On performance study of UWB real time locating system

Real time locating systems (RTLS) with centimeter accuracy have recently been made available for commercial deployment by employing ultra wideband (UWB) technology. DecaWave's DW1000 is a commercial UWB integrated circuit that utilizes time-of-flight (ToF) measurement technique and two-way-ranging (TWR) mechanism to accurately estimate the distance between an anchor and a tag. With the distances between the tag and at least three anchors, a trilateration algorithm can be applied to estimate the tag's location on the same two-dimensional (2D) plane as the anchors. Moreover, if four or more anchors are available, the tag's location in three-dimensional space can also be estimated. This work presents a performance study on location accuracy of DecaWave's TREK1000, a two-way ranging RTLS IC evaluation kit. Four anchors and one tag were set up as an RTLS deployed in two different indoor areas. The difficulties encountered during the calculation of the tag's location at certain locations were pointed out. It was also found that the change in performance of the 2D localization of the system when set up with three and four anchors was insignificant. Additionally, the accuracy in the third dimension or the height of the tag above the ground was found to be less accurate.