Improvement And Research On WSN Node Localization Algorithm Based On The DV-Hop

Wireless sensor network (WSN) is a comprehensive sensor technology. Embedded technology, distributed information processing technology and wireless communication technology is contained in the network which is composed of sensor nodes. It can real-time monitoring, perceive and gathering the information of environment or monitoring object, and transfer the information to the user. It has broad application prospects in the military, the environmental monitoring, medical aid, etc. Node localization is the premise of the application of wireless sensor network such as use it for target recognition, monitoring and tracking, etc. Node localization is one of the key technology in wireless sensor network. The basic method of node localization is to deploy a small amount of location information known anchor node, to measure the distance, angle or network connectivity between the unknown nodes and anchor node to calculate the localization information of unknown nodes.In the existing localization algorithm which is not based on distance measured, DV-Hop localization algorithm has higher localization precision and lower complexity. However, it has obvious error in the calculation of the distance, so this thesis propose to join RSSI measuring technique, and choose the anchor nodes which participate in the trilateral localization calculation to make the localization precision higher. Through the comparison between the real location coordinates and the estimated location coordinates, to find out the estimated localization coordinates which has the highest accuracy. The algorithm is applicable to the dense network, and the simulation experiment prove that the localization accuracy and localization coverage is improved, but the computational cost is higher.In the dense network, DV-Hop localization algorithm has higher localization accuracy, but with an increasing number of nodes, the energy consumption is higher, and localization error accumulate easily. Because of the high energy consumption, accumulation of localization error, lower scalability and localization coverage, this thesis propose that to divide the whole network into every cluster independently, each cluster has a cluster head to management, in each cluster DV-Hop algorithm is executed. This is a cluster management based algorithm called DVHCL which based on the DV-Hop algorithm. The simulation experiment prove that DVHCL algorithm can improve the localization accuracy, improve localization coverage, extended the localization application scope and reduce the energy consumption. It is also applicable to the sparse non-uniform wireless sensor network.