurate ranging and speed measurement,high target recognition rate and all-weather work.Chaff,as an important form of passive interference,has always been a research hotspot of anti-jamming for fuzes.Research on anti-chaff interference of millimeter-wave ranging fuzes can greatly enhance the operational performance of radio fuzes.In this paper,Aiming at the problem of millimeter-wave fuze signal processing,chaff jamming and anti-chaff jamming,the following work is done:1.The working principle of the millimeter-wave LFM fuze short-range detection system is analyzed,the system parameters and signal processing algorithms are determined,and the main algorithms are verified.2.Completed the analysis of chaff cloud echo and chaff interference to radio fuze.Combined with the characteristics of chaff,a chaff cloud model under the background of fuze signal processing is given to verify the time-frequency properties of chaff echoes.For two kinds of chaff jamming models—oncoming interception and air tail pursuit,the target echo signals of Doppler fuze and FM fuze are analyzed,and the influence of chaff jamming on radio fuze detection system is given.3.An anti-chaff interference method for FM ranging fuze is proposed—improved polarization information anti-interference and sparse representation-based anti-jamming.The former considers the influence of the translation and rotation of the chaff on the echo signal,analyzes the polarization scattering matrix of the chaff,improves the expression of the cross polarization ratio,and uses the difference in polarization discrimination between the target and the chaff to identify the target;The latter uses the chaff interference simulation results,using the K-mean singular value decomposition(K-SVD)dictionary learning algorithm to obtain the sparse dictionary of the target and the interference.Then,the reconstruction errors of two sparse dictionaries for the sparse representation of fuze echo signals are obtained by using the orthogonal matching pursuit(OMP)algorithm,and anti-chaff interference is achieved according to the size of the reconstruction errors.4.Completed the hardware and software design of millimeter-wave ranging fuze signal processing based on FPGA.The hardware circuit mainly includes the design,machining,welding,and debugging of the power supply module,the intermediate frequency signal preprocessing module,the modulation signal generation module,and the FPGA configuration module.The software design mainly includes the modulation triangle wave,FIR filter,FFT algorithm,frequency correction processing and execution level control signal,etc,and the overall test result of the circuit is good.Experiments show that the positioning error of the FM fuze short-range detection system is small,which meets the design requirements.