3D non-stationary wideband circular tunnel channel models for high-speed train wireless communication systems

This paper proposes three-dimensional (3D) non-stationary wideband circular geometry-based
stochastic models (GBSMs) for high-speed train (HST) tunnel scenarios. Considering single-bounced (SB)
and multiple-bounced (MB) components from the tunnel’s internal surfaces, a theoretical channel model is first
established. Then, the corresponding simulation model is developed using the method of equal volume (MEV)
to calculate discrete angular parameters. Based on the proposed 3D GBSMs, important time-variant statistical
properties are investigated, such as the temporal autocorrelation function (ACF), spatial cross-correlation
function (CCF), and space-Doppler (SD) power spectrum density (PSD). Results indicate that all statistical
properties of the simulation model, verified by simulation results, can match well those of the theoretical model.
The statistical properties of the proposed 3D GBSMs are further validated by relevant measurement data,
demonstrating the flexibility and utility of our proposed tunnel GBSMs.