Research On Anti-jamming Performance Of MIMO Fuze Based On Phase-encoded Signal

Electronic warfare is the most important and most challenging aspect of modern electronic warfare.Compared to the traditional fuze,MIMO fuze has many advantages,such as low probability of intercepted,improving anti-jamming performance,improving the precision of DOA and so on.The ambiguity function of phase-coded signal is of "map nail" type.This type of waveform can further improve the anti-jamming performance of the MIMO fuze.In this paper,the MIMO fuze based on phase coded signal is taken as the research object,Strong active jamming is taken as the research background.The anti-active suppression jamming performance of MIMO fuze has been analyzed and several jamming suppression algorithms have been proposed.During the study,the main work and contribution of MIMO fuze based on phase coding system are as follows:1.The basic principle and signal processing procedure of MIMO fuze are introduced.The algorithm of distance and velocity measurement of MIMO fuse are analyzed specifiedly.Based on the theory,MIMO fuze signal processing platform is built by Matlab.2.The influence of several common active suppression jamming on the distance and velocity measurement of MIMO fuze have been analyzed.The mathematical model and time-frequency characteristic of jamming have been analyzed.Jamming mechanism is analysed from the jamming waveform.Besides,the influence of three kinds of common active jamming on the range and velocity measurement of phase coding MIMO fuze is analyzed and compared from the aspect of SJR gain.3.Corresponding algorithms are proposed for noise amplitude modulation jamming and noise FM jamming.A frequency domain cancellation algorithm is proposed to reduce the frequency of noise amplitude modulation.The key of this algorithm is to estimate the jamming frequency in the echo signal of MIMO fuze.A correction scheme based on DFT are proposed.A delay autocorrelation algorithm and a time domain cancellation algorithm are proposed for the noise FM jamming.The delay autocorrelation algorithm can effectively suppress the suppressed jamming as a small amplitude sine wave,but may cause the data-loss.In order to solve the problem of data loss,a time domain cancellation algorithm is proposed.Jamming cancellation can be done through estimation of time domain parameters.In the low-SJR situation,The SJR reaches up to about 3dB through this algorithm,and the useful information of target can be saved.4.The influence of active jamming on DOA estimation of MIMO fuze are analysed.The traditional MUSIC algorithm and MIMO-MUSIC algorithm are compared and analyzed.The influence of jamming on DOA estimation is analyzed from the angle of correlation coefficient and vector.RC-ROOT-MUSIC algorithm is put forward based on this way.The complexity is reduced greatly and the signal-to-noise ratio gain is obtained.A preprocessing method is proposed for interference in several directions in the airspace,which can effectively suppress the interferences from various angles and maximize the power of the incoming wave direction signal.