Отправлено AndrewGT 21 февраля 2002 г. 08:43

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DSP Insite
The e-letter of the DSP world
http://www.E-Insite.net
February 20, 2002
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1. Sliding-Mode DFT Revisited

The topic of sliding-mode DFTs a few issues ago was a popular one.
However, several readers had questions about the accuracy of the
sliding-mode FFT because they assumed the algorithm yielded an
approximation. True, when you first start to stream the data into the
window the initial versions of the data look like they're filtered and
then appear to converge to the actual transform. This is because the
algorithm begins operating on the initial points before the window fills
up, and the actual Fourier transform for those few points appears
filtered. Despite the appearance of the initial results, the
sliding-mode DFT is the actual transform for the data stream, not an
approximation.

The discussions of the algorithm are archive at
http://article.E-Insite.net/UM/T.ASP?A5.45.1858.2.80820603
and
http://article.E-Insite.net/UM/T.ASP?A5.45.1858.3.80820603