An Improved DV-Hop Localization Algorithm Based On Coordinate Correction

As one of the most critical technologies in Wireless Sensor Network(WSN),node localization technology is the key technology of the applications of WSN.Based on the criteria whether it is requires to measure the actual distances between nodes,the localization algorithms of WSN can be classified into two categories,that is,the Range-Based and the Range-Free schemes.The Range-Based algorithms present very accurate results.However,the specialized hardware required makes them expensive in large networks,and in some applications,these algorithms are greatly influenced by the surrounding environment,which has limits the application of such methods to some extent;With the advantages of relatively simple implementation,low power consumption and low cost,Rang-Free algorithms are being pursued as a feasible alternative to the Range-Based algorithms in large-scale practical applications.The DV-Hop algorithm,as a classical Rang-Free localization algorithm,with the advantages of simple implementation,high accuracy,low cost and low computational cost has become the most widely used positioning algorithm in WSN.However,the DV-Hop algorithm often produces large location errors under the random topology network scenarios.For the above problems,this paper studies the principle and the sources for the localization error of the DV-Hop algorithm,and an improved algorithm was proposed on the basis of previous research.The maintain contents are as follow:1)The basic principle and implementation of traditional DV-Hop are introduced and the main sources of localization error are analyzed through the simulation experiments.After that the comprehensive generalization and classification of the existing DV-Hop improved algorithms are given.2)A novel algorithm named CC-DV-Hop was put forward in this paper.CC-DV-Hop defines the pseudo-range error factor to select K reference nodes to improve the calculation accuracy of average hop distance,and to decrease the influence of topology random distribution;Furthermore,assumed to be the unknown node,the anchor node broadcast the updated average hop distance together with the location errors which evaluated by trilateral or multilateral measurement;the localization result of each unknown node was modified to improve the localization accuracy through coordinate correction values of specific anchor nodes.3)Matlab7.0 simulation experiments are selected as the simulator.The simulation results show that:each step of CC-DV-Hop algorithm can effectively improve the localization accuracy;The CC-DV-Hop algorithm improves the localization accuracy of traditional DV-Hop algorithm by about 24%~35%,which has higher localization accuracy and positioning stability than some existing improved algorithm;When the value of K is 1/3~1/2of the anchor node,the CC-DV-Hop algorithm achieves the best performance;In terms of communication cost and algorithm complexity,with the same communication cost,the computation of CC-DV-Hop is slightly higher than DV-Hop,but it greatly improves the localization accuracy.