Improved Weighted Localization Algorithm In Wireless Sensor Network

With the large development of electronic communication, semiconductor technology, computer network technology in the1990s, wireless sensor network consisting of sensor nodes with sensing and data processing has aroused wide concern,it is a hotspot in the world in recent years. Through the deployment of a large number of relatively inexpensive sensor nodes, wsn is self-organization network using these nodes in wireless multi-hop communication function. Its prospect in environmental monitoring, military defense, traffic management, intelligent home furnishing and other fields is very good and can be widely used. In wireless sensor networks, obtaining the position monitoring information area sensor is the basis of its various applications, so the node localization technology is one of the key technologies in wireless sensor networks. In practical application, the nodes are randomly deployed by artificial or other means, location information is uncertain, so their localization information must be clear after deploying these nodes.Because of based and important function of node localization in the wireless sensor network, this thesis has focuses on the node localization algorithm. First, a brief overview of the development status and recent research of wireless sensor network has been explained, the existing node localization algorithm principle has also been a key introdunction and detailed analysis. According to whether need to measure the distance between nodes, the existing localization algorithms can be roughly divided into two categories:range-based localization algorithms (Range-based) and range-free localization algorithms (Range-free). Rrange-based localization algorithms can improve the positioning precision of ranging, but the measured distance is vulnerable to the wireless signal, the node energy and other factors.Range-free localization algorithms have been based on network connectivity, hardware support is less and can reduce the energy consumption of node localization process, but the nodes’ distribution of position in the network is largely influenced to these algorithms. Through analyzing the advantages and disadvantages of two kinds of positioning technology, because of most range-free localization algorithms are based on network connectivity and they have been largely dependent on the anchor node.On this premise,in order to improve the positioning anchor nodes, a new method called improved weighted centroid localization algorithm based on Dynamic anchor node (IWLA-DAN) is proposed now. Firstly, we can get weighting formula by proving the conclusion that the result have the least er ror when the triangle consisting of three anchor nodes which can communicated with the unknown node is an equilateral triangle, then the unknown node is loca ted through weighted algorithm and trilateration. At the same time, the node sho uld be updated to pseudo node and participate in the location of other nodes in t he network. Finally, simulation result through Matlab shows that the positioning error is obviously reduced and the node location accuracy is increased after imp rovement.