Hi all, any news on this saturation issue concerning the N310 with UHD 3.13.0.3 RC1? I would like to know if Ettus is aware of this problem, and if a new UHD version is coming with a correction?
Thanks! Best regards, Serge - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - *Serge Malo * CDO & Co-founder, Skydel Solutions Cell: 1-514-294-4017 www.skydelsolutions.com Twitter: @skydelsol <https://twitter.com/skydelsol> Avis : Ce message est confidentiel et protégé par le secret professionnel. Si vous n'êtes pas le destinataire, veuillez informer l'expéditeur par courriel immédiatement et effacer ce message et en détruire toute copie. / Notice: This message is confidential and privileged. If you are not the addressee, please inform the sender by return e-mail immediately and delete this message and destroy all copies. On Wed, 17 Oct 2018 at 16:53, Ali Dormiani via USRP-users < usrp-users@lists.ettus.com> wrote: > Attempt 2. Sorry for breaking mailing list rules with the attachments. > Here is a google drive link to the screenshots, GRC file, and binary files. > (3 MB zip) > > > https://drive.google.com/a/eng.ucsd.edu/file/d/1TvmHuEMFb2QpkiMMdiUEW6aVoUfLYayi/view?usp=sharing > > We have three sliders in GNUradio. > > 1. TX gain > > 2. RX gain > > 3. Digital Gain (multiply constant block between our binary file and the > UHD block. > > We also have one TX connected directly to an RX with a 30 dB analog > attenuation for safety. > > Our binary files were generated in MATLAB and are normalized to unity > magnitude. > > Attached, please find the GRC file and our binary files. For reference, > the waveform we made is a multitone signal so it should be a bunch of > evenly spaced spikes. I have included some screenshots too. Additionally we > have verified this strange behavior with a spectrum analyzer. > By playing around with the sliders you can see how narrow the zone is for > good results. Intuitivly it seems like TX and RX gain don't really matter. > They just shift the narrow usability zone for Digital gain. > > On Wed, Oct 17, 2018 at 12:45 PM Ali Dormiani <sdorm...@eng.ucsd.edu> > wrote: > >> We have three sliders in GNUradio. >> >> 1. TX gain >> >> 2. RX gain >> >> 3. Digital Gain (multiply constant block between our binary file and the >> UHD block. >> >> We also have one TX connected directly to an RX with a 30 dB analog >> attenuation for safety. >> >> Our binary files were generated in MATLAB and are normalized to unity >> magnitude. >> >> Attached, please find the GRC file and our binary files. For reference, >> the waveform we made is a multitone signal so it should be a bunch of >> evenly spaced spikes. I have included some screenshots too. Additionally we >> have verified this strange behavior with a spectrum analyzer. >> By playing around with the sliders you can see how narrow the zone is for >> good results. Intuitivly it seems like TX and RX gain don't really matter. >> They just shift the narrow usability zone for Digital gain. >> >> >> >> On Wed, Oct 10, 2018 at 6:20 PM Marcus D. Leech via USRP-users < >> usrp-users@lists.ettus.com> wrote: >> >>> On 10/10/2018 03:08 PM, Ali Dormiani via USRP-users wrote: >>> >>> Hello, >>> >>> We have the exact same problem. My lab is waiting on some sfp+ cables so >>> in a few days I will share our screenshots, code, and data binary files in >>> order to provide this thread with a second example of this issue. For now, >>> all I can say is this problem is not isolated to your N310 or Windows. >>> >>> We have two N310's running with the same version of UHD (and GNUradio >>> 3.7.13.4) on Linux kernel 4.18. By using amplitude sliders in GNUradio we >>> found that there is a very small and strange gain "Goldilocks" zone around >>> .002 that gives good results. Going higher starts to raise the noise floor >>> until all signal definition is gone. >>> >>> Ali Dormiani >>> UCSD Noiselab >>> >>> What is your RF gain set to in these examples? Does that change things? >>> >>> If you raise things to a level where non-linearity is apparent, does >>> placing a 10dB attenuator in-line fix it (trying to distinguish between >>> the transmitter being non-linear, and your receiver/spectrum analyser). >>> >>> >>> >>> On Wed, Oct 10, 2018 at 11:33 AM Mathieu Lizée via USRP-users < >>> usrp-users@lists.ettus.com> wrote: >>> >>>> Hi, >>>> >>>> When using the UHD "tx_waveforms" example, I can see that the signal >>>> emitted by my N310 USRP is saturated when it’s not supposed to be. >>>> >>>> Here's a snapshot of the signal when I set the amplitude to 0.003: >>>> .\tx_waveforms.exe --rate 12.5e6 --nsamps 1250000000 --freq 1575.42e6 >>>> --ampl 0.003 --otw sc16 --wave-type SINE --wave-freq 10e3 --channels 2 >>>> >>>> [image: tx_waveforms_3e-3_amp] >>>> <https://user-images.githubusercontent.com/15334138/46685506-a7424700-cbc3-11e8-926e-b0da5f416652.png> >>>> >>>> Here's a snapshot of the signal when I set the amplitude to 0.03: >>>> .\tx_waveforms.exe --rate 12.5e6 --nsamps 1250000000 --freq 1575.42e6 >>>> --ampl 0.03 --otw sc16 --wave-type SINE --wave-freq 10e3 --channels 2 >>>> >>>> [image: tx_waveforms_3e-2_amp] >>>> <https://user-images.githubusercontent.com/15334138/46685468-9265b380-cbc3-11e8-9ce7-42908cf9bf2e.png> >>>> >>>> As you can see from the pictures above, it seems that there's a >>>> saturation in the signal when the amplitude is set to 0.03 (which is >>>> unexpected with such a small amplitude). We have double-checked with a X300 >>>> device, and the signal is normal in both cases. >>>> >>>> Do you have an idea of what could be wrong, or a suggestion to try on >>>> our side? >>>> >>>> Technical Information: >>>> >>>> - Windows 10 >>>> - USRP N310 >>>> - UHD 3.13.0.3-rc1 >>>> >>>> >>>> Thank you! >>>> >>>> -- >>>> *Mathieu Lizee* >>>> *Software Development Intern* >>>> >>>> *Skydel Solutions* >>>> WeWork 5th Floor (Skydel) >>>> 1275 Av des Canadiens-de-Montreal >>>> Montreal, QC >>>> H3B 0G4 >>>> _______________________________________________ >>>> USRP-users mailing list >>>> USRP-users@lists.ettus.com >>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>> >>> >>> >>> _______________________________________________ >>> USRP-users mailing >>> listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >>> >>> >>> _______________________________________________ >>> USRP-users mailing list >>> USRP-users@lists.ettus.com >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>> >> _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >
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