WSNs中测距时延与定位精度权衡的研究

Study on Delay-Accuracy Trade-off for Localization

现存的定位算法侧重于定位精度,并没有考虑传输测距信息所产生的时延问题;相比于单播机制,以广播机制传输测距信息时延可缩短时延;据此,面向基于广播机制传输测距信息的定位算法,研究时延-定位精度的权衡关系;先推导协作定位和非协作定位模式下的费舍尔信息矩阵,再推导时延-定位精度的最优权衡关系;仿真数据表明:在节点密集网络条件下,协作定位模式的时延-定位精度间的权衡关系与非协作模式下的相同;但节点密集网络下,时延与定位精度间的权衡关系不能达到最优。

Existing localization algorithm place emphasizes on accuracy of localization,and has no regard for the delay in transmitting ranging information.Compared with unicast,broadcast schemes have an advantage in terms of the delay.Therefore,we analyzed the delay-accuracy trade-off,for localization schemes in which the position estimates were obtained based on broadcasted ranging signals.Then,we established that the optimal trade-off was bounded and the same for cooperative and non-cooperative networks.We find that for dense networks,the trade-off is the same for cooperative and non-cooperative networks.And for dense networks,no better trade-off is achievable.