An L-Shaped Three-Level and Single Common Element Sparse Sensor Array for 2-D DOA Estimation

The degree of freedom (DOF) is an important performance metric for evaluating the design of a sparse array structure. Designing novel sparse arrays with higher degrees of freedom, while ensuring that the array structure can be mathematically represented, is a crucial research direction in the field of direction of arrival (DOA) estimation. In this paper, we propose a novel L-shaped sparse sensor array by adjusting the physical placement of the sensors in the sparse array. The proposed L-shaped sparse array consists of two sets of three-level and single-element sparse arrays (TSESAs), which estimate the azimuth and elevation angles, respectively, through one-dimensional (1-D) spatial spectrum search. Each TSESA is composed of a uniform linear subarray and two sparse subarrays, with one single common element in the two sparse subarrays. Compared to existing L-shaped sparse arrays, the proposed array achieves higher degrees of freedom, up to 4Q(1)Q(2)+8Q(1)-5, when estimating DOA using the received signal covariance. To facilitate the correct matching of azimuth and elevation angles, the cross-covariance between the two TSESA arrays is utilized for estimation. By comparing and analyzing performance parameters with commonly used L-shaped and other sparse arrays, it is found that the proposed L-shaped TSESA has higher degrees of freedom and array aperture, leading to improved two-dimensional (2-D) DOA estimation results. Finally, simulation experiments validate the excellent performance of the L-shaped TSESA in 2-D DOA estimation.

Automated summary

The degree of freedom (DOF) is an important metric for evaluating sparse array designs in the field of DOA estimation. This paper proposes a novel L-shaped sparse sensor array that achieves higher degrees of freedom by adjusting the physical placement of sensors. The array consists of two sets of TSESAs, which estimate azimuth and elevation angles through 1-D spatial spectrum search. Simulation experiments demonstrate the superior performance of the proposed L-shaped TSESA in 2-D DOA estimation, due to its higher degrees of freedom and array aperture.