Efficient Wavenumber Domain Imaging Approach for Boundary Subarray-Based Multiplane MIMO Array

In this article, an efficient wavenumber-domain algorithm is developed for the millimeter-wave imaging scheme with boundary subarray (BSA)-based multiplane multiple-input-multiple-output (MIMO) arrays. Compared to the conventional planar MIMO arrays, the BSA-based multiplane MIMO arrays exhibit superior detection performance of targets. Moreover, the data amount of BSA-based multiplane MIMO arrays can be greatly reduced by restricting the transmit-receive signal channels within each BSA. To enhance the imaging efficiency of this scheme, we formulate a data transformation from each BSA of the multiplane MIMO system to the cylindrical monostatic array (CMA), thereby avoiding the high-dimensional processing and offering an efficient solution for nonuniformly sampled signal processing. Based on the analysis of the error induced by BSA-to-CMA transformations, the independent phase calibration is performed for each BSA, mitigating the degradation of image quality. Simulations and experimental results validate the fast imaging and high-resolution advantages of the proposed approach.