DOA and Range Estimation Using a Uniform Linear Antenna Array without A Priori Knowledge of the Source Number

A new efficient root-propagator method based on a uniform linear antenna array is proposed to estimate the directions of arrival (DOAs) and ranges of near-field sources without a priori knowledge of the source number. A non-Hermitian matrix is first designed, which allows the applications of rooting methods. Then, by constructing two propagators, the parameter estimation for near-field sources can be achieved through rooting methods in a decoupled way without eigenvalue decomposition (EVD) and spectrum searches. Finally, the importance of a priori source number to source localization problems is studied, and especially, an improvement is proposed to get rid of this dependence. Numerical examples are carried out to show the effectiveness and validate the theoretical analysis of the proposed root-propagator method. The results show that the proposed method provides more superior performance for near-field source localization than other existing similar methods. Even in the case without a priori knowledge of the source number, the performance of the proposed method is still satisfactory.