Research On Node Localization Technology Based On RSSI In Wireless Sensor Networks

Node localization technology is one of the important supporting technologies in wireless sensor networks technology. It is obviously that the technology of wireless sensor networks will go-ahead very quickly and its applications will be wider and wider in the coming future, sensor node localization technology has improved the wireless networks technology in theoretical significance and application value.The dissertation focuses on the discussion of the localization technologies of professional applications based on wireless sensor networks.The major analyses and findings are as follows:(1) Summarize the wireless sensor networks technology research status and analyze the key technology and applications of wireless sensor networks, emphasize on the sensor node localization technology and the positioning algorithm in wireless sensor networks,propose the positioning problems to be solved in localization technology.(2) Design and implementation of A RSSI-based Localization Algorithm:By the way of combining RSSI method and optimization in mathematics engineering,the dissertation proposes BFGS Localization Algorithm based on RSSI Localization Algorithm.The method is to set the wireless sensor network node Locatization issue into unconstrained optimization issue.The paper discusses the main features of the algorithm and compare it with the similar algorithm.Finally,it is proved that this algorithm is obviously superior to other algorithms through MATLAB simulation on environmental adaptability.(3) Optimize the Shadowing signal model and centroid localization algorithm based on the current signal model,firstly,select the reference nodes for signal model with an effective constraint,then do the triangular test for the selected reference nodes above to stimate the unknown nodes,finally,use weighted centroid localization algorithm to achieve more accurate node localization.The range between anchor nodes and unknown nodes in RSSI localization system have an effect on the localization results,the closer,the more.So we can weigh the centroid algorithm based on distance,using the weighted coefficient to reflect the importance of the anchor nodes on the localization results of unknown nodes..Finally,simulate the centroid algorithm based on the signal model on MATLAB,the simulation results show that the positioning system can improve the positioning accuracy of the unknown nodes and the system positioning performance.