Dimension-Reduced Rx Beamforming Optimized for Simultaneous Detection and Estimation

Phased array radar systems are indispensable in many applications requiring robust sensing of the environment. To achieve sensitive target detection and accurate direction-of-arrival (DOA) estimation, a large number of receiving antenna elements are needed. The high dimension of the element-level data inevitably leads to a large computational burden for digital signal processing. This problem can be overcome by transforming the element-level data into a lower dimensional beamspace. In this article, we present a novel parameter-controlled design method to construct this transformation. If the dimension reduction is not too drastic, it jointly achieves optimal detection and DOA estimation performance. Otherwise, it meets predefined performance criteria by exploiting an acceptable tradeoff between detection and DOA estimation performance. We propose a general design tool, which is not limited to a specific array configuration. It comprises a precalculated set of plots, providing the radar designer an overview of possible performance for a given scenario. We describe a straightforward method to construct the corresponding transformation. Numerical studies highlight the superiority of the proposed design method.