DOA Estimation of a Novel Three-level Nested Array with Enhanced DOF

In this paper, we propose a novel three-level nested array for direction of arrival (DOA) estimation. Specifically, the configuration is composed of three cascaded uniform linear arrays (ULAs) with different inter-element spacing, which has a simple layout and the closed-form expressions for the degrees of freedom (DOF). Not only can it provide more DOF, but its difference co-array is a hole-free ULA. Based on the above excellent characteristics, the subspace algorithm is employed for DOA estimation. Simulation experiments demonstrate the superior performance of the proposed nested array.