Patent ID: 6222472
Filing Date: 2001-04-24
Classification: H03M

Abstract:
An automatic gain controller including an automatic gain control (AGC) amplifier and an analog-to-digital (A/D) converter for converting an analog signal output from the AGC amplifier to a digital signal, said automatic gain controller comprising:a power estimator connected to the A/D converter, for estimating a power of a signal input from the A/D converter;an IIR (Infinite Impulse Response) filter connected to the power estimator, for filtering the power output from the power estimator to attenuate noises and interferences;a comparator connected to the IIR filter, for receiving the filtered power output from the IIR filter and generating an AGC control gain,wherein said comparator compares the power output from the IIR filter with a plurality of regions, each of said regions having a minimum and maximum threshold value and, upon reaching any one of the threshold values, outputs an AGC correction gain value corresponding to the reached threshold value;a dB-to-D/A (Digital-to-Analog) input converter connected to the comparator, for converting the AGC correction gain output from the comparator to a D/A input signal; anda D/A converter connected to the dB-to-D/A input converter, for converting the D/A input signal output from the dB-to-D/A input converter to an analog AGC control signal and providing the AGC control signal to the AGC amplifier.