Sparsity-Based DOA Estimation of Coherent and Uncorrelated Targets using Transmit/Receive Co-prime Arrays

In this paper, we use transmit/receive co-prime arrays for direction finding of mixed coherent and uncorrelated targets based on the concept of sum coarrays. The sum coarray is defined as the set of pair-wise sums of the position vectors of the elements in the transmit and receive apertures. The data measurements from the transmit/receive co-prime array are used to emulate observations at a virtual array, whose element positions are given by the sum coarray corresponding to the co-prime array. A group sparse reconstruction problem is formulated employing multiple snapshots, where each group corresponding to a specific angle of arrival extends across all the time samples. The number of resolvable targets for the proposed sparsity-based approach is limited by the number of elements in the sum coarray. Supporting simulation results are provided, which validate the effectiveness of the proposed direction finding method.