Frequency estimator by combination of phase difference method and interpolation algorithm
Frequency estimator by combination of phase difference method and interpolation algorithm
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DOI：
10.1177/1748301819833032
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发表时间：
2019-01
影响因子：
0.9
通讯作者：
Haitao Xu;Leng Han;Qingqing Huang;Song Feng;Junhui Cao
中科院分区：
文献类型：
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作者：
Haitao Xu;Leng Han;Qingqing Huang;Song Feng;Junhui Cao
在传统的基于时移的相位差方法中，即使在小尺度湍流噪声中，只要平移系数趋于1，相位包裹问题也会带来相当大的误差。针对相位包络问题，本文提出了一种改进的频率估计器，将相位差法与插值算法相结合。与传统的基于时移的相位差法相比，当平移系数大于1时，改进算法能够得到准确的估计。通过Cramer-Rao下限的均方根误差进行了比较研究。计算机仿真结果表明，在低信噪比的情况下，只要选择适当的平移系数，均方根误差就能越过Cramer-Rao下界，说明该算法具有较强的抗噪性。最后，针对含有强局部随机噪声的仿真信号，说明了该算法的优越性。
In the traditional time-shifting based phase difference method, considerable errors may be introduced by wrapped phase problem as long as translation coefficient tends to one even in a small-scale turbulence noise. In this paper, an improved frequency estimator is proposed to overcome the problem of wrapped phase by combination of phase difference method and interpolation algorithm. Compared with the traditional method of phase difference based on time-shifting, the improved algorithm can obtain an accurate estimate when translation coefficient exceeds one. Comparative studies were done by means of root-mean-square error over Cramer–Rao lower bound. According to the computer simulations, it is demonstrated that root-mean-square errors can cross Cramer–Rao lower bound if the translation coefficient is properly selected even in the case of the low signal-to-noise ratio, which implies that the proposed algorithm has a strong noise immunity. Finally, the advantage of the proposed algorithm is illustrated for the simulation signal which contained strong local random noise.