Network Scalability for Ultra-Wideband Real-Time Location Systems Based on vMISO

For time-based location systems, a common time base is important for obtaining the correct position. However, wireless clock synchronization is considerably easier to deploy in certain environments, such as large areas. A single-region positioning network is often restricted to the anchor communication range. Therefore, multiple master anchors form the basis of an extensible location network and provide an effective means of adapting the system to a complex propagation environment. In this article, we consider simultaneous network scalability with the relative clock synchronization and localization. We first establish an extendable UWB location system model through intelligent response across the routing layer and physical layer. Anchors act as master or slave anchors in different cluster areas and advance the clock check packet (CCP) from an initial region to the surrounding area to achieve clock synchronization of the entire network. The intracluster CCP transmission is achieved by broadcasting, and the intercluster CCP transmissions use vMISO and are automatically driven by the broadcast arrival time for better results. Furthermore, the physical-access and clock synchronization algorithms are discussed. Finally, location tests combined with routing simulations are conducted to demonstrate the performance of the proposed scheme.