Re: Issue in file sink block

[Aditya Arun Kumar]

Ok, thanks.

On Wed, Nov 4, 2020 at 11:28 AM Maitry Raval <
maitry.ra...@azistaaerospace.com> wrote:

> Hello,
>
> Please ignore the previous grc file. please find attached the correct grc
> file.
>
> With Best Regards,
> Maitry Raval,
> R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
> www.azistaaerospace.com
>
> --
> *From: *"Maitry Raval" 
> *To: *"Aditya Arun Kumar" 
> *Cc: *"discuss-gnuradio" 
> *Sent: *Wednesday, November 4, 2020 9:06:09 AM
> *Subject: *Re: Issue in file sink block
>
> Hello,
>
> Please find attached grc file for reference. I have done trial and error
> by converting the output file into online ascii to binary converter, but it
> provides random output.
>
> Please guide which binary viewer I need to use in  check the data in 1 and
> 0 format(binary) ?
>
> With Best Regards,
> Maitry Raval,
> R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
> www.azistaaerospace.com
>
> --
> *From: *"Aditya Arun Kumar" 
> *To: *"Derek Kozel" 
> *Cc: *"Maitry Raval" , "Marcus Müller" <
> mmuel...@gnuradio.org>, "discuss-gnuradio" 
> *Sent: *Tuesday, November 3, 2020 5:49:05 PM
> *Subject: *Re: Issue in file sink block
>
> Or maybe use a gr-baz any sink to view bits?
>
> On Tue, Nov 3, 2020 at 5:43 PM Derek Kozel  wrote:
>
>> Hello Maitry,
>>
>> The File Sink is not producing a text file, it is the raw binary data.
>> You need to look at the contents of the file using a binary viewer.
>>
>> Regards,
>> Derek
>>
>> On 03/11/2020 11:12, Maitry Raval wrote:
>> > Hello sir,
>> >
>> > Please find attached screenshot for the grc file same as given in PSK
>> guided tutorials. also, I have attached output txt file for your reference.
>> still , did not receive binary data stored via file sink.
>> >
>> > Please guide, where am I doing wrong.
>> >
>> >
>> > With Best Regards,
>> > Maitry Raval,
>> > R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
>> www.azistaaerospace.com
>> >
>> > - Original Message -
>> > From: "Marcus Müller" 
>> > To: "discuss-gnuradio" 
>> > Sent: Monday, November 2, 2020 8:47:28 PM
>> > Subject: Re: Issue in file sink block
>> >
>> > Again, the file sink is fine.
>> >
>> > On 02.11.20 04:39, Maitry Raval wrote:
>> >> Hello,
>> >>
>> >> I understand, I think, I need to use PSK demod using below link.
>> >> https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation
>> >>
>> >> But, as I have a requirement of storing the demod data in file , how
>> is it possible using file sink or any other way, please guide.
>> >>
>> >> With Best Regards,
>> >> Maitry Raval,
>> >> R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
>> www.azistaaerospace.com
>> >>
>> >> - Original Message -
>> >> From: "Marcus Müller, CEL" 
>> >> To: "discuss-gnuradio" 
>> >> Sent: Saturday, October 31, 2020 9:06:22 PM
>> >> Subject: Re: Issue in file sink block
>> >>
>> >> Hi Maitry,
>> >>
>> >> I doubt it's the file sink. That tutorial used DPSK Mod, and that's
>> >> among the buggy packet_encoder tooling that we deprecated a long time
>> >> ago, and finally banished two-ish years ago. It just dropped data.
>> >>
>> >> See the more modern packet examples that come with your GNU Radio 3.8.
>> >>
>> >> Cheers,
>> >> Marcus
>> >>
>> >> On 31.10.20 09:34, Maitry Raval wrote:
>> >>> Hello ,
>> >>>
>> >>> I am using GNU radio along with ADRV9361-Z7035 Board for data
>> reception
>> >>> and demodulation. I have faced an issue of using file sink block along
>> >>> with QPSK demod blocks. when I am attaching dpsk/PSK demod block with
>> >>> file sink, I have not received data in binary format. it gives some
>> >>> trunk values. when I am doing wrong, please guide us.
>> >>> I have taken a reference of below link.
>> >>> https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf
>> >>>
>> >>> The only difference is that I am using receiving section only. as I am
>> >>> transmitting from other source. so I have attached fmcommsource block
>> >>> with dpsk demod followed by file sink.
>> >>>
>> >>> Please guide
>> >>>
>> >>> With Best Regards,
>> >>> Maitry Raval,
>> >>> R& D engineer|Azista Industries Pvt Ltd|
>> >>> 079-40605800|www.azistaaerospace.com
>> > >
>>
>>
>>
>
> --
> S. Aditya Arun Kumar
> Security Researcher, Comms
> +919123517465
>
>

-- 
S. Aditya Arun Kumar
Security Researcher, Comms
+919123517465

Re: Issue in file sink block

[Maitry Raval]

Hello, 

Please ignore the previous grc file. please find attached the correct grc file. 

With Best Regards, 
Maitry Raval, 
R& D engineer|Azista Industries Pvt Ltd| 079-40605800|www.azistaaerospace.com 


From: "Maitry Raval"  
To: "Aditya Arun Kumar"  
Cc: "discuss-gnuradio"  
Sent: Wednesday, November 4, 2020 9:06:09 AM 
Subject: Re: Issue in file sink block 

Hello, 

Please find attached grc file for reference. I have done trial and error by 
converting the output file into online ascii to binary converter, but it 
provides random output. 

Please guide which binary viewer I need to use in check the data in 1 and 0 
format(binary) ? 

With Best Regards, 
Maitry Raval, 
R& D engineer|Azista Industries Pvt Ltd| 079-40605800|www.azistaaerospace.com 


From: "Aditya Arun Kumar"  
To: "Derek Kozel"  
Cc: "Maitry Raval" , "Marcus Müller" 
, "discuss-gnuradio"  
Sent: Tuesday, November 3, 2020 5:49:05 PM 
Subject: Re: Issue in file sink block 

Or maybe use a gr-baz any sink to view bits? 

On Tue, Nov 3, 2020 at 5:43 PM Derek Kozel < [ mailto:de...@bitstovolts.com | 
de...@bitstovolts.com ] > wrote: 


Hello Maitry, 

The File Sink is not producing a text file, it is the raw binary data. 
You need to look at the contents of the file using a binary viewer. 

Regards, 
Derek 

On 03/11/2020 11:12, Maitry Raval wrote: 
> Hello sir, 
> 
> Please find attached screenshot for the grc file same as given in PSK guided 
> tutorials. also, I have attached output txt file for your reference. still , 
> did not receive binary data stored via file sink. 
> 
> Please guide, where am I doing wrong. 
> 
> 
> With Best Regards, 
> Maitry Raval, 
> R& D engineer|Azista Industries Pvt Ltd| 079-40605800| [ 
> http://www.azistaaerospace.com/ | www.azistaaerospace.com ] 
> 
> - Original Message - 
> From: "Marcus Müller" < [ mailto:mmuel...@gnuradio.org | 
> mmuel...@gnuradio.org ] > 
> To: "discuss-gnuradio" < [ mailto:discuss-gnuradio@gnu.org | 
> discuss-gnuradio@gnu.org ] > 
> Sent: Monday, November 2, 2020 8:47:28 PM 
> Subject: Re: Issue in file sink block 
> 
> Again, the file sink is fine. 
> 
> On 02.11.20 04:39, Maitry Raval wrote: 
>> Hello, 
>> 
>> I understand, I think, I need to use PSK demod using below link. 
>> [ https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation | 
>> https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation ] 
>> 
>> But, as I have a requirement of storing the demod data in file , how is it 
>> possible using file sink or any other way, please guide. 
>> 
>> With Best Regards, 
>> Maitry Raval, 
>> R& D engineer|Azista Industries Pvt Ltd| 079-40605800| [ 
>> http://www.azistaaerospace.com/ | www.azistaaerospace.com ] 
>> 
>> - Original Message - 
>> From: "Marcus Müller, CEL" < [ mailto:muel...@kit.edu | muel...@kit.edu ] > 
>> To: "discuss-gnuradio" < [ mailto:discuss-gnuradio@gnu.org | 
>> discuss-gnuradio@gnu.org ] > 
>> Sent: Saturday, October 31, 2020 9:06:22 PM 
>> Subject: Re: Issue in file sink block 
>> 
>> Hi Maitry, 
>> 
>> I doubt it's the file sink. That tutorial used DPSK Mod, and that's 
>> among the buggy packet_encoder tooling that we deprecated a long time 
>> ago, and finally banished two-ish years ago. It just dropped data. 
>> 
>> See the more modern packet examples that come with your GNU Radio 3.8. 
>> 
>> Cheers, 
>> Marcus 
>> 
>> On 31.10.20 09:34, Maitry Raval wrote: 
>>> Hello , 
>>> 
>>> I am using GNU radio along with ADRV9361-Z7035 Board for data reception 
>>> and demodulation. I have faced an issue of using file sink block along 
>>> with QPSK demod blocks. when I am attaching dpsk/PSK demod block with 
>>> file sink, I have not received data in binary format. it gives some 
>>> trunk values. when I am doing wrong, please guide us. 
>>> I have taken a reference of below link. 
>>> [ https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf | 
>>> https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf ] 
>>> 
>>> The only difference is that I am using receiving section only. as I am 
>>> transmitting from other source. so I have attached fmcommsource block 
>>> with dpsk demod followed by file sink. 
>>> 
>>> Please guide 
>>> 
>>> With Best Regards, 
>>> Maitry Raval, 
>>> R& D engineer|Azista Industries Pvt Ltd| 
>>> 079-40605800| [ http://www.azistaaerospace.com/ | www.azistaaerospace.com ] 
> > 







-- 
S. Aditya Arun Kumar 
Security Researcher, Comms 
+919123517465 



mpsk_stage6.grc
Description: XML document

Re: Issue in file sink block

[Maitry Raval]

Hello, 

Please find attached grc file for reference. I have done trial and error by 
converting the output file into online ascii to binary converter, but it 
provides random output. 

Please guide which binary viewer I need to use in check the data in 1 and 0 
format(binary) ? 

With Best Regards, 
Maitry Raval, 
R& D engineer|Azista Industries Pvt Ltd| 079-40605800|www.azistaaerospace.com 


From: "Aditya Arun Kumar"  
To: "Derek Kozel"  
Cc: "Maitry Raval" , "Marcus Müller" 
, "discuss-gnuradio"  
Sent: Tuesday, November 3, 2020 5:49:05 PM 
Subject: Re: Issue in file sink block 

Or maybe use a gr-baz any sink to view bits? 

On Tue, Nov 3, 2020 at 5:43 PM Derek Kozel < [ mailto:de...@bitstovolts.com | 
de...@bitstovolts.com ] > wrote: 


Hello Maitry, 

The File Sink is not producing a text file, it is the raw binary data. 
You need to look at the contents of the file using a binary viewer. 

Regards, 
Derek 

On 03/11/2020 11:12, Maitry Raval wrote: 
> Hello sir, 
> 
> Please find attached screenshot for the grc file same as given in PSK guided 
> tutorials. also, I have attached output txt file for your reference. still , 
> did not receive binary data stored via file sink. 
> 
> Please guide, where am I doing wrong. 
> 
> 
> With Best Regards, 
> Maitry Raval, 
> R& D engineer|Azista Industries Pvt Ltd| 079-40605800| [ 
> http://www.azistaaerospace.com/ | www.azistaaerospace.com ] 
> 
> - Original Message - 
> From: "Marcus Müller" < [ mailto:mmuel...@gnuradio.org | 
> mmuel...@gnuradio.org ] > 
> To: "discuss-gnuradio" < [ mailto:discuss-gnuradio@gnu.org | 
> discuss-gnuradio@gnu.org ] > 
> Sent: Monday, November 2, 2020 8:47:28 PM 
> Subject: Re: Issue in file sink block 
> 
> Again, the file sink is fine. 
> 
> On 02.11.20 04:39, Maitry Raval wrote: 
>> Hello, 
>> 
>> I understand, I think, I need to use PSK demod using below link. 
>> [ https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation | 
>> https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation ] 
>> 
>> But, as I have a requirement of storing the demod data in file , how is it 
>> possible using file sink or any other way, please guide. 
>> 
>> With Best Regards, 
>> Maitry Raval, 
>> R& D engineer|Azista Industries Pvt Ltd| 079-40605800| [ 
>> http://www.azistaaerospace.com/ | www.azistaaerospace.com ] 
>> 
>> - Original Message - 
>> From: "Marcus Müller, CEL" < [ mailto:muel...@kit.edu | muel...@kit.edu ] > 
>> To: "discuss-gnuradio" < [ mailto:discuss-gnuradio@gnu.org | 
>> discuss-gnuradio@gnu.org ] > 
>> Sent: Saturday, October 31, 2020 9:06:22 PM 
>> Subject: Re: Issue in file sink block 
>> 
>> Hi Maitry, 
>> 
>> I doubt it's the file sink. That tutorial used DPSK Mod, and that's 
>> among the buggy packet_encoder tooling that we deprecated a long time 
>> ago, and finally banished two-ish years ago. It just dropped data. 
>> 
>> See the more modern packet examples that come with your GNU Radio 3.8. 
>> 
>> Cheers, 
>> Marcus 
>> 
>> On 31.10.20 09:34, Maitry Raval wrote: 
>>> Hello , 
>>> 
>>> I am using GNU radio along with ADRV9361-Z7035 Board for data reception 
>>> and demodulation. I have faced an issue of using file sink block along 
>>> with QPSK demod blocks. when I am attaching dpsk/PSK demod block with 
>>> file sink, I have not received data in binary format. it gives some 
>>> trunk values. when I am doing wrong, please guide us. 
>>> I have taken a reference of below link. 
>>> [ https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf | 
>>> https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf ] 
>>> 
>>> The only difference is that I am using receiving section only. as I am 
>>> transmitting from other source. so I have attached fmcommsource block 
>>> with dpsk demod followed by file sink. 
>>> 
>>> Please guide 
>>> 
>>> With Best Regards, 
>>> Maitry Raval, 
>>> R& D engineer|Azista Industries Pvt Ltd| 
>>> 079-40605800| [ http://www.azistaaerospace.com/ | www.azistaaerospace.com ] 
> > 







-- 
S. Aditya Arun Kumar 
Security Researcher, Comms 
+919123517465 



PSK modem.grc
Description: XML document

Re: explaining i/q

[David Hagood]

Like I said previously:

Think of the spinning dancer illusion. It works because you only see 
from one vantage point. If you saw a real doll spinning, and assuming 
you have two eyes and normal binocular vision, you will have parallax, 
and that will allow you to determine in reality which way the figure is 
spinning, because each eye will have a different view of what is going 
on, and so can work out what direction the figure is spinning in.


I/Q is like that - it allows the SDR to see have "parallax" - to have 2 
points of view on the signal at the same time, and so it can "see" which 
way the signal is rotating - whether the signal is spinning clockwise 
(negative frequencies, cause math) or counter-clockwise (positive 
frequencies).


There - no advanced math, short, and yet accurate.




OpenPGP_0x5B9DC79986207D69.asc
Description: application/pgp-keys


OpenPGP_signature
Description: OpenPGP digital signature

Re: explaining i/q

[Jeff Long]

It's more important to give people some mental picture than to make sure
it's completely correct. But, I would not use the "slope" terminology. The
important things are, as you've said, (1) with the complex type, you can
have a signal at baseband that is not symmetric, and (2) the price for this
is doubling the amount of data needed. The signal you deal with at baseband
is the same signal that is seen centered on the RF carrier.

I don't see a great way to talk about "phase" without going into the math.
It is important to get into "phase" when you talk about any modulation
fancier than slow FSK.

Good luck. Hope you find the right balance between useful, digestible, and
correct.

On Tue, Nov 3, 2020 at 7:20 PM David Hagood  wrote:

> I am sorrowful that you have decided you are going to stick with an
> explanation that is fundamentally incorrect. I know how direct
> conversion systems work - I design the software for them for a living.
> What you are basing your mental model on is an optimization for the case
> where the system is both sub-sampling the signal and going digital in
> the same operation. However, in many extremely high sample rate systems,
> the signal is brought down to baseband by mixing it with analog
> quadrature signals - that's the place where I and Q come from - and I
> assure you the only "delay by 90 degrees" is in the creation of the
> quadrature LO signals, not in the sampling of the actual data. But I've
> been around the Sun enough times to know that since you have decided
> upon this course and don't seem to want to change, there's no point in
> continuing to try to help.
>
>
>

Re: explaining i/q

[Kristoff]

David,



On 4/11/2020 01:18, David Hagood wrote:
I am sorrowful that you have decided you are going to stick with an 
explanation that is fundamentally incorrect. I know how direct 
conversion systems work - I design the software for them for a living. 
What you are basing your mental model on is an optimization for the 
case where the system is both sub-sampling the signal and going 
digital in the same operation. However, in many extremely high sample 
rate systems, the signal is brought down to baseband by mixing it with 
analog quadrature signals - that's the place where I and Q come from - 
and I assure you the only "delay by 90 degrees" is in the creation of 
the quadrature LO signals, not in the sampling of the actual data. But 
I've been around the Sun enough times to know that since you have 
decided upon this course and don't seem to want to change, there's no 
point in continuing to try to help.



As mentioned, the goal here is to explain I/q sampling in 5 minutes to a 
group of average hams (i.e. who have limited knowledge of advanced 
electronics and even less of math).

The question to answer is this:
what is i/q sampling and why does it it matters for him/her when 
creating a GNU Radio flowgraph.



So, you do not have to convince me how i/q sampling works, you have to 
convince this audience.



So, feel free to explain in semi-tech (no math) talk in 5 minutes *why* 
SDR uses i/q sampling.

What is the PURPOSE of i/q sampling?



73
kristoff - ON1ARF

Re: explaining i/q

[David Hagood]

I am sorrowful that you have decided you are going to stick with an 
explanation that is fundamentally incorrect. I know how direct 
conversion systems work - I design the software for them for a living. 
What you are basing your mental model on is an optimization for the case 
where the system is both sub-sampling the signal and going digital in 
the same operation. However, in many extremely high sample rate systems, 
the signal is brought down to baseband by mixing it with analog 
quadrature signals - that's the place where I and Q come from - and I 
assure you the only "delay by 90 degrees" is in the creation of the 
quadrature LO signals, not in the sampling of the actual data. But I've 
been around the Sun enough times to know that since you have decided 
upon this course and don't seem to want to change, there's no point in 
continuing to try to help.





OpenPGP_0x5B9DC79986207D69.asc
Description: application/pgp-keys


OpenPGP_signature
Description: OpenPGP digital signature

Re: explaining i/q

[Kristoff]

Jef, Fabian, Aditya, Anon, David,

I'll just reply to this one message so not to spam the list to much but 
please consider this a "thank you" to all for replying.



As said, this is for a limited and very specific goal:
I will probably be giving a workshop on GRC in a couple of weeks and I 
want to give a quick explanation of iq-sampling and how this impacts 
designing a GR flowgraphs.



I want to keep the workshop focused on that one topic. So I really want 
to avoid going "wondering around" trying to explain everything that is 
related to DSP or SDR. After all, it's a workshop on using GRC, not a 
generic presentation on SDR or signal-processing.



The reason I do want to mention iq sampling in the workshop, is simply 
that does is one of the basic datatypes of GNU Radio and it is an 
important element that affects how to build a flowgraph.



I think I will summarise it like this:

* complex numbers is one of the datatypes of GR, It is the format to 
store signals generated by a process called "i/q sampling".


So, what is iq-sampling?
IQ-sampling is like sampling a normal ("real") signal -i.e. what most 
people are familiar with-, ... except that you sample the data twice for 
each period: once at timer "t" and a second time 1/4 sampling period 
later. (*)


This 2nd sampling-action provides information about the 'direction' a 
signal is going (up or down). (I think the proper term here is its 'slope')

(thx David for the correction about 'phase' vs 'slope')

(*) Just look at the design of a direct-conversion SDR receiver.

The first sample is called the "in phase" sample, the 2nd sample is the 
"quadrature" sample; hence "i/q" sampling.



* as was also mentioned by Heather in the RSGB/BATC presentation, the 
use of iq-signals has a number of consequences on GNU Radio flow-graphs.

The most important ones are:

->  Mixing two complex signals (with a frequency of "f1" and "f2") will 
produce one new signal with a frequency of f1+f2 Hz.


This is in contrast to a mixer of "real" signals which -as most people 
know- produces two new signals (frequencies: f1+f2 and f1-f2)



-> In the "real" frequency-domain, only the frequencies from 0 up to 
sampling-rate / 2 is defined. The frequencies below zero are a mirror of 
the radio-spectrum above DC.


Using complex i/q sampling, both positive and negative frequencies exist 
and are independent of each other.



-> A signal with a "negative" frequency?
Yes, a complex signal can have a 'negative' frequency. This is basically 
the same as a signal with the equivalent positive frequency, but 
mirrored around the x-axis (**).


If you look at such a signal, you see that flipping a signal upside down 
will  inverse the sign of the value of every sample (something that does 
affect the value of the signal, but no its frequency), ... and inverse 
the "direction" of that signal.
And remember that the goal of i/q sampling is ...  to determine the 
direction of a signal?


(**) note: there do are other ways to negate the frequency of a complex 
signal.



-> Combine the two last points, and you get this:

If you mix (multiply) an incoming signal with frequency "f1" with a 
second signal that has a negative-frequency "-f2" will generate a new 
signal with a frequency of f1-f2, effectively moving a signal down in 
the radio-spectrum. (i.e. 'down-converting')



* And finally, ... certain hardware peripherals deals with 'real' 
signals (e.g. an audio-card or a speaker), other hardware create or read 
complex 'iq' signals (like most dedicated SDR peripherals)





Again, the goal is not a full detailed discussion about I/Q signals.
The goal is to give people who are not to SDR, new to GNU Radio and have 
never heard of i/q sampling before some idea of what it is, and how it 
will impact them when they start playing around with GRC.


But I do want my information to be factual correct, so .. if somebody 
sees factual errors in this, feel free to reply! :-)





73
kristoff - ON1ARF




On 3/11/2020 12:47, Jeff Long wrote:
This is a great thing to try to figure out. If we can come up with an 
answer that gives someone a feel for why I/Q is used in SDR in 10 
minutes, and does not include phasors, exponentials to a complex 
power, a derivation of any equation, the concept of orthogonality, 
etc. ... it will win a Nobel prize in education.


On Tue, Nov 3, 2020 at 4:56 AM gilles rubin > wrote:


Hello,

You can have a look here
The Concept of Frequency | Wireless Pi






The Concept of Frequency | Wireless Pi



Qasim Chaudhari CEO of Wireless Pi is great ! You will find plenty
of information on his website.

Gil.


Le mardi 3 novembre 2020 à 00:06:02 UTC+1, Kristoff
mailto:krist...@skypro.be>> a écrit :


Hi all,

I was watching the webinar of Heather on GNU Radio today, 

Re: Issue in file sink block

[Aditya Arun Kumar]

Or maybe use a gr-baz any sink to view bits?

On Tue, Nov 3, 2020 at 5:43 PM Derek Kozel  wrote:

> Hello Maitry,
>
> The File Sink is not producing a text file, it is the raw binary data.
> You need to look at the contents of the file using a binary viewer.
>
> Regards,
> Derek
>
> On 03/11/2020 11:12, Maitry Raval wrote:
> > Hello sir,
> >
> > Please find attached screenshot for the grc file same as given in PSK
> guided tutorials. also, I have attached output txt file for your reference.
> still , did not receive binary data stored via file sink.
> >
> > Please guide, where am I doing wrong.
> >
> >
> > With Best Regards,
> > Maitry Raval,
> > R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
> www.azistaaerospace.com
> >
> > - Original Message -
> > From: "Marcus Müller" 
> > To: "discuss-gnuradio" 
> > Sent: Monday, November 2, 2020 8:47:28 PM
> > Subject: Re: Issue in file sink block
> >
> > Again, the file sink is fine.
> >
> > On 02.11.20 04:39, Maitry Raval wrote:
> >> Hello,
> >>
> >> I understand, I think, I need to use PSK demod using below link.
> >> https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation
> >>
> >> But, as I have a requirement of storing the demod data in file , how is
> it possible using file sink or any other way, please guide.
> >>
> >> With Best Regards,
> >> Maitry Raval,
> >> R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
> www.azistaaerospace.com
> >>
> >> - Original Message -
> >> From: "Marcus Müller, CEL" 
> >> To: "discuss-gnuradio" 
> >> Sent: Saturday, October 31, 2020 9:06:22 PM
> >> Subject: Re: Issue in file sink block
> >>
> >> Hi Maitry,
> >>
> >> I doubt it's the file sink. That tutorial used DPSK Mod, and that's
> >> among the buggy packet_encoder tooling that we deprecated a long time
> >> ago, and finally banished two-ish years ago. It just dropped data.
> >>
> >> See the more modern packet examples that come with your GNU Radio 3.8.
> >>
> >> Cheers,
> >> Marcus
> >>
> >> On 31.10.20 09:34, Maitry Raval wrote:
> >>> Hello ,
> >>>
> >>> I am using GNU radio along with ADRV9361-Z7035 Board for data reception
> >>> and demodulation. I have faced an issue of using file sink block along
> >>> with QPSK demod blocks. when I am attaching dpsk/PSK demod block with
> >>> file sink, I have not received data in binary format. it gives some
> >>> trunk values. when I am doing wrong, please guide us.
> >>> I have taken a reference of below link.
> >>> https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf
> >>>
> >>> The only difference is that I am using receiving section only. as I am
> >>> transmitting from other source. so I have attached fmcommsource block
> >>> with dpsk demod followed by file sink.
> >>>
> >>> Please guide
> >>>
> >>> With Best Regards,
> >>> Maitry Raval,
> >>> R& D engineer|Azista Industries Pvt Ltd|
> >>> 079-40605800|www.azistaaerospace.com
> > >
>
>
>

-- 
S. Aditya Arun Kumar
Security Researcher, Comms
+919123517465

Re: Issue in file sink block

[Derek Kozel]

Hello Maitry,

The File Sink is not producing a text file, it is the raw binary data. 
You need to look at the contents of the file using a binary viewer.


Regards,
Derek

On 03/11/2020 11:12, Maitry Raval wrote:

Hello sir,

Please find attached screenshot for the grc file same as given in PSK guided 
tutorials. also, I have attached output txt file for your reference. still , 
did not receive binary data stored via file sink.

Please guide, where am I doing wrong.


With Best Regards,
Maitry Raval,
R& D engineer|Azista Industries Pvt Ltd| 079-40605800|www.azistaaerospace.com

- Original Message -
From: "Marcus Müller" 
To: "discuss-gnuradio" 
Sent: Monday, November 2, 2020 8:47:28 PM
Subject: Re: Issue in file sink block

Again, the file sink is fine.

On 02.11.20 04:39, Maitry Raval wrote:

Hello,

I understand, I think, I need to use PSK demod using below link.
https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation

But, as I have a requirement of storing the demod data in file , how is it 
possible using file sink or any other way, please guide.

With Best Regards,
Maitry Raval,
R& D engineer|Azista Industries Pvt Ltd| 079-40605800|www.azistaaerospace.com

- Original Message -
From: "Marcus Müller, CEL" 
To: "discuss-gnuradio" 
Sent: Saturday, October 31, 2020 9:06:22 PM
Subject: Re: Issue in file sink block

Hi Maitry,

I doubt it's the file sink. That tutorial used DPSK Mod, and that's
among the buggy packet_encoder tooling that we deprecated a long time
ago, and finally banished two-ish years ago. It just dropped data.

See the more modern packet examples that come with your GNU Radio 3.8.

Cheers,
Marcus

On 31.10.20 09:34, Maitry Raval wrote:

Hello ,

I am using GNU radio along with ADRV9361-Z7035 Board for data reception
and demodulation. I have faced an issue of using file sink block along
with QPSK demod blocks. when I am attaching dpsk/PSK demod block with
file sink, I have not received data in binary format. it gives some
trunk values. when I am doing wrong, please guide us.
I have taken a reference of below link.
https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf

The only difference is that I am using receiving section only. as I am
transmitting from other source. so I have attached fmcommsource block
with dpsk demod followed by file sink.

Please guide

With Best Regards,
Maitry Raval,
R& D engineer|Azista Industries Pvt Ltd|
079-40605800|www.azistaaerospace.com

>

Re: Issue in file sink block

[Aditya Arun Kumar]

Yeah Marcus is right, the file sink will do the trick.




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On Mon, Nov 2, 2020 at 8:48 PM Marcus Müller  wrote:

> Again, the file sink is fine.
>
> On 02.11.20 04:39, Maitry Raval wrote:
> > Hello,
> >
> > I understand, I think, I need to use PSK demod using below link.
> > https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation
> >
> > But, as I have a requirement of storing the demod data in file , how is
> it possible using file sink or any other way, please guide.
> >
> > With Best Regards,
> > Maitry Raval,
> > R& D engineer|Azista Industries Pvt Ltd| 079-40605800|
> www.azistaaerospace.com
> >
> > - Original Message -
> > From: "Marcus Müller, CEL" 
> > To: "discuss-gnuradio" 
> > Sent: Saturday, October 31, 2020 9:06:22 PM
> > Subject: Re: Issue in file sink block
> >
> > Hi Maitry,
> >
> > I doubt it's the file sink. That tutorial used DPSK Mod, and that's
> > among the buggy packet_encoder tooling that we deprecated a long time
> > ago, and finally banished two-ish years ago. It just dropped data.
> >
> > See the more modern packet examples that come with your GNU Radio 3.8.
> >
> > Cheers,
> > Marcus
> >
> > On 31.10.20 09:34, Maitry Raval wrote:
> >> Hello ,
> >>
> >> I am using GNU radio along with ADRV9361-Z7035 Board for data reception
> >> and demodulation. I have faced an issue of using file sink block along
> >> with QPSK demod blocks. when I am attaching dpsk/PSK demod block with
> >> file sink, I have not received data in binary format. it gives some
> >> trunk values. when I am doing wrong, please guide us.
> >> I have taken a reference of below link.
> >> https://courses.washington.edu/ee420/projects/lab2_gnuradio.pdf
> >>
> >> The only difference is that I am using receiving section only. as I am
> >> transmitting from other source. so I have attached fmcommsource block
> >> with dpsk demod followed by file sink.
> >>
> >> Please guide
> >>
> >> With Best Regards,
> >> Maitry Raval,
> >> R& D engineer|Azista Industries Pvt Ltd|
> >> 079-40605800|www.azistaaerospace.com
> >
>
>

Re: explaining i/q

[Jeff Long]

This is a great thing to try to figure out. If we can come up with an
answer that gives someone a feel for why I/Q is used in SDR in 10 minutes,
and does not include phasors, exponentials to a complex power, a derivation
of any equation, the concept of orthogonality, etc. ... it will win a Nobel
prize in education.

On Tue, Nov 3, 2020 at 4:56 AM gilles rubin  wrote:

> Hello,
>
> You can have a look here
> The Concept of Frequency | Wireless Pi
> 
>
> The Concept of Frequency | Wireless Pi
> 
>
> Qasim Chaudhari CEO of Wireless Pi is great ! You will find plenty of
> information on his website.
>
> Gil.
>
>
> Le mardi 3 novembre 2020 à 00:06:02 UTC+1, Kristoff 
> a écrit :
>
>
> Hi all,
>
> I was watching the webinar of Heather on GNU Radio today, when it came
> to me that one of the most difficult part doing a presentation of GNU
> Radio is the data-types, .. and especially these 'complex numbers'.
> The problem, or at least for me, is that when you mention 'GNU Radio
> complex numbers', you also have to mention iq-signals, which is a topic
> that is very difficult to explain in 10 seconds to an audience who has
> never seen anything about i/q sampling before.
>
>
> I have been thinking on how to explain the concept of I/Q signalling in
> just a few lines, e.g. in the context of -say- a workshop on GR.
>
>
> I have this idea in my head:
>
> Statement:
> The main difference between sampling with reals ('floats') and i/q
> sampling with complex numbers, is that the latter does not only provide
> the  instantaneous value (voltage) of a signal at a certain point of
> time, but also includes phase information (i.e. the slope of the signal
> at that point).
>
>
> To make this visual:
> Take half a sine-wave and plot it out for every 45 degrees.
> This gives you 5 points: 0 (0 degrees), sqrt(2)/2 (45 degrees), 1 (90
> degrees), sqrt(2)/2 (135 degrees) and 0 (180 degrees).
>
> Now look at the 2nd and the 4th point (45 degrees and 135 degrees), if
> you sample this using only real/float values, these two points are
> exactly the same (sqrt(2)/2). Just based on these values by themselves
> (i.e. remove all other points from the graph), there is no way you can
> tell that at the first point (45 degrees) the graph was going up, while
> at the 135-degrees point the graph was going down.
>
> So, ... what i/q sampling does, is for every point "x", it not only
> provide the value of the graph at that point of time, but also
> information of the slope of the graphs at that time.
>
>
> This also explains while i/q sampling is done by not just taking the
> value of a signal at point "t", but also at 1/4 period later (which is
> the information you need to determine the 'slope' of that graph at point
> 't')
>
>
> So, ... is this statement correct?
>
> If it is more-or-less correct and it can help provide a basic mental
> image of the concept of i/q sampling, I would be more then happy! :-)
>
>
>
>
> 73
> kristoff - ON1ARF
>
>
>
>
>

Re: explaining i/q

[Fabian Schwartau]

Hi Kristoff,

As some people already pointed out here, it is always good to give
multiple views for the concept of complex numbers, as different minds
work differently and some explanation may push the right buttons for
someone, but not for someone else. Especially for such a complex (pun
intended) and quite theoretical topic. So, here is an other view which I
like to use when I teach the concept to students and it is based on a
frequency point of view:
If you have a purley real valued signal (like all signals in reality
are) they have a mirrored spectrum. So the positive frequencies are the
same as the negative ones (except for inverse phase values). This is
logical, as there is no real intuitive concept of negative frequencies
in reality. Let's assume a signal at (and around) a carrier frequency
fc. This will show up as two "hills" of signals around fc and -fc in the
spectrum. One definition of complex signals is now that I use a
(complex) mixer to mix the signal from the positive frequencies down to
zero, so that fc is now at zero frequency (in time domain I multiply by
exp(-j*2*pi*fc), which is the one-sided version of a cosine). -fc is now
at -2fc. Then I use an ideal low pass filter to remove the part at -2fc
and I am left with a signal around zero frequency, which is not
symmetrical any more (in general). As the original real-values signal is
symmetrical I do not remove any information with the low pass filter, so
the original signal is reconstructable by mixing it back up to fc and
taking the real part of the complex result to get the real-values
two-sided spectrum again (and I have to multiply the amplitudes by 2 to
compensate the "lost" energy due to the low pass filtering and taking
only the real part of the result).
Hope that is clear, but when your audience does not come from an
electrical engineering point of view it might be even more confusing to
introduce the concept of a spectrum - although it is a vital part of
signal processing and you will have to introduce it at somepoint anyway.

Best regards,
Fabian


Am 03.11.20 um 00:02 schrieb Kristoff:
> Hi all,
> 
> I was watching the webinar of Heather on GNU Radio today, when it came
> to me that one of the most difficult part doing a presentation of GNU
> Radio is the data-types, .. and especially these 'complex numbers'.
> The problem, or at least for me, is that when you mention 'GNU Radio
> complex numbers', you also have to mention iq-signals, which is a topic
> that is very difficult to explain in 10 seconds to an audience who has
> never seen anything about i/q sampling before.
> 
> 
> I have been thinking on how to explain the concept of I/Q signalling in
> just a few lines, e.g. in the context of -say- a workshop on GR.
> 
> 
> I have this idea in my head:
> 
> Statement:
> The main difference between sampling with reals ('floats') and i/q
> sampling with complex numbers, is that the latter does not only provide
> the  instantaneous value (voltage) of a signal at a certain point of
> time, but also includes phase information (i.e. the slope of the signal
> at that point).
> 
> 
> To make this visual:
> Take half a sine-wave and plot it out for every 45 degrees.
> This gives you 5 points: 0 (0 degrees), sqrt(2)/2 (45 degrees), 1 (90
> degrees), sqrt(2)/2 (135 degrees) and 0 (180 degrees).
> 
> Now look at the 2nd and the 4th point (45 degrees and 135 degrees), if
> you sample this using only real/float values, these two points are
> exactly the same (sqrt(2)/2). Just based on these values by themselves
> (i.e. remove all other points from the graph), there is no way you can
> tell that at the first point (45 degrees) the graph was going up, while
> at the 135-degrees point the graph was going down.
> 
> So, ... what i/q sampling does, is for every point "x", it not only
> provide the value of the graph at that point of time, but also
> information of the slope of the graphs at that time.
> 
> 
> This also explains while i/q sampling is done by not just taking the
> value of a signal at point "t", but also at 1/4 period later (which is
> the information you need to determine the 'slope' of that graph at point
> 't')
> 
> 
> So, ... is this statement correct?
> 
> If it is more-or-less correct and it can help provide a basic mental
> image of the concept of i/q sampling, I would be more then happy! :-)
> 
> 
> 
> 
> 73
> kristoff - ON1ARF
> 
> 
> 
> 

Re: explaining i/q

[gilles rubin]

 Hello,
You can have a look hereThe Concept of Frequency | Wireless Pi


|  |  | 
The Concept of Frequency | Wireless Pi
 |


Qasim Chaudhari CEO of Wireless Pi is great ! You will find plenty of 
information on his website.

Gil.

Le mardi 3 novembre 2020 à 00:06:02 UTC+1, Kristoff  a 
écrit :  
 
 Hi all,

I was watching the webinar of Heather on GNU Radio today, when it came 
to me that one of the most difficult part doing a presentation of GNU 
Radio is the data-types, .. and especially these 'complex numbers'.
The problem, or at least for me, is that when you mention 'GNU Radio 
complex numbers', you also have to mention iq-signals, which is a topic 
that is very difficult to explain in 10 seconds to an audience who has 
never seen anything about i/q sampling before.


I have been thinking on how to explain the concept of I/Q signalling in 
just a few lines, e.g. in the context of -say- a workshop on GR.


I have this idea in my head:

Statement:
The main difference between sampling with reals ('floats') and i/q 
sampling with complex numbers, is that the latter does not only provide 
the  instantaneous value (voltage) of a signal at a certain point of 
time, but also includes phase information (i.e. the slope of the signal 
at that point).


To make this visual:
Take half a sine-wave and plot it out for every 45 degrees.
This gives you 5 points: 0 (0 degrees), sqrt(2)/2 (45 degrees), 1 (90 
degrees), sqrt(2)/2 (135 degrees) and 0 (180 degrees).

Now look at the 2nd and the 4th point (45 degrees and 135 degrees), if 
you sample this using only real/float values, these two points are 
exactly the same (sqrt(2)/2). Just based on these values by themselves 
(i.e. remove all other points from the graph), there is no way you can 
tell that at the first point (45 degrees) the graph was going up, while 
at the 135-degrees point the graph was going down.

So, ... what i/q sampling does, is for every point "x", it not only 
provide the value of the graph at that point of time, but also 
information of the slope of the graphs at that time.


This also explains while i/q sampling is done by not just taking the 
value of a signal at point "t", but also at 1/4 period later (which is 
the information you need to determine the 'slope' of that graph at point 
't')


So, ... is this statement correct?

If it is more-or-less correct and it can help provide a basic mental 
image of the concept of i/q sampling, I would be more then happy! :-)




73
kristoff - ON1ARF