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October 25th 04, 04:21 AM

Telamon

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In article ,
(Mark Zenier) wrote:

In article
,
Telamon wrote:

How about below? The upper harmonics are a sure thing but I expect the
DRM signal to spread out as far below the frequency transmitted on.

Digital signals spread out above and below the frequency they are on.
Upper frequency spread is from multiple carrier mixing products and
higher frequency harmonics of the fast switching edges and phase noise
or random jitter. The low frequency spread is from data dependent
effects or data dependent jitter and the data mixing with the carriers.

Huh? There're no fast edges. It's a COFDM signal that consists of
hundreds of closely spaced subcarriers modulated as some slow baud rate
(around 30-50 Hz). It shouldn't slop over much, but it'll fill up all
the spectrum it's using. It's very similar to a FDM telegraph (Droning
DC-3) signal, only about 5-20 times as wide.

Mark Zenier Washington State resident

There are not hundreds of carriers. I believe the number is sixteen.

It is not the rate that they are switched at but how fast they actually
turn on and off. Think dV/dT.

--
Telamon
Ventura, California

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