#### In-depth

## Examples of FDMA/CDMA and FDMA/FDMA combinations

An example of a CDMA/FDMA combination is the IS-95 cellular system described earlier which uses spread spectrum over 1.25 MHz channels, with a number of these wideband channels being used to make up a typical cellular service. The GSM system we have seen is both a TDMA and frequency hopped CDMA technique. There are even some applications of so-called FDMA/FDMA systems such as the DC/MA system (see in-depth), where 25 kHz FDMA channels are further subdivided by frequency into five or more individual voice and data channels, each user being able to access some or all of these channels to give a higher composite data rate. |