[USRP-users] N32x - Signal amplitude distorted when NOT using coherent frontend ?
Hello!
I have been doing a simple test where an impulse (with a rather small duty
cycle) is sent over a (short) wire and then captured by two N32x boards
synchronized with White Rabbit. The B210 has a sampling rate of 4 Msps, while
I’ve tried using both 10 Msps and 5 Msps for the N32x (with the bandwidths
adjusted correspondingly).
To my surprise, the amplitudes of the signals seem to be “modulated” — see, for
instance, a plot of the absolute value of the signals here:
https://ibb.co/PggyT06
This effect “magically” disappears if I configure the two boards to have a
coherent frontend — by connecting “out0” of the N321 board to the LO input on
the N320, and “out1” to “in1”, where I do the latter despite using only the
first channel of each board. Even weirder, if I just configure the N321 board
to use the coherent frontend (thus being a timing source and destination),
while I leave the N320 as it is, the signal on the N321 is just fine while the
other gets largely distorted: https://ibb.co/Q9qqKcq
My guess is that I’ve misconfigured something…. but what?\
The only differences are the commands:
`usrp->set_rx_lo_source("external", "lo1", 0);`\
`usrp->set_rx_lo_source("external", "lo1", 1);`\
`usrp->set_rx_lo_export_enabled(true, "lo1", 0);`\
`usrp->get_device()->get_tree()->access("/blocks/0/Radio#0/dboard/rx_frontends/0/los/lo1/lo_distribution/LO_OUT_0/export").set(true);`\
`usrp->get_device()->get_tree()->access("/blocks/0/Radio#0/dboard/rx_frontends/0/los/lo1/lo_distribution/LO_OUT_1/export").set(true);`
on the N321, with just the first two lines for the N320 — but I cannot see how
this could affect the acquired signals…
Thanks a lot in advance for any help!
Best,\
Rob
(note: I’ve also asked help on this on dsp-related, thinking this was an issue
with my understanding of SDRs, but the last test mentioned above made me wonder
whether this was an issue due to a misconfiguration of the N32x boards…)
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[USRP-users] Re: N32x - Signal amplitude distorted when NOT using coherent frontend ?
Could this be an issue related to automatic DC bias calibration? If you are
using a "DC" pulse (that is, at 0 Hz relative to the LO), perhaps you are
seeing effects from DC bias cancellation. You can either turn off this
calibration using the appropriate "args" at startup or you could request an
LO offset or you could modify your digital waveform to be not at DC.
Rob
On Wed, Mar 16, 2022 at 8:28 AM tebetix672--- via USRP-users <
usrp-users@lists.ettus.com> wrote:
> Hello!
>
> I have been doing a simple test where an impulse (with a rather small duty
> cycle) is sent over a (short) wire and then captured by two N32x boards
> synchronized with White Rabbit. The B210 has a sampling rate of 4 Msps,
> while I’ve tried using both 10 Msps and 5 Msps for the N32x (with the
> bandwidths adjusted correspondingly).
>
> To my surprise, the amplitudes of the signals seem to be “modulated” —
> see, for instance, a plot of the absolute value of the signals here:
> https://ibb.co/PggyT06
>
> This effect “magically” disappears if I configure the two boards to have a
> coherent frontend — by connecting “out0” of the N321 board to the LO input
> on the N320, and “out1” to “in1”, where I do the latter despite using only
> the first channel of each board. Even weirder, if I just configure the N321
> board to use the coherent frontend (thus being a timing source and
> destination), while I leave the N320 as it is, the signal on the N321 is
> just fine while the other gets largely distorted: https://ibb.co/Q9qqKcq
>
> My guess is that I’ve misconfigured something…. but what?
> The only differences are the commands:
>
> usrp->set_rx_lo_source("external", "lo1", 0);
> usrp->set_rx_lo_source("external", "lo1", 1);
> usrp->set_rx_lo_export_enabled(true, "lo1", 0);
>
> usrp->get_device()->get_tree()->access("/blocks/0/Radio#0/dboard/rx_frontends/0/los/lo1/lo_distribution/LO_OUT_0/export").set(true);
>
> usrp->get_device()->get_tree()->access("/blocks/0/Radio#0/dboard/rx_frontends/0/los/lo1/lo_distribution/LO_OUT_1/export").set(true);
>
> on the N321, with just the first two lines for the N320 — but I cannot see
> how this could affect the acquired signals…
>
> Thanks a lot in advance for any help!
>
> Best,
> Rob
>
> (note: I’ve also asked help on this on dsp-related, thinking this was an
> issue with my understanding of SDRs, but the last test mentioned above made
> me wonder whether this was an issue due to a misconfiguration of the N32x
> boards…)
> ___
> USRP-users mailing list -- usrp-users@lists.ettus.com
> To unsubscribe send an email to usrp-users-le...@lists.ettus.com
>
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[USRP-users] Re: N32x - Signal amplitude distorted when NOT using coherent frontend ?
Hello Rob, Thanks for your reply! Actually I was observing the same phenomenon, though significantly less pronounced, with a sine wave. In the dsp-related forum they’ve pointed me to the fact that it could be due to the sampling phase (emitter and receivers do not share the LOs), I still have to meditate a bit about this but it might be the cause… :S Best,\ Rob ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
[USRP-users] pybombs install of rfnoc onto ubuntu 20.04 lts
Hi, I am trying to install rfnoc usiing pybombs per https://kb.ettus.com/Getting_Started_with_RFNoC_Development#Create_the_development_environment_manually It seems to fail in the gnuradio portion, as shown below. I have found references to issues like gnuradio branch should be maint-3.7, but the recipes already have that, and I have found references to qt4 should be replaced by qt5 in the recipes, but they already have that fix , too. How should I be re - running this command ? is there cleanup I need to do first? I've just been trying things and repeating... pybombs prefix init ./rfnoc -R rfnoc -a rfnoc I see that uhd and gnuradio can be installed by apt install, but how can I do that and get rfnoc installed successfully to work with them? Finally, it appears that the uhd portion built and installed correctly, however I have this problem... /uhd_config_info ./uhd_config_info: error while loading shared libraries: libuhd.so.4.2.0: cannot open shared object file: No such file or directory Thanks for any suggestions, Mike ... [INFO] Installing package: gnuradio [WARNING] Build dir already exists: /home/mpc/projects/gryphon/payload/rfnoc/src/gnuradio/build Configuring: (100%) [==] [WARNING] Configuration failed. Re-trying with higher verbosity. -- Build type set to RelWithDebInfo. -- Extracting version information from git describe... -- Compiler Version: cc (Ubuntu 9.4.0-1ubuntu1~20.04) 9.4.0 Copyright (C) 2019 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. -- Compiler Flags: /usr/bin/cc:::-O2 -g -DNDEBUG -std=gnu99 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized /usr/bin/c++:::-O2 -g -DNDEBUG -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -- ADDING PERF COUNTERS -- Building Static Libraries: OFF -- Could NOT find PythonLibs (missing: PYTHON_LIBRARIES PYTHON_INCLUDE_DIRS) (Required is at least version "2.7") -- -- Checking for module SWIG -- Found SWIG version 3.0.12. -- -- The build system will automatically enable all components. -- Use -DENABLE_DEFAULT=OFF to disable components by default. -- -- Configuring python-support support... -- Dependency PYTHONLIBS_FOUND = FALSE -- Dependency SWIG_FOUND = TRUE -- Dependency SWIG_VERSION_CHECK = TRUE ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
[USRP-users] Re: pybombs install of rfnoc onto ubuntu 20.04 lts
On 2022-03-16 12:05, Caffrey, Michael Paul via USRP-users wrote: Hi, I am trying to install rfnoc usiing pybombs per https://kb.ettus.com/Getting_Started_with_RFNoC_Development#Create_the_development_environment_manually It seems to fail in the gnuradio portion, as shown below. I have found references to issues like gnuradio branch should be maint-3.7, but the recipes already have that, and I have found references to qt4 should be replaced by qt5 in the recipes, but they already have that fix , too. How should I be re - running this command ? is there cleanup I need to do first? I've just been trying things and repeating... pybombs prefix init ./rfnoc -R rfnoc -a rfnoc I see that uhd and gnuradio can be installed by apt install, but how can I do that and get rfnoc installed successfully to work with them? Finally, it appears that the uhd portion built and installed correctly, however I have this problem... /uhd_config_info ./uhd_config_info: error while loading shared libraries: libuhd.so.4.2.0: cannot open shared object file: No such file or directory WHere did these get installed? Since this is a pybombs install, you need to run setup_env.sh to get various environment variables set correctly based on where your pybombs run installed things, including shared libraries. Thanks for any suggestions, Mike ... [INFO] Installing package: gnuradio [WARNING] Build dir already exists: /home/mpc/projects/gryphon/payload/rfnoc/src/gnuradio/build Configuring: (100%) [==] [WARNING] Configuration failed. Re-trying with higher verbosity. -- Build type set to RelWithDebInfo. -- Extracting version information from git describe... -- Compiler Version: cc (Ubuntu 9.4.0-1ubuntu1~20.04) 9.4.0 Copyright (C) 2019 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. -- Compiler Flags: /usr/bin/cc:::-O2 -g -DNDEBUG -std=gnu99 -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized /usr/bin/c++:::-O2 -g -DNDEBUG -fvisibility=hidden -Wsign-compare -Wall -Wno-uninitialized -- ADDING PERF COUNTERS -- Building Static Libraries: OFF -- Could NOT find PythonLibs (missing: PYTHON_LIBRARIES PYTHON_INCLUDE_DIRS) (Required is at least version "2.7") -- -- Checking for module SWIG -- Found SWIG version 3.0.12. -- -- The build system will automatically enable all components. -- Use -DENABLE_DEFAULT=OFF to disable components by default. -- -- Configuring python-support support... -- Dependency PYTHONLIBS_FOUND = FALSE -- Dependency SWIG_FOUND = TRUE -- Dependency SWIG_VERSION_CHECK = TRUE This looks like you're missing Python2.7 libraries--it may be the case that 20.04 doesn't installed 2.7 libraries by default and you'll have to install them. ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
[USRP-users] Re: pybombs install of rfnoc onto ubuntu 20.04 lts
From: Marcus D. Leech Sent: Wednesday, March 16, 2022 10:15 AM To: usrp-users@lists.ettus.com Subject: [USRP-users] Re: pybombs install of rfnoc onto ubuntu 20.04 lts On 2022-03-16 12:05, Caffrey, Michael Paul via USRP-users wrote: Since this is a pybombs install, you need to run setup_env.sh to get various environment variables set correctly based on where your pybombs run installed things, including shared libraries. Aw, this made the difference, thank you Marcus. This looks like you're missing Python2.7 libraries--it may be the case that 20.04 doesn't installed 2.7 libraries by default and you'll have to install them. Indeed, Ubuntu hasn’t included 2.7 for some time apparently, so I installed it, but I get the same error from pybomb. Does pybomb not handle dependencies? Where might I find a list of python2.7 library dependencies that need to be installed for gnuradio? Thank you for the input -Mike ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
[USRP-users] Re: pybombs install of rfnoc onto ubuntu 20.04 lts
On 2022-03-16 12:41, Caffrey, Michael Paul via USRP-users wrote: *From:* Marcus D. Leech *Sent:* Wednesday, March 16, 2022 10:15 AM *To:* usrp-users@lists.ettus.com *Subject:* [USRP-users] Re: pybombs install of rfnoc onto ubuntu 20.04 lts On 2022-03-16 12:05, Caffrey, Michael Paul via USRP-users wrote: Since this is a pybombs install, you need to run setup_env.sh to get various environment variables set correctly based on where your pybombs run installed things, including shared libraries. Aw, this made the difference, thank you Marcus. This looks like you're missing Python2.7 libraries--it may be the case that 20.04 doesn't installed 2.7 libraries by default and you'll have to install them. Indeed, Ubuntu hasn’t included 2.7 for some time apparently, so I installed it, but I get the same error from pybomb. Does pybomb not handle dependencies? Where might I find a list of python2.7 library dependencies that need to be installed for gnuradio? Thank you for the input -Mike I think you may be heading down a path of grief here, since GR 3.7 is now quite obsolete, and the RFNoC bits and pieces for it are also quite obsolete. With the part1 and part2 RFNOC 4 workshop slide deck: https://www.gnuradio.org/grcon/grcon20/grcon20_RFNoC_4_Part1.pdf https://www.gnuradio.org/grcon/grcon20/grcon20_RFNoC_4_Part2.pdf And the migration guide: https://kb.ettus.com/RFNoC_4_Migration_Guide I think you're probably a new user of this stuff, so it's better to point you at "newer" stuff, than let you go down a path that is obsolete before your start ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
[USRP-users] LP0965 Antenna
Dear community, I have purchased a few LP0965 Antennas (https://www.ettus.com/all-products/lp0965/) because I would like to do a 5G transmission at 3.5 GHz (using OpenAirInterface). Is there any guidelines that I can follow for deployment? For example, in the link it mentions that "The SMA connector is supplied but needs to be soldered in place.", but soldered how? Thanks in advance, Giuseppe ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
[USRP-users] Re: LP0965 Antenna
On 2022-03-16 17:34, Giuseppe Santaromita wrote: Dear community, I have purchased a few LP0965 Antennas (https://www.ettus.com/all-products/lp0965/) because I would like to do a 5G transmission at 3.5 GHz (using OpenAirInterface). Is there any guidelines that I can follow for deployment? For example, in the link it mentions that "The SMA connector is supplied but needs to be soldered in place.", but soldered how? Thanks in advance, Giuseppe ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com I believe those antennas are manufactured by WA5VJB, and there's a bit of a user guide here: https://www.wa5vjb.com/pcb-pdfs/LP8565A2.pdf ___ USRP-users mailing list -- usrp-users@lists.ettus.com To unsubscribe send an email to usrp-users-le...@lists.ettus.com
