Real-Time Frequency and 2-D Angle Estimation Method with Sub-Nyquist Sampling

A method is proposed to estimate real-time frequency and azimuth and elevation angles of arrival with parallel uniform linear arrays and elements output signal delay.The method uses PRO-ESPRIT algorithm in DFT beam-space.It can estimate the frequency and angles with sub-Nyquist sampling.The analog frequency is estimated by general eigenvalue in the direct method.The alias zone of frequency can be determined by the estimation of analog frequency.Then,the digital frequency is estimated,and the analog frequency is calculated by digital frequency in the indirect method.The variance of the frequency estimates of indirect method is more little than that of the direct method.Simulations are presented demonstrating the capabilities of the method.