基于时变钟差消除的室内载波相位定位算法

Indoor carrier phase positioning algorithm based on time-varying clock error elimination

针对室内无线环境下传统定位算法定位精度不高以及系统时钟不同步影响定位精度等问题,提出一种基于三差分载波相位测量与到达时间差(TDoA)融合的三维定位算法。考虑到无线接入点之间存在的时变钟差会导致定位精度变低,所提算法结合参考终端测量来消除时变钟差的影响,基于三差分载波相位测量进行相对位置的精确估计,并将其与具有无偏性的差分TDoA定位结果进行融合粗估计。进一步通过泰勒展开方法对载波相位观测方程线性化,并通过解算整周模糊度实现更高精度的定位。仿真结果表明,所提算法可以克服时变钟差对定位性能的影响,并能在短时间内完成整周模糊度解算,最终可实现高精度定位。

To solve the problems of low positioning accuracy of traditional positioning algorithm and unsynchronized system clock in indoor wireless environment,a 3D positioning algorithm was proposed based on the fusion of triple-differential carrier phase measurements and time difference of arrival(TDoA)positioning.Considering that the time-varying clock offsets between wireless access points lead to lower positioning accuracy,the measurements from a reference terminal were used to eliminate the influence of time-varying clock offsets.The relative positions were estimated based on triple-differential carrier phase measurements,which were fused with unbiased differential TDoA positioning results to obtain the interim estimated positions.Furthermore,the carrier phase observation equations were linearized by Taylor expansion method,and the high-accuracy positioning was realized by solving the integer ambiguities.Simulation results show that the proposed algorithm eliminates the influence of time-varying clock offsets on positioning performance,and the integer ambiguities are resolved in a short time to achieve high-accuracy positioning.