Techniques for fast automatic gain control

A system for providing quick automatic gain control in a receiver, the receiver operable in a wireless communication system, the system comprising:

• a plurality of variable gain amplifiers (VGAs) for amplifying an analog signal;
• a peak detector block including:
• a plurality of peak detectors, wherein at least one peak detector is connected to one node before the VGAs, another node between the VGAs, and yet another node after the VGAs, each peak detector for detecting an amplitude of the analog signal;
• a comparator having first and second input terminals, the first input terminal for receiving a programmable threshold value;
• a switch for selectively connecting one peak detector to the second input terminal of the comparator;
• a mixer set for converting an amplified output of a last VGA of the plurality of VGAs into in-phase (I) and quadrature (Q) components;
• a filter set for receiving the I and Q components and generating a baseband signal;
• an analog to digital converter (ADC) for converting the baseband signal to a digital signal;
• and
• an automatic gain control (AGC) for receiving an output of the comparator of the peak detector block and providing a control signals to the plurality of VGAs.