An HW-In-the-Loop Approach for the Assessment of GNSS Local Channel Effects in the Railway Environment
Gianluca Falco, Mario Nicola, and Emanuela Falletti, Istituto Superiore Mario Boella, Italy
Date/Time: Wednesday, Sep. 26, 10:40 a.m.
The European Rail Traffic Management System/European Train Control System (ERTMS/ETCS) has been developed by the European Union to enhance safety and efficiency of the railway transportation. So far, the positioning and monitoring of the trains have been based mainly on trackside equipment named balises: the introduction of Global Navigation Satellite Systems (GNSS) to implement an absolute positioning system on trains could lead to a better utilization of the line with a consequent line capacity increase, along with reliability increasing and cost reducing due to the removal of expensive infrastructures. This paper describes the insertion of a state-of-the-art channel model, named Land Mobile Satellite Channel Model (LMSCM) properly adapted to represent railways scenarios, into a hardware-in-the-loop system, where the parameters generated by LMSCM are used to configure an RF GNSS signal generator. The use of the hardware generator eases the simulation of the entire GNSS constellation, while the availability of the RF signal enables the assessment of the effects of rail-domain multipath on commercial receivers. The resulting model, named Rail-Land Mobile Satellite Channel Model (Rail-LMSCM), has been enhanced with the support of different kind of scenarios a train may encounter around the rail track, as well as with the introduction of GNSS outages due to the presence of tunnels. Such enhancements make the RailLMSCM a more realistic average representation of the railway environment. The implemented Rail-LMSCM has been used to test in the lab the local propagation effects on the performance of a complete GNSS receiver.