Digitized automatic gain control system and methods for a controlled gain receiver

Abstract

An automatic gain control (AGC) system () for a controlled gain receiver () includes a magnitude generator () and a gain corrector (). The magnitude generator () generates a binary voltage squared signal () having a binary value that is directly proportional to a recovered signal power of an intercepted signal (). The gain corrector () determines an adjustment of a gain control value () as a multiple of increments that are approximately 3 decibel (dB), by shifting () a reference threshold by one or more bits and comparing () the shifted reference threshold to the binary voltage squared signal. An initial setting of a state of a step attenuator () during a track mode () is determined during a warm up mode () by comparing the binary voltage squared signal () to two different thresholds (). A filter () accommodates a variety of bandwidths and symbol rates by settings of an accumulator () and scaler () that are included in the filter (). A received signal strength indicator function () of the controlled gain receiver () generates a low resolution or high resolution RSSI signal (), depending on the mode. The value of the low resolution RSSI signal () is directly proportional to the power of the intercepted signal ().