[PCR-1000] 900 Mhz Cordless freq??

[Marcus]

hey... thats all but NOT basic ;-)

i will to try to explain it.. but if my english comes to
a point on that it isnt the best - please excuse...

spread spectrum signals are like signals with a "normal"
bandwith, but stretched so much over the frequency that
they will have a much higher bandwith. the cause for doing
this is that you can "hide" signals in the ground noise and
nevertheless demodulate it without errors - but you have to
know where the signal "is".

why? in case of a signal is spreaded the energy of the
signal will be same like when it is not spreaded, so the
signal will not be "visible" on a spectrum analyzer if the
spreading factor is high enough... yeah, you think right,
it was used first by military and intelligence ;-)

in umts for example the signal ist spreaded and encoded
with a "gold-code" (-> cdma), that allows to decode it out
of the many other signal laying on the same channel. the
number of transmissions per channel is no longer limited by
the bandwith, only by the number of existing gold-codes.

i hope i did explain it in the right words, at this moment
i dont know the word for this thing that describes the
power of a signal over the frequency... sorry but here its
6 a.m. and i didnt sleep last night.
i will look for it and try to tell it in other words later
today, i you want me to do...

greetings
marcus

  

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