Re: [Discuss-gnuradio] constellation mapping

[Eric Blossom]

On Sun, Mar 04, 2007 at 06:20:07PM -0500, address@hidden wrote:

> I want to do constellation mapping in pyhton.  I have code that does
> a gr.packed_to_unpacked_bb and then gr.chunks_to_symbols_bc using a
> constellation of:
> 
> constellation=array((1+1j,1-1j,-1-1j,-1+1j),Complex)

Use this:

  constellation=(1+1j,1-1j,-1-1j,-1+1j)

> My understanding is that this is the constellation mapping for QPSK.
> I want to do constellation mapping for BPSK and 64-QAM.  I don't
> have a lot of GNU radio experience so I'm not really sure how to do
> this.  Is all I do is change the array (all the possibilities from
> 4+4j to -4-4j for 64-QAM and 1+0j to -1+0j for BPSK) and the code
> will do the rest to map the data for the other modulation schemes?

Have you looked at the mpsk code that's in the tree?  Most of this
stuff is already in place.  I believe that Tom Rondeau is working on
QAM too.

> Thanks for the help in advance,
> Nick

Eric