Hi,

I've been investigating the pack /unpack /repack block since the problem raised by Maitry where not  originating from modulation/demodulation (which I tested and was correct).

  • Maitry did some test using repetitive pattern of bits  such as 1100, 1010,, and lead to the conclusion that its file sink was correct (*).
  • I did similar test with small repetitive pattern but found that only some of them give correct file sink (see explanation further)

From this it seems that somewhere in its flowgraph bytes to bit or bits to bytes conversion.

The attached flowgraph (GR 3.8 and 3.9, not compatible with GR 3.7) illustrates my investigation. Running this flowgraph shows that whatever conversion is in use give the same series of bytes and bits.

However, in order to obtain this I had to set endianness to MSB for both repack blocks (all other blocks set to LSB). Il all endianness are set to LSB, repack blogk reverse bit ordering compared to pack/unpack blocks, OR uses symmetric pattern as Maitry does (*).

  • I was expecting that unpack(8) and repack(8,1) should give the same result
  • What am I missing or misunderstanding ?
  • Or is this a bug?

Maitry, please try to set Endianness to MSB in your repack block. Not sure it cans solve your issue!

Regards,



On 11/11/2020 09:30, Maitry Raval wrote:
Dear sir,

Thank you for your response.

As I have a final application to use only demodulation and data storage using GNU radio as my transmitter is external. after that also I am facing an issue for stored data which is random not as transmitted. so request you to please guide me further in this demodulation.

Thank you in advance

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


From: "Christophe Seguinot" <christophe.segui...@orange.fr>
To: "Maitry Raval" <maitry.ra...@azistaaerospace.com>
Cc: "discuss-gnuradio" <discuss-gnuradio@gnu.org>
Sent: Wednesday, November 11, 2020 1:53:34 PM
Subject: Re: Issue in file sink block

Hi

I've been investigating but did not yet found the origin of this problem. I'm working under GR 3.9/Ubuntu 20.04

  • the bit sequence is correctly demodulated, whatever the source (txt or random) is. There is a 58 sample delay between bit source and demodulated bit. (so modulation/demodulation is OK)
  • however, the received bytes don't match the emitted bytes.
  • I'm further investigating if "pack bits" and "unpack bits" block are used correctly (I'm not familiar to them)

Regards

On 11/11/2020 04:25, Maitry Raval wrote:
Hello,

I think there is some misunderstanding here, I am using the attached grc file which includes all the ok blocks such as polyphase clock sync, costas loop, CMA equilizer etc for demodulation. Please check the attached file. for the attached grc, I am facing the below issue.

I understand that I have use online ASCII to binary converter and for that I am using below online converter.

But I am facing an issue, while I am transmitting repetitive pattern such as 1100, 1010 , the data stored in the file after mod-demod is almost similar( only some initial bits are changed) . Please check the screenshot attached. 

But when I am transmitting some random pattern instead of repetitive using file source, I am not receiving the same pattern, while I am converting the stored ASCII to binary using converter. 

Please help.

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


From: "Cinaed Simson" <cinaed.sim...@gmail.com>
To: "Maitry Raval" <maitry.ra...@azistaaerospace.com>
Cc: "discuss-gnuradio" <discuss-gnuradio@gnu.org>
Sent: Wednesday, November 11, 2020 12:51:54 AM
Subject: Re: Issue in file sink block

Hi Maitry - okay, then Marcus has already updated you - DPSK Mod is depreciated.

That is, it has bugs which can't or won't be fixed and is no longer supported.

-- Cinaed



On 11/9/20 7:43 PM, Maitry Raval wrote:
Hello,

I understand that I have use online ASCII to binary converter and for that I am using below online converter.

But I am facing an issue, while I am transmitting repetitive pattern such as 1100, 1010 , the data stored in the file after mod-demod is almost similar( only some initial bits are changed) . Please check the screenshot attached. 

But when I am transmitting some random pattern instead of repetitive using file source, I am not receiving the same pattern, while I am converting the stored ASCII to binary using converter. 

 I have sent the GRC file in previous mail. Kindly let me know, where is the problem?

Waiting for your positive response.

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


From: "Cinaed Simson" <cinaed.sim...@gmail.com>
To: "discuss-gnuradio" <discuss-gnuradio@gnu.org>
Sent: Monday, November 9, 2020 1:15:51 PM
Subject: Re: Issue in file sink block

Hi Maitry - if by update you mean dumping a binary file as binary instead of hexadecimal, then on Linux  use

  xxd -b <infile> <outfile>

-- Cinaed


On 11/8/20 8:13 PM, Maitry Raval wrote:
Hello experts,

Any updates?

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


From: "Aditya Arun Kumar" <adityaarunkumar...@gmail.com>
To: "Maitry Raval" <maitry.ra...@azistaaerospace.com>
Cc: "discuss-gnuradio" <discuss-gnuradio@gnu.org>
Sent: Wednesday, November 4, 2020 11:46:32 AM
Subject: Re: Issue in file sink block

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" <maitry.ra...@azistaaerospace.com>
To: "Aditya Arun Kumar" <adityaarunkumar...@gmail.com>
Cc: "discuss-gnuradio" <discuss-gnuradio@gnu.org>
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" <adityaarunkumar...@gmail.com>
To: "Derek Kozel" <de...@bitstovolts.com>
Cc: "Maitry Raval" <maitry.ra...@azistaaerospace.com>, "Marcus Müller" <mmuel...@gnuradio.org>, "discuss-gnuradio" <discuss-gnuradio@gnu.org>
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 <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|www.azistaaerospace.com
>
> ----- Original Message -----
> From: "Marcus Müller" <mmuel...@gnuradio.org>
> To: "discuss-gnuradio" <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
>>
>> 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" <muel...@kit.edu>
>> To: "discuss-gnuradio" <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
>>>
>>> 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






Attachment: packing_test.grc
Description: application/gnuradio-grc

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