1. US20040137868 - Automatic gain control

The invention relates to gain control for an amplifier for received radio signals by means of an automatic gain control signal (c). A down converter (103) produces signal components (I; Q) that are amplified in a respective amplifier (104, 105). Then, the resulting signal components (I_P-LP; Q_P-LP) are digitised in A/D-converters (110; 111) for further processing in a digital signal processor (112) and are also fed to a respective signal level detector (113; 114) whose output signals ([I]; [Q]) are combined (115) into a combined signal (V_Σ). This signal (V_Σ) is forwarded to a gain control unit (116), which produces the automatic gain control signal (c). The automatic gain control signal (c) controls the gain of the amplifiers (104; 105) such that the resulting signal components (I_P-LP; Q_P-LP) are maintained at signal level ([I]; [Q]) less than a predetermined limit level being adapted to the A/D-converters (110; 111).