A comparative study of near-field blockages in 14 GHz and 140 GHz indoor wireless channels

Further increase in the volume and speed of data transfer requires the use of the subterahertz frequency range as the next stage in the evolution of wireless communication systems. Problems emerge due to large propagation losses of subterahertz signals in the atmosphere and a drop in the output power and sensitivity of subterahertz transceivers. This leads to the necessity of highly directional communication channels. Such channels will rely on the use of antenna arrays in both the base station and the user equipment. Given the inherent limitation to relatively small coverage areas, the deployment of subterahertz systems in indoor environments will emerge as a key aspect of their practical implementation. It is expected that line-of-sight channel blockages by users in crowded premises will significantly affect the communication stability. Signal scattering effects are to be different from those observed at microwaves. Moreover, near-field wireless operation becomes possible and probable. In this paper, we perform a comparative study of near-field blockages in 14 GHz and 140 GHz indoor wireless channels. Different trajectories of the blocking user are studied. A diffraction model describing dynamics of the blockage process is parameterized. The results obtained allow one to enhance the existing cluster models of subterahertz channels and to determine the available time budget for communication systems with real-time blockage avoidance.