Re: GSoC'21 - View Only Mode

[Jeff Long]

Thanks for posting these updates. Here are a few questions, maybe you
already have plans for these.

The user might want to disable saving of evaluated params for size,
security, etc. Would saving be optional?

Some evaluated expressions could be huge, filter taps for instance, and can
be readily regenerated. Should some things never be saved? Should some
expressions be recognized as safe? Do we need to change the way we specify
some params, e.g., don't use a Python expression in some places?

Many grc files, new and old, will not contain saved values. What will it
look like when one of these files is opened?

Can expressions that are not evaluated be shown as a hover, the same way
IDEs show references. Or some other way?

On Fri, Jun 18, 2021 at 10:42 Oscar Ekholm  wrote:

> Hello,
>
> A new Friday means a new *GSoC - View Only Mode* blog update! This time
> it focuses on using the stored parameter values (from last week) instead of
> evaluating the expressions. Read more about it on my blog:
>
> https://oscekh.github.io/
>
> Best regards,
> Oscar Ekholm
> 
>
> On Fri, Jun 11, 2021 at 5:24 PM Oscar Ekholm  wrote:
>
>> Hello everyone!
>> I have now published the first blog post for my GSoC work on the GRC
>> View-Only Mode. This week I have mainly worked at saving evaluated values
>> of parameters in the grc-file. You can read about it here:
>>
>> https://oscekh.github.io/
>>
>> I will be posting an update on the blog each Friday, with a corresponding
>> announcement on this list.
>>
>> Best regards,
>> Oscar Ekholm
>>
>> On Mon, May 24, 2021 at 11:19 AM Oscar Ekholm  wrote:
>>
>>> Hello,
>>>
>>> I've been accepted to work with GnuRadio for this year's Google Summer
>>> of Code. I will be working on implementing a GRC View-Only Mode, which is a
>>> security feature disabling execution of block parameters in untrusted
>>> flowgraphs.
>>>
>>> I will be posting weekly progress updates on my blog:
>>> https://oscekh.github.io/
>>>
>>> If you are interested in reading more about the View-Only mode it is
>>> described further in my project proposal:
>>>
>>> https://docs.google.com/document/d/1dL6PziJSopcY3O7gJ6CXiedTSdbhrHVFhR-UJRTmsng/edit?usp=sharing
>>>
>>> Please reach out if you have any questions, advice or thoughts you want
>>> to share.
>>>
>>> Best regards,
>>> Oscar Ekholm
>>>
>>

Software Defined Radio Programme ready

[Markus Heller]

Dear lists,

the Software Defined Radio Academy 2021 is going to take place next
weekend, in one week's time, on Saturday June 26 and Sunday June 27. 

I'd also like to take the opportunity to point your attention to the
European GnURadio Days which start slightly before, and overlap with
the SDRA in form of a common programme. 

The SDRA is also part of the virtual HAMRADIO World that takes place as
a subtitute to Europe's greatest HAM event in Friedrichshafen, but
comes as a virtual fair. 

So for all radio amateurs among you, please check here (most is in
German): https://www.hamradio-friedrichshafen.de/


But be sure to check the programme of the Software Defined Radio
Academy 2021 here (all in English): 
https://2021.sdra.io/pages/programme.html

And we'd like to welcome next week you on the SDRA's Youtube channel,
where you can participate and follow our live stream:

https://youtube.sdra.io

See you next week!

BR / vy73
Markus 
DL8RDS

Optional Output Custom Python Block

[Cameron Matson]

Hello everyone,

Using gnuradio3.8 on Mac.

I'm trying to write a custom python block (not an embedded python block)
with an optional output.  I have the "optional" flag set to true in the
YAML file, so GRC doesn't complain when it isn't connected.  The block is
working fine when the second port is connected, but if it isn't it
complains:

insufficient connected output ports (2 needed, 1 connected)

It's an interp block with vector i/o--don't know if that makes a
difference.  The constructor looks like this:


gr.interp_block.__init__(self,
name="optional_output",
in_sig=[(np.float32, self.vlen)],

out_sig=[(np.float32, self.vlen),
(np.float32, self.vlen)],
interp=self.interp_rate)

Thank you,

Cameron

Re: GSoC'21 - View Only Mode

[Oscar Ekholm]

Hello,

A new Friday means a new *GSoC - View Only Mode* blog update! This time it
focuses on using the stored parameter values (from last week) instead of
evaluating the expressions. Read more about it on my blog:

https://oscekh.github.io/

Best regards,
Oscar Ekholm


On Fri, Jun 11, 2021 at 5:24 PM Oscar Ekholm  wrote:

> Hello everyone!
> I have now published the first blog post for my GSoC work on the GRC
> View-Only Mode. This week I have mainly worked at saving evaluated values
> of parameters in the grc-file. You can read about it here:
>
> https://oscekh.github.io/
>
> I will be posting an update on the blog each Friday, with a corresponding
> announcement on this list.
>
> Best regards,
> Oscar Ekholm
>
> On Mon, May 24, 2021 at 11:19 AM Oscar Ekholm  wrote:
>
>> Hello,
>>
>> I've been accepted to work with GnuRadio for this year's Google Summer of
>> Code. I will be working on implementing a GRC View-Only Mode, which is a
>> security feature disabling execution of block parameters in untrusted
>> flowgraphs.
>>
>> I will be posting weekly progress updates on my blog:
>> https://oscekh.github.io/
>>
>> If you are interested in reading more about the View-Only mode it is
>> described further in my project proposal:
>>
>> https://docs.google.com/document/d/1dL6PziJSopcY3O7gJ6CXiedTSdbhrHVFhR-UJRTmsng/edit?usp=sharing
>>
>> Please reach out if you have any questions, advice or thoughts you want
>> to share.
>>
>> Best regards,
>> Oscar Ekholm
>>
>

Re: How to remove channel noise?

[Johannes Demel]

Hi,

besides the hint to work through textbooks, I'd like to point out that 
you will probably have more success if you start with nearly perfect 
"Channel Model" coefficients and then observe changes in the following 
order:

1. Noise Voltage: 0 (and raise it slowly e.g. in 1e-2 increments.
2. Taps: 1 + 0j (play around with more values, change it to a vector 
e.g. [1., .3+.3j])
3. Frequency Offset: 0 (Increase this value slowly observe the 
constellation sink)
4. Epsilon: 1.0, supposed to simulate sample rate mismatch between 
transmitter and receiver.


Further, it'd be a good idea to start with e.g. QPSK as an initial 
constellation. It is sufficiently simple and easy to observe channel 
influences.


Cheers
Johannes


On 18.06.21 08:50, Kyeong Su Shin wrote:

Hello 能书能言,

You can take multiple samples and average out the noise (if the 
transmitted signal is not varying quickly), but you need to obtain 
channel estimates in order to recover the original phase and amplitude. 
You will have to transmit additional signals (known by the receiver) and 
use them as the reference signals to recover the channel state.


Please note that long-term averaging may not work as expected on 
real-world environments, due to the non-stationary channel and various 
hardware imperfections, like CFO.


You are probably better off if you just use off-the-shelf digital 
transceivers to transmit data in digital manner (if you are not required 
to implement things in this way.. by some weird reason).  If you have to 
implement this by yourself (in real-world, especially), I recommend 
going through information theory and communication theory textbooks 
before jumping into the implementation.


(Also, 2V noise in the channel noise block is somewhat... high. Pretty 
low SINR it is. )


Regards,
Kyeong Su Shin

*보낸 사람:* 能书能言 <2127629...@qq.com> 대신 Discuss-gnuradio 


*보낸 날짜:* 2021년 6월 18일 금요일 오후 12:46
*받는 사람:* discuss-gnuradio 
*제목:* How to remove channel noise?
Hi,guys.
My flowchart is attached in the attachment, this is just a test case. I 
sent a constant complex number directly to pass it through a channel 
module, and the received result was also expected, and it was seriously 
disturbed. The real situation is like this. I have several such complex 
constant data (there may be hundreds or thousands). If I send it 
directly like this, I will definitely suffer similar interference, so is 
there any good way to make it? Can I send and receive these data 
accurately? In other words, there may still be interference, but at 
least it is within a controllable range.

Remarks: These data are plural data, not file dataThanks in advance!
Sincerely

Re: How to remove channel noise?

[Kyeong Su Shin]

Hello 能书能言,

You can take multiple samples and average out the noise (if the transmitted 
signal is not varying quickly), but you need to obtain channel estimates in 
order to recover the original phase and amplitude. You will have to transmit 
additional signals (known by the receiver) and use them as the reference 
signals to recover the channel state.

Please note that long-term averaging may not work as expected on real-world 
environments, due to the non-stationary channel and various hardware 
imperfections, like CFO.

You are probably better off if you just use off-the-shelf digital transceivers 
to transmit data in digital manner (if you are not required to implement things 
in this way.. by some weird reason).  If you have to implement this by yourself 
(in real-world, especially), I recommend going through information theory and 
communication theory textbooks before jumping into the implementation.

(Also, 2V noise in the channel noise block is somewhat... high. Pretty low SINR 
it is. )

Regards,
Kyeong Su Shin

보낸 사람: 能书能言 <2127629...@qq.com> 대신 Discuss-gnuradio 

보낸 날짜: 2021년 6월 18일 금요일 오후 12:46
받는 사람: discuss-gnuradio 
제목: How to remove channel noise?

Hi,guys.
My flowchart is attached in the attachment, this is just a test case. I sent a 
constant complex number directly to pass it through a channel module, and the 
received result was also expected, and it was seriously disturbed. The real 
situation is like this. I have several such complex constant data (there may be 
hundreds or thousands). If I send it directly like this, I will definitely 
suffer similar interference, so is there any good way to make it? Can I send 
and receive these data accurately? In other words, there may still be 
interference, but at least it is within a controllable range.
Remarks: These data are plural data, not file data Thanks in advance!
Sincerely