Perturbed Sparse Array for Direction of Arrival Estimation

Sparse arrays with non-uniform element spacing offer significant advantages in Direction of Arrival (DOA) estimation, including enhanced spatial resolution and degrees of freedom (DOF). However, practical implementations are often restricted by perturbations such as mutual coupling and element position errors, which degrade performance. This paper investigates the impact of these perturbations on various sparse array configurations, including Nested Arrays (NA), Super Nested Arrays (SNA), Fractal-Based Sparse Arrays (FBSA) and Augmented Nested Arrays (ANA). We analyze these perturbations by effectively addressing mutual coupling and position errors simultaneously. Extensive simulations demonstrate that while traditional sparse arrays like NA, SNA, and ANA suffer significant accuracy losses under perturbation, FBSA maintains robust performance, exhibiting minimal degradation in DOA estimation accuracy. These results emphasize the relevance of array design under perturbation for real-world DOA estimation.