There are two very distinct types of CDMA system,classified as direct sequence CDMA and frequency hopping
CDMA. Both of these systems involve transmission bandwidths that are many times that
required by an individual user, with the energy of each user's signal spread with time throughout this wide channel. Consequently these
techniques are often referred to as spread spectrum systems.
One of the most prominent proponents of CDMA in the cellular market is Andrew Viterbi, and
his book on the subject (Viterbi, 1997) is well worth reading. |