An Improved Weighted Centroid Location Algorithm

A weighted centroid location algorithm is proposed to improve location precision by using received signal strength indication(RSSI)ratio(RR-WCL).In the RR-WCL algorithm,the anchor nodes send their own information periodically,and the unknown nodes only record the RSSI mean values sent from the same anchor node.When the number of beacon messages that an unknown node received is larger than the threshold,the unknown node will establish a collection of anchor nodes,a collection of signal strength and a collection of anchor nodes'locations.Then the RSSI ratios received from anchor nodes are used as weights to determine the position of an unknown node.The results obtained from simulation and real-system experiments show that the environment has little impact on the performance of locating.Moreover,there is an improvement of 6.4% to 37.25% in location precision compared with the centroid location algorithm and 5.12% to 11.23% in location precision compared with the weighted centroid location algorithm when the number of anchor nodes increases.