如何计算信号的能谱? [英] How to calculate the energy spectrum of a signal?

问题描述

我从理论上知道，给定信号的能谱是傅里叶平方系数的总和.

I know by theory that the energy spectrum of a given signal is the sum of the squared fourier coefficient.

如果我具有相应傅立叶系数的实部和虚部，该怎么办?给定信号的能谱等于(实部+虚部)^ 2的和

What if I have the real and imaginary part of the corresponding fourier coefficient, can I say that energy spectrum of a given signal is equal to sum of (real part + imaginary part)^2

推荐答案

不太正确.您想要:

sum of fft_result_magnitudes^2

这是:

sum of (sqrt(real_part^2 + imaginary_part^2)^2

这是:

sum of (real_part^2 + imaginary_part^2)

获得复杂FFT结果的平方量之和.

to get the sum of the squared magnitude of a complex FFT's results.

有关Parseval定理的更完整说明，请参见:

As for a fuller statement of Parseval's theorem, see:

http://en.wikipedia.org/wiki/Parseval%27s_theorem

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