# Tx\_ofdm.grc start\_of\_burst end\_of\_burst

**URL:** <https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246>\
**Category:** GNU Radio\
**Created:** [July 30, 2014, 4:16am UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246 "2014-07-30T04:16:52Z")\
**Posts on this page:** 9\
**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:** [July 30, 2014, 4:16am UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/1 "2014-07-30T04:16:52Z")

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Hi all:  
I know a packet in the example tx\_ofdm.grc include a preamble,a  
header,the payload and crc value.Recently I have used the UHD API to  
send packet.And I want to know whether the tx\_ofdm.grc add  
start\_of\_burst and end\_of\_burst automatically.Namely,need I add  
start\_of\_burst at the beginning of every packet and add end\_of\_burst at  
the end of every packet?  
Thank you very much.  
Best regards,  
xd

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**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 4:07pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/2 "2014-07-30T16:07:28Z")

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On 07/30/2014 03:59 AM, xianda wrote:

> Hi all:  
> I know a packet in the example tx\_ofdm.grc include a preamble,a  
> header,the payload and crc value.Recently I have used the UHD API to  
> send packet.And I want to know whether the tx\_ofdm.grc add  
> start\_of\_burst and end\_of\_burst automatically.Namely,need I add  
> start\_of\_burst at the beginning of every packet and add end\_of\_burst at  
> the end of every packet?

usrp\_sink understands tagged streams. So, the OFDM code does _not_ add  
EOB, but that doesn’t matter if you have an up-to-date gr-uhd.

M

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**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 4:51pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/3 "2014-07-30T16:51:32Z")

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Hi:  
Thank you so much for your kindly reply.I write c++ code use the uhd  
not gnuradio.So need I add start\_of\_burst at the beginning of every  
packet and add end\_of\_burst at the end of every packet?Thank you.  
Best regards,  
xd

---

<div class="post-metadata">

**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 5:40pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/4 "2014-07-30T17:40:17Z")

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Hi Xianda,  
if you don’t use gnuradio, this might not be the right list for you…  
Anyway, I think it’s possible you’re confusing something. start\_of\_burst  
/ end\_of burst are stream tags that are GNU Radio concepts. There is not  
something like this without GNU Radio.  
UHD supports timed commands, which might be close to what you need, but  
I really don’t understand what your question aims at.

Greetings,  
Marcus

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<div class="post-metadata">

**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 6:05pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/5 "2014-07-30T18:05:16Z")

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Sorry Xianda,  
I’m still not understanding completely.  
Is this question about a) tx\_ofdm.grc, or b) not about GNU Radio?

Best regards,  
Marcus

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<div class="post-metadata">

**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 6:08pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/6 "2014-07-30T18:08:15Z")

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Hi Marcus:  
Thank you.I just want to know whether the example  
tx\_ofdm.grc add start\_of\_burst at the beginning of every packet and add  
end\_of\_burst at the end of every packet?  
Best regards,  
xd

---

<div class="post-metadata">

**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 5:52pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/7 "2014-07-30T17:52:47Z")

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Hi Marcus:  
Thank you so much.I just want to make some changes on  
the example of tx\_ofdm.grc.And I use the UHD not the gnuradio.But the  
example is about the gnuradio.I know a packet in the example tx\_ofdm.grc  
include a preamble,a header,the payload and crc value.And I want to know  
whether need I add start\_of\_burst at the beginning of every packet and  
add end\_of\_burst at the end of every packet?Am I right?  
Best regards,  
xd

At 2014-07-30 11:39:02, “Marcus M.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:  
Hi Xianda,  
if you don’t use gnuradio, this might not be the right list for you…  
Anyway, I think it’s possible you’re confusing something. start\_of\_burst  
/ end\_of burst are stream tags that are GNU Radio concepts. There is not  
something like this without GNU Radio.  
UHD supports timed commands, which might be close to what you need, but  
I really don’t understand what your question aims at.

Greetings,  
Marcus

On 30.07.2014 16:50, xianda wrote:

Hi:  
Thank you so much for your kindly reply.I write c++ code use the uhd  
not gnuradio.So need I add start\_of\_burst at the beginning of every  
packet and add end\_of\_burst at the end of every packet?Thank you.  
Best regards,  
xd

At 2014-07-30 10:05:47, “Martin B.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

On 07/30/2014 03:59 AM, xianda wrote:

Hi all:  
I know a packet in the example tx\_ofdm.grc include a preamble,a  
header,the payload and crc value.Recently I have used the UHD API to  
send packet.And I want to know whether the tx\_ofdm.grc add  
start\_of\_burst and end\_of\_burst automatically.Namely,need I add  
start\_of\_burst at the beginning of every packet and add end\_of\_burst at  
the end of every packet?

usrp\_sink understands tagged streams. So, the OFDM code does _not_ add  
EOB, but that doesn’t matter if you have an up-to-date gr-uhd.

M

* * *

Discuss-gnuradio mailing list  
removed\_email\_address@domain.invalid://lists.gnu.org/mailman/listinfo/discuss-gnuradio

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<div class="post-metadata">

**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 6:29pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/8 "2014-07-30T18:29:39Z")

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But you don’t _need_ it, either. So, don’t add EOB if you’re using a  
current GNU Radio.

M

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<div class="post-metadata">

**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\
**Post date:** [July 30, 2014, 6:26pm UTC](https://www.ruby-forum.com/t/tx-ofdm-grc-start-of-burst-end-of-burst/231246/9 "2014-07-30T18:26:05Z")

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Hi Xianda,  
as Martin said:

> So, the OFDM code does _not_ add EOB

Greetings,  
Marcus