Invisible wrote:
> Darren New wrote:
> 
>> http://denbeste.nu/special/cdma_spreading.html
>>
>> Not magic, but certainly very difficult to understand intuitively.
> 
> Hey, neat.
> 
> So it's kind-of like this?
> 
> http://en.wikipedia.org/wiki/Visual_cryptography

Not too different, except you do it with dozens of different masks. :-)

> I'm still trying to figure out exactly how it works, but it's quite neat.

Once you figure it out, then realize you can talk at two different speeds at 
the same time on the same frequencies (which is what the phone does for 
voice vs signaling), you can talk to two different carriers on the same 
frequency at the same time, and you have to account for round-trip speed of 
light delays, including predicting how much that delay will change before 
the next packet based on the fact that you're driving towards or away from 
the tower...   And the tower has to modify the timing of the chips for each 
phone based on the round-trip delays.

> And now I'm wondering... can you implement this stuff using only 
> analogue electronics? 

No idea. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   There's no CD like OCD, there's no CD I knoooow!

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