摘要: |
针对运动目标源定位问题,提出了一种基于约束加权最小二乘(Constrained Weighted Leas
t-Squares, CWLS)的时差频差定位算法。该算法利用目标源到达多个接收站的时差和频
差信息,对目标源的位置和速度进行估计。通过引入中间变量,将时差频差非线性方程转换
成伪线性方程(中间变量与目标源位置和速度之间存在约束关系),再对此约束条件引入拉格
朗日乘子技术,将此伪线性方程的求解转化为求条件极值问题,创造性地求解了此非线性定
位方程,提高了定位精度,并能满足实时性和全局收敛要求。仿真实验表明,该算法在保持
相近复杂度的同时,进一步提高了定位性能,优于两步加权最小二乘算法,在噪声较高时仍
然能达到克拉美罗下限。 |
关键词: 目标源定位 约束加权最小二乘 到达时差 到达频差 拉格朗日乘子技术 |
DOI: |
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基金项目:国家高技术研究发展计划(863计划)项目(2010AA7010422) |
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Constrained weighted least-squares algorithm for moving source location using TDOA and FDOA measurements |
ZHU Hua-jin,ZHANG Yang,E Mei,YU Hua-gang |
() |
Abstract: |
By utilizing the time difference of arrival (TDOA) and
frequency difference of arrival (FDOA) measurements of a signal received at a nu
mber of receivers, a constrained weighted least-squares (CWLS) algorithms for e
stimating the position and velocity of a moving source is proposed. By utilizing
the Lagrange multipliers technique, the known relation between the intermediate
variables and the source location coordinates can be exploited to constrain th
e solution. And, on basis of convolute and polynomial rooting operations, the La
grange multipliers can be obtained efficiently and robustly, which can allow rea
l-time implementation as well as ensure global convergence. Simulation results
show that the proposed estimator achieves remarkably better performance than the
two-step weighted least squares(WLS) approach especially for higher measuremen
t noise level, which makes the Cramér-Rao lower bound(CRLB) at a sufficiently h
igh noise level before the threshold effect occurs possible. |
Key words: source localization constrained weighted least-squares(CWLS) time difference
of arrival(TDOA) frequency difference of arrival(FDOA) Lagrange multipliers |