FFT-DC and Nyquist components

Question

Ken W 2015-12-12

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/260030-fft-dc-and-nyquist-components

回答： Ken W 2015-12-14

Dear All,

I compute the power spectrum using FFT.

Sampling frequency = 10 Hz Data length = 16384 Nyquist frequency = 5 Hz Fast Fourier transform (FFT) of 16384 data points Discard the DC component Take the first half FFT components i.e. from 2 to 8193 ((16384/2)+1, Nyquist theorem) df = 5/8192 = 0.000610351 For each of the 8192 components, Power spectrum = Real^2 + Imaginary^2

Please correct me if i’m wrong.

My questions are: What is the use of Nyquist component? Should i discard the Nyquist component?

I read some of the internet source, the Nyquist component were discarded.

Thank you.