Application Research Of MIMO Millimeter Wave Radar Technology For Automobile

With the progress of science and technology,automobile have become an indispensable "daily item" in humans’ dailylife.In 2021,the number of cars in China will rank first around the world,and also the loss of people’s life and property caused by traffic accidents every year will increase rapidly.Against this backdrop,the demand for vehicles equipped with advanced driver assistance systems(ADAS)is also increasing year by year.Millimeter-wave(MMW)radar is a key technology for ADAS system and autonomous driving.Compared with other sensors,such as cameras,infrared detection and lidar sensors,millimeter-wave radar has a strong performance against poor visibility environmental conditions such as bad weather and limited illumination conditions.In this paper,the application of MIMO(Multiple Input Multiple Output)millimeter-wave radar is studied,and the method to improve the Angle measurement performance of millimeterwave radar is discussed.To improve the accuracy and resolution of radar Angle measurement,this paper mainly studies and discusses the array design optimization and the analysis of superresolution algorithm in the signal processing stage.Firstly,the paper shows the key role of virtual array and aperture expansion in the performance of the radar Angle measurement in MIMO system by introducting the working principle of the radar.Combined with the concept of redundancy and nonuniform linear array,the paper optimates the transceiver array of MIMO radar.The joint optimization method is adopted to solve the minimum redundant MIMO linear array(MRLA)under the precondition of a given aperture and a given number of array elements.The optimization effect of the array is verified by the Angle measurement results and the simulation results of adaptive interference suppression.To solve the problem that the algorithm can only use exhaustive method to obtain the solution,the paper gives an optimized and convenient algorithm flow,and verifies the correctness of the algorithm through Matlab simulation.After the targets are confirmed,DOA(Direction-of-Arrival)estimation algorithm can further improve the performance Of the radar.This paper introduces a variety of classical target Angle measurement algorithms,based on the algorithm principle,application conditions and performance of the experimental verification.Combined with the actual working scene of automobile radar,the algorithm is simulated and compared,and the Angle measurement effect of each algorithm is analyzed.FMCW(frequency modulated continuous wave)radar is an important field of practical car millimeter wave radar,in this paper,through the analysis in the Angle measurement due to the array extension is encountered in the process of the sparse array of false target problems,first of all a false target weed out algorithm is proposed,and its validity is verified by simulation,and then aiming at the problem of insufficient traditional resolution Angle measuring algorithm,this paper proposes a super resolution based on the relative movement between target and radar DOA algorithms,It is proved that the algorithm can achieve a high resolution of 0.2° with only four receiving antennas.Finally,the effectiveness of the algorithm is verified by field measurement.