Motivation and Technical Background
A non-linear channel is generally introduced when the transponder’s power amplifier is saturated. Standard equalization techniques are not sufficient to handle this distortion. The NovelSat NS3000 and NS300 Satellite Modems and the NovelSat NS1000 Satellite Modulator use an advanced Dynamic Distortion Compensation algorithm, NovelSat DDC, which dynamically characterizes the non-linearity (AM-AM and AM-PM as seen in Figure below) of the channel and compensates for it on the receiver side.
This is a post-equalizing technique which is much more convenient than standard non-linear pre-equalization techniques as the later require the utilization of a return channel to the transmitter, constantly providing feedback on the channel’s distortion.
Dynamic Distortion Compensation