# Tag Info

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 ...
• 7,283
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
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
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
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
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

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