Contents I. Introduction
Facing the challenge of 6G high-speed transmission re-quirements, the currently adopted frequency bands (e.g., mi-crowave, millimeter wave) can no longer meet the require-ments of wireless communications. The terahertz (THz) band (from 0.1Hz to 10Hz), which provides large bandwidth and realizes up to several terabits per second (Tbqs), has attracted a great deal of attention worldwide[1], [2]. Terahertz waves have numerous advantages, but also some disadvantages that need to be overcome. For example, the high-frequency nature of terahertz waves makes them subject to very severe path losses and molecular absorption losses, resulting in limited communication distances in the THz band[3], [4].Radio frequency planning can be difficult for this reason, especially for non-line-of-sight (NLoS) scenarios. In various indoor corridor environments, the propagation path of terahertz signals is difficult to cover the entire space due to wall corners and excessive obstructions in the way. Therefore, in ultra-high-speed indoor THz communication scenarios, the strong di-rectionality of the terahertz beam causes it to be controlled only at the line-of-sight (LoS) space, while the non-line-of-sight (NLoS) space is hardly covered by terahertz signals[5]. In this context, signal propagation characteristics in various bands of THz frequencies [6], [7] are investigated and studied. Conventional solutions to the coverage problems that arise in terahertz communication systems rely on improving the transmitter and receiver ends of the communication link, for example, there are high power radiation sources, high gain antennas, beam forming designs, adaptive modulation, coding techniques, distance-adaptive waveform design, and bandwidth-adaptive resource allocation [8], [9].
