Channel Sounding and Ray Tracing for Intrawagon Scenario at mmWave and Sub-mmWave Bands

• Published in: IEEE transactions on antennas and propagation Vol. 69; no. 2; pp. 1007 - 1019
• Main Authors: Guan, Ke, Peng, Bile, He, Danping, Eckhardt, Johannes M., Yi, Haofan, Rey, Sebastian, Ai, Bo, Zhong, Zhangdui, Kurner, Thomas
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Azimuth; Bandwidth; Bandwidths; Channel sounding; Frequencies; Frequency measurement; High speed rail; intrawagon; millimeter wave (mmWave); Millimeter waves; Rails; railway communications; Ray tracing; ray tracing (RT); smart rail mobility; Solid modeling; Sounding; sub-mmWave; Three dimensional models; Ultrawideband; Wireless communication
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2020.3016399

In order to realize the vision of "smart rail mobility," a seamless high-data rate wireless connectivity with up to dozens of gigahertz bandwidth will be required. This forms a strong motivation for exploring the underutilized millimeter wave (mmWave) and sub-mmWave bands. In this article, the wireless channel in one "smart rail mobility" scenario- the intrawagon scenario-is characterized through ultrawideband (UWB) channel sounding and ray tracing (RT) at mmWave and sub-mmWave bands. To begin with, a series of horizontal directional scan-sounding measurements are performed inside a real high-speed train wagon at 60 and 300 GHz frequency bands with a bandwidth of 8 GHz. Correspondingly, the channel characteristics such as Rician K-factor, root-mean-square (rms) delay spread (DS), azimuth spread of arrival, and azimuth spread of departure are extracted and analyzed. Based on the measurements, a self-developed RT simulator is validated through the reconstruction of the three-dimensional wagon model and the calibration of the electromagnetic (EM) properties of the main materials. This gives the chance to physically interpret the measurement results and characterize the intrawagon mmWave and sub-mmWave channels more comprehensively through extensive RT simulations.