Multiple snapshot spatial smoothing with improved effective array aperture for high-resolution direction-of-arrival estimation

This paper presents multiple snapshot spatial smoothing with improved aperture (MS-SSIA) for high-resolution direction of arrival (DOA) estimation by uniform linear array (ULA). Spatial smoothing preprocessing (SSP) is often used for DOA estimation of correlated sources, but it reduces the effective array aperture and leads to low DOA estimation accuracy. SSIA is a method that solves this SSP problem; however, it can only be applied to the case of a single snapshot. Spatial smoothing with overlapped and augmented array (SSOA), which has also been proposed and can be used for the case of multiple snapshots, solves the SS and SSIA problem, but its DOA estimation accuracy often becomes the same as that of the SSP method. We try to improve SSIA so that it can correspond to the case of multiple snapshots, but we take a different approach with SSOA. The performance of the proposed method is evaluated through computer simulation.