rfsa error

[waciuri]

Hi Robert,

I did the gausssian filter,i fetched the signal as "F64", i resampled the waveform,MSK demodulated but when i try to get "ModtGetRecoveredBitStream" i get an error as outlined in this link

http://forums.ni.com/t5/LabWindows-CVI/msk-demodulation/td-p/2897406

Thanks,

Moses

[USBarnes]

Moses,

A while back you mentioned that when you run the ModAcc example that you started with, you get the data that you expect. Is that still the case? Would you mind posting some images of the GSM signal you are acquiring and trying to demodulate?

[waciuri]

Hi Robert,

Attached is an image of the signal output am acquiring.

Thanks,

Moses.

[USBarnes]

Moses,

Can you send an image of the spectrum you get with the RFSA soft front panel?

[waciuri]

Hi Robert,

Find attached the images.

Thanks

Moses

[USBarnes]

Moses,

Based on those images, this looks like the noise floor. Were you trying to acquire the GSM signal when these pictures were taken? What frequency is your GSM signal being generated at? Also are you using an Antenna to acquire it or are you cabling between the generator and the 5663E?

Would you mind trying to run the LabVIEW version of the niGSM Measure ModAcc Example.vi? You won't need to perform any coding on the block diagram. I just want to see if we get any different behavior. You can find the example in the following directory:

C:\Program Files (x86)\National Instruments\LabVIEW 2013\examples\RF Toolkits\GSM-EDGE\Analysis\GSM\niGSM Measure ModAcc Example.vi

All you'll need to do is change the RFSA Device control to match your device name and any of the other RF parameters to match your expected GSM Signal. Let me know if you get the data you expect.

[waciuri]

Hi Robert,

My GSM-EDGE analysis toolkit has no labview examples very strange, it only has examples for CVI but labview manuals are there.

Soft panel images attached are for GSM generated frequencies(start->890MHZ & Stop-> 915MHZ). My equipment has an antennae attached but i dont know how i can have acquired signals reflect on the soft panel, is there a way?

Thanks,

Moses

[waciuri]

Hi Robert,

Eventually am getting some results after demodulation and my function "checkWarn (ModtGetRecoveredBitStream ( mtSession, GetArray_Size (hMskDemodulatedData),  GetArray_pData (hMskDemodulatedData))); "

if i  do "printf("%u\n",  (unsigned)GetArray_pData (hMskDemodulatedData));  "

i get the following results, a repetetive value ->39409520. My hope is as per the manual for the above function is to get a bit stream of 1's & 0's. Please advice if am on the right track and how to attain this final result so that i can tell what the bits contains.

Thanks,

Moses

[USBarnes]

Moses,

The RFSA soft front panels will use the one channel on the 5663E to acquire on. Have you tried using the Analysis Interactive Example instead of the RFSA soft front panels? You can find it at Start>>All Programs>>National Instruments>> NI GSM-EDGE+ Analysis Toolkit>>Analysis Interactive Example for GSM-EDGE+.

In terms of returning 1's and 0's, the printf is only going to allow you to format values into integers. You'll need to convert the integer values to binary or use a different function to display the data. Here is a stackoverflow that suggests one way you might be able to convert it to binary.

http://stackoverflow.com/questions/111928/is-there-a-printf-converter-to-print-in-binary-format

[waciuri]

Hi Robert,

What other function can i use?

I tried to convert to binary using the examples you referred me but what i was getting is an alphabet A' (A with a mark like an apostrophe) instead of text content.

When my output is a repetetive value like

33839040
33839040
33839040
33839040
33839040

is this data valid as per the content i wish to get after conversion?

Thanks,

Moses