| 释义 |
Wiener-Khintchine TheoremRecall the definition of the Autocorrelation function of a function ,
 | (1) |
Also recall that the Fourier Transform of is defined by
 | (2) |
giving a Complex Conjugate of
 | (3) |
Plugging and into the Autocorrelation function therefore gives
so, amazingly, the Autocorrelation is simply given by the Fourier Transform of the Absolute Squareof ,
 | (5) |
The Wiener-Khintchine theorem is a special case of the Cross-Correlation Theorem with .See also Autocorrelation, Cross-Correlation Theorem, Fourier Transform
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