Extended Nested Array Configuration with Increased Degrees of Freedom for DOA Estimation

Abstract

Abstract: In this paper, a new linear array configuration inspired by the two-level Nested Array concept has been proposed. The proposed geometry comprises of two Uniform Linear Arrays (ULAs) with different spacings and an additional element, this geometry results in a hole-free Difference Co-Array (DCA). In comparison to most of the existing sparse array configurations, the proposed geometry has simple closed-form expressions for the element positions and Degrees of Freedom (DoFs), also providing consecutive DoFs hence, avoiding the need for spatial interpolation. Spatially Smoothed MUltiple SIgnal Classification (SS-MUSIC) algorithm has been deployed for Direction of Arrival (DOA) estimation. Numerical simulations using MATLAB are performed to exhibit the superior performance of the proposed geometry. Keywords: DOA estimation, Co-array Processing, Spatial Smoothing, Degrees of Freedom, Non-Uniform Linear Arrays