Integrated Sensing and Communication in 6G: the Deterministic Channel Models for THz Imaging

In this paper, the channel modeling for integrated sensing and communication for 6G systems are studied. The channel modeling approaches, requirements, and challenges for communication cases and sensing cases are summarized and discussed. In particular, a 3-D metallic test chart is designed as a reference for studying electromagnetic imaging quality. The deterministic channel modeling approaches, i.e., geometrical optics method, physical optics method, and integral equation method, are introduced to simulate the imaging channel of the designed 3-D test chart. And the electromagnetic inverse scattering method is adopted as an imaging tool. The test is experimentally measured by 140 GHz signal with horn antennas in a chamber. The modulation transfer function (MTF) is applied to assess the imaging quality numerically, and the simulated and measured images are compared, which suggests that the imaging by integral equation is in agreement very well with that of measurement for 3-D test chart, and the geometric optics and physical optics methods can only show the characteristics of 2-D optical imaging.