Frequency resolution of random process

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Raziur Rahman
Raziur Rahman on 11 Oct 2015
Commented: Walter Roberson on 13 Oct 2015
I have got a random process with 100 samples. What frequency resolution can be obtained with traditional methods of Power Spectral Density calculation? How can I do this in matlab?

Answers (2)

Image Analyst
Image Analyst on 11 Oct 2015
Have you tried using pwelch() or periodogram()?
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Raziur Rahman
Raziur Rahman on 13 Oct 2015
I can pass the signal with this method. Then I have got a power spectrum density. Now what is frequency resolution?

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Walter Roberson
Walter Roberson on 11 Oct 2015
Neither traditional methods nor MATLAB can obtain any frequency resolution based solely on 100 random samples. In order to obtain any frequency resolution, it is necessary for there to be times associated with each of the samples, as frequency has to do with change in time.
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Raziur Rahman
Raziur Rahman on 13 Oct 2015
The signal is in time domain. If I calculate power spectrum density with different traditional method, then what is frequency resolution?
Walter Roberson
Walter Roberson on 13 Oct 2015
Question:
Let X = 0:0.01:100 . Let it be in the time domain. What is the frequency resolution of that X, using any method you want?
Answer: You cannot know based upon only that information.
Question: add the assumption that the times of the samples are
t = sort( rand(1,100) * 20 );
Answer:
Now you have a chance of determining the frequency resolution.
The frequency resolution is 1/2 of the lowest common multiple of the time differences diff(t) when expressed in rational form.

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