View Full Version : TDF DRM experimentation result

11-11-2007, 13:31
Result of experimentation on 999 kHz and 26 MHz (in french) :
http://www.csa.fr/upload/radionum/pr%e9sentation%20comite%20technique%20CSA%20110907 _DRM.pdf

11-11-2007, 14:23
Conclusions 26 MHz:
The audio quality was considered comparable to that of FM.
Compared to the diffusion of two programs which utilize two channels independent 10kHz each (total flow 20.8 kb / s), this method of disseminating at 20 kHz wide channel multiplexer allows these programs in only one issue and share more flexibly and dynamically digital resource of 43 kb / s between two programs.
Subject to reduce the flow on one of the programs is also possible to have a significant resource for disseminating accompanying data (files, RSS… etc.)
The spread of two radio programs to Channel DRM 20 kHz of channel width to 26 MHz is very realistic; coverage in 26 MHz looks promising with limited means of dissemination. Nevertheless; coverage of a city of a certain size could require the construction of a network SFN consists of three small sites Issue adequately positioned to prevent the phenomena of "fading flat "produced by reflections on the rack dense.

Conclusions 999 kHz:
There are a lack of coverage of the area north and northwest of Paris under the conditions of this experiment.
The diffusion of power used in this experiment on sites Romainville and Villebon are insufficient to guarantee a service fully covering Paris. A power of 60 kW for Villebon and 6 kW Romainville to ensure good coverage of Paris.
A level field from 70 to 80 dB μ V / m is needed for a reception correct, in the current state of receivers, in a highly urbanized city.
It was found that the presence of the tramway catenary is an element very disruptive for the reception in this band.
A third issuer northwest of Paris would improve significantly comfort of receipt.
In semi-rural area, the reception is correct from 57 dB μ V / m.

12-11-2007, 10:14
Hello,there. I want to know if there is any test data (esp. the IF WAVE file) open to public access. I'm really interested in the so called 'tramway' interference which is causing problems according to their assessment.

12-11-2007, 16:12
Hi f1tay!

I have a question: On page 10 of the pdf a TX-Power of 6.5 kW is shown for Villebon and some pages laster text says something of 60 kW (1.5 kw versus 6 kW in Romainville). Is this a typo or speaks the text of a "calculated" Reception?



12-11-2007, 16:16
The tramway :


12-11-2007, 16:18
Other info on tramway at Paris :