Bluetooth Low Energy Direction Finding Principle

The ubiquitous implementation of 5G networks and the Internet of Things (IoT), brings about the importance of indoor localization. Even though Global Positioning System (GPS) provides an efficient outdoor Positioning System (PS), indoor positioning techniques fail to provide the same level of accuracy and efficiency. The previous methods were based merely on Received Signal Strength Indication (RSSI). Recently, with the introduction of the new Bluetooth standard v5.1, the Angle of Arrival (AoA) method provides new opportunities for asset tracking and indoor positioning. However, Bluetooth suffers from an inherent problem of multipath effects, noise, phase/frequency shift, and fluctuations. In this paper, we propose a curve fitting and correction method to improve the accuracy of the received signal from Bluetooth Low Energy (BLE) modules. The results illustrate a potential improvement in increasing the overall angular accuracy of BLE-direction finding.