[BC] CDMA Cellphones

[stanleybadams]

In the CDMA system ALL cell sites and mobiles use the same exact frequency
until that becomes so congested that we just lay in an other channel layer,
which can be as close as 1.25 mhz to the original channel.  How we fool the
system into thinking that all of this digital noise is not noise is to use a
long multiplier code that is extremely complex.  It is so complex that I
have never seen an adequate explanation of it.  There are several versions
of it but basically it is what we call the long Walsh code and the short
Walsh code.  The long Walsh code provides a phase modulated offset that
gives just enough information to trick the system into thinking that it is
it's own channel; the short code is the demodulated trick.  All of this is
done on AM suppressed carrier dual sideband Quam modulation. We are now up
to 16 bit modulation schemes in a 1.25 mhz bandwidth at 2 ghz and at 12
watts.

Now what do you think about that?

The entire system works on about 12 different layers all operating at the
same time with in perfect sync.  It is complicated in the extreme but it
also is about the best thing that is out there.  We are going to be mixing
TDMA with CDMA to offer 3 meg digital data this year in the Sprint network.
Just imagine having a better than average DSL line in your Sprint phone.

www.howcdmaworks.com is a plug for a good friend and acquaintance for some
on this web site, Scott Baxter who left the lowly world of broadcast a
number of years ago to teach the world about CDMA wireless.

Stanley Adams
Memphis