Indoor Location Estimation by Bluetooth Low Energy for Pedestrian Navigation

Abstract

The global navigation satellite system (GNSS) is a satellite positioning system. However, when the signal is shielded by reinforced concrete or metal, it is difficult to be received indoors. This study introduces an indoor location estimation scheme based on bluetooth low energy (BLE) for pedestrian navigation that can save power and reduce the installation density. We investigated indoor positioning methods with the use of the received signal strength indicator (RSSI) in association with two BLE transmitters as the main axis. The error of the single RSSI ranging is more than several tens of meters, and is insufficient for use for pedestrian navigation. However, this error is reduced to a few meters when the proposed simple proportional correction calculation is performed for the estimated distance. The target accuracy required for pedestrian navigation for healthy people is approximately 10 m. This is equivalent to the accuracy of outdoor satellite positioning. For example, given that the size of the Shibuya underground shopping street is approximately 4,676 m², twenty BLE beacons can cover the entire area. If this technology is established, indoor positioning can become possible within a wider range with a lower cost and lower labor effort compared with the current state-of-the-art.