**2.4 Code division multiplexing or code division multiple access**

Code Division Multiple Access (CDMA) is a multiple access method that allows multiple users to share the same time and frequency resources.

In a CDMA system, each user is assigned with specific spreading code, and all users can send information simultaneously over a single communication channel. Since CDMA is based on the spread spectrum principle, each transmitter will use a pseudo-random code to modulate the data, and the receiver decodes the modulated signal using its own pseudo-random code. The principle of CDMA is illustrated in **Figure 7**.
