Research On MIMO Radar Waveform Design Based On Maximized Sinr Criterion

MIMO radar is a new system of multi-antenna radar,which is a hot research direction in the current radar field.Compared with the traditional phased array(PA)radar,MIMO radar can independently transmit different waveforms from each transmitting antenna to obtain waveform diversity gain,which makes the signal processing at the transmitting and receiving ends of MIMO radar have more degrees of freedom(DOF)and more advantages in low-speed and weak target detection and anti-interference.Waveform design is an important link to exploit the advantages of MIMO radar.Obtaining transmitting waveforms with good characteristics through waveform design to dynamically match the radar with the detection environment is of great benefit to improve the system performance of MIMO radar for target detection and parameter estimation in complex electromagnetic interference environments.Therefore,this thesis focuses on how to improve MIMO radar target detection performance through waveform design,and conducts research on MIMO radar waveform design algorithm based on maximizing SINR criterion,which is mainly as follows:(1)Firstly,the fundamental working principle of MIMO radar is described,and then the basic signal models of colocated MIMO radar and distributed MIMO radar are given respectively.Finally,the main types of robust waveform design problems and the modeling process under current inaccurate a priori information are summarized.(2)The problem of joint design of MIMO radar constrained transmit waveform and receive filter for maximizing SINR under signal-dependence interference is investigated.The objective function of waveform design is given,and the joint transceiver waveform design algorithm(JD-SFR)based on Semidefinite relaxation(SDR),fractional programming and randomization techniques is completed.In addition,a joint transceiver design algorithm based on coordinate descent for continuous/discrete phase waveforms(JD-CD)is proposed.Both waveform design methods consider constant modulus and similarity constraints.The design step consists of two parts,first completing the transmit waveform design of an approximate orthogonal LFM signal using the above two methods,and then calculating the receive filter weight vector using MVDR.Simulation results show that both methods above form the nulls in the interference azimuth,effectively suppressing interference and improving the output SINR value of the MIMO radar system.(3)The problem of robust waveform design for MIMO radar with inaccurate a prior information under signal-dependence interference is investigated.In the case of inaccurate prior information of the scatterers,the signal model with mismatch of the steering vector matrix and the objective function of the worst SINR(WSINR)are first derived,and then a waveform design algorithm based on coordinate descent and discrete Fourier transform(CDDFT)is proposed for calculating the finite-phase robust transmit waveform.The simulation results show that the proposed algorithms can improve the system output WSINR values to different degrees under the control of various uncertainty parameters,which in turn improves the target detection performance,and the designed waveforms meet the expected results.