Re: [Discuss-gnuradio] Re: Regarding OFDM implementation

[Bob McGwier]

The LTS at U. Md. has implemented (in GnuRadio) general QAM 
constellation mapping for modulate and demodulate.    This was done by 
interns working for Charles Clancy.  I will work with them to add the 
slicer and then check that stuff in but it might be the first of 
September before I can do this because of the workload this summer.

Bob

Tom Rondeau wrote:
> Shravan,
>
> I copied this to the listserv as I hope others find the discussion 
> useful.
>
> Shravan Rayanchu wrote:
> > Hi Tom,
> >
> > I have a few questions regarding the OFDM implementation in gnuradio
> > (I am a networking guy and I have a little knowledge of DSP, so some
> > of my questions might be trivial):
> >
> > 1. Can you point me to the version with 16-QAM (or 64-QAM) running
> > over OFDM on the air?
> The code is checked in, but I can't guarantee that it will work 
> (especially the receiver). We have currently separated the modulators 
> into gr_ofdm_<mod>_mapper; there's one for QAM, which was meant to be 
> a generalized QAM modulator, but we just hard-coded 16QAM for now.
>
> Eventually, these will go away into a single gr_ofdm_mapper function 
> that takes a constellation vector as an argument, allowing any type of 
> modulation per subcarrier.


--
Robert W. McGwier, Ph.D.
Center for Communications Research
805 Bunn Drive
Princeton, NJ 08540
(609)-924-4600
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