A High-precision TOA-based Positioning Algorithm Without the Restriction of Strict Time Synchronization for Wireless Systems

摘要

Time-of-arrival (TOA) is a range-based positioning method with high positioning precision. However, TOA-based methods require strict time synchronization between nodes, which puts forward high requirements on the hardware and power consumption of sensor nodes. For the high cost hardware problem of TOA-based methods, we propose a TOA-based iterative algorithm (iTOA) that can be applied to the wireless system under the condition of low time synchronization precision to achieve high positioning precision. Without the restriction of strict time synchronization, iTOA can reduce the difficulty of hardware implementation. iTOA eliminates the time synchronization error via iteration and minimizes the non-line-of-sight propagation error by using the weighted least square method at the same time. Moreover, iTOA can be applied to the network with changing beacons. The simulation results show that the average positioning precision improves at least 27.2% and 38.3% compared to CCTG and LOP, respectively. As the time synchronization precision decreases, the positioning precision improvement is more obvious compared to CCTG and LOP. For a low time synchronization precision system, the positioning error of iTOA is almost 99.99% less than both CCTG and LOP.