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Hello Everyone,

I am generating the Random white Noise and restricting the noise to 5KHZ and after the 5KHZ noise should decay 6db per Octave but I have used many of the filter option but I am unable get the Result. The below attached vi shows the details Noise is generating please help me with this

thanks in Advance

In code I am generating the Noise and adding with the Signal just to verify 

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Message 1 of 19
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Hi Gowtham,

 

but I am unable get the Result.

Can you show the expected result in a graph/image/scientific paper/whatever?

 

Why do you add a (sine) signal when you want to create a certain noise?

check.png

Did you change the filter order?

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Message 2 of 19
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hello Sir,

Here is the snapshot of my output. The reason why I have added the signal is just to verify that the signal is present within the noise. after 5KHZ the noise should not decay above 6db per octave hence I kept the order  as 1(since it gives 20db per decade which is nothing but 6db per octaveSnapshot.PNG)

 

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Message 3 of 19
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Hi Gowtham,

 

after 5KHZ the noise should not decay above 6db per octave hence I kept the order  as 1

So your problem is solved?

 

 

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Message 4 of 19
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Hello Sir,

I kept order as 1 but still I don't think it is coming properly

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Message 5 of 19
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And more over in the PSD waveform as u can see there are many samples and their peak value keep on changing ....in Signal Analyzer device we see the PSD in average mode how can we do averaging psd in LabVIEW

 

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Message 6 of 19
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Hi Gowtham,

 

this is the result with your 1st order filter (and a little bit of "smoothening" the plot):

check.png

Again: please explain your expected result with a meaningful image/paper/reference…

 

in the PSD waveform as u can see there are many samples and their peak value keep on changing

No, the values don't "keep on changing" as your VI only runs once as there is no loop in your code…

When you run the VI multiple times the plot has to change because you are generating a noise signal - which is random by its nature!

When you need to average several plots you need to average the plot data…

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Message 7 of 19
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Hello Sir,

Actually the thing is I am generating the white noise and limiting it to 5KHZ after 5KHZ noise should start decay so that it will not decay more than 6db per octave so I am using Low Pass Filter with order as 1.

as you can see in the Below pic of PSD there are huge samples in which I should show that the Decaying is not more than 6db per Octave after the 5KHZ noise. And How to Smoothening the PSD plot signal...?? because in your plot its looks like a single line but in mine its showing huge samplesSnapshot.PNG

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Message 8 of 19
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Hello Sir

How to Average the Plot I have seen the Option like blow but what are the settings I need to change...??PSD.PNG

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Message 9 of 19
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Hi Gowtham,

 

what are the settings I need to change...??

Whatever your requirements tells you…

 

because in your plot its looks like a single line but in mine its showing huge samples

As I wrote: I smoothened the plot data by applying a running average on the plot data. (I used the PtByPt-Mean…)

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Message 10 of 19
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