Re: garage remote jamming

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Jeff Volp" <JeffVolp@xxxxxxx> wrote in message

RG>> Right now, my admittedly limited understanding of radio
RG>> transmissions tells me that a stronger transmitter will completely
RG>> drown out a weaker one on the same frequency.

> There is a technique that uses spread-spectrum and correlation between a
> received signal and a pseudo-random pattern.

Sounds interesting.  But as Dave notes, when you are talking about
spread-spectrum techniques, you've strayed outside the limits of my original
words "same frequency."

I am sure that by using multiple frequencies and high levels of redundancy
that a delayed radio message can be sent intact through heavy interference.
It will always take longer than a straight-up message sent on a single
frequency because of the reconstitution required.  It would be nice to know
if Lutron Radio RA use such a method . . .

> It is possible to recover a weak signal even in the presence of jamming
with this
> method.  Bandwidth is limited, and it takes time to search until a pattern
match is
> found.  But it amazing how that signal pops out of the noise when
correlation is
> achieved. GPS receivers use this technique to recover the weak satellite
signals.

Would it work if more than one of those frequencies were deliberately
jammed?