Reweighted $l_{1}$ Norm Optimization-Based Design of Cross MIMO Arrays for Near-Field Imaging

A sparse array synthesis (SAS) method for cross multiple-input-multiple-output (MIMO) array in near-field imaging is proposed in this letter. We first formulate the MIMO-SAS model as a stepwise optimization of the orthogonally distributed transmit and receive arrays. In each step, a modified reweighted $l_{1}$ norm regularization is utilized to suppress the sidelobe levels. To avoid broadening of the main lobe, we set a strip focusing area at a specified distance in the direction of the array. The width of the focusing area is adjusted to balance the levels of resolution and sidelobes. Simulations and experimental results demonstrate the superiority of the array synthesized by the proposed method when compared to other state-of-the-art sparse arrays with the same number of antennas.