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Re: [USRP-users] Waveform Shape Not Accurate

NF
Nick Foster
Wed, Jun 19, 2019 11:59 AM

Can you post the flowgraph you're using again? If you changed transmit gain
and amplitude, the result should have changed in amplitude, while the image
you just sent has the fame magnitude the last one did.

On Wed, Jun 19, 2019, 5:03 AM Simona Sibio ssibio2@gmail.com wrote:

Thank you very much.
I tried to send a signal with this features, but the result is the same
(IMG_6590).
I tried with every amplitude and every gain (Screenshot from 2019).
Before, I thought that it was a problem of reference signal and I changed
it but the situation is not changed.

Thank you in advance for your help.

Best Regards,

Simona

Il giorno mar 18 giu 2019 alle ore 18:06 Nick Foster bistromath@gmail.com
ha scritto:

Turn up the transmit gain on the USRP sink. Start with ~40dB and transmit
amplitude 0.3.

Nick

On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio ssibio2@gmail.com wrote:

Thank you for the assistance.
I tried to change the amplitude but the amplitude and frequency are not
accurate in the oscilloscope yet.
If I lower the amplitude, the S/N is lowered then it is worst.

Best Regards,

Simona

Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster <
bistromath@gmail.com> ha scritto:

Waveform source amplitude is too high. Turn it down to <0.4.

On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via USRP-users <
usrp-users@lists.ettus.com> wrote:

Hi Michael,

thank you for your interest.

I have two N200 and each one have two daughterboard UBX-40; the
transmitters are connected by coaxial cable to an oscilloscope
(Rhode&Schwarz RTO2064) to check the waveform.
The version of UHD is 3.13.0.

I tried to send a constant signal using the flowgraph (Screenshot from
2019-06-18 14-56-57) in attachment on GNU radio Companion 3.7.13.4, and on
the oscilloscope I saw this "IMG_6586".
Also, I tried to generate a constant signal in Simulink model
(16-42-17 & 16-14-04) on Matlab R2019a but, on the oscilloscope, I saw this
"IMG_6584".

I tried to send a sine signal with the Simulink model in attachment
(16-46-10) and, on the oscilloscope, I saw this "IMG_6583".
Also I tried to generate the sine signal with GNU radio (17-08-58) and
I saw this "IMG_6588".

It is possible to see how the amplitude and frequency change in every
case, I need to obtain an accurate signal because I have to measure the
amplitude and phase in a particular point in the circuit.
And in the previous email, I added that the problem increases when I
lower the carrier frequency. All these measures were taken with a carrier
frequency at 3 GHz, but if I change the fc at 1 GHz the shape is worst,
e.g. IMG_6589.

Thank you in advance.

Best Regards,

Simona

Il giorno mar 18 giu 2019 alle ore 15:34 Michael Dickens <
michael.dickens@ettus.com> ha scritto:

Hi Simona - Can you please educate us as to a few items?

  • your setup: you have an N200 + some daughterboard (which one) +
    some spectrum analyzer (which one), connected ?somehow? -> are you doing
    actual wireless Tx -> Rx, or do you have a cable hooked up between the N200
    & spectrum analyzer?

  • what waveform you're trying to generate, and what is the actual
    flowgraph you're using for GNU Radio? how are you generating the waveform
    in MATLAB?

  • which version of GNU Radio and UHD are you trying to use?

  • which version of MATLAB and it's UHD are you trying to use?

The above might help someone to diagnose your issue ... without it,
we can make some guesses but not much in the way of specifics.

Please remember to "reply all", so that others can see your response
and be able to chime in to provide help. - MLD

On Tue, Jun 18, 2019, at 8:42 AM, Simona Sibio via USRP-users wrote:

Dear Sir/Madam,

I am Simona Sibio, a student in Heriot Watt University.
I am working with USRPs both on Matlab and on Gnuradio, and with both
softwares I have the same problem: the shape (generated by
N200+daughterboard 10 MHz to 6 GHz) is not accurate, in attacched some
photos.
At 1 GHz, the shape is worst than when the carrier frequency is 3GHz.
It is not possible to measure the amplitude and frequency because,
also at 3 GHz, it is not stable.
Could you help me?

Thank you in advance.

Best Regards,

Simona

Can you post the flowgraph you're using again? If you changed transmit gain and amplitude, the result should have changed in amplitude, while the image you just sent has the fame magnitude the last one did. On Wed, Jun 19, 2019, 5:03 AM Simona Sibio <ssibio2@gmail.com> wrote: > Thank you very much. > I tried to send a signal with this features, but the result is the same > (IMG_6590). > I tried with every amplitude and every gain (Screenshot from 2019). > Before, I thought that it was a problem of reference signal and I changed > it but the situation is not changed. > > Thank you in advance for your help. > > Best Regards, > > Simona > > Il giorno mar 18 giu 2019 alle ore 18:06 Nick Foster <bistromath@gmail.com> > ha scritto: > >> Turn up the transmit gain on the USRP sink. Start with ~40dB and transmit >> amplitude 0.3. >> >> Nick >> >> On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio <ssibio2@gmail.com> wrote: >> >>> Thank you for the assistance. >>> I tried to change the amplitude but the amplitude and frequency are not >>> accurate in the oscilloscope yet. >>> If I lower the amplitude, the S/N is lowered then it is worst. >>> >>> Best Regards, >>> >>> Simona >>> >>> >>> Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster < >>> bistromath@gmail.com> ha scritto: >>> >>>> Waveform source amplitude is too high. Turn it down to <0.4. >>>> >>>> On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via USRP-users < >>>> usrp-users@lists.ettus.com> wrote: >>>> >>>>> Hi Michael, >>>>> >>>>> thank you for your interest. >>>>> >>>>> I have two N200 and each one have two daughterboard UBX-40; the >>>>> transmitters are connected by coaxial cable to an oscilloscope >>>>> (Rhode&Schwarz RTO2064) to check the waveform. >>>>> The version of UHD is 3.13.0. >>>>> >>>>> I tried to send a constant signal using the flowgraph (Screenshot from >>>>> 2019-06-18 14-56-57) in attachment on GNU radio Companion 3.7.13.4, and on >>>>> the oscilloscope I saw this "IMG_6586". >>>>> Also, I tried to generate a constant signal in Simulink model >>>>> (16-42-17 & 16-14-04) on Matlab R2019a but, on the oscilloscope, I saw this >>>>> "IMG_6584". >>>>> >>>>> I tried to send a sine signal with the Simulink model in attachment >>>>> (16-46-10) and, on the oscilloscope, I saw this "IMG_6583". >>>>> Also I tried to generate the sine signal with GNU radio (17-08-58) and >>>>> I saw this "IMG_6588". >>>>> >>>>> It is possible to see how the amplitude and frequency change in every >>>>> case, I need to obtain an accurate signal because I have to measure the >>>>> amplitude and phase in a particular point in the circuit. >>>>> And in the previous email, I added that the problem increases when I >>>>> lower the carrier frequency. All these measures were taken with a carrier >>>>> frequency at 3 GHz, but if I change the fc at 1 GHz the shape is worst, >>>>> e.g. IMG_6589. >>>>> >>>>> Thank you in advance. >>>>> >>>>> Best Regards, >>>>> >>>>> Simona >>>>> >>>>> >>>>> Il giorno mar 18 giu 2019 alle ore 15:34 Michael Dickens < >>>>> michael.dickens@ettus.com> ha scritto: >>>>> >>>>>> Hi Simona - Can you please educate us as to a few items? >>>>>> >>>>>> * your setup: you have an N200 + some daughterboard (which one) + >>>>>> some spectrum analyzer (which one), connected ?somehow? -> are you doing >>>>>> actual wireless Tx -> Rx, or do you have a cable hooked up between the N200 >>>>>> & spectrum analyzer? >>>>>> >>>>>> * what waveform you're trying to generate, and what is the actual >>>>>> flowgraph you're using for GNU Radio? how are you generating the waveform >>>>>> in MATLAB? >>>>>> >>>>>> * which version of GNU Radio and UHD are you trying to use? >>>>>> >>>>>> * which version of MATLAB and it's UHD are you trying to use? >>>>>> >>>>>> The above might help someone to diagnose your issue ... without it, >>>>>> we can make some guesses but not much in the way of specifics. >>>>>> >>>>>> Please remember to "reply all", so that others can see your response >>>>>> and be able to chime in to provide help. - MLD >>>>>> >>>>>> On Tue, Jun 18, 2019, at 8:42 AM, Simona Sibio via USRP-users wrote: >>>>>> >>>>>> Dear Sir/Madam, >>>>>> >>>>>> I am Simona Sibio, a student in Heriot Watt University. >>>>>> I am working with USRPs both on Matlab and on Gnuradio, and with both >>>>>> softwares I have the same problem: the shape (generated by >>>>>> N200+daughterboard 10 MHz to 6 GHz) is not accurate, in attacched some >>>>>> photos. >>>>>> At 1 GHz, the shape is worst than when the carrier frequency is 3GHz. >>>>>> It is not possible to measure the amplitude and frequency because, >>>>>> also at 3 GHz, it is not stable. >>>>>> Could you help me? >>>>>> >>>>>> Thank you in advance. >>>>>> >>>>>> Best Regards, >>>>>> >>>>>> Simona >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>> USRP-users mailing list >>>>> USRP-users@lists.ettus.com >>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>> >>>>
SS
Simona Sibio
Wed, Jun 19, 2019 12:24 PM

In attachment, there is the flowgraph on GNU radio.
In the previous email, I meat that the result is the same regarding the
amplitude accuracy, not regarding the value.
When I change the amplitude or the gain on GNU radio, also the amplitude
changes in the oscilloscope.

Thank you for your time.

Simona

Il giorno mer 19 giu 2019 alle ore 13:00 Nick Foster bistromath@gmail.com
ha scritto:

Can you post the flowgraph you're using again? If you changed transmit
gain and amplitude, the result should have changed in amplitude, while the
image you just sent has the fame magnitude the last one did.

On Wed, Jun 19, 2019, 5:03 AM Simona Sibio ssibio2@gmail.com wrote:

Thank you very much.
I tried to send a signal with this features, but the result is the same
(IMG_6590).
I tried with every amplitude and every gain (Screenshot from 2019).
Before, I thought that it was a problem of reference signal and I changed
it but the situation is not changed.

Thank you in advance for your help.

Best Regards,

Simona

Il giorno mar 18 giu 2019 alle ore 18:06 Nick Foster <
bistromath@gmail.com> ha scritto:

Turn up the transmit gain on the USRP sink. Start with ~40dB and
transmit amplitude 0.3.

Nick

On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio ssibio2@gmail.com wrote:

Thank you for the assistance.
I tried to change the amplitude but the amplitude and frequency are not
accurate in the oscilloscope yet.
If I lower the amplitude, the S/N is lowered then it is worst.

Best Regards,

Simona

Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster <
bistromath@gmail.com> ha scritto:

Waveform source amplitude is too high. Turn it down to <0.4.

On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via USRP-users <
usrp-users@lists.ettus.com> wrote:

Hi Michael,

thank you for your interest.

I have two N200 and each one have two daughterboard UBX-40; the
transmitters are connected by coaxial cable to an oscilloscope
(Rhode&Schwarz RTO2064) to check the waveform.
The version of UHD is 3.13.0.

I tried to send a constant signal using the flowgraph (Screenshot
from 2019-06-18 14-56-57) in attachment on GNU radio Companion 3.7.13.4,
and on the oscilloscope I saw this "IMG_6586".
Also, I tried to generate a constant signal in Simulink model
(16-42-17 & 16-14-04) on Matlab R2019a but, on the oscilloscope, I saw this
"IMG_6584".

I tried to send a sine signal with the Simulink model in attachment
(16-46-10) and, on the oscilloscope, I saw this "IMG_6583".
Also I tried to generate the sine signal with GNU radio (17-08-58)
and I saw this "IMG_6588".

It is possible to see how the amplitude and frequency change in every
case, I need to obtain an accurate signal because I have to measure the
amplitude and phase in a particular point in the circuit.
And in the previous email, I added that the problem increases when I
lower the carrier frequency. All these measures were taken with a carrier
frequency at 3 GHz, but if I change the fc at 1 GHz the shape is worst,
e.g. IMG_6589.

Thank you in advance.

Best Regards,

Simona

Il giorno mar 18 giu 2019 alle ore 15:34 Michael Dickens <
michael.dickens@ettus.com> ha scritto:

Hi Simona - Can you please educate us as to a few items?

  • your setup: you have an N200 + some daughterboard (which one) +
    some spectrum analyzer (which one), connected ?somehow? -> are you doing
    actual wireless Tx -> Rx, or do you have a cable hooked up between the N200
    & spectrum analyzer?

  • what waveform you're trying to generate, and what is the actual
    flowgraph you're using for GNU Radio? how are you generating the waveform
    in MATLAB?

  • which version of GNU Radio and UHD are you trying to use?

  • which version of MATLAB and it's UHD are you trying to use?

The above might help someone to diagnose your issue ... without it,
we can make some guesses but not much in the way of specifics.

Please remember to "reply all", so that others can see your response
and be able to chime in to provide help. - MLD

On Tue, Jun 18, 2019, at 8:42 AM, Simona Sibio via USRP-users wrote:

Dear Sir/Madam,

I am Simona Sibio, a student in Heriot Watt University.
I am working with USRPs both on Matlab and on Gnuradio, and with
both softwares I have the same problem: the shape (generated by
N200+daughterboard 10 MHz to 6 GHz) is not accurate, in attacched some
photos.
At 1 GHz, the shape is worst than when the carrier frequency is 3GHz.
It is not possible to measure the amplitude and frequency because,
also at 3 GHz, it is not stable.
Could you help me?

Thank you in advance.

Best Regards,

Simona

In attachment, there is the flowgraph on GNU radio. In the previous email, I meat that the result is the same regarding the amplitude accuracy, not regarding the value. When I change the amplitude or the gain on GNU radio, also the amplitude changes in the oscilloscope. Thank you for your time. Simona Il giorno mer 19 giu 2019 alle ore 13:00 Nick Foster <bistromath@gmail.com> ha scritto: > Can you post the flowgraph you're using again? If you changed transmit > gain and amplitude, the result should have changed in amplitude, while the > image you just sent has the fame magnitude the last one did. > > On Wed, Jun 19, 2019, 5:03 AM Simona Sibio <ssibio2@gmail.com> wrote: > >> Thank you very much. >> I tried to send a signal with this features, but the result is the same >> (IMG_6590). >> I tried with every amplitude and every gain (Screenshot from 2019). >> Before, I thought that it was a problem of reference signal and I changed >> it but the situation is not changed. >> >> Thank you in advance for your help. >> >> Best Regards, >> >> Simona >> >> Il giorno mar 18 giu 2019 alle ore 18:06 Nick Foster < >> bistromath@gmail.com> ha scritto: >> >>> Turn up the transmit gain on the USRP sink. Start with ~40dB and >>> transmit amplitude 0.3. >>> >>> Nick >>> >>> On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio <ssibio2@gmail.com> wrote: >>> >>>> Thank you for the assistance. >>>> I tried to change the amplitude but the amplitude and frequency are not >>>> accurate in the oscilloscope yet. >>>> If I lower the amplitude, the S/N is lowered then it is worst. >>>> >>>> Best Regards, >>>> >>>> Simona >>>> >>>> >>>> Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster < >>>> bistromath@gmail.com> ha scritto: >>>> >>>>> Waveform source amplitude is too high. Turn it down to <0.4. >>>>> >>>>> On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via USRP-users < >>>>> usrp-users@lists.ettus.com> wrote: >>>>> >>>>>> Hi Michael, >>>>>> >>>>>> thank you for your interest. >>>>>> >>>>>> I have two N200 and each one have two daughterboard UBX-40; the >>>>>> transmitters are connected by coaxial cable to an oscilloscope >>>>>> (Rhode&Schwarz RTO2064) to check the waveform. >>>>>> The version of UHD is 3.13.0. >>>>>> >>>>>> I tried to send a constant signal using the flowgraph (Screenshot >>>>>> from 2019-06-18 14-56-57) in attachment on GNU radio Companion 3.7.13.4, >>>>>> and on the oscilloscope I saw this "IMG_6586". >>>>>> Also, I tried to generate a constant signal in Simulink model >>>>>> (16-42-17 & 16-14-04) on Matlab R2019a but, on the oscilloscope, I saw this >>>>>> "IMG_6584". >>>>>> >>>>>> I tried to send a sine signal with the Simulink model in attachment >>>>>> (16-46-10) and, on the oscilloscope, I saw this "IMG_6583". >>>>>> Also I tried to generate the sine signal with GNU radio (17-08-58) >>>>>> and I saw this "IMG_6588". >>>>>> >>>>>> It is possible to see how the amplitude and frequency change in every >>>>>> case, I need to obtain an accurate signal because I have to measure the >>>>>> amplitude and phase in a particular point in the circuit. >>>>>> And in the previous email, I added that the problem increases when I >>>>>> lower the carrier frequency. All these measures were taken with a carrier >>>>>> frequency at 3 GHz, but if I change the fc at 1 GHz the shape is worst, >>>>>> e.g. IMG_6589. >>>>>> >>>>>> Thank you in advance. >>>>>> >>>>>> Best Regards, >>>>>> >>>>>> Simona >>>>>> >>>>>> >>>>>> Il giorno mar 18 giu 2019 alle ore 15:34 Michael Dickens < >>>>>> michael.dickens@ettus.com> ha scritto: >>>>>> >>>>>>> Hi Simona - Can you please educate us as to a few items? >>>>>>> >>>>>>> * your setup: you have an N200 + some daughterboard (which one) + >>>>>>> some spectrum analyzer (which one), connected ?somehow? -> are you doing >>>>>>> actual wireless Tx -> Rx, or do you have a cable hooked up between the N200 >>>>>>> & spectrum analyzer? >>>>>>> >>>>>>> * what waveform you're trying to generate, and what is the actual >>>>>>> flowgraph you're using for GNU Radio? how are you generating the waveform >>>>>>> in MATLAB? >>>>>>> >>>>>>> * which version of GNU Radio and UHD are you trying to use? >>>>>>> >>>>>>> * which version of MATLAB and it's UHD are you trying to use? >>>>>>> >>>>>>> The above might help someone to diagnose your issue ... without it, >>>>>>> we can make some guesses but not much in the way of specifics. >>>>>>> >>>>>>> Please remember to "reply all", so that others can see your response >>>>>>> and be able to chime in to provide help. - MLD >>>>>>> >>>>>>> On Tue, Jun 18, 2019, at 8:42 AM, Simona Sibio via USRP-users wrote: >>>>>>> >>>>>>> Dear Sir/Madam, >>>>>>> >>>>>>> I am Simona Sibio, a student in Heriot Watt University. >>>>>>> I am working with USRPs both on Matlab and on Gnuradio, and with >>>>>>> both softwares I have the same problem: the shape (generated by >>>>>>> N200+daughterboard 10 MHz to 6 GHz) is not accurate, in attacched some >>>>>>> photos. >>>>>>> At 1 GHz, the shape is worst than when the carrier frequency is 3GHz. >>>>>>> It is not possible to measure the amplitude and frequency because, >>>>>>> also at 3 GHz, it is not stable. >>>>>>> Could you help me? >>>>>>> >>>>>>> Thank you in advance. >>>>>>> >>>>>>> Best Regards, >>>>>>> >>>>>>> Simona >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>> USRP-users mailing list >>>>>> USRP-users@lists.ettus.com >>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >>>>>> >>>>>
Attached image
MD
Marcus D. Leech
Wed, Jun 19, 2019 6:13 PM

On 06/19/2019 08:24 AM, Simona Sibio via USRP-users wrote:

In attachment, there is the flowgraph on GNU radio.
In the previous email, I meat that the result is the same regarding
the amplitude accuracy, not regarding the value.
When I change the amplitude or the gain on GNU radio, also the
amplitude changes in the oscilloscope.

Thank you for your time.

Simona

What happens if, instead of using a constant, using a 10kHz tone, and
offset your Fc by 10kHz, does it look better then?

Il giorno mer 19 giu 2019 alle ore 13:00 Nick Foster
<bistromath@gmail.com mailto:bistromath@gmail.com> ha scritto:

 Can you post the flowgraph you're using again? If you changed
 transmit gain and amplitude, the result should have changed in
 amplitude, while the image you just sent has the fame magnitude
 the last one did.

 On Wed, Jun 19, 2019, 5:03 AM Simona Sibio <ssibio2@gmail.com
 <mailto:ssibio2@gmail.com>> wrote:

     Thank you very much.
     I tried to send a signal with this features, but the result is
     the same (IMG_6590).
     I tried with every amplitude and every gain (Screenshot from
     2019).
     Before, I thought that it was a problem of reference signal
     and I changed it but the situation is not changed.

     Thank you in advance for your help.

     Best Regards,

     Simona

     Il giorno mar 18 giu 2019 alle ore 18:06 Nick Foster
     <bistromath@gmail.com <mailto:bistromath@gmail.com>> ha scritto:

         Turn up the transmit gain on the USRP sink. Start with
         ~40dB and transmit amplitude 0.3.

         Nick

         On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio
         <ssibio2@gmail.com <mailto:ssibio2@gmail.com>> wrote:

             Thank you for the assistance.
             I tried to change the amplitude but the amplitude and
             frequency are not accurate in the oscilloscope yet.
             If I lower the amplitude, the S/N is lowered then it
             is worst.

             Best Regards,

             Simona


             Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster
             <bistromath@gmail.com <mailto:bistromath@gmail.com>>
             ha scritto:

                 Waveform source amplitude is too high. Turn it
                 down to <0.4.

                 On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via
                 USRP-users <usrp-users@lists.ettus.com
                 <mailto:usrp-users@lists.ettus.com>> wrote:

                     Hi Michael,

                     thank you for your interest.

                     I have two N200 and each one have two
                     daughterboard UBX-40; the transmitters are
                     connected by coaxial cable to an oscilloscope
                     (Rhode&Schwarz RTO2064) to check the waveform.
                     The version of UHD is 3.13.0.

                     I tried to send a constant signal using the
                     flowgraph (Screenshot from 2019-06-18
                     14-56-57) in attachment on GNU radio Companion
                     3.7.13.4, and on the oscilloscope I saw this
                     "IMG_6586".
                     Also, I tried to generate a constant signal in
                     Simulink model (16-42-17 & 16-14-04) on Matlab
                     R2019a but, on the oscilloscope, I saw this
                     "IMG_6584".

                     I tried to send a sine signal with the
                     Simulink model in attachment (16-46-10) and,
                     on the oscilloscope, I saw this "IMG_6583".
                     Also I tried to generate the sine signal with
                     GNU radio (17-08-58) and I saw this "IMG_6588".

                     It is possible to see how the amplitude and
                     frequency change in every case, I need to
                     obtain an accurate signal because I have to
                     measure the amplitude and phase in a
                     particular point in the circuit.
                     And in the previous email, I added that the
                     problem increases when I lower the carrier
                     frequency. All these measures were taken with
                     a carrier frequency at 3 GHz, but if I change
                     the fc at 1 GHz the shape is worst, e.g. IMG_6589.

                     Thank you in advance.

                     Best Regards,

                     Simona


                     Il giorno mar 18 giu 2019 alle ore 15:34
                     Michael Dickens <michael.dickens@ettus.com
                     <mailto:michael.dickens@ettus.com>> ha scritto:

                         Hi Simona - Can you please educate us as
                         to a few items?

                         * your setup: you have an N200 + some
                         daughterboard (which one) + some spectrum
                         analyzer (which one), connected ?somehow?
                         -> are you doing actual wireless Tx -> Rx,
                         or do you have a cable hooked up between
                         the N200 & spectrum analyzer?

                         * what waveform you're trying to generate,
                         and what is the actual flowgraph you're
                         using for GNU Radio? how are you
                         generating the waveform in MATLAB?

                         * which version of GNU Radio and UHD are
                         you trying to use?

                         * which version of MATLAB and it's UHD are
                         you trying to use?

                         The above might help someone to diagnose
                         your issue ... without it, we can make
                         some guesses but not much in the way of
                         specifics.

                         Please remember to "reply all", so that
                         others can see your response and be able
                         to chime in to provide help. - MLD

                         On Tue, Jun 18, 2019, at 8:42 AM, Simona
                         Sibio via USRP-users wrote:

                         Dear Sir/Madam,

                         I am Simona Sibio, a student in Heriot
                         Watt University.
                         I am working with USRPs both on Matlab
                         and on Gnuradio, and with both softwares
                         I have the same problem: the shape
                         (generated by N200+daughterboard 10 MHz
                         to 6 GHz) is not accurate, in attacched
                         some photos.
                         At 1 GHz, the shape is worst than when
                         the carrier frequency is 3GHz.
                         It is not possible to measure the
                         amplitude and frequency because, also at
                         3 GHz, it is not stable.
                         Could you help me?

                         Thank you in advance.

                         Best Regards,

                         Simona

                     _______________________________________________
                     USRP-users mailing list
                     USRP-users@lists.ettus.com
                     <mailto: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

On 06/19/2019 08:24 AM, Simona Sibio via USRP-users wrote: > In attachment, there is the flowgraph on GNU radio. > In the previous email, I meat that the result is the same regarding > the amplitude accuracy, not regarding the value. > When I change the amplitude or the gain on GNU radio, also the > amplitude changes in the oscilloscope. > > Thank you for your time. > > Simona What happens if, instead of using a constant, using a 10kHz tone, and offset your Fc by 10kHz, does it look better then? > > Il giorno mer 19 giu 2019 alle ore 13:00 Nick Foster > <bistromath@gmail.com <mailto:bistromath@gmail.com>> ha scritto: > > Can you post the flowgraph you're using again? If you changed > transmit gain and amplitude, the result should have changed in > amplitude, while the image you just sent has the fame magnitude > the last one did. > > On Wed, Jun 19, 2019, 5:03 AM Simona Sibio <ssibio2@gmail.com > <mailto:ssibio2@gmail.com>> wrote: > > Thank you very much. > I tried to send a signal with this features, but the result is > the same (IMG_6590). > I tried with every amplitude and every gain (Screenshot from > 2019). > Before, I thought that it was a problem of reference signal > and I changed it but the situation is not changed. > > Thank you in advance for your help. > > Best Regards, > > Simona > > Il giorno mar 18 giu 2019 alle ore 18:06 Nick Foster > <bistromath@gmail.com <mailto:bistromath@gmail.com>> ha scritto: > > Turn up the transmit gain on the USRP sink. Start with > ~40dB and transmit amplitude 0.3. > > Nick > > On Tue, Jun 18, 2019 at 9:40 AM Simona Sibio > <ssibio2@gmail.com <mailto:ssibio2@gmail.com>> wrote: > > Thank you for the assistance. > I tried to change the amplitude but the amplitude and > frequency are not accurate in the oscilloscope yet. > If I lower the amplitude, the S/N is lowered then it > is worst. > > Best Regards, > > Simona > > > Il giorno mar 18 giu 2019 alle ore 18:33 Nick Foster > <bistromath@gmail.com <mailto:bistromath@gmail.com>> > ha scritto: > > Waveform source amplitude is too high. Turn it > down to <0.4. > > On Tue, Jun 18, 2019 at 9:31 AM Simona Sibio via > USRP-users <usrp-users@lists.ettus.com > <mailto:usrp-users@lists.ettus.com>> wrote: > > Hi Michael, > > thank you for your interest. > > I have two N200 and each one have two > daughterboard UBX-40; the transmitters are > connected by coaxial cable to an oscilloscope > (Rhode&Schwarz RTO2064) to check the waveform. > The version of UHD is 3.13.0. > > I tried to send a constant signal using the > flowgraph (Screenshot from 2019-06-18 > 14-56-57) in attachment on GNU radio Companion > 3.7.13.4, and on the oscilloscope I saw this > "IMG_6586". > Also, I tried to generate a constant signal in > Simulink model (16-42-17 & 16-14-04) on Matlab > R2019a but, on the oscilloscope, I saw this > "IMG_6584". > > I tried to send a sine signal with the > Simulink model in attachment (16-46-10) and, > on the oscilloscope, I saw this "IMG_6583". > Also I tried to generate the sine signal with > GNU radio (17-08-58) and I saw this "IMG_6588". > > It is possible to see how the amplitude and > frequency change in every case, I need to > obtain an accurate signal because I have to > measure the amplitude and phase in a > particular point in the circuit. > And in the previous email, I added that the > problem increases when I lower the carrier > frequency. All these measures were taken with > a carrier frequency at 3 GHz, but if I change > the fc at 1 GHz the shape is worst, e.g. IMG_6589. > > Thank you in advance. > > Best Regards, > > Simona > > > Il giorno mar 18 giu 2019 alle ore 15:34 > Michael Dickens <michael.dickens@ettus.com > <mailto:michael.dickens@ettus.com>> ha scritto: > > Hi Simona - Can you please educate us as > to a few items? > > * your setup: you have an N200 + some > daughterboard (which one) + some spectrum > analyzer (which one), connected ?somehow? > -> are you doing actual wireless Tx -> Rx, > or do you have a cable hooked up between > the N200 & spectrum analyzer? > > * what waveform you're trying to generate, > and what is the actual flowgraph you're > using for GNU Radio? how are you > generating the waveform in MATLAB? > > * which version of GNU Radio and UHD are > you trying to use? > > * which version of MATLAB and it's UHD are > you trying to use? > > The above might help someone to diagnose > your issue ... without it, we can make > some guesses but not much in the way of > specifics. > > Please remember to "reply all", so that > others can see your response and be able > to chime in to provide help. - MLD > > On Tue, Jun 18, 2019, at 8:42 AM, Simona > Sibio via USRP-users wrote: >> Dear Sir/Madam, >> >> I am Simona Sibio, a student in Heriot >> Watt University. >> I am working with USRPs both on Matlab >> and on Gnuradio, and with both softwares >> I have the same problem: the shape >> (generated by N200+daughterboard 10 MHz >> to 6 GHz) is not accurate, in attacched >> some photos. >> At 1 GHz, the shape is worst than when >> the carrier frequency is 3GHz. >> It is not possible to measure the >> amplitude and frequency because, also at >> 3 GHz, it is not stable. >> Could you help me? >> >> Thank you in advance. >> >> Best Regards, >> >> Simona > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > <mailto: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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