FDMA  is a channel access method which is used in multiple access protocols as a channelization protocol. It is currently used by all the mobile communication systems providing audio communication services. The Mobilesatellite system also uses SCPC DAMA for communication between mobile stations and base stations.

The two satellites in the mobile satellite system are non-linear region.

As shown in figure, then an amplifier is operated in the non-linear region signals that are amplified together are subjected to the following effects:

1. Intermodulation products
2. Spectral spread due to signal distortion
3. Suppression of small signals

The principle non-linear effects of satellite repeater

In non-linear effects of FDMA, 

1. Many channels share the same antenna at the base station
2. When operated near saturation for maximum power efficiency, the power amplifiers are non-linear.
3. Can cause signal spreading and generateinter-modulation frequencies and adjacent- channel interference.