MIMO Radar Angle Measurement

MIMO(Multiple-input multiple-output)radar is a new radar system and has been a research hotspot in the field of detection technology.On transmit,the elements of MIMO radar transmit waveforms that are not perfectly correlated,which may be orthogonal or relational,and form a low gain wide beam in space.And on receive,a method of joint processing is used.A bank of matched filters are used to separate the echo signals due to different transmitters.Then the DBF is employed to form both receive and effective transmit beams.Compared with the traditional phased array radar,the effective transmit-reveive joint beam can achieve narrower beamwidth and lower sidelobes,so the angle accuracy is better.Firstly,the thesis studies the basic principle and characteristics of MIMO radar,and on its basis to establish the target echo model.Then,two different signal processing methods for MIMO radar are introduced,and the simulation proves the consistency of the two methods and the calculation of the two methods.The thesis analyses the mono-pulse angle measuring techology,including the amplitude comparison angle measurement and phase comparison angle measurement.Because of the particularity of MIMO radar,mono-pulse angle measurement can be divided into three methods: the transmit,the receive and the transceive.Based on the different MIMO radar signal processing,we apply different implementations of mono-pulse angle measuring techology.So all the mono-pulse angel measurement methods of MIMO radar are analyzed and the conclusions are also given.We analyze the effect of SNR,the target angle,and double beam spacing on the performance of angle measurement.At last,this thesis studies the maximum likelihood method of MIMO radar angle measurement,and gives the method of applying maximum likelihood method to MIMO radar.Then it also deduces the accuracy of the angle measurement of the maximum likelihood method based on arbitrary transmitting waveforms.And compare the experimental values with the theoretical values.This thesis also proposes an improved maximum likelihood algorithm,which reduces the amount of computation while ensuring the accuracy of the angle measurement.We also study the effect of waveform diversity on the aperture expansion,and the effect on angle measurement.Finally,the MIMO radar performance evaluation software is introduced.Through this software,we can evaluate various performances of the MIMO radar.And it provides a theoretical basis for the practical application of the MIMO radar,and we briefly introduce the software.