Automatic gain control circuit with multiple input signals

摘要

An automatic gain control circuit in a receiver estimates an AGC gain using information from an estimated amplitude signal derived from a received signal before a carrier signal is recovered from the received signal. The carrier signal is recovered from the received signal using the estimated AGC gain. After the carrier signal is recovered, the amplitude of the estimated amplitude signal decreases below the amplitude of the recovered carrier signal. The Automatic Gain Control circuit uses the amplitude of the recovered I and/or Q signal to accurately set the AGC gain.