Topic
Discrete-time Fourier transform
About: Discrete-time Fourier transform is a research topic. Over the lifetime, 5072 publications have been published within this topic receiving 144643 citations. The topic is also known as: DTFT.
Papers published on a yearly basis
Papers
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TL;DR: The effects of aliasing (including pseudoaliasing), picket-fence effect, and leakage in the fast Fourier transform (FFT) are presented.
Abstract: The effects of aliasing (including pseudoaliasing), picket-fence effect, and leakage in the fast Fourier transform (FFT) are presented. A computer program was written to perform the FFT analysis of known inputs. The program has the capability of detecting aliasing by calculating an "aliasing coefficient" (Q), and will increase the sampling frequency and the number of points in the input sequence if aliasing occurs. The term "pseudoaliasing" is a phenomenon which is similar to aliasing (or fold-over) but related to the effects of picket fence and leakage. The "leakage coefficient" (ri) is a quantitative measure of the deviation from the fundamental frequency component with respect to the sampling frequency, when the input sequence has only one frequency component.
265 citations
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01 Jan 1998
TL;DR: In this paper, the Discrete Fourier Transform and Numerical Computations (DFT) were used for time-frequency analysis in periodic signals and periodical signals.
Abstract: Signals and Systems.- Periodic Signals.- The Discrete Fourier Transform and Numerical Computations.- The Lebesgue Integral.- Spaces.- Convolution and the Fourier Transform of Functions.- Analog Filters.- Distributions.- Convolution and the Fourier Transform of Distributions.- Filters and Distributions.- Sampling and Discrete Filters.- Current Trends: Time-Frequency Analysis.- References.
263 citations
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263 citations
01 Jan 2002
TL;DR: This report tries to give a practical overview about the estimation of power spectra/power spectral densities using the DFT/FFT and includes a detailed list of common and useful window functions, among them the often neglected flat-top windows.
Abstract: This report tries to give a practical overview about the estimation of power spectra/power spectral densities using the DFT/FFT. One point that is emphasized is the relationship between estimates of power spectra and power spectral densities which is given by the effective noise bandwidth (ENBW). Included is a detailed list of common and useful window functions, among them the often neglected flat-top windows. Special highlights are a procedure to test new programs, a table of comprehensive graphs for each window and the introduction of a whole family of new flat-top windows that feature sidelobe suppression levels of up to −248dB, as compared with −90dB of the best flat-top windows available until now.
262 citations
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14 Nov 1991TL;DR: In this paper, the authors define the notion of Fourier series and apply it in quantum mechanics filtering, frequency detection, and removal of noise summation kernals arising from poisson summation.
Abstract: Basic aspects of fourier series definition of fourier series examples of fourier series fourier series of real functions pointwise convergence of fourier series further aspects of convergence of fourier series fourier sine series and cosine series convergence of fourier sine and cosine series the discrete fourier transform (DFT) the fast fourier transform (FFT) some applications of fourier series fourier transforms properties of fourier transforms inversion of fourier transforms convolution - an introduction the convolution theorem an application of convolution in quantum mechanics filtering, frequency detection, and removal of noise summation kernals arising from poisson summation fourier optics fresnel diffraction fraunhofer diffraction circular apertures the phase transformation induced by a thin lens imaging with a single lens user's manual for fourier analysis software some computer programmes the schwarz inequality.
261 citations