基于超宽带测距的定位精度及时延的研究

Study on Delay-Accuracy for Localization Based on Ultra-Wide Bandwidth Ranging

定位是现今位置感知应用的关键技术。而超宽带UWB(Ultra-Wide Bandwidth)测距已成为估计节点位置的有效技术。然而,现存的多数定位算法仅限于定位精度的提高,并没有考虑定时时延。为此,基于超宽带测距,对定位精度与时延间的权衡关系进行研究。首先,基于双向到达时间差TW-TOA(Two-Way Time Of Arrival)测距,推导了协作和非协作模式下的定位误差下限和时延表达式;然后,引入时延与定位精度间的权衡参数,并通过该参数量化了定位误差下限与时延间的权衡关系。数据分析表明,通过增加锚节点数提高了定位精度,但会引入较大的时延。

Position information is a necessary part of today ’ s location-aware application. Ultra-wide bandwidth(UWB)ranging has been shown to be a promising technology to tackle the positioning problem. However,most of the existing localization algorithms are limited to the improvement of positioning accuracy and do not consider timing delay. Therefore,based on UWB ranging,the tradeoff between positioning accuracy and time delay is studied. First,based on two-way Time of Arrival(TW-TOA)distance measurement,both lower limit of positioning error and delay expressions in cooperative and non-cooperative modes were deduced. Then,the tradeoff between delay and positioning accuracy is introduced,and the tradeoff between the lower limit of positioning error and delay is quantified. Results show that the way to increase accuracy by increasing the number of anchors may lead to large delays.