SELECT operates not only with conventional ultra high frequency (UHF) radio technology, but also with the new ultra wideband technology (UWB). The system participants — objects or people — are equipped with semi-passive tags whose position is determined based on the signal delay.
Fraunhofer IIS was involved in SELECT from the start, beginning with a user study to determine the existing framework. The system architecture was then developed to correspond to the desired requirements. Fraunhofer IIS focused its contribution on the hardware platform for the reader and the associated firmware. The institute was additionally involved in the design of the reader and the infrastructure and will also carry out a validation and analysis of the results.
UWB signals feature short pulses that facilitate precise ranging of the incoming signal and allow the signal delay to be determined. The returning UWB signal is modulated in the tag using a special technique. This allows the system to isolate it from the reflections and clearly identify it. . The semi-passive tag is activated by means of a UHF signal. Now active, the tag can receive the UWB signal, modulate it and send it back. Fraunhofer IIS and its partners are actively pursuing innovative detection methods that can be used to optimize the positioning accuracy of localization systems.