| With the development of military technology and the evolution of warfare from mechanization to information technology, MIMO radar as a new radar system came into being in order to adapt to the new information battlefield environment; and many new problems have cropped up; among them, direction-finding in MIMO system is an important issue. Through the overview of the present situation of the research on MIMO radar basic knowledge of MIMO and radar direction finding method, based on the existing radar theory and research results, this paper analyzes the traditional radar-direction finding spectrum Capon algorithm and MUSIC algorithm based on MIMO radar direction finding, and compares with the phased array radar, which aims to explore the possibility and effect of MIMO radar direction finding.This paper introduces the basic principle and algorithm steps of Capon minimum variance method, presents the theoretical formulas in detail, and constructs a simulation model on the Matlab/Simulink platform. Simulation and experimental results show that Capon algorithm for phased array radar direction finding, as SNR decreases, spectrum estimation curve will form several pseudo peak angle, and generate estimation error of angle. MIMO radar direction finding and signal to noise ratio do not affect the estimation precision of angle, and can accurately get the angle estimation, strong anti-interference ability; it can accurately estimate the number of snapshots of different angl-es, and with the increase of the number of snapshots, spectral estimation of peak point of the curve width improves the estimation precision. The simulation results verify the validity of the proposed method.This paper introduces the basic principle and steps of MUSIC algorithm, presents the theoretical formulas in detail, and constructs a simulation model on the Matlab/Simulink platform. Simulation and experimental results show that in the same condi-tion, the MUSIC method was significantly higher than that in the direction finding ac-curacy of phased array radar system. The signal is no coherent signal source, and the performance of MUSIC method for MIMO radar angle estimation of signal-to-noise ratio and the number of snapshots, along with the decreased signal-to-noise ratio, spec-tral peaks become smooth, resolution will decrease; with the snapshot number in-creased, the more accurate data covariance matrix, spectral peaks become sharper, im-proving resolution. The signal for the coherent signal source, MUSIC method for MIMO radar angle estimation appear false peaks, resolution performance also drop -s, can’t correctly estimate the source direction. The simulation results verify the validity of the proposed method.The emission signal method mentioned above is only applicable for MIMO radar for the no coherent signal source conditions, which aims to the special condition of the signal to launch special case of coherent signal source. This paper further puts forward spatial smoothing MUSIC method applied to MIMO radar direction finding, and introduces the basic theory and steps of spatial smoothing MUSIC method, gives the theoretical formulas in detail, and constructs a simulation model on the Matlab/Simulink platform. Simulation and experimental results show that with coherent sources, smoothing MUSIC algorithm can correctly detect the coherent source direction of arrival. When other conditions are the same, the forward backward smoothing algorithm has higher resolution. With the increase of the number of MUSIC smoothing, the decor relations performance of the former algorithm is improved, and at the same time, the sub array aperture reduces resolution performance. Through the analysis of MIMO in the field of the radar direction finding method, it shows that the advantage of MUSIC spatial smoothing method is applicable to non-orthogonal signal, and the method has a solution correlation technology, which achieves better testing effects. The simulation results verify the effectiveness of the method. |
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