Power Spectral Density Estimates Using FFT

3 ビュー (過去 30 日間)
Yigao Shao
Yigao Shao 2015 年 5 月 21 日
回答済み: Jeremy 2015 年 6 月 18 日
http://www.mathworks.com/help/signal/ug/psd-estimate-using-fft.html
In the code example, psdx = (1/(Fs*N)) * abs(xdft).^2;
why isn't it instead (Fs/N) such that psdx = (Fs/N) * abs(xdft).^2? Isn't the period equal to the length of the signal, which is N, multiplied by the sampling interval, which is 1/Fs ?

サインインしてこの質問に回答する。

回答 (1 件)

Jeremy
Jeremy 2015 年 6 月 18 日
There are different ways of looking at it but the PSD is often written as:
(fft*conj(fft))/(bin_width*NFFT^2)
(fft*conj(fft)) = abs(fft) and bin_width = Fs/NFFT, so you can see how it reduces down.

カテゴリ

Help Center および File Exchange で Spectral Estimation についてさらに検索

タグ

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by