DOA estimation with k-times extended co-prime arrays

Sparse arrays such as co-prime arrays, nested arrays and minimum redundancy arrays (MRAs) can achieve larger number of degrees-of-freedom (DoFs) with fewer sensors by exploring their difference co-arrays. Co-prime arrays become more attractive, as there exist no exact expressions of MRA configurations for an arbitrary number of sensors and the nested arrays suffer greatly from mutual coupling. However, in order to achieve a large number of DoFs, traditional extended co-prime arrays have a large array aperture compared to the DoFs gained. In this paper, we propose a novel advanced co-prime array geometry that can not only further reduce the number of required sensors but also significantly reduce the array aperture while achieving the same number of DoFs. On the other hand, it has better performance than nested arrays in the presence of mutual coupling. Simulation results demonstrate the feasibility and effectiveness of our proposed array geometry in achieving higher quality direction-of-arrival (DOA) estimation.