WSNs中基于TW-ToA测量的目标定位算法

A Target Localization Algorithm Based on TW-ToA Measurement with Clock Skewing

针对时钟偏差问题,提出基于双向到达时间(Two-way time of arrival,TW-ToA)测量的目标定位算法(Target Localization-based on TW-ToA,TL-TW-ToA)。TL-TW-TOA算法考虑了周转时间和时钟偏差问题。由于利用直接处理方法难以获取目标位置的最优解,TL-TW-TOA算法选用次优、强健算法进行近似,并将定位问题建立成广义信赖域次优问题(Generalized Trust Region Sub-Optimal,GTRS),然后再利用二分算法获取精确解,进而缓解时钟偏差和周转时间(Turn-around Times,TATs)对定位精度的影响。实验数据表明,提出的TL-TW-TOA定位算法降低了计算复杂度,并减少了均方根误差(Root Mean Square Error,RMSE)。

This work addresses the problem of target localization based on two-way time of arrival(TW-To A)measurements with clock skewing.In addition to the target location,the turn-around times and clock skewings are considered unknown.Since an optimal estimator for this problem can not be tackled directly,we approximate it by a sub-optimal,robust one,formulated as a generalized trust region sub-problem(GTRS).Even though non-convex in general,exact solution of the derived estimator can be obtained by just a bisection procedure,in order to mitigate the influence of the CSs and the TATs.Simulation results show that TL-TW-ToA localization algorithm performs better than state-of-the-art algorithm in terms of Root Mean Square Error and computational complexity.