Research on Direction Finding Algorithm Based on Bluetooth AOA Measurement

With the broad deployment of Bluetooth in IoT devices, the Bluetooth SIG has incorporated a measurement-based AOA direction finding algorithm specification into the Bluetooth protocol to facilitate location-based services. In this study, we found that these errors in AOA measurements originate from phase noise and multipath effects. In order to solve these problems, we employ the MUSIC algorithm to enhance the accuracy of AOA measurements, incorporating phase noise into the measurement process, and introduce an improved MUSIC algorithm aimed at mitigating phase noise. Furthermore, we propose an AOA correction algorithm utilizing mean-value optimization to counter the fluctuations in angle measurements induced by multipath effects. Simulation experiments demonstrate that, relative to the mean phase difference algorithm and the original MUSIC algorithm, the improved AOA direction finding algorithm significantly reduces measurement errors by 47% and 28%. Moreover, the likelihood of achieving a measurement error of less than 5° reaches to 97%, signifying a substantial enhancement in positioning accuracy.