Position-based wireless channel characterization for the high-speed vactrains in vacuum tube scenarios using propagation graph modeling theory

Wireless channel modeling is regarded as a pivotal research topic, since the analysis and evaluation of the wireless communication system requires a reliable model of the channel impulse response (CIR). This paper presents a novel and practical study on the position-based radio propagation channel for high-speed vactrains in the vacuum tube scenarios using the propagation graph channel modeling theory. Based on the Lambertian scattering pattern, the propagation graph channel modeling method considers the diffusion effect of radio waves. A multiple-input multiple-output (MIMO) wideband system channel is emulated for obtaining the virtual channel data. During the emulation process, the line-of-sight (LoS), single-bounced and double-bounced components are considered to yield the virtual CIR. Then, small-scale fading properties such as K factor, time delay spread (DS), and Doppler frequency feature are parameterized particularly, which presents dynamic variances at different train locations. Moreover, the simulation performance analysis of the MIMO system focuses on the ergodic capacity and the singular value spread (SVS). The corresponding results indicate a MIMO capacity performance degradation in this scenario. The proposed model can facilitate the reliable simulation and evaluation of MIMO systems for the high-speed vactrains in the vacuum tube scenarios.