New answers tagged

0 votes
Accepted

How to calculate to power of a uniformly distributed noise?

(This answer is only valid under certain assumptions; see comments below original question) The definition of power for a random signal is the same regardless of the distribution. For a [update: ...
  • 14.4k
1 vote

Correct Windowing Effect at Amplitude Scale

Some observations: Your Parseval equation is incorrect, should be $\frac{1}{N^3}\sum_{k=0}^{N-1}|X[k] * W[k]|^2$, where $*$ is circular convolution and FFT is such that iFFT does ...
2 votes
Accepted

frequency present in FFT but not in PSD

This is not a definitive answer because I think your question needs a little more detail (see last paragraph), but since this is too long to write as a "comment", I'll leave this here for ...
  • 3,455
1 vote

IIR bandpass filter attenuates frequencies within the pass band

Do not use a power spectral density measurement to measure the power of sinusoidal tones, but instead use a power spectrum (this may have been done, incorrectly, as I can’t see the code actually used- ...
  • 43.4k
2 votes
Accepted

Definitions of Discrete Power Spectrum and Discrete Power Spectral Density

The power spectrum is useful for discrete tones, but for random signals as well as many other "almost" deterministic signals (such as modulated waveforms with random or pseudo-random data) ...
  • 43.4k
2 votes
Accepted

What does the covariance of a power spectral density between frequency points mean

See this related question which details further an intuition for covariance. From that we see that covariance is a correlation indicating a linear similarity between two functions. To be clearer, the ...
  • 43.4k
0 votes
Accepted

How to interprete the standard deviation of the psd in dB?

The power is always a positive quantity, and assuming the noise on the signal is white Gaussian noise, the distribution of the power will be Ricean (and Rayleigh distributed when there is only noise). ...
  • 43.4k
0 votes
Accepted

Calculate standard deviation of spectral desity in a Bartlett's method fashion?

The standard deviation is an indication of how accurate the given mean is to the "true" underlying power spectral density. What the Bartlett Method does (as well as the related Welch Method) ...
  • 43.4k
1 vote
Accepted

Bartlett's method: Order of normalisation?

The reason the DFT results are squared first and then divided by $M$, where $M$ is the length of the DFT is because the power spectrum is the Fourier Transform of the auto-correlation function. Doing ...
  • 43.4k

Top 50 recent answers are included