Exploiting Time Synchronization as Side Effect in UWB Real-Time Localization Devices

The availability of low-cost Ultra Wide Band (UWB) chipsets is changing the scenario of applications for real-time localization systems. By means of commercially available two-way ranging devices it is possible to achieve indoor positioning on the order of few centimeters. However, despite the picosecond accuracy of the counters used for position calculation, the low-cost entry level devices do not offer direct support to the distribution of time among nodes. This paper first introduces the architecture of the proposed system that is aimed to exploit standard behavior of off-the-shelf UWB transceivers (such as Decawave modules) combined with straightforward software based on the modules APIs. Then, the paper describes the method to obtain fast time reference signals from off-the-shelf nodes with an accuracy in the order of few microseconds. The experimental results show the possibility of obtaining, from all the nodes belonging to the same network, accurate time reference pulses with a maximum jitter of 3.3 μs and a standard deviation of 0.7 μs without any additional hardware.