DOA estimation in the presence of unknown non-uniform noise with coprime array

The aim is to present a new direction-of-arrival (DOA) estimation algorithm, which is better suited for dealing with unknown non-uniform noise, as well as estimating more sources with less sensors. To achieve this goal, three key steps are exploited: a first step is to extend the array aperture by using coprime array and conjugate symmetry strategy, a second step is to avoid phase ambiguity via vector element reorganisation and a third step is to obtain a full-rank covariance matrix through subvector division, which has the same form with the covariance matrix obtained in uniform Gaussian white noise. Simulation results show that the proposed algorithm can provide better DOA estimation performance than the compared algorithms.