An alternative method to zero-padded DFT

Zero-padding method is usually used to increase the number of points in the DFT and consequently to improve the DFT’s approximation of the DTFT. This way the picket fence effect is reduced and a better approximation of DTFT local peaks is achieved for a finite number of measured points. In order to overcome the high computational demand problem of the zero padding method, an alternative one, is further presented in this paper. This method, making use of non-integer number of cycles in DFT kernel orthogonal signals, provide the same results in spectral analysis as zero padding method but with significant reduction of the computational effort. Moreover, the use of non-integer arguments for DFT evaluation open the possibility to develop DFT with variable bins resolution, narrow band DFT and bins interpolation algorithms.