An automatic gain control circuit including a variable gain amplifier (11) adapted to receive a received signal (R) and to output an amplified signal (A) to an analog to digital converter (20), and a gain controller (12) which is connected to said variable gain amplifier (11) for receiving said amplified signal (A) and for controlling a gain of said variable gain amplifier (11). The gain controller (12) is adapted to determine an occurrence of a threshold event each time the amplified signal (A) has reached a predetermined threshold, decrease the gain of the variable gain amplifier (11) at each occurrence of a threshold event, measure a delay since the last threshold event, increase the gain of the variable gain amplifier (11) if the delay is greater than a delay specified value and if the gain of the variable gain amplifier (11) is not maximum.