Ray-Tracing-Based Data Expansion From Limited Sub-THz Channel Measurements in Urban Street

Various measurement campaigns and studies have been conducted on the sub-THz frequency band (above 100 GHz) for potential future mobile communication use. However, collecting sufficient measurement data is challenging due to the high pathloss, and there is also a possibility that the measurement data is biased from measurement equipment outages. This letter proposes a ray-tracing simulation to complement measurements of the 159 GHz band in an urban street-canyon. Using virtual measurement points generated by a ray-tracing simulator, the pathloss exponent of the 159 GHz band is estimated after checking some results against the measurement data. In the censored environment, the pathloss estimation result is compared with the ray-tracing using the Tobit Maximum Likelihood (ML) estimation. The results show that the pathloss exponent estimated by ray tracing simulation with virtual measurement points matches the result of the ML estimation method. Based on these, small scale channel parameters such as a delay spread and angular spreads were also estimated, and they can be used for 159 GHz channel simulation.