Multiparameter Estimation for Monostatic FDA-MIMO Radar With Polarimetric Antenna

The monostatic polarimetric sensitive frequency diverse array multiple-input–multiple-output (PS-FDA-MIMO) radar is able to provide polarization information regarding targets in comparison to the FDA-MIMO radar. A monostatic PS-FDA-MIMO radar can differentiate targets with the same range bin and spatial-polarization angle, but different ambiguous range regions, compared to PS-MIMO radar. The high pulse repetition frequency (PRF) will lead to range ambiguity in practical applications. The monostatic FDA-MIMO radar with electromagnetic vector sensor (EVS) is equipped with a resolving range ambiguous method for joint parameter estimation of range and spatial-polarization angle in this article. In the receiver, spatial-polarization angles are estimated with the ESPRIT-based algorithm. In the transmitter, range dependence compensation can resolve the coupling problem between spatial angles with the range due to the frequency increment. By using the maximum likelihood estimator (MLE) method, the monostatic EVS-FDA-MIMO radar can jointly calculate the spatial-polarization angle and range parameters of targets based on degrees-of-freedom (DOF) in the spatial angle and range domains. Cramér–Rao bounds (CRBs) are also derived for the spatial-polarization angles and range, and the property of the proposed approach is evaluated. A variety of simulated scenarios demonstrate the effectiveness of the estimated estimation strategies.