Measurements of a MIMO train-to-wayside communication system on tunnels

This paper presents a deep insight on a real implementation of a train-to-wayside radio on subway tunnels that makes use of a 2×2 MIMO-OFDM setup. The following parameters on the performance of such a system are investigated: polarization diversity, antenna separation, tunnel cross-section influence and MIMO capacity. Moreover, two different channel matrices have been calculated, assuming uniform power allocation and performing the waterfilling algorithm. Finally, the purpose of this paper is to evaluate the feasibility of a real MIMO-based train-to-wayside broadband radio. Measurements were carried out on Line 3 of Metro de Madrid, Spain.