Application Of High-resolution And Low-complexity DOA Estimation In Multi-carrier Frequency MIMO Radar

High resolution and high speed have become major trends of modern radar.In this trend,how to distinguish the target azimuth efficiently and accurately has become the focus of researchers in the related fields.The signal processing method of multi carrier frequency MIMO radar based on LFMCW has been analyzed in this paper.DOA estimation algorithms with high resolution and low complexity have been studied,and the feasibility of the algorithms has been validated through the outdoor test of MIMO radar system.The main work of this article includes:1.The model of multi carrier frequency MIMO radar signal based on LFMCW is studied.The classical angle estimation methods are applied to the model proposed in this paper.2.High-resolution DOA estimation methods of MIMO radar have been researched.The reflected signals of adjacent targets with same distance and speed are coherent sources.Based on decorrelated methods of improved spatial smoothing algorithm,low rank approximation method and conjugate reconstruction method,the resolution is improved by jointing eigenvector weighting or SSMUSIC algorithm.The simulation results show that all the proposed algorithms are suitable for the multi carrier frequency MIMO radar system proposed in this paper,but the weighting-conjugate joint algorithm has the best performance under the system model.3.Maintaining the resolution performance of the algorithm,fast calculation methods are studied in depth.By using the MUSIC algorithm based on the subspace rotation transformation and the DOA estimation method based on MUSIC symmetric compression spectrum,successfully reduce the complexity of the algorithm.At the same time,an improved algorithm based on spectral width analysis for MUSIC symmetric compression spectrum is proposed,which can discriminate neighboring targets and the targets with larger interval,and improve the efficiency of the algorithm.4.Aboard of data acquisition for multi carrier frequency MIMO radar system of this paper has been designed and researched.Algorithms are verified with data collected through outdoor experiments,ensuring effective practical applications of the proposed ones in the article.