Never really delved into the 802.11 protocol, but it uses DSSS, Direct-Sequence Spread-Spectrum, so yeah, the sequence is a know.
CDMA by the way, stands for Code Division Multiple Access.... basically it means that, for example, 10 mobile phones could at the same time be on one frequency, but with no interference. Each of the 10 mobiles receives all 4.5 conversations(huh? think about it
), but each packet of data, that each phone receives is preceded by an identifier, so the phones would just ignore the other 9 packets of data because the identifiers don't match the one it is looking for.
A nice way for the telco's to get thousands of phone calls onto a limited number of channels in the band... sound familiar?