Re: [Discuss-gnuradio] DVBT Tx

[Eric Blossom]

On Mon, Mar 05, 2007 at 08:18:06AM +0100, Vincenzo Pellegrini wrote:
> Hi Eric,
> I just saw your cool gnuradio presentation and heard you talking about a not
> yet realtime ATSC transmitter.
> I am a telecommunication engineering student in italy at Pisa University
> (Italy) at the moment, and it is quite likely that my final thesis (to be
> started in about a year from now) will be a DVB-T transmitter.
> 
> So I'm slowly approaching the subject, and starting to figure out some
> preliminary choices  and possibilities...
> 
> My  first  questions  then are :
> 
> ..Do you think it is possible to reach real time, considering hardware
> improvements  since the video was recorded?

I could be.  I'm unfamiliar with the DVB-T spec, so can't really offer
an opinion.  Transmitters are always easier than receivers.

One of my goals is a port of GNU Radio to the Cell processor.  
I expect that we'll be able to realize about 30 GFLOPS on that
platform, which is about 10x what we can get out of a commodity PC
today.

On the Cell and with some optimization work on the ATSC tx and rx, 
I suspect that both can be made to run in real time.

> ..How  could  I  test a non  real  time  transmitter?  (I  think  I
> understand  not   real  time  receiver but how did you test the
> transmitter?)

Write the generated samples to a file, then "play it back" in real time
from the disk.

With the ATSC work, we wrote the transmitter and receiver at the same
time, then looped them back at compatible places in the pipeline.

> Best Regards
> -- 
> Vincenzo Pellegrini

Eric