Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

[Martin Braun (CEL)]

On Thu, Sep 26, 2013 at 06:25:50PM +0000, Monahan-Mitchell, Tim wrote:
> > On Wed, Sep 25, 2013 at 04:57:55PM -0700, Daniel Domínguez wrote:
> >> The solution I found was to set the Fixed Frame Length parameter to 1 
> >> on the OFDM Frame Equalizer block of the "Header Stream".
> 
> > 1 is the correct setting. I'm currently adding a tx into the example so it 
> > runs as-is (like benchmark).
> 
> It would be interesting to keep the original diagram, and then also show a 
> replacement diagram that instead uses the OFDM Demod block and any other 
> newer ones that consolidate the equivalent function.

Nothing's going to change with the original diagram. I'll just add an
ofdm_tx so it runs in loopback mode.

> > The reason: The headers have constant length, therefore it is not necessary 
> > to propagate them as tagged streams. The way the header/paylod demux work, 
> > it splits off the header and passes that regularly. There's no need to 
> > generate a length tag.
> 
> Maybe that explains why my earlier issue about the Length Tag Key value for 
> that same block does not matter (see GR issue # 593), since "1" implies it is 
> not needed.

Yep, exactly.


MB

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

Dipl.-Ing. Martin Braun
Research Associate

Kaiserstraße 12
Building 05.01
76131 Karlsruhe

Phone: +49 721 608-43790
Fax: +49 721 608-46071
www.cel.kit.edu

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

pgpM8k2VUUqmO.pgp
Description: PGP signature