Localization Algorithm Optimization And Localization Accuracy Evaluation For Wireless Sensor Networks

The node localization technology is one of the support technologies of WSN (wireless sensor networks). With simple implementation and lower requirewment, the DV (distance vector)-based localization algorithms meet the requirement of WSN. This paper takes the DV-based localization algorithms as the research object, which is supported by the National High Technology Research (863 Program) "the optimization method of node localization for WSN".To minimize the localization error of the existing DV-based algorithms, an optimized distance vector (ODV) localization algorithm is presented. The average size of one hop is computed by the unknown nodes and the number of the location information from the anchors is limited. The result of the trilateration or mutilateration is treated as the initialization of the iterative refinement. The simulation results show that the novel algorithm has higher localization accuracy and stability.For evaluating the qualification of localization algorithms, the Cramer-Rao bound in estimation theory is presented as an evaluation criterion of the localization accuracy. The Cramer-Rao bound for range-based localization and DV-based range-free localization are derived according to the estimation theory. Through computing the Cramer-Rao bound, the lowest localization error and the highest localization accuracy can be got obtained, which provides a theoretical basis for the choice and optimization of localization algorithms. The classical localization algorithms of wireless sensor networks are simulated through MATLAB and the simulation results are consistent with the theoretical analysis.