DOA estimation and object localization based on multi-harmonic multi-beam characteristic of 1-bit time-modulated reflectarray

A method for direction of arrival (DOA) estimation and object localization based on 1-bit time-modulated reflectarray (TMRA) is presented. The multi-harmonic multi-beam (MHMB) characteristic of 1-bit TMRA is analyzed firstly to reveal the mapping relationship between target's angular feature and received spectrum feature. Then the operating principle and perception procedures for single and multiple targets scenarios are discussed in detail. Benefited from the mapping relationship, the proposed method shows flexibility on simultaneous multi-target detection, which is difficult to realize by conventional methods. Furthermore, the proposed method enables the environment-perception capability of existing 1-bit TMRA without increasing the system complexity, making it suitable for the realization of a low-cost multifunctional reconfigurable intelligent surface (RIS).