[Drm-devel] MDI based transmissions, Experimental live broadcast in Budapest

[Ádám K. <kis...@si...>]

Dear DReaM Developers,

I am a student of the Budapest University of Technology and Economics,
taking part in our DRM transmitter project. Basically we are on the air
now, aiming to provide opportunity for signal propagation experiments and
receiver tests still in the development phase.

We currently play out a 25-hour prerecorded program via mplayer to the
onborad soundcard of a PC running Linux. Dream receives the data of the
monitor port of this card, encodes the sound using FAAC, generates the
baseband IQ samples of the DRM signal to be transmitted, then outputs these
IQ signals through a SoundBlaster Live! card, which we feed into a Rohde &
Schwarz IQ modulator (R&S SMIQ). This later one drives the consecutive
power amplifier chain and antenna. (Further details can be found on
www.drm.org and the monitored transmission is available here: nmhh.hu/drm).

Since our goal is to provide opportunity for all receiver manufacturers
worldwide to test their products on a live system, we intend to transmit a
stream which contains Journaline data and slide show as well in addition to
the audio data. To this end we would have to feed an MDI stream into the
DREAM modulator software. We tried to reconfigure DReaM to use this data
stream, then we saw that this feature is not implemented yet. I checked the
source code of DREAM and saw that MDI decoding is implemented, although it
is not integrated with the transmitter module.
Do you have any plans for implementing this feature in the near future? I
would like to rely on free software as long as I can, and DReaM fits well
to this objective.

Thank you for your consideration.
With best regards
Adam Kiss
Budapest University of Technology and Economics
Department of Broadband Infocommunications and Electromagnetic Theory
HAM: HA8KDA