Research Of WSN Node Locating Algorithm For DV-Hop Improvement

Wireless Sensor Networks(WSN)is composed of a large number of nodes distributed in complex environments,real-time monitoring of complex environments by collecting and monitoring node data.The positioning technology of nodes is the foundation and important link of WSN other technology research.Wireless sensor node positioning technology is mainly divided into range-based and range-free.Range-based of the positioning algorithm positioning accuracy,the need for additional hardware support,high cost,and range-free localization without hardware support,so the range-free based localization has been a hot research,this paper focuses on the research of DV-Hop algorithm in range-free algorithm.According to the positioning procedure of DV-Hop algorithm,the reasons of location error of DV-Hop algorithm are analyzed in detail,and a large number of literatures are read.Based on the existing improvements,two improved algorithms are proposed:(1)Coefficient-optimized DV-Hop algorithm,the main idea of the algorithm is to use the coefficient of the following three aspects of the amendment: First,the coefficient correction communication range of the number of nodes.Since the number of hops in the communication range of the anchor node is recorded as 1 hop,but when the communication radius is large,the number of hops of the two nodes with large difference from the anchor nodes is 1,and the hop count and the average jump The distance is bound to produce a large error,so this paper proposed based on the ideal number of hysteresis error coefficient correction method;second,the coefficient of the anchor node to modify the average jump distance,if the two anchor nodes to go through the multi-hop and non-linear communication,Then the distance between the unknown node and the anchor node is estimated by the traditional DV-Hop algorithm.The weighting coefficient method is used to modify the average distance of the anchor node per hop.Thirdly,The distance between the unknown node and the anchor node,using the corrected average distance between each hop and the number of hops to estimate the distance between the unknown node and the anchor node.The traditional algorithm is estimated by using an anchor nodenearest to the unknown node,Ignoring the impact of other anchor nodes on the unknown node,so the text using the compensation coefficient method so that other anchor nodes are also involved in the calculation.(2)Based on the DV-Hop algorithm,which is based on the limited jump and the preferred anchor node,the algorithm mainly improves on the basis of the traditional algorithm.First,the setting of the hop threshold is due to the randomness of the sensor network node distribution,In order to prevent the above situation from the number of hops to limit the number of hops to reach the set threshold,the node will no longer forward this time,in order to prevent the above situation occurs to limit the number of hops.And the average jump distance of the anchor nodes is the key to estimate the coordinates of the unknown nodes.However,the original algorithm will produce some errors,so the error factor is used to optimize the average hop distance of the anchor nodes.Thirdly,it is preferable to use the triangulation method to calculate the coordinates of the unknown nodes.The preferred principle for the anchor nodes participating in the calculation is that when the three anchor nodes closest to the unknown node are involved in the calculation,When the collinear can not calculate the coordinates of the unknown node,the anchor node furthest from the unknown node is discarded,and the nearest node is selected from the remaining anchor nodes.The anchor node to continue to judge.In this paper,we use the above two improved schemes to optimize the traditional DV-Hop calculation,and use Matlab simulation platform to do comparative experiments,experiments show that the two correction schemes used in this paper than the traditional positioning of the positioning error is reduced.