New Phase Difference Measurement Method for Non-Integer Number of Signal Periods Based on Multiple Cross-Correlations

ABSTRACT

In this paper, a new phase difference measurement method is proposed for non-integer number of signal periods based on multiple cross-correlations, which is derived from the error analysis of the correlation method. Firstly, threesegment signals with the same center frequency are chosen. Then, the Hilbert transformation is conducted on the selected three-segment signals to make it have 90 degree phase shift. And then, the correlation functions of the selected three signals and its phase shifted signals are computed respectively. Certain properties of correlation and sine functions are adopted to obtain the computational formula of phase difference. Theory analyses show that the measurement accuracy of the proposed method is not affected by whether the signal is in integer periods or not, even if the frequency is unknown. Simulations and comparisons are presented to validate the effectiveness of the proposed method.

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