One- and two-dimensional direction-of-arrival estimation: An overview of search-free techniques

One of major challenges in applying traditional subspace-based direction finding techniques to real-time practical problems is in that they normally require an exhaustive spectral search over the angular parameter(s). Therefore, methods avoiding such a computationally demanding spectral search step are of great interest. In this paper, an overview of one- and two-dimensional search-free direction-of-arrival (DOA) estimation methods is presented. Both cases of uniform and non-uniform sensor arrays are addressed.