非半周期采样信号相位差估计的相位校正相关法

针对非半周期采样信号的相位差估计问题，提出一种非半周期采样信号相位差估计的相位校正相关法。首先，利用频率估计的相位匹配方法对采样信号进行频率估计，得到采样信号的频率估计值；其次，对采样信号进行互相关，得到互相关信号，并通过采样信号的信号时移和互相关构造一路新的互相关信号，使两路互相关信号具有相同的误差项；然后，利用两路互相关信号得到相位校正互相关信号；最后，利用相位校正互相关信号和频率估计值获得采样信号的相位差估计值。理论分析表明，该方法消除了采样信号非半周期采样对相位差估计的影响，无需预知信号幅值即可实现采样信号相位差的无偏估计。为验证所提方法的有效性和优越性，在不同相位差、信噪比和信号长度条件下对本文方法进行了仿真实验，并利用科氏流量计进行了应用实验。仿真实验结果表明，本文方法有效提高了非半周期采样信号的相位差估计精度，其相位差估计精度优于互相关方法、数据延拓式相关方法和正交时延估计方法的相位差估计精度，更接近克拉美罗下限。科氏流量计流量测量实验验证了本文方法在实际应用中的有效性。

Phase Correction Correlation-based Phase Difference Estimation Method for Non-half Period Sampled Signals

Aiming at the problem of phase difference estimation for non-half period sampled signals,a phase correction correlation-based of phase difference estimation for non-half period sampled signals was proposed.Firstly,a phase match-based frequency estimation method was utilized to estimate the frequency of sampled signals.Secondly,cross-correlation signals were gained by cross-correlation of sampled signals and the new cross-correlation signals were constructed by shifting sampled signals and cross-correlation,which had the same error term with the original cross-correlation signals.Thirdly,phase correction cross-correlation signals were gained by means of two cross-correlation signals.Finally,estimated phase difference was obtained by utilizing phase correction cross-correlation signals and estimated frequency.Theoretical analysis indicated that the proposed method had eliminated the influence of non-half period sampled signals on phase difference estimation,and achieved unbiased phase difference estimation without estimating signal amplitudes.To validate the effectiveness and superiority of the proposed method,simulation on conditions of different phase differences,signal-to-noise ratios(SNRs),signal lengths was performed.Then,the application experiment was conducted by using Coriolis mass flowmeters.Simulation and experimental results demonstrated that the proposed method improved the estimation precision of phase difference.Its estimation performance was better than those of the cross-correlation method,the data extension-based correlation method and the quadrature delay estimator and its estimation errors were closer to CRLB by comparison.The measurement results of Coriolis mass flowmeters validated the effectiveness of the proposed method in practice.