Large- and Small-Scale Fading Characteristics of mmWave HST Propagation Channel Based on 28-GHz Measurements

Considering a linear cell layout, millimeter-wave (mmWave) high-speed train (HST) measurements were conducted at 28 GHz with a speed up to 170 km/h in two different HST scenarios: viaduct and tunnel scenarios. In this paper, large-and small-scale fading characteristics, such as path loss (PL), K-factor, and etc., were investigated based on the measurements. Since there were significantly different patterns of measured PL for the two scenarios, we proposed multi-slope PL models to cover the characteristics. By observing the measurement data, we characterize multipath components (MPCs) caused by railway structures such as overhead line equipment which were installed along the railway.