Server based Bluetooth Low Energy (BLE) Positioning using Received Signal Strength (RSS) Measurements

Bluetooth Low Energy (BLE) technology has gained significant attention in recent years due to its low power consumption, wide availability, and compatibility with a variety of devices. This article proposes a novel BLE based positioning system utilizing received signal strength (RSS) measurements. We introduce a server based BLE positioning method. Here, the mobile devices, e.g. smartphones, act as BLE beacons. Static BLE sniffers are installed in the environment. They record RSS measurements and send them to a server. The position of the mobile device is calculated at the server using a particle filter (PF) and can be communicated back to the mobile device. To enhance the distance and position estimation accuracy, each receiver is equipped with multiple BLE receivers which are closely spaced, which helps to reduce fading effects caused by multipath propagation. Furthermore, the RSS measurements are smoothed by a smoothing filter. The proposed method is evaluated by indoor measurements, where we obtain a positioning error with a mean root mean square error (RMSE) of 0.85 m for a mobile device carried by a robot and a mean RMSE of 1.3 m for a walking pedestrian.