Re: B200-mini not detected thru GNU Radio

[Marcus Müller]

Hi Alex,

On 13.03.24 21:13, Woods, Alex C wrote:

Hello,

I've constructed the Spectrum Analyzer as seen on this page (see following link to GNU 
radio wiki) in hopes to test the functionality of GNU radio's compatibility with the 
b200-mini I plan to use for a project:


https://wiki.gnuradio.org/index.php?title=Guided_Tutorial_Hardware_Considerations 



Unfortunately, when I run execute the flow graph, I get:

RuntimeError: LookupError: KeyError: No devices found for -> Empty Device 
Address

and it doesn't run as intended. I've verified the connection of the device through UHD 
command uhd_find_devices (as well as several other commands), where it sees the b200-mini 
just fine, but GNU Radio isn't seeing it for some reason. The device is interfaced via USB.


This is similar to the error this StackExchange user encountered (see link below), but I 
was slightly confused on how to fix it with the advice provided in the highest-upvoted 
response.


https://stackoverflow.com/questions/33304828/when-trying-to-use-my-usrp-in-gnu-radio-i-get-a-no-devices-found-for
 



Ha, that's my answer :)

If it has any effect on anything, I downloaded GNU Radio using the three lines at the top 
of the UbuntuInstall page on the wiki (linked below):


https://wiki.gnuradio.org/index.php/UbuntuInstall#:~:text=There%27s%20generally%20no%20need%20to%20build%20GNU%20Radio,for%20anyone%20who%20is%20new%20to%20GNU%20Radio.
 




What's the reason for going this complicated route rather than the easy, 
https://wiki.gnuradio.org/index.php?title=InstallingGR recommended route of


`apt-get install gnuradio`

here? That has effect on what I'd recommend you do.

Best regards,
Marcus

Re: B200-mini not detected thru GNU Radio

[Marcus Müller]

Hi Alex,

On 13.03.24 21:13, Woods, Alex C wrote:

Hello,

I've constructed the Spectrum Analyzer as seen on this page (see following link to GNU 
radio wiki) in hopes to test the functionality of GNU radio's compatibility with the 
b200-mini I plan to use for a project:


https://wiki.gnuradio.org/index.php?title=Guided_Tutorial_Hardware_Considerations 



Unfortunately, when I run execute the flow graph, I get:

RuntimeError: LookupError: KeyError: No devices found for -> Empty Device 
Address

and it doesn't run as intended. I've verified the connection of the device through UHD 
command uhd_find_devices (as well as several other commands), where it sees the b200-mini 
just fine, but GNU Radio isn't seeing it for some reason. The device is interfaced via USB.


This is similar to the error this StackExchange user encountered (see link below), but I 
was slightly confused on how to fix it with the advice provided in the highest-upvoted 
response.


https://stackoverflow.com/questions/33304828/when-trying-to-use-my-usrp-in-gnu-radio-i-get-a-no-devices-found-for
 



Ha, that's my answer :)

If it has any effect on anything, I downloaded GNU Radio using the three lines at the top 
of the UbuntuInstall page on the wiki (linked below):


https://wiki.gnuradio.org/index.php/UbuntuInstall#:~:text=There%27s%20generally%20no%20need%20to%20build%20GNU%20Radio,for%20anyone%20who%20is%20new%20to%20GNU%20Radio.
 




What's the reason for going this complicated route rather than the easy, 
https://wiki.gnuradio.org/index.php?title=InstallingGR recommended route of


`apt-get install gnuradio`

here? That has effect on what I'd recommend you do.

Best regards,
Marcus

Re: B200-mini not detected thru GNU Radio

[Marcus D. Leech]

On 13/03/2024 16:13, Woods, Alex C wrote:

Hello,

I've constructed the Spectrum Analyzer as seen on this page (see 
following link to GNU radio wiki) in hopes to test the functionality 
of GNU radio's compatibility with the b200-mini I plan to use for a 
project:


https://wiki.gnuradio.org/index.php?title=Guided_Tutorial_Hardware_Considerations

Unfortunately, when I run execute the flow graph, I get:

RuntimeError: LookupError: KeyError: No devices found for -> Empty 
Device Address


and it doesn't run as intended. I've verified the connection of the 
device through UHD command uhd_find_devices (as well as several other 
commands), where it sees the b200-mini just fine, but GNU Radio isn't 
seeing it for some reason. The device is interfaced via USB.


This is similar to the error this StackExchange user encountered (see 
link below), but I was slightly confused on how to fix it with the 
advice provided in the highest-upvoted response.


https://stackoverflow.com/questions/33304828/when-trying-to-use-my-usrp-in-gnu-radio-i-get-a-no-devices-found-for

If it has any effect on anything, I downloaded GNU Radio using the 
three lines at the top of the UbuntuInstall page on the wiki (linked 
below):


https://wiki.gnuradio.org/index.php/UbuntuInstall#:~:text=There%27s%20generally%20no%20need%20to%20build%20GNU%20Radio,for%20anyone%20who%20is%20new%20to%20GNU%20Radio.

I am new to GNU Radio as well as the operation of the b200-mini and 
SDRs in general. Help would be greatly appreciated!


Thanks,
Alex

Try:

"type=b200" in the device address field in your Gnu Radio UHD USRP source.

B200-mini not detected thru GNU Radio

[Woods, Alex C]

Hello,

I've constructed the Spectrum Analyzer as seen on this page (see following link 
to GNU radio wiki) in hopes to test the functionality of GNU radio's 
compatibility with the b200-mini I plan to use for a project:

https://wiki.gnuradio.org/index.php?title=Guided_Tutorial_Hardware_Considerations

Unfortunately, when I run execute the flow graph, I get:

RuntimeError: LookupError: KeyError: No devices found for -> Empty Device 
Address

and it doesn't run as intended. I've verified the connection of the device 
through UHD command uhd_find_devices (as well as several other commands), where 
it sees the b200-mini just fine, but GNU Radio isn't seeing it for some reason. 
The device is interfaced via USB.

This is similar to the error this StackExchange user encountered (see link 
below), but I was slightly confused on how to fix it with the advice provided 
in the highest-upvoted response.

https://stackoverflow.com/questions/33304828/when-trying-to-use-my-usrp-in-gnu-radio-i-get-a-no-devices-found-for

If it has any effect on anything, I downloaded GNU Radio using the three lines 
at the top of the UbuntuInstall page on the wiki (linked below):

https://wiki.gnuradio.org/index.php/UbuntuInstall#:~:text=There%27s%20generally%20no%20need%20to%20build%20GNU%20Radio,for%20anyone%20who%20is%20new%20to%20GNU%20Radio.

I am new to GNU Radio as well as the operation of the b200-mini and SDRs in 
general. Help would be greatly appreciated!

Thanks,
Alex

Re: FW: Bug in File Meta Source: Repeat does not work for detached headers

[Marcus Müller]

Hi Adrian,

thanks for the report! Yes, if you can, please create a ticket! If you want, you could 
throw your recording and your playback flow graphs into a zip file and attach that to your 
issue text, that makes reproduction 100% reliable.


This is excellent bug reporting, by the way, thank you very much!

Just as perspective:

We have two other issues, https://github.com/gnuradio/gnuradio/issues/3516 and 
https://github.com/gnuradio/gnuradio/issues/5568 , concerning the metadata file sink. Both 
of them use the non-detached header, so they seem to be different from yours.


Best,
Marcus

On 13.03.24 13:27, Adrian Winter wrote:

Hey,

I'm pretty sure I discovered a bug in GNURadio and am now following the steps 
to report the bug, starting with sending this mail to the mailing list 
according to the development instructions.

Short description:

The File Meta Source block does not repeat the file, if a detached header is 
used.

Used Software:

   *   GNURadio 3.10.9.2
   *   Python 3.11.8
   *   Installed through radioconda
   *   X86-64 running Ubuntu 20.04 LTS

Steps to reproduce:


   1.  Create any IQ file using the File Meta Sink block with Detached Header being set 
to "True"
   2.  Replay this file with File Meta Source block, Detached Header = True and 
Repeat = True, with the data being sent to any sink (e.g. Tag Debug)

Observed Behaviour:

The file's contents are being loaded, but when EOF is reached no more samples 
are being produced, essentially stalling the flowgraph

Expected Behaviour:

The file should reset to the beginning and continue to produce samples 
indefinitely.

Other Notes:

   *   Replaying the IQ file without the information in the header using File 
Source and Repeat = True works as expected.
   *   Replaying a file using the File Meta Source with Repeat = True, but 
inline headers works as expected.
   *   The data type does not appear to have an influence (same behaviour for 
IShort and Complex Float)

Any help would of course be appreciated, and please let me know if you can 
reproduce the issue and if I should create a ticket in Github.

Thank you in advance and kind regards!
Adrian Winter

Researcher,
SINTEF Digital
Trondheim, Norway

PS: this is the third time I send this message in various states of being 
subscribed to this mailing list. I really hope that the older two versions are 
actually filtered and I'm not spamming the mailing list. If I accidentally did, 
please accept my apologies - first time interacting with a mailing list.

FW: Bug in File Meta Source: Repeat does not work for detached headers

[Adrian Winter]

Hey,

I'm pretty sure I discovered a bug in GNURadio and am now following the steps 
to report the bug, starting with sending this mail to the mailing list 
according to the development instructions.

Short description:

The File Meta Source block does not repeat the file, if a detached header is 
used.

Used Software:

  *   GNURadio 3.10.9.2
  *   Python 3.11.8
  *   Installed through radioconda
  *   X86-64 running Ubuntu 20.04 LTS

Steps to reproduce:


  1.  Create any IQ file using the File Meta Sink block with Detached Header 
being set to "True"
  2.  Replay this file with File Meta Source block, Detached Header = True and 
Repeat = True, with the data being sent to any sink (e.g. Tag Debug)

Observed Behaviour:

The file's contents are being loaded, but when EOF is reached no more samples 
are being produced, essentially stalling the flowgraph

Expected Behaviour:

The file should reset to the beginning and continue to produce samples 
indefinitely.

Other Notes:

  *   Replaying the IQ file without the information in the header using File 
Source and Repeat = True works as expected.
  *   Replaying a file using the File Meta Source with Repeat = True, but 
inline headers works as expected.
  *   The data type does not appear to have an influence (same behaviour for 
IShort and Complex Float)

Any help would of course be appreciated, and please let me know if you can 
reproduce the issue and if I should create a ticket in Github.

Thank you in advance and kind regards!
Adrian Winter

Researcher,
SINTEF Digital
Trondheim, Norway

PS: this is the third time I send this message in various states of being 
subscribed to this mailing list. I really hope that the older two versions are 
actually filtered and I'm not spamming the mailing list. If I accidentally did, 
please accept my apologies - first time interacting with a mailing list.

Re: Ofdm transmitter and receiver

[Marcus Müller]

Hi Sourya,

On 12.03.24 20:09, Sourya Saha wrote:

I am working with an OFDM transmitter and receiver. Some article says that
the number of subcarriers decides the SCS. I could not find any formula
that relates to it.


Is SCS = subcarrier spacing?

In that case, yes,  the number of subcarriers is directly inverse to the subcarrier 
spacing. Remember that OFDM is "just" doing a DFT, so you get the sampling rate divided by 
the number of DFT bins. Which is the number of subcarriers.


You shouldn't be reading "some articles"; OFDM isn't hard when one learns it from a good 
textbook. It *is* hard when one needs to learn it from research articles, spectrum 
analyzer application notes and random blog articles :)


If you have a good basic education in digital communications, Proakis' "Digital 
Communications", I think starting from 4th or 5th edition. In the third edition (which can 
be bought very cheaply used), it's called "An FFT-based Multicarrier System",  but it's 
really OFDM, just without the name. Either way, that chapter would have explained the same 
as I did above!


If you need a slightly gentler entry to OFDM (in the lectures on digital communications 
that I've been part of, we treated it as something rather advanced, because explaining 
*why* it is like it is requires understanding of a lot of channel concepts), you would 
probably *not* want to rely on Proakis.


Instead, you could try the free "Software-Defined Radio for Engineers" by Travis Collins 
et al.,

https://www.analog.com/en/resources/technical-books/software-defined-radio-for-engineers.html

it does come with the motivation, it illustrates the OFDM spectral shape well, and 
introduces the terminology; it is nice and will (mostly) only require you to have 
understood the chapters 2, 4 and 9.


> Also, if I want to operate the OFDM in a frequency

range of 490Mhz to 680 Mhz for example, how do i make the blocks use that
frequency range?


None. Because OFDM deal with the radio frequencies at all, it deals with the *equivalent 
baseband*.


You might be really a bit confused about the basics here; I'd recommend "SDR for 
engineers" as quoted above, or the even gentler entry through pysdr.org (but pysdr.org 
doesn't cover OFDM, so you'd need to switch to different material once you're through with 
the content on pysdr.org).


Best regards,
Marcus