Bias reduction for TDOA localization in the presence of receiver position errors and synchronization clock bias
Bias reduction for TDOA localization in the presence of receiver position errors and synchronization clock bias
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DOI：
10.1186/s13634-019-0602-z
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发表时间：
2019-01-28
影响因子：
1.9
通讯作者：
Wu, Ying
中科院分区：
文献类型：
--
作者：
Chen, Xin;Wang, Ding;Wu, Ying
到达时间差（TDOA）定位不需要对源信号加时间戳，在无源定位中发挥着越来越重要的作用。除了测量噪声外，接收机位置误差和同步时钟偏差是影响时差定位性能的两个重要因素。本文提出了一种在接收机位置误差和同步时钟偏差存在的情况下，利用时差测量进行无源定位的减小偏差的方法。像原来的两步加权最小二乘解决方案，新技术有两个阶段。在第一阶段，该方法扩展了加权最小二乘（WLS）公式中的参数空间，并施加了二次约束来抑制偏差。在第二阶段，一个有效的WLS估计器，以减少非线性操作产生的偏差。通过二阶误差分析，推导出原算法和改进算法的理论偏差，证明改进算法在中等高斯噪声下能达到Cramer-Rao下界性能，同时具有比原算法更小的偏差.仿真结果表明，较小的估计偏差和更好的鲁棒性的所有估计，包括源位置，细化接收机的位置，和时钟偏差矢量，当测量噪声或接收机的位置误差增加。
Time difference of arrival (TDOA) localization does not require time stamping of the source signal and is playing an increasingly important role in passive location. In addition to measurement noise, receiver position errors and synchronization clock bias are two important factors affecting the performance of TDOA positioning. This paper proposes a bias-reduced solution for passive source localization using TDOA measurements in the presence of receiver position errors and synchronization clock bias. Like the original two-step weighted least-squares solution, the new technique has two stages. In the first stage, the proposed method expands the parameter space in the weighted least-squares (WLS) formulation and imposes a quadratic constraint to suppress the bias. In the second stage, an effective WLS estimator is given to reduce the bias generated by nonlinear operations. With the aid of second-order error analysis, theoretical biases for the original solution and proposed bias-reduced solution are derived, and it is proved that the proposed bias-reduced method can achieve the Cramer-Rao lower bound performance under moderate Gaussian noise, while having smaller bias than the original algorithm. Simulation results exhibit smaller estimation bias and better robustness for all estimates, including those of the source position, refined receiver positions, and clock bias vector, when the measurement noise or receiver position error increases.