A V-Shaped Fourth-Order Sparse Array Design for 2-D Direction of Arrival Estimation

Degrees of freedom (DOF) serves as a critical metric for evaluating the design of sparse arrays. Developing novel sparse arrays with enhanced degrees of freedom and mathematically expressible structures constitutes a significant research direction in the field of direction of arrival (DOA) estimation. In this paper, an innovative V-shaped sparse sensor array is proposed through the strategic adjustment of sensor positions within the array which is called V-shaped fourth-order linear array (VFLA). Compared to existing V-shaped sparse arrays, the proposed configuration demonstrates superior degrees of freedom when exploiting the covariance of received signals for DOA estimation. Furthermore, relative to commonly used V-shaped arrays and other sparse arrays, the VFLA exhibits not only higher degrees of freedom but also a larger array aperture, thereby enhancing the accuracy of two-dimensional (2-D) DOA estimation. Finally, simulation experiments validate the outstanding performance of the VFLA in 2-D DOA estimation.