相干态相位的最优估计与跟踪方法

Optimal estimation and tracking of coherent state phase

在传统量子相位跟踪方法中,通常对输出结果进行线性化处理,这对本振相位和信号相位有严格的限制要求,且并不适用于如干涉法测角等导航系统。为此,本文将零拍输出形式进行等价变换,设计了一种最大似然估计迭代算法,实现了相干态相位跟踪。与传统线性化的量子相位跟踪方法相比,避免引入线性化误差,更加适用于导航系统中信号相位跟踪;通过计算Fisher信息矩阵,证明此方法在理论上能够达到量子克拉美-罗下界,具有最优估计性能。

In the traditional quantum phase tracking method,the output results are usually linearized,which has a strict limit on the local oscillator phase and signal phase,therefore,it is not applicable to the angle measurement by interferometry.In this paper,the quantum homodyne output is transformed and an iterative algorithm for maximum likelihood estimation is designed to realize the coherent state phase tracking.The Fisher information matrix is calculated to show that the proposed method can reach the quantum Cramer-Rao bound theoretically and has the best estimation.