Multi-level Off grid DOA estimation of sparse arrays Using OMP algorithm

Direction Of Arrival (DOA) estimation plays a major role in the operation of smart antennas. It has been a research area in array signal processing since decades. Although there are many algorithms to solve this problem, each algorithm has its own advantages and disadvantages. Recently, Compressive Sensing (CS) technique revolutionised the idea of sampling in signal processing. We can have sparse representation of DOA problem using angular grid model and hence CS techniques can be used to solve for DOA's. Using the idea of CS, even one snapshot is sufficient to estimate the angles. Orthogonal Matching Pursuit (OMP), one of the algorithm in the class of greedy algorithms is used in this paper for DOA estimation. The simulations using this algorithm for uniform linear array and sparse array shows the performance of the algorithm. Also off grid model is employed to find DOA of sources that are impinging in grid spaces i.e., between grid points.