Setting up an Ultra-Wideband positioning system using off-the-shelf components

Abstract

With the advanced performance offered by modern embedded systems and the continuous development of ever more complex applications, integration of positioning techniques into these systems gets increased attention. The pressure to reduce the time to market creates a need to rapidly designing subsystems for localization. For indoor applications, quickly employable received signal strength-based methods like Bluetooth or WLAN have the drawback of poor accuracy. In contrast, proprietary solutions providing high accuracy, e.g. FMCW radar, require enormous development efforts and thus are costly. Furthermore, most systems suffer from multi-path effects, finally degrading positioning performance. Ultra-Wideband offers accuracy in the centimetre range, moreover alleviating multi-path due to utilizing high bandwidth. After including positioning support in the IEEE 802.15.4a standard, the first commercial Ultra-Wideband IC are now available. The paper presents the steps taken to build a fully working positioning system based on off-the-shelf components and introduces the necessary background knowledge. Specifically, the hardware and software design is described, costs are evaluated, and measurements regarding the accuracy of the final system are executed. Two positioning techniques, i.e. Circular and Hyperbolic, are compared. Both provide an average error of around 30 cm, but differ in the maximum error.