Gnuradio companion

i ask if it’s possible to run bbn code on grc
specially the physical layer blocks

The bbn can be but a mere block within the mighty GRC! ~Muhaha

Meaning…
There is no bbn stuff in currently in grc. You can always add blocks:
http://gnuradio.org/trac/wiki/GNURadioCompanion#AddingCustomBlocks

How easy this is depends on how well the bbn code adheres to the block
model… If it uses function callbacks to pass messages (like the
blks2.packet mod) then we are probably out of luck.

Perhaps when we start using PMTs and someone adds PMT-based message
passing into the bbn code, then it will be a more possible. But I am not
familiar with the bbn code, so maybe it is possible now?

-josh

I think the only part which will be a potential stumbling block is
the PLCP block - which does the de-framing of the demodulated signal,
and puts it in a message queue. As I understand it you can have
message queues in GRC, but since there’s no ‘display’ it may seem
non-obvious about what to do with it. The rest of the blocks are
pretty well-behaved as far as going in GRC - I believe I got it
working once without much difficulty. So if you’re just concerned with
the 'lower level’s - i.e. the physical layer, as the original poster
apparently is - you can put the FIR filter, slicer (which together do
the de-spreading), and demodulation blocks in GRC, no problem. Bear in
mind, since the PLCP is where the de-scrambling happens in the current
code, you either have to instantiate a de-scrambler block (I believe
the one defined in the BBN code works, but isn’t even used as a
stand-alone block), or just remember the bits coming out of the demod
are still scrambled.
Doug

On Wed, Sep 30, 2009 at 11:56 AM, Josh B. [email protected] wrote:

Perhaps when we start using PMTs and someone adds PMT-based message passing
into the bbn code, then it will be a more possible. But I am not familiar
with the bbn code, so maybe it is possible now?

-josh


Doug G.
[email protected]

It is possible, but you will have to create the custom XML files for GRC
to
‘see’ the BBN blocks. Take a look at:
http://gnuradio.org/trac/wiki/GNURadioCompanion#AddingCustomBlocks
Doug

how to add blocks to gnu radio companion ,somebody help me by giving me
the instructions, thank you