Design of novel sparse arrays for DOA estimation of noncircular sources

Abstract

ABSTRACT In this paper, we first propose a novel sparse array (NSA) composed of three adjoined sparse subarrays, among which the first and third ones can form the prototype coprime array (CA), and the second one is nested to them. When deploying NSA for direction of arrival (DOA) estimation, two virtual CAs with larger apertures than the physical ones can be generated by vectorising the covariance matrices corresponding to specific subarray pairs. Accordingly, improved DOA estimation performance can be achieved. Afterwards, to enhance the DOA estimation of noncircular sources, four improved NSAs are designed, which have minimised redundancy between the difference and sum coarrays. Hence, they have larger utilised apertures than NSA. In addition, due to the larger physical aperture and inter-element spacing, all the five proposed arrays have less mutual coupling and better DOA estimation performance than the prototype CA. Numerical simulations confirm their effectiveness and superiority.