Joint Location Planning and Cluster Assignment of UWB Anchors for DL-TDOA Indoor Localization.

One of the crucial factors in improving the localization performance of an Ultra-wideband (UWB) downlink time-difference-of-arrival (DL-TDOA) system is the optimal location planning and cluster assignment of the UWB anchors. Prior research takes into account the dilution-of-precision (DOP) or the anchor-user device channel conditions, to solve the anchor location planning. However they do not consider the joint cluster assignment problem, and thus do not include the DL-TDOA cluster-specific metrics to optimize the anchor locations. This often leads to intra-cluster anchor-anchor clock offset related errors affecting the overall performance of DL-TDOA localization. In this paper, we propose a novel joint anchor location planning and cluster assignment algorithm for DL-TDOA. We not only take into account the anchor-user device channel conditions and the DOP, but also the channel conditions between anchors of the same cluster, which may lead to anchor-anchor clock offset based ranging errors. The simulation results show that our proposed algorithm achieves lower average localization error compared to baseline methods derived from prior research, as well as lower values of anchor-anchor clock offset based error, while having a fairly low computational complexity.