predistorted

Predistorted is a term used in signal processing and related fields to describe a signal that has been intentionally modified to counteract a known distortion that will be applied to it later. The goal of predistortion is to ensure that the signal, after undergoing both the predistortion and the subsequent distortion, arrives at its destination in a form that is as close as possible to the original, undistorted signal.

This technique is commonly employed in communication systems, particularly in wireless transmission. Amplifiers, for instance, can introduce nonlinear distortions, especially when operating at high power levels. If a signal is predistorted to be the inverse of the amplifier's distortion characteristic, the combined effect of the predistortion and the amplifier's nonlinearity can effectively cancel out, resulting in a cleaner output signal.

The process typically involves characterizing the distortion introduced by the system component (like an amplifier) and then generating a predistorted signal that compensates for this characteristic. This predistorted signal is then passed through the distorting component. The success of predistortion relies on an accurate model of the distortion to be countered. If the distortion characteristics change over time or with operating conditions, the predistortion algorithm may need to adapt dynamically.