Spread spectrum is much more hype than real benefit.  Frequency hopping
is good to prevent eavesdropping.  Direct Sequence spreading helps you
hide in the noise.  Both are useful for military applications, but have
limited ligitimate civilian use.

If you had four channels of space with a varying number of users,
sometimes more than four, who couldn't agree on who should use what
space when, then spread spectrum helps to arbitrate the use of bandwith.
 When too many users occupy the band everybody's signal to noise ratio
degrades, and everybody suffers equally.

I can stay on this soapbox for longer than anybody wants to read...

Sherpa Doug

> -----Original Message-----
> From: Brandon Irwin [mailto:BrandonI@LEAKED.INFO]
> Sent: Friday, April 12, 2002 1:30 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [OT]:Spread Spectrum Efficiency for Continuous signals
>
>
>       I've been reading about spread spectrum and I don't see
> how spread
> spectrum techniques could be used for continuous transmissions.
>
>       Everyone seems to want to convert everything to spread spectrum
> because of its greater efficiency. I don't see how it could
> be any more
> efficient when used on continuous transmissions such as a TV
> video signal.
> The following assumes that they would keep the signal in the
> analog form.
> If you have four available channels with four TV stations and
> you implement
> the freq hopping method, then all four channels will always
> be full because
> the TV stations would never have a pause to allow a fifth channel to
> transmit. If you where to use a method similar to TDMA, then
> you would see
> little gaps in the picture.
> It seems to me that the only way the "more efficient" spread spectrum
> methods could be used would be to convert the signal to a
> digital form so
> it could be buffered on the TV side while the transmission ceased for
> whatever amount of time.
>
>       Is there something I'm missing? Maybe the whole concept?
>
>
>
>
> -Brandon Irwin
>
>
>
>
>
>
> -------------------------------------
> This message was written using the Dvorak keyboard layout.
>
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