High-resolution 2-D DOA estimation by 3-D array configuration based on CRLB formulation

This paper presents a simple 3-D array configuration for high-resolution 2-D Direction-Of-Arrival (DOA) estimation. In order to improve elevation angle estimation accuracy, a naive approach would be to put more number of array elements, or to develop a three-dimensional (3-D) array structure by putting multiple planar arrays in vertical direction to make long antenna aperture in elevation direction. However they require very large hardware and computational cost. Based on the analysis of Cramer-Rao Lower Bound (CRLB) formulation and its dependency on the height of array elements, we develop a simple 3-D array structure which improves elevation angle estimation accuracy while preserving azimuth angle estimation accuracy.