Chained wireless synchronization algorithm for UWB-TDOA positioning

The Time Difference of Arrival is a popular method for UWB-based positioning, since it allows high position update rate even for multiple users. However, it requires the network infrastructure (anchors) to be synchronized, preferably with sub-nanosecond accuracy. Herein, an approach for synchronizing multiple anchors in a wireless, line-of-sight manner is described. This method is able to deal with UWB modules equipped with inexpensive drift-prone oscillators, as such impairments are estimated and compensated. By applying the proposed approach the influence of generally variable environment (e.g. temperature) on timing and positioning performance is reduced. Moreover, the presented algorithm is suitable for straightforward chaining of the line-of sight-segments in order to allow synchronization of distant anchors that cannot be synchronized with the master anchor directly.