An Energy Analysis of Indoor UWB Localization Using RF and Photovoltaic Energy Harvesting

Accurate asset tracking in industrial Internet of Things often relies on precise but power-hungry Ultra-Wideband (UWB) localization. In this work, we aim to assess the operating boundaries of a commercial UWB module in power-constrained applications, such as battery-less operation with UHF wireless power transfer or photovoltaic (PV) energy harvesting (EH). Current consumption measurements of a UWB transceiver performing Two-Way Ranging are compared against the power available indoors from EH. The results show that a single ranging operation can be repeated every 221 seconds at a distance of 5 meters from a 2W-ERP source in the 868 MHz ISM band, and every 19 minutes and 5 seconds at a distance of 10 meters. Moreover, a 4.8 cm2 PV cell can provide sufficient power to perform a ranging operation every 8 minutes and 7 seconds under indoor office illumination, and every 101 seconds next to a window in cloudy weather. These results are compatible with low-sampling-rate localization in industrial environments.