Accurate amplitude estimation of a sine-wave harmonic component by frequency-domain approach

This paper focuses on the amplitude estimation of a sine-wave harmonic component by the Interpolated Discrete Fourier Transform (IpDFT) method with maximum sidelobe decay windows. A constraint is derived ensuring that the influence of systematic errors due to the contribution from fundamental component on the amplitude estimation of a harmonic component can practically be neglected. This constraint permits an optimal choice of the window used. In addition, for a sine-wave corrupted by a stationary white noise, a constraint on the number of acquired samples is derived ensuring accurate estimates of the amplitude of a harmonic component with a high confidence level. Carried out computer simulations confirm the validity of the derived constraints. Finally, the performance of the IpDFT method is compared with the one of the energy-based method on the basis of theoretical and simulations results.