A Research On The Localization Technology Of Wireless Sensor Network

Wireless sensor network is a combination of sensor technology, embedded computing,distributed information processing technology and communications technology. It can realizethe real-time monitoring, sensing, collecting and processing information of various objects inthe network area in a collaborative manner. It enables the monitoring of a variety ofenvironments for applications that include home security, machine failure diagnosis andbiological detection. In the process of access to relevant information when a wireless sensornetwork is used for environment monitoring, often need to know the source of the data, onlyknow the exact location of the information then the data has the practical significance.Localization technology is one of the key technologies of wireless sensor networks. Thispaper studies the impact on localization of radio irregularity on the basis of the existingpositioning technology of wireless sensor network. The paper also focus on four localizationalgorithms include Centroid algorithm, DV-hop algorithm, Amorphous algorithm and APITalgorithm, form change the radio irregularity, anchors heard, node density and anchor to noderange ratio to illustrate algorithms’ performance and the application situation.Aim at the impact on localization of radio irregularity, this paper studies RSSItechnology and Centriod-Weighted algorithm. Base on these researches, this paper proposesan improved RSSI technology by the distance between the fixed beacon nodes as a referenceto calibrate the unknown nodes’ distance. In order to verify the effectiveness of the improvedRSSI technology, we combine the improved RSSI technology into the Centriod-Weightedalgorithm. Simulation results show that the positioning error of the improved Centroid-RSSIalgorithm less than the positioning error of the Centriod under the same DOI value. With theincrease of DOI values, the superiority of the improved Centroid-RSSI algorithm will becomemore apparent. The simulation results also indicate the improved RSSI technology is moresuitable for radio irregular environment，for example，undergroundd and massive building and so on.