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

With the rapid development of wireless communication,wireless sensor networks have played an important role in various high-tech fields.The positioning technology of wireless sensor networks has become the focus of many experts and scholars.In practical applications,when a sensor node monitors a specific object and performs information processing,only when the corresponding position information of the monitoring object is known can the corresponding data analysis and processing be performed at the control end,so the position information of the monitoring object is important for the sensor node to collect and process information.Therefore,it is of great significance to effectively improve the performance of the node location algorithm.This paper introduces a classic location algorithm based on ranging and non-ranging.Through the study of the basic principles of the classic DV-Hop positioning algorithm,analyzes and summarizes the source of the positioning error of the classic DV-Hop algorithm.After detailed analysis of the source of positioning error,the three steps of algorithm positioning were proposed respectively.In the network initialization phase,a threshold number of reference anchor nodes is introduced to improve the minimum number of hops between nodes.When an anchor node that is far away from an unknown node broadcasts its own location information,too many intermediate nodes pass through the unknown node,resulting in error in the hop count information.At this time,if only some anchor nodes closer to the unknown node are selected as the reference nodes for obtaining the hop count information,it has a good effect.Selecting the nearest anchor node can effectively reduce the the error caused by data conflicts when the node broadcasts the position information in flooding mode.When estimating the distance between the node to be measured and the anchor node,an anchor node closer to the node to be measured has greater influence on the positioning result,so a weighted processing method is used to optimize the average hop distance of the node to be measured.Anchor nodes closer to the measuring node are given a larger weight when calculating the average hop distance.In the calculation of the unknown node coordinates,there is no solution to the trilateration method or the maximum likelihood estimation method in some special cases.The particle swarm algorithm is used to optimize the positioning results.Finally,under the conditions of monitoring area,communication radius of nodes and dynamic change of anchor node ratio,different simulation environments are set up.The classical DV-Hop positioning algorithm and two improved algorithms are simulated and analyzed.The simulation results show that the improved algorithm is much better than the classical algorithm in terms of positioning algorithm performance and positioning accuracy.In the case of improvement,using Particle Swarm Optimization to optimize the positioning results further improves the positioning accuracy.