Make sure that the SMA cables are
connected so that the first two TX RF ports (TX1-TX2) are connected to the two
FB RF ports (FB1-FB2, respectively).
Copy your waveform file from the
host pc to the Arm node using the command scp <path to the waveform
file> root@192.168.0.1:/home/root/jesd_tools/data/ in PowerShell. For
the setup, the command scp .\jesd\TM3.1a_FDD_737.28MHz_eSOM_ACLRver.txt
root@192.168.0.1:/home/root/jesd_tools/data/ was used.
The format of the
waveform file is such that each sample occupies a line with a 16-bit hex
value for the I portion in the first column and a 16-bit hex value for
the Q portion in the second column.
On the Arm node (Teraterm), run
the command below to simultaneously playback the samples of the waveform to each
of the first two TX channels channels from the FPGA and capture the samples from
each of the two FB channels in 4T4R2F mode.
Figure 5-1 Expected Output After
Running the Loop-Back Command
At the end of the execution,
there should be two capture files created with names of
cw_capture_fb[0-1].txt in jesd_tools/log folder on the Arm
node. Copy one of them to the host PC in the
Hitek_RF_INTF_Common_Files_2023-06-07\software\x64_64\analysis\jesd
folder using the command scp
root@192.168.0.1:/home/root/jesd_tools/log/cw_capture_fb0.txt <location
to copy>. In our setup the command, scp
root@192.168.0.1:/home/root/jesd_tools/log/cw_capture_fb0.txt jesd/ was
used.
Run the .\run_freq_plot.exe 2
.\\cw_capture_fb0.txt 737280000 command from the
Hitek_RF_INTF_Common_Files_2023-06-07\software\x64_64\analysis\jesd
directory to display a Fast Fourier Transform (FFT) with Hamming window of the
FB capture. The FB is sampled at 737.28Msps in 4T4R2F mode and is shown in Figure 5-2. You can zoom in to adjust the view in the image.
Figure 5-2 FFT Showing the
Loop-Backed TM3.1a Waveform
Figure 5-3 Zoom of the FFT
Showing the Loop-Backed TM3.1a Waveform