Post processing of experimental data.

[Khaledamallick@01]

Hello everyone,

I Khaleda Mallick, postdoc fellow in  TU Braunschweig. I want to do post processing of my experimental data via lab view. Actually, I did the experiment in the lab and extract the data (I and Q data) from real time oscilloscope and try to do post processing in lab view. It will be helpful for me if anyone help me in this regard. Looking forward to hearing from you.

[GerdW]

Hi Khaleda,

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Khaledamallick@01 wrote:

Actually, I did the experiment in the lab and extract the data (I and Q data) from real time oscilloscope and try to do post processing in lab view. It will be helpful for me if anyone help me in this regard.

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I see two main steps in your work:

1. Get the measurement data from your scope into the computer/to your LabVIEW VI.
2. Post-process the data by applying your algorithm

What have you tried and where are you stuck?

[Bob_Schor]

Are you at all familiar with LabVIEW?  Have you taken any classes (tutorials, actual class, working with mentors) and do you understand the basic concepts behind LabVIEW (including the idea that "data travels in Wires" and that LabVIEW is a "Data Flow" language, where the "steps" are determined by the order that the data "flows" in the wire from structure to structure)?  Do you have colleagues in your lab or department who can help?

Bob Schor

[Khaledamallick@01]

Thanks for your response. Actually, I am new in lab view, I have just uploaded my I and Q data to lab view but I don't know how to build digital signal processing block in LabVIEW.

[Khaledamallick@01]

Thanks for your response. Actually, I am new in lab view, I have just uploaded my I and Q data to lab view but I don't know how to build digital signal processing block in LabVIEW.

[GerdW]

Hi Khaleda,

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Khaledamallick@01 wrote:

Thanks for your response. Actually, I am new in lab view,

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You are also new to this forum when you need to respond twice with the same content…

When you are (very) new to LabVIEW than you should take note of all the Learning stuff presented at the top of the LabVIEW board!

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Khaledamallick@01 wrote:

I have just uploaded my I and Q data to lab view but I don't know how to build digital signal processing block in LabVIEW.

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How do you "upload data to LabVIEW"?

[altenbach]

One of the signs that you have learned the basics is once you can correctly spell LabVIEW (not "lab view", no space, correct lettercase).

If you have IQ data, it would be best to treat it as complex 1D array. How familiar are you with complex math? Is the time axis known and equally spaced?

LabVIEW is a full featured programming language that has all functionality to do math, signal processing, and signal analysis. Unfortunately, you have not told us what kind of processing you want to do (simple scaling? Basic metric (min/max magntude, dominant frequency and phase, offset from zero, etc.), Filtering, Transforms? convolutions? Nonlinear fitting? etc.).

What does the data represent and how does it look like? What kind of information do you want to get out of it?

[Khaledamallick@01]

Thanks for your response. My data is a QPSK data. I want  to do postprocessing by the following process-

Filtering

Resampling

Quadrature Imbalance (QI) Compensation

Chromatic Dispersion (CD) Compensation

Nonlinear (NL) Compensation

Adaptive Equalizer

Down-sampling

Frequency Offset Estimation

Carrier Phase Estimation

and finally I can get the proper constellation diagram for QPSK data.  Basically , I want to demodulate my data via LabView.

Yes, I did the complex 1-D array with the help of my colleague.

[altenbach]

Do you have just plain vanilla LabVIEW or also some toolkits?

What kind of instrument is generating the data? Depending on what you have, maybe the USRP software radio forum or even the Communication Design Suite forum might be a better place.

Of course everything can be done in plain LabVIEW (except maybe LabVIEW base). How solid is you math background in this field? Do you have all the theory and formulas for your various listed needs?