同步时钟偏差存在下的时差定位性能分析及改进的定位方法

同步时钟偏差会显著增加时差（TDOA）定位误差，该文针对这一问题进行了理论性能分析，并提出了改进方法.首先，分析了时钟偏差存在下参数估计方差的克拉美罗界（CRB），给出了关于目标位置估计方差更为闭式的CRB表达式，随后基于最大似然（ML）估计准则和泰勒级数（TS）定位方法，定量推导了时钟偏差对于TDOA定位精度的影响.接着，提出了可抑制时钟偏差的降维TS定位方法，并且给出了时钟偏差的ML闭式解.最后，数值实验验证了文中理论分析的有效性，并且新方法可以有效抑制同步时钟偏差的影响.

Performance Analysis and Improvement for TDOA Source Localization in the Presence of Synchronization Clock Bias

Synchronization clock bias can significantly increase the localization errors.In order to solve this problem,this paper presents theoretical analysis and the improved method.First,the Cramér-Rao bound(CRB) on the parameter estimation is shown in the presence of synchronization clock bias.A more compact CRB expression for the source position estimation is obtained.Based on the maximum likelihood(ML)criterion and the Taylor series(TS) localization method,an analytical expression for the mean square error(MSE) of the source position estimation is also derived when the estimator assumes the clock bias does not exist.Subsequently,the localization method based on dimension-reduction TS iteration is presented and the closed-form ML solution for the clock bias is also given.Finally,numerical experimental results support the validation of the theoretical analysis,and also demonstrate that the proposed method can mitigate the effects of clock bias.