Root-MUSIC based source localization using transmit array interpolation in MIMO radar with arbitrary planar arrays

We consider the problem of target localization in MIMO radar with arbitrary planar arrays. A method for mapping a two-dimensional (2D) arbitrary transmit array into a uniform rectangular array or an L-shaped array with uniform element displacement is developed. The uniform structure of the mapped array enables applying the computationally efficient 2D root-MUSIC algorithm for estimating the elevation and azimuth parameters of the targets. The transmit array interpolation is achieved by properly designing the mapping matrix via solving a minmax convex optimization problem. We show that there is a tradeoff between the mapping accuracy within a certain desired 2D spatial sector and the sidelobe levels. The performance of the root-MUSIC for the mapped transmit array is shown to achieve the performance of the root-MUSIC associated with a perfect uniform array of the same shape as the mapped one. Simulation examples are used to validate the effectiveness of the proposed method.