Re: [Discuss-gnuradio] OFDM

[Tom Rondeau]

Johnathan Corgan wrote:
> address@hidden wrote:
>
>   
> > I'm pretty new to gnu radio and I want to transmit an OFDM signal
> > using different modulation types (BPSK, QPSK, and 64-QAM).  The
> > concept is pretty simple: read data, map it to a specified
> > constellation map, and then send it through an IFFT.  I don't know if
> > this code already exists but I could use some help.
> >     
>
> There is work underway in this area to create a parameterized OFDM
> modulator/demodulator pair, but it is incomplete and not yet merged into
> the trunk.  You can see the code in:
>
> http://gnuradio.org/trac/browser/gnuradio/branches/developers/n4hy/ofdm2/gnuradio-examples/python/ofdm
>
> These examples depend on C++ elsewhere in the tree in this developer
> branch so they won't run as-is. You can, however, see how the transmit
> path is put together.
>
> By the way, you're right--the modulator is the easy part.  It's the
> receiver synchronization that always turns out to be the black magic
> part. (Why is this always glossed over? :-)
>
> Johnathan Corgan
> Corgan Enterprises LLC
> http://corganenterprises.com

As Johnathan said, we've pretty much got the modulator and demodulator 
done. A few of us will be working next week on pulling it all together 
and finishing the synchronization. With any luck and the alignment of 
the Zodiac (or whatever astrological/mythological concept you want to 
wish on), we'll get this merged into the trunk by the end of next week.

From there, hack away and make improvements.

Tom