How to do PSD measuremnet for the given signal
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Hi, I am doing PSD (ms2) analysis for the frequency spectrum attached in the figure. I am able to find PSD but the results are not in PSD(ms2).
Here is the code:
[pxx,f] = pwelch(rwave_decimate_1,,,,fs/N);
mean = 0;
mean = mean + pxx(i);
M = mean/length(pxx);
var = 0;
var = var + (pxx(j)-M)^2;
V = var/length(pxx);
It plots the PSD as in the attached figure. however, I want PSD in (ms2 or s2) on yaxis as in the figure 2, to make proper analysis on LF/HF region. Also, how can I highlight the LF and HF region with some shadded areas as in the figure2 ?
:- ms2 = mean-variance square
it would be appreciated if someone give solution.
Thanks in the advacnce.
Arthi Sathyamurthi on 19 Jul 2021
The units of the PSD estimate from the pwelch function are in squared magnitude units of the time series data per unit frequency. Thus, if the input data, rwave_decimate is in ms and the sample rate given as fs/N is in Hz, the PSD estimate which in your case pxx, ms^2/Hz.