Way to filter out a portion of a time domain signal when its amplitude drops below a certain value?

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Richard Ingham
Richard Ingham 2016-2-28
评论： John BG 2016-2-29
Is there any way to filter a time domain signal such that portions of the signal, where the amplitude drops below a certain level, are ignored?
In the attached image, the real parts of two complex signals are plotted against time. I essentially need to ignore the portions of the signal where the amplitude of the peaks are less than 1E-7 and the troughs are greater than -1E-7 since they are causing phase jumps when I subsequently unwrap the complex signal.
Many Thanks.
  2 个评论
jgg
jgg 2016-2-28
If your signal is s couldn't you just do:
incl_idx = (abs(s) < 1e-7);
s = s(incl_idx);
Then you get a new, truncated signal. For instance:
s = rand(1000,1);
inclu_idx = (s < 0.5);
s = s(inclu_idx );
John BG
John BG 2016-2-29
do you really mean 'clipping' what you really want to do to this signal?
holding x>1e-7 right on 1e-7 as long as signal above 1e-7 and anything below -1e-7 remains -1e-7 while signal below threshold?
If you really remove the samples out of [-1e-7 1e7] you will shrink the signal.
if so, clipping so low may cause more phase jumps than without clipping.
Why don't you hang the data in a file so readers can use the sample directly?
John
jgb2012@sky.com

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