The localization of trains in a railway network is necessary for train control or applications such as autonomous train driving or collision avoidance systems. Train localization is safety critical and therefore the approach requires a robust, precise and track selective localization. Satellite navigation systems (GNSS) might be a candidate for this task, but measurement errors and the lack of availability in parts of the railway environment do not fulfill the demands for a safety critical system. Therefore, additional onboard sensors, such as an inertial measurement unit (IMU), odometer and railway feature classification sensors (e.g. camera) are proposed. In this paper we present a top-down train localization approach from theory. We analyze causal dependencies and derive a general Bayesian filter. Furthermore we present a generic algorithm based on particle filter in order to process the multi-sensor data, the train motion and a known track map. The particle filter estimates a topological position directly in the track map without using map matching techniques. First simulations with simplified particular state and measurement models show encouraging results in critical railway scenarios.

This paper presents results for active and passive measurements using a novel method based on multiple compact antenna test range (CATR) reflectors to perform simultaneous multiple angle measurements in order to characterize the beam-forming characteristics in a real environment of the 5G devices operating in the millimeter wave frequency band: 24–44 GHz. The over-the-air (OTA) system generates four planar wavefronts with different incidence angles, realizing up to five pairs of angular spreads or four switched/simultaneous angles of arrival. The initial target application is radio resource management (RRM) testing, where the execution of mobility procedures and radio link monitoring of a 5G millimeter wave device are evaluated. The applicability of the multi-reflector approach to RRM testing is measured with commercial 5G handsets, through three test scenarios. The paper demonstrates that baseband (non OTA) testing is not sufficient for RRM FR2, as the results are influenced by the direction of arrival of the signal. It is further shown that OTA testing in a multi-reflector CATR system and a careful selection of a representative set of test directions is critical for full characterization of the performance of a wireless device operating in the millimeter wave bands.