Anti-Noise Performance and Parameter Estimation Accuracy of FFT and FT Discrete Spectrum Correction

The parameters estimation accuracy of continuous zoom FFT spectrum by Fourier transform under noiseless and Gaussian white noise is investigated. The relationship between parameters estimation errors and zoom multiples is revealed in the presence of noise-free signal. The probability of finding wrong maximum spectral line is increased with the rise of zoom multiples when the signal is accompanied with Gaussian white noise. Considering the influence of frequency resolution on frequency estimation accuracy and the probability mentioned above, two new indicators are proposed to evaluate the estimation accuracy. Based on above analysis, optimal zoom multiples under different signal-to-noise ratios are presented and a method is proposed to improve accuracy of this method. The results of simulations demonstrate that the improved method has higher correction accuracy and better anti-noise performance.