Joint direction-of-arrival and frequency estimation based on multiple-delay method and two-dimensional composite uniform array

To address the challenge of joint space-frequency domain parameter estimation for multiple sources in complex electromagnetic environments, this paper proposes a joint estimation method based on the multiple-delay method and a two-dimensional composite uniform array. The two-dimensional composite uniform array forms a sparse array by selecting elements from an existing uniform planar array. The proposed spatial-frequency domain parameter estimation method consists of three main steps. First, a multiple-delay matrix is constructed to extract signal frequencies using ESPIRIT algorithm. Then, filters are employed to separate signals into different frequency bands based on the frequencies estimated. Finally, the MUSIC algorithm is applied to the selected narrowband signals for high-precision two-dimensional DOA estimation, achieving joint estimation of frequency, azimuth, and elevation angles. Simulation results demonstrate that the multiple-delay method provides high accuracy in frequency estimation, while the two-dimensional composite uniform array effectively increasing the array's aperture while maintaining the same number of elements, thereby enhancing the resolution of Direction of Arrival (DOA) estimation, it outperforms traditional uniform arrays in DOA estimation under the same number of elements, validating the effectiveness of the proposed approach.