Technology And Analysis Of MIMO Radar Angle Measurement

In multiple-input multiple-output(MIMO) radar system, the transmit antennas sends different signals, which result in wide and low gain beam in space. On receive, a set of matched filters is used to separate the echo signals due to different transmitters and then many plurality of high-gain narrow beam is formed use digital beamforming(DBF). Compared with the conventional phased array radar of wide transmit beam and narrow receive beam, MIMO radar can form a beam with narrower beamwidth and lower side lobes, which can achieve a more accurate measurement of the angle of target.This thesis focuses on the angle measurement of MIMO radar, first the performance of the array scanning method and monopulse angle measurement method used to MIMO radar are studied, and then the orthogonal waveform and relational waveform of MIMO radar are analyzed, and the effect of transmit waveforms on angle measurement performance of MIMO radar is analyzed through simulation. The specific contents of this paper are as follows:Firstly, we study the basic principle of MIMO radar and the model of orthogonal transmit signal, then derive the model of received signal. And compare the performance and computation of two different signal processing structures. Secondly, the angle measurement accuracy of array scanning method and monopulse angle measurement method are mainly studied. The virtual array aperture of MIMO radar is introduced, and the performance of angle measurement of MIMO radar and conventional phased array radar are compared through computer simulation. Focus on the monopulse angle measurement method including amplitude comparison monopulse angle measurement method and phase comparison monopulse angle measurement method. The implementation process of monopulse angle measurement methods are given. The effect of the target angle, double beam spacing and SNR on the performance of angle measurement are analyzed. The simulation compares the amplitude comparison methods and phase comparison methods as well as array scanning method. Finally, the transmit waveform and the effects of transmit waveform on the angle measurement performance of MIMO radar are studied. The design methods of OFDM-LFM waveform and relational waveform based on linear frequency modulation signals are given. Then compare the angle measurement performance when MIMO radar use orthogonal waveform and relational waveform respectively. The influence of the correlation of waveform on the angle measurement accuracy of MIMO radar is studied.