Three-Dimensional Parameter Estimation of Uniform Circular Frequency Diverse Array Radar With Two-Stage Estimator

Frequency diverse array (FDA) radar has been studied by many researchers due to the range-angle dependent beampattern which is different from the conventional phased array radar. However, the contribution of previous studies has received little attention within the circular frequency diverse array radar and no known empirical research has focused on investigating the three-dimensional (3D) parameter estimation (azimuth, elevation, and range). In this paper, we proposed a two-stage estimation algorithm for 3D parameter estimation of uniform circular frequency diverse array (UC-FDA) radar and firstly demonstrate the capability and performance of 3D parameter estimation. The first step of the two-stage estimation is the estimation of azimuth and elevation from the beamspace which is transformed from the element space by the beamformer. The second step is to substitute the angle obtained in the first step into the transmitting steering matrix for the range estimation. Cramér-Rao bound (CRB) that is used to evaluate the 3D parameter estimation performance is derived to compare. Theoretical analysis and numerical simulation demonstrate that the UC-FDA radar has superior 3D parameter estimation performance and the effectiveness of the proposed two-stage estimation algorithm. The research findings can contribute to a better 3D localization method and represent an additional step towards developing multi-dimensional localization and interference suppression for UC-FDA radar.