Three-dimensional through-the-wall imaging with multiple-input multiple-output (MIMO) radar

One of the main drawbacks of three-dimensional (3-D) through-the-wall imaging (TWI) with synthetic aperture radar is the long data acquisition time. The movement of the target during the long data collection time in TWI causes smearing and target displacement in the image. In this paper, a generalized 3-D imaging algorithm is presented for TWI with multiple-input multiple-output (MIMO) radar which is real time in data collection. The far field layered medium Green's function is incorporated in the MIMO through-the-wall beamformer to take into account and compensate for the wall effects. This makes the imaging algorithm simply applicable to the imaging of targets behind either single- or multilayered building walls, which has promising potential application in urban sensing of building interior targets. The MIMO through-the-wall beamformer can also be simply applied to two-dimensional TWI. Numerical results show that the through-the-wall MIMO beamformer provides high-quality focused images in various wall-target scenarios.