Improved localization algorithm based on RSSI in low power Bluetooth network

Due to the low power feature of Bluetooth, network based on Bluetooth has been considered as one of the promising positioning technology candidates by the research and industry communities. In order to reduce the positioning error being introduced by the Received Signal Strength Indication (RSSI) algorithm, an optimized RSSI ranging and positioning algorithm is proposed, which is fully based on the low power Bluetooth positioning technology. First, this algorithm uses the trilateral algorithm to get the rough region estimation which covers all the unknown nodes. Second, by breaking down the area, the algorithm forms the RSSI value for the beacon nodes at the centroid of each region, and also forms the RSSI value at the unknown nodes. Thirdly, the RSSI values that are formed by the beacon node at the unknown node and at the centroid of each region are compared against each other to determine the unknown node's location. Experiments and simulation results show that this algorithm can increase accuracy of distance estimation by 63.3% compared to the traditional centroid localization algorithm.