Phase Correction Method for Coherent Processing of Quasi-coherent MIMO Radar Networks

Multiple-input-multiple-output (MIMO) radar networks expand the virtual array aperture by coherently combining the virtual arrays synthesized at different locations, thereby improving angular resolution and facilitating wide-area illumination. To achieve coherent estimation of the target angle along the entire virtual array, it is necessary to ensure phase coherence of all channels. In this paper, error analysis and signal model are conducted for the radar networks employing a quasi-coherent architecture. Based on the properties of the redundant virtual elements synthesized under opposite bistatic paths, a subarray-level phase error correction method is proposed. Remarkably, this method does not require known targets or individual prominent scatter in the operating scenario. Numerical experiments have been conducted to analyze the performance and validate the effectiveness of the proposed method.