New Generalized Multi-Structured MIMO Radar Configuration With Increased Degrees of Freedom

Unlike traditional phased-array-radar, multiple-input multiple-output (MIMO) radar is capable of achieving more degrees-of-freedom (DOF) and larger virtual aperture (VA) for the direction-of-arrival (DOA) estimation. In this letter, a new universal antenna array approach employing a one-level transmitter (Tx) and generalized receiver (Rx) is presented for MIMO radar to enhance the DOA estimation performance. The proposed configuration significantly improves the DOF capacity and expands VA by utilizing difference co-array of sum co-array method. The first-level of the Rx and a Tx with increased inter-element spacing is constructed using the nested-coprime array with displaced sub-arrays structure. The proposed Rx is transformable, generic, and easier to realize. It exploits symmetrical array geometry, such that once the initial-level is designed, the remaining stages will be known. The Rx also reveals an inbuilt Tx. Moreover, it achieves increased DOF and enlarged VA, reflecting the multifaceted advantages of the new Rx approach. The configuration is also benefited with closed-form expressions for VA, sensor locations, and DOF. Simulation results demonstrate the superiority of the proposed MIMO radar.