The power-spectral-density tag has no wiki summary.
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1answer
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Spectrum of a zero-order-hold signal
would be nice, if someone could help me with following question:
How does a spectrum of a sampled signal locks like, if one use a zero-order-hold?
There is some information in:
Sampling theorem and ...
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How exactly does MATLAB zeropad?
I am doing some massive number crunching in MATLAB which involves millions of PSD estimations. Each data segment has length 41. So I have been using the multi-taper method with nfft=41 (details below ...
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1answer
59 views
Cross Power Spectral Density of Unevenly Sampled Data
Here's my problem. The input signals $x$ and $y$ will be having the time value aligned with each other. However, the data are not evenly sampled. I would like to calculate CPSD of both signals.
The ...
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1answer
33 views
Windowing a time domain OFDM signal
Windowing is a popular method of reducing the spectral sidelobes of OFDM. A popular window usually used for this purpose in the raised cosine (RC) window, because of its tapered and smooth edges. I ...
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2answers
131 views
variance of white gaussian noise
it could seem an easy question and without any doubts it is but I'm trying to calculate the variance of white gaussian noise without any result.
PSD of AWGN is $\frac{N_0}{2}$ while autocorrelation ...
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1answer
50 views
RF mask (power spectrum measurement bandwidth)
I'm reading an IEEE standard and it says that the first channel needs to be 50dB below the highest power in a 6 MHz operating channel in 100 KHz bandwidth. It was mentioned several times that the ...
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fit theoretical spectrum to simulated one
I have a bunch of simulated time series, for which I can compute the power spectrum. Generally, the simulated power spectrum can be sketched as follows:
I now aim to calculate the features of the ...
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2answers
69 views
Random signal power spectrum
I have a signal $X(t)=\sum_{n=-\infty}^{\infty} Z_n \delta(t-n\tau)$, $Z_n$ is a random variable with equal possibility of +-1 and I know the power spectrum of this signal is $\frac {1}{\tau}$ from ...
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2answers
174 views
PSD (Power spectral density) explanation
I'm trying to understand how the PSD is calculated. I've looked in a few of my Communication Engineering textbooks but to no avail. I've also looked online. Wikipedia seems to have the best ...
2
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1answer
147 views
Working backwards from PSD to possible signal
I have been trying to reconstruct a random signal from its PSD and am running into trouble. I know that many different signals in the time or spatial domains can result in the same PSD-- I am ...
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45 views
Recover High Frequency Loss in a Simulated Power Spectrum
I'd like to ask a theoretical question about power spectra.
In MATLAB, by means of a particular approach, I'm trying to generate a Gaussian variable which embodies a particular power spectrum.
The ...
4
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1answer
92 views
What does double hat mean in Spectral theory?
I was confused about the double hat notation $\hat{\hat .}$ and my teacher and I thought it probably means an estimate of an estimate most of the time, but we could not be 100% sure of its meaning.
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difference (or relationship ?) between power spectral density, power density function and periodogram
What exactly is the difference or relationship between power spectral density and power density function? I thought they referred to the same thing but one article I need says to calculate both of ...
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2answers
211 views
When negative frequencies cannot exist in practice, why do we calculate power in negative frequency?
Suppose a signal with two-sided power spectral density $N/2$ is passed through an ideal LPF having cutoff frequncy $B\,\mathrm{Hz}$. The output power is equal to $N/2 \times 2B = NB$ Watts. Why not ...
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1answer
365 views
What is the difference between PSD and squared magnitude of frequency spectrum?
The power spectrum of a signal can be calculated by taking the magnitude squared of its Fourier transform. Being an audio person, the signal of interest for me would be a time series.
How does this ...
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1answer
290 views
Variance of periodogram estimate of the power spectrum
I have been reading chapter 13.4. ("Power Spectrum Estimation Using the FFT") of the Numerical Recipies Book.
Some things related to the expectation value of the "periodogram estimate of the power ...
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1answer
203 views
I have a noisy ECG Signal. want to use PSD to analyse the Signal to noise ratio
I have a really noisy ECG Signal which contain, motion artifacts,muscle noise, a very high amplitude noise.
I am beginner to DSP. Can someone tell me in a simple language,how do i interpret the ...
4
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1answer
904 views
Is autospectrum the same as power spectrum density?
In my slides about signal processing, there is one that mentions the same thing as the beginning of this and this answer, namely that the Fourier transform of a signal, squared is the power spectrum ...
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1answer
2k views
Difference between Power spectral density, spectral power and power ratios?
What 'exactly' is power spectral density for discrete signal? I was always under the assumption that taking the Fourier transform of the signal, and then the ratio of desired freq range magnitude over ...
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2answers
2k views
Why so many methods of computing PSD?
Welch's method has been my go-to algorithm for computing power spectral density (PSD) of evenly-sampled timeseries. I noticed that there are many other methods for computing PSD. For example, in ...
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3answers
852 views
How do you calculate spectral flatness from an FFT?
Ok, the spectral flatness (also called Wiener entropy) is defined as the ratio of the geometric mean of a spectrum to its arithmetic mean.
Wikipedia and other references say the power spectrum. ...
