Frequency Estimation of Multisection Signals with Same Frequency and Length based on Spectrum Correlation

Aiming at multisection sinusoidal signals with the same frequency and length, a frequency estimation algorithm of multisection signals with the same frequency and length based on spectrum correlation is proposed. It can improve the frequency estimation precision of short-time sinusoidal signal under the condition of low SNR. Firstly, generate a spectrum zoom sequence and calculate the spectra of corresponding frequencies; Secondly, design a phase-difference compensating factor matrix to overcome phase discontinuity among different sections of signals, and generate a search-frequency array to modify unknown parameters in the phase-difference compensating factor matrix; Thirdly, adjust the spectrum zoom sequence corresponding to accumulation spectrum and calculate the accumulation spectrum; Finally, calculate spectrum correlation sequence with corrected power spectra and accumulation spectrum, and search the maxima of spectrum correlation sequence and then its corresponding frequency is the frequency estimation value. Simulated experiment results demonstrate that the proposed algorithm has better frequency estimation precision and noise immunity than existing methods, and significant theoretical and practical value.