Re: S-band BPSK

[Daniel Estévez]

Hello Yotam,

Please keep your replies on the list.

The constellation modulator has in fact an RRC filter that cannot be 
disabled, so if you don't want that you'll need to use something else.


Modulating BPSK is rather easy (1 goes to +1, 0 goes to -1, or the other 
way around, depending on your convention), so you don't even need to use 
any of the more complicated blocks that deal with constellations. It 
might be better to do something simple that you understand well (such as 
multiply your unipolar signal by 2 and subtract 1) instead of using a 
more complicated block of which you don't understand all the details 
(yes, there are some surprising details with the constellation 
modulators and demodulators in general).


In any case, this applies to modulation (and ignores the aspect of 
pulse-shape filtering). The original topic seemed to be demodulation 
(the flowgraph you used as a starting point was a receiver).


Best,
Daniel.

On 22/06/2023 11:11, יותם זיס wrote:

Hi Daniel,
Thank you for answering us, we’re big fans of your work.
in our experience the constellation modulator block doesn’t work very 
well since it has a built-in rrc filter that didn’t quite work for us. 
We were recommended to use the constellation encoder block instead and 
to use your flowgraph as an example. Do you think we should go back to 
using the constellation modulator?

Thanks

נשלח מה-iPhone שלי

‫ב-21 ביוני 2023, בשעה 23:26, ‏‏Daniel Estévez ‏ 
כתב/ה:‬


On 21/06/2023 17:17, יותם זיס wrote:

Hi everyone,
I'm trying to convert Daniel Estevez's QPSK flowgraph to BPSK and I'm 
having some issues. I tried replacing the FIR filter with an RRC 
filter and modifying the parameters.

The transmission looks fine but it won't demodulate properly.
I'm attaching the flowgraph's grc file and screenshots, the upper GUI 
window is the modulation and the lower one is the demodulation.

Would love some tips and corrections,
Thanks and 73
Original flowgraph
https://github.com/daniestevez/jupyter_notebooks/blob/master/ArtemisI/oqpsk_demodulator.grc
 



Hello,

That flowgraph is a not-so-good (but successful) approach at OQPSK 
demodulation specifically made for Artemis-1 (it could fail with other 
OQPSK waveforms depending on the pulse-shape filtering).


If you want to demodulate BPSK, why don't you use the BPSK demodulator 
from gr-satellites of follow this example?


https://wiki.gnuradio.org/index.php/Simulation_example:_BPSK_Demodulation

Best,
Daniel.





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gr-ieee803-11

[Mike Sousa]

 Hi

First off, I want you to know that I have limited gnuradio and grc experience.  
I have gr-ieee803-11, maint-3.10 loaded into grc. I am planning to just use the 
transmit parts of the package. It looks like it takes a number of blocks on the 
output of the the USRP (in my case, a B210) to get Wi-Fi. My B210 is physically 
wired to the input of another radio (not sure of make but I've been told it 
operates on a Xilinx  Zynq UltraScale - if that helps).What I would like to do 
is command the B210 to send Wi-Fi to the radio that is physically connected to 
it. Can I do this with gr-ieee803-11? If not, is it possible to modify 
gr-ieee803-11 to do this? If not, is it possible to do this some other way with 
gnuradio?
Thanks for your time...  

Re: gr-ieee803-11

[Mike Sousa]

 

The flow of control/signals




On Thursday, June 22, 2023 at 03:22:45 PM EDT, Mike Sousa 
 wrote:  
 
  Hi

First off, I want you to know that I have limited gnuradio and grc experience.  
I have gr-ieee803-11, maint-3.10 loaded into grc. I am planning to just use the 
transmit parts of the package. It looks like it takes a number of blocks on the 
output of the the USRP (in my case, a B210) to get Wi-Fi. My B210 is physically 
wired to the input of another radio (not sure of make but I've been told it 
operates on a Xilinx  Zynq UltraScale - if that helps).What I would like to do 
is command the B210 to send Wi-Fi to the radio that is physically connected to 
it. Can I do this with gr-ieee803-11? If not, is it possible to modify 
gr-ieee803-11 to do this? If not, is it possible to do this some other way with 
gnuradio?
Thanks for your time...

Using volk_profile for all users on shared server

[Richard Bell]

Hello,

I am managing a server that is connected to several USRP N320s and USRP
X300s, that many users access. The server is running Ubuntu 22.04 with GNU
Radio 3.10.6.0 and UHD 4.4.0.0, installed from source.

I would like to know if there is a way to run "volk_profile" once, for all
users, instead of every user needing to run this individually. Is this
possible?

Thank you,

Rich

Re: Using volk_profile for all users on shared server

[Marcus D. Leech]

On 22/06/2023 20:50, Richard Bell wrote:

Hello,

I am managing a server that is connected to several USRP N320s and 
USRP X300s, that many users access. The server is running Ubuntu 22.04 
with GNU Radio 3.10.6.0 and UHD 4.4.0.0, installed from source.


I would like to know if there is a way to run "volk_profile" once, for 
all users, instead of every user needing to run this individually. Is 
this possible?


Thank you,

Rich

/etc/volk/volk_config from a very very cursory inspection of the code...

Re: gr-ieee803-11

[Mike Sousa]

 
My image of the flow of control did not go through, so here it is using plain 
text
GNU Radio  commands --->  B210  ---  output from TX/RX port on a wire  ---> 
 Xlinx Zynq UltraScale
I've connected and sent commands to the B210, but I'm curious about how to get 
wifi from the B210 to the Xilinx.  Is it possible to create a block, if none 
exists to send the output from the gr-ieee-11 block to the Xlinx?