Max-MUSIC: A Low-Complexity High-Resolution Direction Finding Method for Sparse MIMO Radars

In this paper, we propose a low-complexity high-resolution direction-of-arrival (DoA) method (max-MUSIC) by exploiting multiple subarrays of a sparse multiple-input multiple-output (MIMO) radar. In this method, specific subarrays for different MIMO configurations are selected according to a proposed selection criterion for generating diverse MUSIC spatial spectrums. Subsequently, we design a new spatial spectrum function that can perform high DoA estimation accuracy and resolution without spatial aliasing, by leveraging the advantages of the diverse spatial spectrums. With a given number of antenna elements, enhancements in array aperture size can improve estimation accuracy while causing severe aliasing, which cannot be mitigated. To define a legitimate MIMO configuration for aliasing suppression, a criterion that offers an optimal compromise between DoA estimation performance and anti-aliasing ability is provided. Simulations are provided to verify the effectiveness of the proposed method.