[sdiy] Re: mobile phones gettin' OT but..

[John L Marshall]

----- Original Message -----
From: "Richard Wentk" >
<snip>
Is there any reason why CDMA would keep working if you used bandpass
filtered noise to modulate an RF oscillator -transmitter? I'm thinking if
you dump enough noise into every possible frequency channel the receiver is
eventually going to lose any hope of a lock on its pseudonoise carrier. You
probably spend some time in jail too if you're caught, but hey. :)
</snip>

The answer is yes. If you crank out enough broadband noise you will knock
out a CDMA cell phone. It will take some power though. CDMA is designed to
work in a noise environment. All of the phones on the same channel are in
fact interferring with each other; the desired voice channel and ten to 20
interferrers. It is the orthogonal nature of Walsh Codes that separates the
voice channels.

I keep mentioning Walsh Codes because there are a few of us interested in
using Walsh Codes for sound synthesis. Yes there are a few real world
applications for Walsh Codes.

Take care,
John
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Pacific Northwest DIY Synthesizer meeting, January 18, 2003
See: www.sound-photo.com
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