Automatic gain control using multiple equalized estimates dynamic hysteresis

A method of automatic gain control for one or more cascaded adjustable-gain analog amplifiers, the method comprising:

• providing one or more digitally equalized power estimates for one or more respective cascaded adjustable-gain analog amplifiers;
• selecting a first digitally equalized power estimate from the one or more digitally equalized power estimates, the selected first digitally equalized power estimate being associated with a first adjustable-gain analog amplifier in the one or more cascaded adjustable-gain analog amplifiers;
• determining whether to digitally adjust the selected first digitally equalized power estimate associated with the first adjustable-gain analog amplifier;
• providing, responsive to the determining, a gain control signal to the first adjustable-gain analog amplifier corresponding to the selected first digitally equalized power estimate;
• comparing the selected first digitally equalized power estimate to a first predefined digital threshold of power associated with the first adjustable-gain analog amplifier;
• and
• determining in the affirmative to digitally adjust the selected first digitally equalized power estimate associated with the first adjustable-gain analog amplifier if the comparing indicates that the selected first digitally equalized power estimate is greater than the first predefined digital threshold of power.

An integrated circuit, comprising:

• a circuit-supporting substrate;
• and
• an electronic circuit disposed on the circuit-supporting substrate, the electronic circuit comprising:
• a plurality of analog filters in an RF front-end section of an RF receiver;
• a plurality of adjustable-gain analog amplifiers in the RF front-end section for amplifying by a gain a signal received by the RF receiver, each adjustable-gain analog amplifier operable at one gain separately selected from a plurality of gains, the RF front-end section producing an analog signal at an analog output;
• a digital-to-analog converter, coupled to the analog output, for converting the analog signal to a digital signal at a digital output;
• and
• a digital automatic gain control (AGC) system, communicatively coupled with the plurality of adjustable-gain analog amplifiers, for controlling the one gain of each adjustable-gain analog amplifier, the digital AGC system including:
• a plurality of digital equalizer filters, one of the digital equalizer filters communicatively coupled with the digital output of the RF front-end section, thereby monitoring a digital signal estimate of the analog signal at the analog output of the RF front-end section, each digital equalizer filter having an inverse magnitude response of a corresponding analog filter in the RF front-end section;
• a plurality of digital estimation devices, each digital estimation device coupled to one of the digital equalizer filters, each digital estimation device providing a digital signal estimate representative of an analog signal at an input of a respective one of the adjustable-gain analog amplifiers in the RF front-end section;
• and
• an AGC controller, communicatively coupled with each digital estimation device, for monitoring the digital signal estimate provided by each digital estimation device, thereby monitoring a level of the analog signal at the input of the respective one of the adjustable-gain analog amplifiers in the RF front-end section, the AGC controller having a control output communicatively coupled with a respective control input of each adjustable-gain analog amplifier for separately controlling the one gain of each respective adjustable-gain analog amplifier.