2D Augmented Coprime Array Geometry Based on the Difference and Sum Coarray Concept

The concept of difference and sum (diff-sum) coarray has attracted a lot of attentions in the estimation of direction-of-arrival (DOA) for the past few years, due to its high degrees-of-freedom (DOFs). A vectorized conjugate augmented MUSIC (VCA-MUSIC) algorithm is applied to generate an equivalent signal model which contains the virtual sensor positions of both the difference and sum of the physical sensors in the two-dimensional (2D) arrays, by utilizing both the spatial and temporal information. Besides, an augmented 2D coprime array configuration is presented with the basis on the concept of difference and sum coarray. By compressing the inter-element spacing of one subarray and introducing the proper separation between the two subarrays of 2D coprime array, the redundancy between the difference coarray and the sum one can be reduced so that more virtual sensors in both coarrays can make contributions to the DOFs. As a result, a much larger consecutive area in the diff-sum coarray can be achieved, which can significantly increase the DOFs. Numerical simulations verify the superiority of the proposed array configuration.