基于线性校正的TOA联合同步与定位算法

摘要

针对传统到达时间定位中出现的目标节点与传感器锚节点不同步的问题,提出了一种时钟同步与目标定位联合估计算法.该算法分为两个阶段,首先通过引入辅助变量,根据加权最小二乘准则求出时钟偏差和目标位置的初始值;在此基础上,利用线性校正技术对初始值的偏差进行校正.理论分析和实验结果表明,与传统方法相比,该算法不仅可以得到闭式解,而且在目标位于传感器内部和外部两种情况下都可以逼近克拉美罗下界,具有较高的定位精度.%A new algorithm for jointly estimating the clock bias and the position of a source node is developed to address the asynchronous problem of time-of-arrival (TOA) based localization.The proposed methods consist of two processing stages.First,the initial estimates of the clock bias and node location are obtained based on the weighted least square (WLS) criterion by introducing an intermediate variable.Then,a linear-correction technique is used to revise the initial estimation.Theoretical analysis and experiments results indicate that compared with the traditional methods,the proposed algorithm has a closed-form solution and can achieve the Cramer-Rao lower bound (CRLB) for both cases where the source node lies within and outside the sensor array with a higher localization accuracy.