A General 3-D Nonstationary GBSM for Underground Vehicular Channels

Reliable and efficient communications are indispensable for vehicles in underground environments. Underground wireless channels present a number of unique properties, such as guided propagation, rich scatterers, and near-field/far-field effect. In this article, a 3-D twin cluster geometry-based stochastic model (GBSM) is proposed to describe underground vehicular channel characteristics in both pillar and tunnel scenarios. The proposed model supports arbitrary trajectory mobility of vehicles and multiple antenna configurations at the transmitter (Tx) and the receiver (Rx). The cluster time evolution is modeled by different scatterer generation and updating methods to simulate the channel characteristics such as nonstationarity, near-field/far-field differences, and waveguide effects. Based on the proposed channel model, the statistical characteristics of the channel are derived and simulated, including the temporal autocorrelation function (ACF), spatial cross-correlation function (CCF), delay power spectrum density (PSD), Doppler PSD, and so on. Besides, underground channel measurements at 2.5/3.5 GHz are conducted in a garage scenario. Comparison results of channel measurements and simulations validate the accuracy and usefulness of the proposed GBSM.

Automated summary

This article proposes a 3-D twin cluster geometry-based stochastic model (GBSM) to describe the characteristics of underground vehicular channels in different scenarios. The model can simulate nonstationarity, near-field/far-field differences, and waveguide effects. Statistical characteristics of the channel, such as temporal autocorrelation function, spatial cross-correlation function, delay power spectrum density, and Doppler PSD, are derived and simulated based on the proposed model. Channel measurements and simulations in a garage scenario validate the accuracy and usefulness of the proposed GBSM.