Multitarget 2-D DOA Estimation Using Wideband LFMCW Signal and Triangle Array Composed of Three Receiver Antennas

Direction of arrival (DOA) estimation has been a primary focus of research for many years. Research on DOA estimation continues to be immensely popular in the fields of the internet of things, radar, and smart driving. In this paper, a simple new two-dimensional DOA frame-work is proposed in which a triangular array is used to receive wideband linear frequency modulated continuous wave signals. The mixed echo sig-nals from various targets are separated into a series of single-tone signals. The unwrapping algorithm is applied to the phase difference function of the single-tone signals. By using the least-squares method to fit the un-wrapped phase difference function, the DOA information of each target is obtained. Theoretical analysis and simulation demonstrate that the frame-work has the following advantages. Unlike traditional phase goniometry, the framework can resolve the trade-off between antenna spacing and go-niometric accuracy. The number of detected targets is not limited by the number of antennas. Moreover, the framework can obtain highly accurate DOA estimation results.