Dynamics of a digital automatic gain control for Gaussian signals

Abstract

A simple digital automatic gain control loop, suitable for stabilizing the level of a slowly varying Gaussian signal in single-channel or multichannel applications is described. The probabilities of the excursion levels of the feedback control signal are derived and presented in normalized charts. These enable tradeoff between the signal level accuracy and the magnitude of the gain change steps to be readily accomplished and the corresponding increase in signal rms deviation due to the control signal to be determined.