Research On DV-Hop Algorithm For Anisotropic Wireless Sensor Networks

Wireless sensor network technology is everywhere,and it is used in many fields such as smart home,military security,logistics,fine agriculture,and environmental awareness.The implementation of these applications needs to be combined with the location information of the nodes.Therefore,the accuracy and real-time performance of the node location information have a great impact on the entire wireless sensor network system.The DV-Hop algorithm provides a simple,feasible and low-cost positioning solution for isotropic networks,which is widely concerned at home and abroad.Compared to idealized isotropic networks,anisotropic networks are more practical.However,the positioning accuracy of DV-Hop in an anisotropic network drops sharply and cannot meet the positioning requirements.Therefore,it is important to improve the the localization accuracy of DVHop under anisotropic networks.To this end,the work of this thesis mainly shows as follows:(1)Starting from the theory,the basic concept of WSN is briefly introduced,and the related theories of node location technology are elaborated.Then based on a large number of documents,the existing improved DV-Hop algorithm is summarized.(2)In order to solve the problem of poor performance of DV-Hop in anisotropic networks,a locally weighted linear regression DV-Hop algorithm based on loop optimization(ILWLR-DV-Hop)is proposed.The algorithm uses the weighted least squares method to solve the equation,and the weighting coefficient is the laplace kernel function.Then the equations are solved cyclically,and the solution with the smallest difference is regarded as the optimal solution of the equation.Experiments show that in the isotropic network and the X,H,C,S topology,compared with the traditional DVHop algorithm,the ILWLR-DV-Hop algorithm can significantly improve the accuracy of the node position estimation.(3)In view of the large computational complexity of ILWLR-DV-Hop,the improved ILWLR algorithm(TLWLR-DV-Hop)is proposed.Based on the implementation of the original ILWLR-DVHop positioning algorithm,a hop limit mechanism is introduced to limit the number of hops of data packets to reduce traffic and computation.The comparison experiments show that the computation of the improved ILWLR-DV-Hop is smaller than the original ILWLR-DV-Hop and the positioning accuracy is basically the same.