Computation of spectra with unequal resolution using the fast Fourier transform
Alan V. Oppenheim, D. Johnson, Ken Steiglitz · Proceedings of the IEEE · 1971
The discrete Fourier transform of a sequence, which can be computed using the fast Fourier transform algorithm, represents samples of the z transform equally spaced around the unit circle. In this letter, a technique is discussed and illustrated for transforming a sequence to a new sequence whose discrete Fourier transform is equal to samples of the z transform of the original sequence at unequally spaced angles around the unit circle.