Re: [Discuss-gnuradio] IT++ functions

[Martin Braun]

On Fri, Mar 05, 2010 at 06:15:13PM -0500, Pradyumna Desale wrote:
> Hey Per,
> 
> Thanks for replying! I wanted to start by incorporating channel models
> (channel.h if you are familiar with IT++) and was wondering if just writing a
> wrapper function in swig would do the necessary work for us or we have to make
> some specific changes to incorporate those codes in gnuradio framework. Any
> thoughts?

I've been wanting to use the channel coders from IT++ in GNU Radio, and
found writing wrappers is not difficult. I never finished packaging any code
(though I've got some code somewhere, if I find it I'll send it to you),
but here's some of the knowledge I gathered:

- The data types of GNU Radio and IT++ are in theory compatible, but in
  practice I found you either need to subclass IT++' "Vec"-class to
  directly access the memory, or you need to copy everything by hand
  from your input data to the IT++ vector.
- In any case, IT++' structure is pretty coherent, so writing a wrapper
  for pretty much anything is fairly straightforward:
  1) Include an object to your channel model (or whatever) in your
     block, e.g. a d_rayleigh_channel attribute
  2) In your work function, you need to shift your data from input_data
     to your Vec
  3) Load that into d_rayleigh_channel or whatever
  4) Take the results and copy them to the output_data
- What's really simple about it all is that these steps are virtually
  the same no matter what you include, be it channels, encoders etc.
- Perhaps slightly more difficult would be to adapt the build system
  (check for libs etc).

Perhaps this was of any help to you...

MB

-- 
Karlsruhe Institute of Technology (KIT)
Communications Engineering Lab (CEL)

Dipl.-Ing. Martin Braun
Research Associate

Kaiserstraße 12
Building 05.01
76131 Karlsruhe

Phone: +49 721 608-3790
Fax: +49 721 608-6071
www.cel.kit.edu

KIT -- University of the State of Baden-Württemberg and
National Laboratory of the Helmholtz Association

pgp6Zw8PtkSaH.pgp
Description: PGP signature