Research And Improvement Of DV-Hop Localization Algorithm In Wireless Sensor Networks

Wireless sensor networks are composed of a large number of cheap micro sensor nodes deployed in the monitoring area,which forms a multi-hop and self-organized network system through wireless communication.With the development of this technology,wireless sensor networks have been widely used in many fields.Generally speaking,in the application process of wireless sensor networks,it is very important to determine the specific location of nodes or events in the network for the normal operation of the system.Therefore,as one of the key technologies in wireless sensor networks,node localization has been widely concerned by domestic and foreign experts and scholars.This paper also focus on the problem of node localization to do further research and analysis.At present,there are a lot of node localization algorithms,which can be classified according to different criteria,such as can be divided into range-based localization algorithm and rangefree localization algorithm.This paper studied the DV-Hop localization algorithm which is widely used in range-free localization algorithm,by consulting a large number of references related to this algorithm,the causes of the positioning error are analyzed.On the basis of the existing improved algorithms,this paper makes further improvements on the DV-Hop Localization algorithm.The main works are as follows:1.In this paper,the principle of DV-Hop localization algorithm is analyzed,and on the basis of a large number of existing improved DV-Hop algorithms,the subjective and objective reasons for the error of the algorithm are summarized,which points out the direction for the new improved algorithms.Through simulation experiments,this paper created an experimental environment of node localization where the positioning performance of the DV-Hop algorithm is simulated and analyzed with the positioning accuracy as the performance evaluation index.2.This paper proposes an improved twice-refinement DV-Hop localization algorithm based on centroid error correction,which is called DV-Hop-WCR localization algorithm.The improved algorithm uses RSSI ranging technology to get the distance between adjacent nodes for auxiliary positioning,and also uses the centroid coordinates of the unknown nodes to correct their own initial positioning results,then re-positions the unknown nodes using the corrected coordinates.Simulation results show that in different simulation conditions,compared with the traditional DV-Hop algorithm,the positioning performance of DV-Hop-WCR algorithm is improved obviously.3.Another improved twice-refinement DV-Hop localization algorithm based on anchor node error correction is proposed in this paper,which is called DV-Hop-ACR localization algorithm.Aiming at the problem that the DV-Hop-WCR localization algorithm cannot fully play its role,when the node density is low or the node distribution is uneven,the DV-Hop-ACR algorithm presents a method to correct the initial positioning coordinates of unknown nodes by using anchor node localization error.The simulation results show that,compared with the traditional DV-Hop localization algorithm,the positioning accuracy of DV-Hop-ACR algorithm and DV-Hop-WCR algorithm have all greatly improved under different experimental conditions,and these two improved algorithms also have the characteristics of strong fault tolerance and high stability.At the same time,it can be found that the positioning performance of the DV-Hop-ACR localization algorithm is better than the DV-Hop-WCR localization algorithm,Therefore,the effectiveness of these two improved algorithms is proved.