On Oct 2, 4:26 am, wrote:
On Oct 1, 1:42 pm, Ratata wrote:

wrote:
"To counter the effects of Doppler shift and Doppler spread the
frequency separation between the OFDM carriers in the DRM signal is
progressively increased (e.g. the carrier spacing in Mode D is more
than 2.5 times that in Mode A). This ensures that the frequency
spread experienced is kept to a sufficiently small fraction of the
carrier spacing to allow correct demodulation."

better than IBOC ??


- Digital Radio Mondiale *is* IBOC. (Like HD Radio, it sits right
next-
- door to the AM signal, widening the channel by a few more kilohertz)

SFTV -aka- "Hybrid Digital" Man,

DOH ! - You had beeter go back and re-do your
DRM 101 and IBOC 101 Classes again. ~ RHF

Digital Radio Mondiale (DRM)
http://en.wikipedia.org/wiki/Digital_Radio_Mondiale
Unique Digital Broadcast Signal Mode {Non-Analog AM}

In-Band On-Channel (IBOC) so called "HD" Radio
http://en.wikipedia.org/wiki/IBOC
Combined Analog and Digital Broadcast Signal Modes
http://en.wikipedia.org/wiki/HD_Radio

DRM is All Digital Mode of Shortwave (HF) Radio Transmission
http://www.eiinfo.fh-konstanz.de/dow...rm/image35.jpg

DRM Digital Signal at 13,790 kHz with AM Analog
http://shortwaveradio.org/drm_13_Af_010511_2100.jpg
Signals at 13770 kHz; 13800 kHz; and 13810 kHz.
* Clearly you can see that DRM requires at least
15 kHz of Channel "Spacing" for it not to interfere
with any 'adjacent' DRM or Analog Radio Broadcast.

Note - That the DRM Shortwave Radio Broadcasts are
independent and separate from the older Analog "AM"
Radio Transmission Mode Broadcasts.
* International, National and Local DRM Broadcasts
Underway in Markets Worldwide
http://www.drm.org/livebroadcast/livebroadcast.php

From what I have read and heard DRM appears to work
best as a Directed Beam Radio {Audio} Delivery System
up to 1000 Miles and out to 2500 Miles.
* DRM Tropical Band {With-In-Country} Omni-Directional
Radio Broadcasting best up to 300 Miles and out to 1000
Miles.

Analog "AM" And DRM Can Not Co-Exist On The Same
Channel {Frequency} At The Same Time [.]

As with all Shortwave Radio Broadcasting the Coordinated
Scheduling of Broadcast Time and Frequency is important
for DRM Broadcasters since they take up Four Times (4X)
the Bandwidth as the Analog "AM" Broadcasters.

High Frequency Co-ordination Conference (HFCC)
HFCC = http://www.hfcc.org/

drm ain't iboc -and- iboc ain't drm ~ RHF