Měření vlastností optické komunikace v dopravních systémech

Abstract

This thesis focuses mainly on VLC technology and its use in automotive transportation and ITS. It discusses the advantages, disadvantages, possible complications and a brief analysis of a few experiments already carried out with VLC technology in transportation applications. The paper discusses the LabVIEW development environment and describes the compiled code used to perform the experimental measurements using a software defined radio (USRP N210) used for signal generation, modulation and demodulation. The modulated signal generated by the SDR device is emitted in the form of visible light (VLC) by an automotive reflector with a solid-state light-emitting diode (LED) light source. The emitted light is detected by a PIN photodiode and the signal is then fed to the SDR where it is demodulated using LabVIEW. LabVIEW application is also used to evaluate the transmission quality. Measurements were performed under different temperature, wind and humidity conditions (calm weather, rain, fog and thermal turbulence), thanks to a special box to simulate these conditions. The measurements were also performed with the maximum possible deflection of automotive reflector, during which it was still possible to establish communication. Finally, the results of the measurements are evaluated, together with a reflection on the direction in which this technology could be further developed.