DRM uses Coded Orthogonal FDM which is resilient to specific types of
fading. You can find out more about it he

http://www.bbc.co.uk/rd/pubs/papers/...paper_15.shtml

There's plenty of scope within the scheme for tinkering by broadcasters, so
that it's more resilient to observed conditions within the particular band.

But, whether or not you think the results are any good is of course
subjective. When the signal's weak I would liken the results to how GSM
sounds; it drops out and echos. There were some mp3's knocking about on the
web of actual received results at different SNR's. I listened to some of
these, which were of classical music, and I thought the results were pretty
good.

By the way, I agree with you about DAB - the more crap they cram into the
same bandwidth, the worse it's going to sound. I know BBC engineers who've
been involved with it and who also agree with you! But, it's all about money
and getting people to sign up. Anyway back to DRM:

This from http://www.hard-core-dx.com/index.php?topic=drm&page=4

BBC Monitoring has listened to the latest broadcasts using a Franhofer DRM
software enabled PC receiver coupled to an AOR shortwave receiver with an
active whip antenna. The low bit-rate digital audio from DRM does exhibit
slight evidence of the process of audio compression. Occasional drop-outs
have been observed and the audio quality can degrade to an echo and then
either recover or cut to silence for a short period. The audio quality on
speech and music is good and all the signals heard so far have sounded less
distorted than the lowest bit rates of 48 and 64 kb/s via DAB (Eureka 147
digital audio broadcasting).



"GT" wrote in message
...
Hello,

What happens when the signal fades out? With a normal AM transmission it
is still possible to hear the station into the noise and back again. With
digital it will be on and then completely off - so will be difficult to
listen to.
I certainly wouldn't associate digital radio with audio quality. When DAB
first come out it was great, but not now as so many stations are crammed
into each multiplex to make money. Audio quality suffers because of low
bitrates and a lot of stations are in mono.
Digital radio has a long way to go.