Study Of Localization Algorithm In Wireless Sensor Networks

Wireless sensor network, a new data gather technique, integrate multifold subjects such as microelectronic, wireless communication and wireless network, and is widely used in military, industrial controlling, environmental monitoring and medical assistance fields. Self-localization of sensor node is to get the position information of node by using information of some already known nodes and some special mechanisms. Correct self-localization of sensor nodes is the promotion of monitoring events normally. In different point of view, localization algorithm can be divided into many kinds: centralized, distributed, infrastructure-based, range-based and range-free localization algorithm. The researchers indeed provide many resolutions for the fault of these algorithms. However, many problems can be found if these algorithms are applied into the physical WSN. The localization technique has been more and more focused on as a wireless sensor networks key support technique.In this thesis, we discuss the self-localization technology in detail. Since the nodes are restricted by size, cost, energy and work under the environment that people are hardly closed to. So the basic approach is to use beacons that aware of their positions as reference, and the other nodes compute their positions through the relationship of distance, angle, or network connectivity to the beacons.The research of this paper is based on the analysis of a great deal of recent technical reports and research results on WSN. Its main work includes:(1)The research background, article configuration and present investigatory headway of WSN at home and abroad are introduced.(2)The concept of WSN and basic principles of node localization in WSN are also introduced.(3)The evaluate system and basic theory of self-localization in WSN are analyzed, and current localization algorithms and localization systems are classified.(4)The thesis focuses on the investigation of APIT location algorithm, and an improved node positioning algorithm is proposed, together with the discussion of algorithm principle and realization issues.(5)A simulation experimentation has been done. The simulation results show that the performance of improved algorithm is significantly improved compared with the APIT algorithm and can improve location accuracy and coverage rate.(6)Summary and the direction of the next research are made.