Non-Line-of-Sight Targets Localization Algorithm via Joint Estimation of DoD and DoA

Non-line-of-sight (NLOS) radar has the feature of detecting the targets that are in the blind area, while the existing time-of-arrival (ToA)-based methods limit its further development in multitarget environments. To deal with it, we investigate the problem of multiple target localization behind L-shaped corners for multiple-input–multiple-output (MIMO) millimeter-wave (MMW) radar. Specifically, the multipath signal model that accounts for range, Doppler, direction of departure (DoD), and direction of arrival (DoA) is established first. After echo preprocessing, the position of the reflector wall is estimated using static point clouds. To achieve multiple NLOS target localization with low false alarms, a multipath recognition method, by fully considering the DoD and DoA relationships of multipath, is proposed. Furthermore, the real target positions are derived by mirror symmetry. Finally, the performance of the method is tested by the experiments, which reveal that the proposed method can work in the presence of multiple NLOS targets with high accuracy and low false alarms.