Patent ID: 7466776

Claim:
An automatic gain control method used in a wireless receiver, the wireless receiver being for receiving a plurality of signal blocks sent by a wireless transmitter, each of the plurality of signal blocks comprising at least one frame, the wireless transmitter having a discontinuous transmission mode, the method comprising: receiving a first frame, amplifying a RF signal corresponding to the first frame with a gain value and down converting the RF signal to generate a baseband signal; updating the gain value according to the power level of the baseband signal corresponding to the first frame, wherein the updated gain value is for amplifying the RF signal corresponding to a second frame when receiving the second frame; determining whether a first signal block is in the discontinuous transmission mode or not, wherein the first frame belongs to the first signal block, wherein determining whether the first signal block is in the discontinuous transmission mode or not further comprises: computing a first number of valid frames belonged to the first signal block; comparing the first number with a predefined number; determining that the first signal block is not in the discontinuous transmission mode if the first number is larger than or equal to the predefined number; and determining that the first signal block is in the discontinuous transmission mode if the first number is smaller than the predefined number; and resuming the gain value according to the power level of the baseband signal corresponding to a third frame if the first signal block is in the discontinuous transmission mode; wherein the third frame belongs to a third signal block which is sent before the first signal block and the third signal block is not in the discontinuous transmission mode.