copies of the codes through the process of autocorrelation. The major problem in
OCDMA is the interference between user signals, called multiple access interference
(MAI). The discrimination achieved between user signals is determined primarily by
the set of codes chosen. Essentially good discrimination means long codes, but recall
from above that long codes mean a high channel chip rate and hence high channel
bandwidths are required, e.g., if each user were to require 1 GBPS and the code length
was 50 chips, then the channel bandwidth would be required to be 50 GBPS; codes
must be chosen so that the cross-correlation function between codes is low when
compared with the peak autocorrelation value. The combination of OCDMA with
CWDM technology in