# Questions about tdma\_engine.py

**URL:** <https://www.ruby-forum.com/t/questions-about-tdma-engine-py/227087>\
**Category:** GNU Radio\
**Created:** [March 4, 2013, 2:49am UTC](https://www.ruby-forum.com/t/questions-about-tdma-engine-py/227087 "2013-03-04T02:49:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Gong\_Z](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/d07c76/32.png) [@Gong\_Z](https://www.ruby-forum.com/u/Gong_Z)\
**Post date:** [March 4, 2013, 2:49am UTC](https://www.ruby-forum.com/t/questions-about-tdma-engine-py/227087/1 "2013-03-04T02:49:21Z")

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Hi,  
I have read the file tdma\_engine.py in PreCog.It seems they deal with  
data and update local time according to the time tags.But how can we  
demodulated the signal from antenna in the start without knowing the  
time.Is this imply we can only transmission at the fixed frequency?I  
appreciate any tips.  
Thank you.

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<div class="post-metadata">

**Author:** ![Gong\_Z](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/d07c76/32.png) [@Gong\_Z](https://www.ruby-forum.com/u/Gong_Z)\
**Post date:** [March 4, 2013, 3:51am UTC](https://www.ruby-forum.com/t/questions-about-tdma-engine-py/227087/2 "2013-03-04T03:51:52Z")

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You are correct. The demodulated will demodulate continuous. The  
receive  
samples are routed to the TDMA engine for timing information of the  
transmissions.

-John

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**Author:** ![Gong\_Z](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/d07c76/32.png) [@Gong\_Z](https://www.ruby-forum.com/u/Gong_Z)\
**Post date:** [March 4, 2013, 4:57am UTC](https://www.ruby-forum.com/t/questions-about-tdma-engine-py/227087/3 "2013-03-04T04:57:53Z")

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hello John,

I am wondering, in future, if the receiver will also work in a tdma  
manner  
at the waveform level,i.e, the demodulation can be done within specified  
time slot. One of the benefits is that the computing on the receiver can  
be  
decreased significant.

Thanks.

On Sun, Mar 3, 2013 at 8:50 PM, John M.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)wrote:

> > I have read the file tdma\_engine.py in PreCog.It seems they deal with
> 
> * * *
> 
> Discuss-gnuradio mailing list  
> [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
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–

Alex,  
_Dreams can come true just believe._