Performance of OFDM-MIMO Radar for Mulpath Suppression

A method based on orthogonal frequency division multiplexing-multiple input multiple output (OFDM-MIMO) radar configuration is proposed to solve the multipath problem and detect moving target at low altitude. As the phase difference between the multipath echo is random, Vector superposition of the received echo is sometimes strong and sometimes weak, and the detection performance declined rapidly. Through carrying different frequency carrier, OFDM can provide frequency diversity, and through array distribution, MIMO can provide spatial diversity and different Doppler shifts over different paths. The frequency and spatial diversity reduce the probability of multipath cancellation, and solve the specular multipath problem more effectively. Parametric measurement models are developed under the generalized multivariate analysis (GMANOVA) framework, and generalized likelihood ratio test (GLRT) is employed to detect target. The simulation results verify the improvement of performance under OFDM-MIMO radar configuration.