4×4 MIMO channel sounding in tunnels for train-to-wayside communications

This paper presents MIMO channel sounding measurements performed in the underground road tunnel of Roux, in south of France, at 5.8 GHz. Different scenarios for antennas (spacing and polarization) and moving vehicles speeds were carried out in the tunnel. The aim was to be as close as possible to scenarios one can encountered in railway environments. From these measurements, MIMO channel matrices are computed, in order to determine the correlation level of the channel and its capacity along the tunnel, according to different antenna spacing and polarization.