An Improved DV-Hop Localization Algorithm Based on Error Vector Modification for Wireless Sensor Network

Abstract

Node Localization in Wireless Sensor Network (WSN) is the process of localizing the unknown node in use of anchor nodes' coordinates which are known in advance or can be got by GPS. As one of typical range-free localization algorithms, Distance Vector Hop (DV-Hop) algorithm is low-cost and doesn't require for additional hardware for ranging. However, the localization accuracy of DV-Hop algorithm is low because as parameters in localization algorithm the distances between the unknown node and anchor nodes are estimated by multiplying number of hops and average hop distance. The error in estimated distance leads to error accumulation in localization result. Therefore DV-Hop algorithm is usually applied under circumstances with low requirement for localization accuracy. In view of the main reason of the error in DV-Hop algorithm, an improved algorithm i.e. DV-Hop algorithm based on Error Vector Modification (EVM-DV-Hop) is proposed in this paper. The improved algorithm reduces the localization error by modifying the estimated coordinate of the unknown node with the help of Error Vector determined by anchor nodes with a certain degree of similarity to the unknown node. It is shown in simulation results that the improved algorithm reduces the localization error and raise the localization accuracy of DV-Hop algorithm effectively.