Multi-Layer Building Material Modeling and Parameter Estimation Method by Wide-Band Free Space Measurement

Computer technology has made significant progress recently, and various radio propagation simulation techniques have been utilized for the performance evaluation and design of wireless networks, for example, in cyber-physical systems. As accurate site-specific radio propagation simulations are desired in these systems, it is important to create accurate propagation environment models from the viewpoint of radio propagation. In this paper, we propose the building material model for the radio propagation simulation. In our model, building materials are modeled by the multi-layer plates. The dielectric and geometric model parameters of each material layer are estimated from the free space measurement by the maximum likelihood-based algorithm. The experiment was conducted in the 33 GHz band in indoor environments for the investigation of millimeter-wave band radio propagation characteristics in Beyond 5G system, and the model parameters of the building materials were estimated by our proposed method. The results showed that wood and glass walls had significant frequency dependencies on the radio wave reflection characteristics, and the modeling accuracy was significantly improved by introducing our multi-layered building material model. The research results are expected to be utilized in radio propagation simulations for wireless system evaluations and designs.