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AD-FMCOMMS3-EBZ HIL example: QPSK modulation with raised cosine filter

Question asked by elvisjohndowson on Nov 22, 2014
Latest reply on Dec 4, 2014 by elvisjohndowson

Hi,

 

I'm trying to create a hardware-in-the-loop example for QPSK modulation with a raised cosine filter, using the AD-FMCOMMS3-EBZ in a 1x1 channel configuration, by merging the simulink iio_sys_obj example located here:

 

https://github.com/analogdevicesinc/mathworks_tools/tree/master/hil_models/fmcomms4_data_stream

 

and the simulink models described here:

 

http://wiki.analog.com/resources/eval/user-guides/ad-fmcomms2-ebz/software/datafiles

 

The problem is that even though I've configured the model to use QPSK modulation, I'm still getting the standard continuous IQ signals.

 

According to the ad_fmcomms3_ebz.cfg file that I created, data_in_device = cf-ad9361-dds-core-lpc

 

Q01: Is that the correct device to feed the TX signals from a QPSK or QAM modulator?

 

Additionally, upon launching the ZC706 target board, the IIO Scope tool defaults to running the fmcomms2_test.sh script, which generates these continuous IQ signals, which leads me to believe that the Simulink libiio block isn't somehow affecting the settings of the AD-FMCOMMS3-EBZ board.

 

Q02: What is the correct way to go about realizing this example?

 

Here is a screenshot of the simulink model, and the corresponding RX1 time scope output.

 

201411222250-ad-fmcomms3-ebz-hil-qpsk.png

 

201411222251-ad-fmcomms3-ebz-hil-qpsk-time-scope-rx1.png

 

Regards,

 

Elvis Dowson

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