# Burst Transmissions

**URL:** <https://www.ruby-forum.com/t/burst-transmissions/234562>\
**Category:** GNU Radio\
**Created:** [March 13, 2015, 6:11pm UTC](https://www.ruby-forum.com/t/burst-transmissions/234562 "2015-03-13T18:11:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [March 13, 2015, 6:11pm UTC](https://www.ruby-forum.com/t/burst-transmissions/234562/1 "2015-03-13T18:11:35Z")

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Hi all,

This is kind of a reword of a previous question I asked yesterday. I  
don’t  
think I did a good job.

I am receiving data bursts that can be separated by no transmissions  
(noise) for extended periods of time. I want to figure out a way to get  
the  
bursts of data into a file without the noise. I can identify the bursts  
and  
how long the bursts are in terms of bytes. I can’t figure out a way to  
then  
get the burst into a file without all dead time between them. The dead  
time  
translates to large chunks of zeros in the output file.

I’m attaching a flowgraph of what allows me to identify the burst  
header,  
remove the header and claim the payload. The problem remains that along  
with the payload going to the file, large chunks of zeros are also  
making  
it into the file.

I would really appreciate some guidance.

v/r,  
Rich

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**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\
**Post date:** [March 13, 2015, 6:27pm UTC](https://www.ruby-forum.com/t/burst-transmissions/234562/2 "2015-03-13T18:27:33Z")

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Only gave your FG a quick glance, but if you give the HPD the right  
packet length, you should end up with only the data packet.

Things to check:

- Is the packet length passed to the HPD correct?
- Are there packing/unpacking issues that would add zeros? Are you maybe  
calculating the packet length in the wrong domain?

M

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<div class="post-metadata">

**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\
**Post date:** [March 13, 2015, 6:32pm UTC](https://www.ruby-forum.com/t/burst-transmissions/234562/3 "2015-03-13T18:32:38Z")

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Thanks for confirming the functionality of the HPD block. That’s what I  
was  
hoping it would do. I’ll assume the problem lies in how I’m using it and  
debug around it.

Thanks for the help.

Rich

On Fri, Mar 13, 2015 at 10:25 AM, Martin B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)