关键词: 水下传感器网络, 定位, 非完全序列, 加权估计, 3D Voronoi图

Abstract: Aiming at the problems of low accuracy and high complexity of localization algorithm in three-dimensional space, a non-full sequence-based localization (NFSL) algorithm for 3D underwater sensor networks was proposed. Different from traditional sequence-based localization algorithms, a more realistic situation where communication range of beacon nodes is not entire network coverage was taken into consideration by NFSL. Firstly, 3D Voronoi diagram was used to divide the 3D location space and thus virtual beacon nodes as well as their rank sequences were determined. Then the nearest beacon node was obtained according to the rank correlation coefficient between the unknown node sequence which is based on RSSI and the beacon node sequence, and the nearest sequence table was constructed. Next, an algorithm which aims at the similarity of sequences with unequal lengths was designed and utilized to obtain the rank correlation coefficients between the non-full sequences of unknown nodes and each sequence in the nearest sequence table. Finally, the weighted estimate of the unknown node’s location was realized by taking the rank correlation coefficients as the weight. In simulation experiments, the localization accuracy of NFSL was compared with that of DV-Hop and Centroid by taking the ratio of beacon nodes, communication range, total number of nodes and network scale as variables. Extensive simulation results verify the algorithm effectiveness. Besides, its localization accuracy will be significantly improved with the increasing number of beacon nodes. Compared with traditional localization algorithms, the localization accuracy of NFSL is improved by as much as 23%.

Key words: underwater sensor network, localization, non-full sequence, weighted estimate, 3D Voronoi diagram