Multi-Target Radar Imaging Based on Phased-MIMO Technique—Part I: Imaging Algorithm

Radar imaging provides the shape structure information for target recognition. In this paper, a multi-target radar imaging method based on the emerging phased-MIMO (multiple-input multiple-output) technique is proposed. Each single-element transmit antenna in traditional MIMO radar imaging system is replaced by a transmit array (TA), which operates in phased-MIMO mode. In the phased-MIMO mode, each TA is divided into several sub-arrays operating in phased-array radar mode, and the transmitted waveform by each sub-array is orthogonal to each other. The sub-arrays steer different transmit beams to different targets' directions with optimized waveform for the corresponding target. The virtual aperture produced by the waveform diversity is used for coherent processing to improve the signal-to-noise ratio and the signal-to-interference ratio, and then the single-snapshot imaging for multi-target with high azimuth resolution can be achieved based on dictionary optimization and orthogonal matching pursuit. Simulation results indicate the effectiveness of the proposed method.