I am working with zc706 and ADRV9371 evaluation boards. I'd like to transmit QAM4 data from transmitter end of the AD9371 with DMA mode on. According to "https://wiki.analog.com/resources/eval/user-guides/mykonos/software/basic_iq_datafiles" data is composed of In-phase and Quadrature parts. I am using only the TX1 path of the AD9371 and I assume the data file(LUT - array) to only composed of data related to TX1 path. Considering this and the following data :
In my case data is 32bits long and ı arranged my custom data according to sine_lut_iq and
(there was a already existing "const uint32_t sine_lut_iq" lut in NO_OS2018_R2).
However, after few trials, I observed that received data (both i and q parts) is only composed of q part of I/Q pairs. SO, I tried different methods to see the response of the system to IQ data;
After seeing results above, I couldn't conclude any cause to my problem. Apparently there is a problem but why this is problem is occuring is a mystery to me.
Lastly, I tried to see the example LUT included in No_OS 2018R2. As it seems, the lut is a sinus. If I run this LUT, ı would expect to see 2 signals (I and Q) with 90 degree phase difference. But what I see is following :
The Red is "I" part and blue is "Q" part. As you may see, they are nearly identical just like my own trials. I ınclude the "original" test LUT below.
As a result, I think that problem might be related to configuration of "IP core - AXI_AD9371_v1_0". There are registers to configure the format of IQ format as 2s complement or not. So, not configuring those registers might be a problem I believe.
Additional IMPORTANT Information: If I run the DDS mode, the I and Q values are different than each other as expected and resulting graph is a Sinusoidal.
Summary: I want to transmit a QAM signal with non-identical I and Q data (as it should be for QAM) but I observe the same identical data on I and Q parts of the received data. How can I solve it (My custom data is created according to const uint32_t sine_lut_iq" lut in NO_OS2018_R2 => 0x16bits_I_data+16bits_Q_data = 32bits in total).
Correction : In DDS mode, I and Q parts of the received data are also same. Sorry for misleading. I just conducted a new trial :)
I hope this thread is not forgotten sorry for spamming but I need a solution urgently.
Can you share your iq_rx1.csv generated file in DMA mode? Are you using VisualAnalog to plot the the received data? If so, make sure that from the Pattern Loader window, the I/Q - Interleaved File Format is selected.
Also, I assume that the setup was successful.
Looking forward to your answer!
Thank you for response in advance :)
1) The iq data is indeed generated in DMA mode, I am trying to use my custom data for modulation. Here is the iq_rx1.csv (used capture.tcl to be sure capturing is successful without doubt) .
(I couldnt upload the .csv format, so uploaded .txt version. Content is the same).
2) The results I have posted first is plotted by me on MATLAB. I was using 32 bit hex data and was processing that. But the "VisiualAnalog" gives the same results. You can see it below:
Thanks a lot.
We will perform a test and come back to you.
Is there any progress or results related to tests you run?