An Improved DV-Hop Localization Algorithm in Wireless Sensor Networks

Localization as a fundamental issue has a challenge in wireless sensor networks (WSNs). Many approaches have been proposed to solve the inaccurate node localization. Among range-free algorithms, DV-Hop (Distance Vector-hop) is a well-known localization algorithm that utilizes of hop-distance estimation to locate sensor nodes. This has lead positioning accuracy is limited. In this paper, an improved DV-HOP algorithm based on the hop-size correction and localization optimization is put forward. Firstly, based on difference of actual and estimated distance between reference nodes an effective hop-size is calculated for whole network; secondly, a correction value is added to the hops between unknown nodes and reference nodes while received signal strength indicator (RSSI) value is used to correct the distance of single hop. Finally, the Levenberg-Marquardt algorithm is applied to estimate an optimize position for each sensors. In evaluation step, various factors that affect the localization accuracy of the DV-Hop are investigated. Simulation results show that the proposed algorithm has been significantly improved compared to the basic DV-Hop and some existing improved algorithms.