Frequency measurement approach based on linear model for increasing low SNR sinusoidal signal frequency measurement precision

Abstract

In order to improve the frequency measurement accuracy of low signal‐to‐noise ratio (SNR) sinusoidal signal, a frequency measurement approach based on a linear model is proposed. Firstly, the precision of frequency measurement affected by random noise while transforming the wave is analysed. Then, a linear model of frequency measurement is established according to the characteristics of frequency measurement, and the model is fitted by least‐square regression analysis with the measured data of several periods. Finally, the formula for frequency calculation is obtained from the regression results, and the relative error of frequency measurement is deduced and compared with other method. Simulation results and frequency measurement experimental results show that, the proposed method can effectively suppress noise and improve the frequency measurement accuracy of low SNR sinusoidal signal.