衍生于全相位FFT的双子段相位估计法

Double-subsegment measuring phase method derived from all-phase FFT

为提高给定样本数量下的相位估计精度,提出双子段测相法。该方法是从全相位快速傅里叶变换(fast Fourier transform,FFT)测相法衍生的,只需取出全相位FFT包含的N路子数据段中的首、尾两个子段,再综合这两个子段的FFT谱提取峰值谱相位信息即可完成高精度测相。理论分析了在噪声环境中,所提方法测相精度高于全相位FFT测相法的原因。仿真实验表明,在信噪比不太低的场合,双子段测相法的相位估计方差处于全相位FFT估计法和两参数克拉美罗限之间,因而具有广泛应用前景。

To enhance the phase measurement accuracy with a fixed amount of samples,a double-subsegment measuring phase method is proposed,which is derived from all-phase fast Fourier transform（FFT）.In the proposed method,only the first subsegment and the last subsegment among the N subsegments included in all-phase FFT are taken out,and accurate phase measurement can be finished through synthesizing the phase information of the peak spectra from these two segments FFT spectrums.Theoretic analysis is also conducted to analyze the reason why the proposed method has higher phase measurement accuracy than that of all-phase FFT in noisy circumstance.Moreover,simulation also shows that,when the signal-to-noise rate is not too low,the phase estimation variance of the proposed method is between that of all-phase FFT and Cramer-Rao lower bound CRLB of two parameters,which endows the proposed method with wide application prospects.