Measurement-Based Channel Characterization in Indoor IIoT Scenarios at 220 GHz

Terahertz (THz) communication technology holds significant potential for applications in the industrial internet of things (IIoT). Accurately characterizing the THz channel is critical for designing and optimizing communication systems in IIoT scenarios. However, the significantly higher frequencies in the THz band impede the effective utilization of channel models designed for microwave or millimeter-wave frequency bands. To overcome this challenge, extensive measurement campaigns are necessary to thoroughly investigate the characteristics of THz channels in indoor IIoT scenarios. This paper presents a measurement-based channel characterization in indoor IIoT scenarios at a frequency range of 215-225 GHz. We first present VNA-based channel measurement campaigns in micro drillingmilling and large milling areas. The measured data are further processed to obtain the channel impulse response. The key propagation channel parameters, e.g., path loss, power delay angle profile, delay spread, and angular spread, are calculated and analyzed in the line-of-sight case. Results demonstrate a favorable spatio-temporal consistency in multipath signal propagation and the physical spatial environment. Furthermore, significant correlations are observed between the channel characteristics and scatterer distribution within IIoT scenarios. The findings of this paper will make substantial contributions to the design and development of THz communication systems in IIoT scenarios.