Proportional automatic gain control

Abstract

Automatic gain control in a digital signal processor. An incoming electrical signal is sampled and multiplied by a gain factor with the resulting product compared to a constantly changing maximum value. If the magnitude of the changing maximum value lies outside a predetermined range of values, then the gain factor is adjusted proportionally to the error calculated by the amount the maximum value is outside the threshold range. In an alternative embodiment, the gain is adjusted according to whether or not one of the resulting products lies outside such upper and lower threshold range. The running maximum value decays with time in order to allow the automatic gain control to rack a signal which slowly weakens in strength. A time dependent factor enables the gain to be adjusted much more radically when a signal is first received.

Dependencies are inferred from the claim text.