Abstract: In order to reduce the positioning error of the DV-hop algorithm（range-free）, an improved DV-hop algorithm（JDV-Hop） based on the Jaccard coefficient hop correction factor is proposed. Improved algorithm uses the Jaccard coefficient of the number of nodes to refine the hop count between nodes, reducing the estimation error of the hop count of an unknown node within one-hop distance of a node, then uses the differential error coefficient in the DDV-hop algorithm to further correct the average hop distance between nodes. Finally, it introduces a trust factor that can be cooperatively located between nodes, and nodes with high accuracy of positioning result are upgraded to a new anchor node, the next round of positioning is carried out. MATLAB simulation results show that under the same conditions, the improved algorithm not only does not need to add extra hardware overhead, but also has significantly higher positioning accuracy than existing improved algorithms such as DDV-hop.

Key words: node localization, Jaccard similarity coefficient, differential error, cooperative localization

摘要： 为了减小无需测距的DV-hop算法的定位误差，提出基于杰卡德系数跳数修正因子的DV-hop改进算法（JDV-Hop）。改进算法使用节点个数集合的杰卡德系数细化节点间的跳数，减小对节点单跳距离内未知节点跳数的估计误差，然后利用DDV-hop算法中的差分误差系数进一步修正节点间的平均跳距。最后在选择参与定位计算的锚节点时，引入一种节点间可以协作式定位的可信度因子，将定位结果精度高的节点升级为新的锚节点，进行下一轮定位。MATLAB仿真结果显示，在相同条件下，改进算法不仅无需增加额外的硬件开销，且与DDV-hop等现有改进算法相比具有明显更高的定位精度。

关键词: 节点定位, 杰卡德系数, 差分误差, 协作定位