Investigation Of Wireless Sensor Network Localization Technology

Wireless Sensor Network is integration of sensor techniques,nested computation techniques,distributed computation techniques and wireless communication techniques.It can be used to testing,sensing,collecting and processing information of monitored objects and transferring the processed information to users.Since many applications of wireless sensor networks depend on the location information of sensor nodes,how to obtain the accurate localization has become thefocus of attentions.Since the nodes are restricted by size,cost,energy,and work under the environment that should not be accessed,the basic approach is to use anchor nodes that aware of their positions as reference,and the other nodes compute their positions through the relationship of distance,angel,or network connectivity to the anchor nodes.The thesis focuses on the investigation of DV-Hop localization algorithm.The traditional DV-Hop algorithm use the hop distance instead of straight distance.During the location phase,it need to obtain the distances from the unknow node to at least three or more anchor nodes.Due to the restrictions of the the condition of random deployment,it can not be achieved location,and the localization Performance is not perfect.Based on the DV-Hop algorithm,utilizeing the theory of the sencond broadcasting,and taking the model of two anchor nodes,a improved node localization algorithm is designed.Then the algorithm principle and realization issues are discussed,and this algorithm improves on location accuracy and coverage.The reasonability and validity of the simulation model are testified by the simulation result based on OMNeT++.Simulations show the average positioning error of each algorithm in different scenarios,and the effect of different parameters on network performance is also analyzed.The results show that the location accuracy and coverage of this algorithm are significantly improved compared with the DV-Hop algorithm.Finally, we sum up this paper and the directions of research in this area introduced.