On 2021-09-07 5:55 p.m., Ivan Zahartchuk wrote:
I am setting 256 points FFT with the following parameters:
fft_amplitude = uhd.libpyuhd.rfnoc.fft_magnitude.MAGNITUDE_SQUARED
fft_direction = uhd.libpyuhd.rfnoc.fft_direction.FORWARD fft_shift =
uhd.libpyuhd.rfnoc.fft_shift.NORMAL After that I do abs and display
the data. Tell me how to do it better? And do I need to set a
different type for the array which is passed to the recv function when
setting Mag ** 2?
YOu're already setting Mag**2, so there's no need to ABS. Typically,
after that you'll use a 10*log10 function which is then itself scaled by
the FFT length and a few other factors. I'd suggest looking at the
Gnu Radio FFT code to see how it scales the FFT output. There are
MANY ways to scale an FFT (and even the MAG**2 output of an FFT)--the
RFNOC FFT produces a linear-form output, so if you
want to see it in dB units you have to do that yourself from what I
understand. Implementing a 10*log10 in the FPGA would likely
be prohibitive, and usually you do that after you've done some
averaging and frame-rate reduction.
ср, 8 сент. 2021 г. в 00:43, Marcus D. Leech <patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>>:
On 2021-09-07 4:17 p.m., Ivan Zahartchuk wrote:
Hello. There is any information on my question. I also noticed
that if you take the data after the FFT, then the sensitivity
drops very much. I see a -30 dBm signal but -60 dBm is no longer
displayed.
How are you scaling and displaying your FFT output? What options
do you have set on your FFT? DO you have it using Mag**2, how do
you scale it
after that?
сб, 4 сент. 2021 г. в 00:04, Ivan Zahartchuk <adray0...@gmail.com
<mailto:adray0...@gmail.com>>:
Here is my script. I am trying to read different amounts of
data from DDC and from FFT. Are there any new statements on
my question?
чт, 2 сент. 2021 г. в 10:06, Jonathon Pendlum
<jonathon.pend...@ettus.com <mailto:jonathon.pend...@ettus.com>>:
Great, thanks. Can you also share your latest python script?
Jonathon
On Wed, Sep 1, 2021 at 6:37 PM Ivan Zahartchuk
<adray0...@gmail.com <mailto:adray0...@gmail.com>> wrote:
Yes, I can try it but next week. But I still wanted
to do FFT on FPGA. And one more question. Is it
possible to create two streamers and read 256 samples
one at a time and another 8192 for example? I want to
do FFT on one channel and start a stream with DDC for
demodulation on the other. What is possible?
ср, 1 сент. 2021 г. в 21:09, Jonathon Pendlum
<jonathon.pend...@ettus.com
<mailto:jonathon.pend...@ettus.com>>:
Hi Ivan,
Can you try running your script with the SPP set
to 512 and without the FFT block, i.e. Radio ->
Rx Streamer? This may be a general issue with SPP
unrelated to the FFT. I'm getting the same "Bad
CHDR packet" error on a different device with the
FIR filter block, but it goes away when I remove
the block.
Jonathon
On Mon, Aug 30, 2021 at 3:46 PM Marcus D. Leech
<patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>> wrote:
On 2021-08-30 2:30 p.m., Ivan Zahartchuk wrote:
Thanks. Still trying to work this out. In
UHD 4, the interface to the FPGA changed from
a straightforward DMA implementation--done by
ADI for
their IIO subsystem, to a driver that makes
the FPGA/Radio "look" like a network device
with an MTU of 9000.
With an MTU that large, you should have no
trouble with 512-bin FFTs. But clearly, you are.
The "int0" network interface exists only
while there's a session with the radio, so it
won't show up in "ifconfig" unless there's a
session active,
and it indeed has an MTU of 9000. So MTU
isn't your problem. It's something else, and
I'm not sure what at the moment.
пн, 30 авг. 2021 г. в 15:08, Marcus D. Leech
<patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>>:
On 2021-08-29 7:17 a.m., Ivan Zahartchuk
wrote:
Thanks a lot. Here is my output with
uhd_usrp_probe and my code:
Could you share with us the output of:
ip link
or ifconfig
сб, 28 авг. 2021 г. в 20:19, Marcus D.
Leech <patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>>:
On 2021-08-28 10:49 a.m., Ivan
Zahartchuk wrote:
Tell me who I can turn to for help
or how can I solve the problem
with the fact that I cannot set
the number of FFT points> 256. I
apologize for my persistence, but
this is critical for me. Thank you
for understanding.
Ivan, I've been poking around all
morning try to find where there may
be a limit. I can't find it. I'm
hampered by not being an RFNOC expert.
I have a query in to Ettus R&D, but
it being the weekend, I don't
expect any kind of answer until Monday.
Could you share your Python code,
and the output of uhd_usrp_probe on
your E310?
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