An Improved RSSI-Based Centroid Localization Algorithm In Wireless Sensor Networks

Since the 21st century, wireless sensor networks (WSN) as a kind of new information acquisition and processing technology has attracted widespread attention and became a hot issue in many countries. Wireless sensor network (WSN) is a multiple hops self-organization network formed by lots of cheap miniature sensor nodes in monitoring area and these sensor nodes communicate with each other through wireless signals. The network can real-time monitor a certain area by the nodes'collaborative work. Its purpose is to perceive, collect and process the information of the area, and then send it to the observer. Wireless sensor network has many applications, and can be applied in national defense, environmental monitoring, space exploration, medical and health, agriculture, transportation management, manufacturing, disaster relief and so on.In practice, the sensor nodes'localization information is very important for monitoring, so it is extremely significant. The sensor nodes are deployed randomly and their positions are unknowable, so we need to get their position information. Because of low survival cycle,poor reliability and low localization accuracy of wireless sensor network, the localization research faces huge challenge, and also make the localization become a hotspot in recent years.This paper firstly review wireless sensors networks, and then introduce the localization technology, including the basic concept and terms,classification of localization algorithm,several typical localization algorithms and performance evaluation index etc.Based on the triangle centroid algorithm of wireless sensor network, we begin our research around RSSI localization algorithm. In order to overcome receiving signal strength measurement error of the wireless sensor network (WSN) nodes, we propose an improved RSSI centroid localization algorithm based on the triangle centroid algorithm. It measures the distance between the nodes point-to-point by the improved RSSI technology, and then we use the triangle centroid localization algorithm.The simulation results show that the positioning accuracy of this algorithm has been improved greatly compared to the triangle centroid localization algorithm.