On Features of Reconstruction of Finite-Length Discrete-Time Signal with Nonzero Constant Component Using Sinc Interpolation

In practice, one of the most important question is how accurate the method used for the finite-length discrete-time signal reconstruction. In the paper, research results of influence of the constant component as a zero-frequency component of signal spectrum on accuracy of finite-length signal reconstruction using truncated Whittaker–Kotelnikov sampling series and trigonometric interpolation are discussed. It was found that, in contrary to the truncated Fourier series, truncated Whittaker–Kotelnikov sampling series reconstruction error of model signals vs constant component values is nonmonotonic. It was also pointed out that mean-square error of constant signal interpolation by means of truncated Whittaker-Kotelnikov sampling series is much greater than mean-square error of trigonometric interpolation. The results are explained. The obtained results can be used in designing of the finite-length discrete-time signal reconstruction by means of sinc-function interpolation.