Re: [Discuss-gnuradio] Some new 802.15.4 stuff

[Bastian Bloessl]

Hey Brian,

first, thank you for your comment.

On 04/15/2013 03:37 PM, Brian Padalino wrote:
> I think it would be great for the community to get a rundown of the
> entire standard itself, modulation/demodulation within GNU Radio, how
> you handled frequency/sampling offsets, etc.


I thought about that and as it is all-supervisors-are-at-infocom-week, I 
tried something...

I made an IPython notebook, and reimplemented the transmitter iterative 
(i.e. non-stream) in python in the browser. I annotated it with text and 
plots and pictures.
It leads the reader step by step through the whole encoding process 
until we are at complex baseband representation. Than it writes the 
samples into a file. (The whole stuff happens in the browser, or is 
controlled through the browser).

I included a script, that creates a Linux pipe and starts the file_tx 
program, which is part of the UHD library. So the samples are really 
transmitted.
I can receive the signal that I send in the browser with my TelosB mote.

It's somehow funny and you can look at the signal in every stage of the 
encoding process.

It's a bit hard to describe and maybe some don't have ipython installed. 
So I made a really, really ugly video [1], but maybe it helps to see 
what going on.

You can have a look at the notebook here [2]. It is a Gist rendered by 
the notebook viewer. You can download the Gist [3] and run it 
interactively in your browser.

The whole stuff is not prove read, contains a lot of errors, is just 4 
fun and should just show the idea.

Best,
Bastian


[1] http://www.youtube.com/watch?v=OKeRCZGHi1E
[2] http://nbviewer.ipython.org/5394322
[3] https://gist.github.com/bastibl/5394322


--
Dipl.-Inform. Bastian Bloessl
Institute of Computer Science
University of Innsbruck, Austria
Phone: +43 512 507-53288 / Fax: -53079
http://ccs.uibk.ac.at/~bloessl/