A sub-gigahertz UWB positioning system with automatic network configuration

This paper presents a full 2-D positioning system based on sub-gigahertz ultra-wideband (UWB) radio, which does not rely on a pre-existing infrastructure and is intended for emergency scenario. Relative positions of up to eight anchors and/or mobile nodes are updated four times per second. Each beacon includes an UWB emitter, a receiver based on 1-bit quantization, baseband processing and a 433 MHz ISM radio for data exchange and synchronization. Positions are calculated on a computer in real-time from the time-of-arrival (TOA) matrix. The system also achieves medium range capability (85 m) thanks to coherent integration of very long sequences of pulses (64 k pulses). Measurements have shown a 2-D positioning accuracy of 25 cm, and the system has been successfully tested in an underground parking with coverage of 1000 m².