Accurate estimation method of sinusoidal frequency based on FFT

In order to further improve the estimation precision of sinusoidal frequency, a new estimation method based on Fast Fourier Transform (FFT) is proposed. Zero-padding is used before the coarse estimation. And three sample values of Discrete-Time Fourier Transform (DTFT) of the original signal is used to perform the fine estimation. In the computer simulations, it can be shown that the proposed estimation method follows the Cramer-Rao Bound in the whole region of frequency offset. The estimation precision is higher than the existing estimators. The proposed estimator has low SNR threshold, and outperforms the existing estimators.