The noise influence on frequency estimation in multipoint interpolated DFT

We point out the possibility of error reduction of frequency estimation with the multipoint interpolated discrete Fourier transform (DFT). The study of the influence of time-domain noise on the results of a DFT is made. The noise influence on the amplitude coefficients of a DFT is in a first approximation modeled by white noise in the time domain and Gaussian noise in the frequency domain. The noise influences on estimations are increased with the root of the number of interpolation points. The interpolations with a larger number of points decrease the systematic errors and increase the noise distortion of the results; with smaller number of points there is an inverse appearance