Patent ID: 8660221

Claim:
A fast and robust automatic gain control (AGC) apparatus, comprising: a power detector, electrically connected to a first analog-to-digital converter and a second analog-to-digital converter, used for providing a plurality of measured power (P i ), wherein P i is equal to the sum of squares of a first signed signal (I i ) provided by the first analog-to-digital converter and a second signed signal (Q i ) provided by the second analog-to-digital converter; a statistics-aided AGC algorithm unit, electrically connected to the first analog-to-digital converter, the second analog-to-digital converter and the power detector, used for determining an additional AGC gain adjustment (Δ Aided ) according to a amplitude statistics of a plurality of M pairs of the first signed signal (I i ) and the second signed signal (Q i ), or a power statistics of the plurality of measured power (P i ), wherein M is an integer from 1 to 100; a subtractor, electrically connected to the power detector, used for evaluating a power differences between a desired received signal power (P D ) and each of the plurality of measured power (P i ) and providing a plurality of AGC power error signals, wherein the plurality of AGC power error signals are equal to the desired received signal power (P D ) minus the plurality of measured power (P i ); an average unit, electrically connected to the subtractor, used for averaging the plurality of AGC power error signals and providing an average AGC power error signal; an adder, electrically connected to the average unit and the statistics-aided AGC algorithm unit, used for providing a gain adjustment by adding the additional AGC gain adjustment (Δ Aided ) to the average AGC power error signal; a multiplier, electrically connected to the adder, used for controlling a AGC loop gain by an adjustable gain (k); an accumulator, electrically connected to the multiplier, used for tracking a plurality of average AGC power error, adding the plurality of average AGC power error signals up, storing and providing an appropriate digital gain value (G linear ); and a LNA and VGA control mapping unit, electrically connected to the accumulator, used for converting the appropriate digital gain value (G linear ) into a LNA and VGA gain control signal.