Re: garage remote jamming

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:45e86add.852970015@xxxxxxxxxxxxxxxx
> "Jeff Volp" <JeffVolp@xxxxxxx> wrote:
>
>>"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
>>news:9N2dncCwPcN4VHrYnZ2dnUVZ_vTinZ2d@xxxxxxxxxx
>>
>>>  Right now, my admittedly limited
>>> understanding of radio transmissions tells me that a stronger
>>> transmitter
>>> will completely 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.  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.
>
> But, by definition "spread-spectrum" is not "on the same frequency".

I understand that Dave.  I was just pointing out there are techniques to get
around being jammed by a stronger signal.  The ICs developed for GPS may
make it feasible to use that approach for mid-price automation products.
While not totally jam proof, such a system could be much more resistant to
external interference.

Jeff