Frequency Estimation Algorithm Based on Rife Algorithm and Phase Difference Correction Method

In view of the fact that the Rife algorithm has large estimation error when the estimated frequency is close to the fast Fourier transform(FFT) quantization frequency under low signal to noise ratio(SNR), but the window-length changing phase difference correction method is of high estimation accuracy, the spectrum subdivision technique is used to improve the Rife algorithm, and a synthesis algorithm of sinusoidal frequency estimation based on the improved Rife algorithm and the window-length changing phase difference correction method is proposed. The theoretical calculation process and related formulas derivation are given. Simulation results show that even if the SNR is as low as -15 dB, the improved algorithm still gains high estimation accuracy and stable performance in the whole frequency band, and the root mean square error(RMSE) is close to the Cramer-Rao lower bound(CRLB). The improved algorithm needs small calculation amount and is easy for hardware implementation.