Automatic gain control method and apparatus in communication system having discontinuous transmission mode

A wireless receiver 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 wireless receiver comprising:

• an antenna for receiving a RF signal corresponding to a first frame of a first signal block sent by the wireless transmitter;
• a receiver module connected to the antenna for amplifying the RF signal corresponding to the first frame with a gain value and down converting the RF signal to generate a baseband signal;
• a discontinuous transmission detection module connected to the receiver module for determining whether the first signal block is in the discontinuous transmission mode or not by comparing a first number with a predefined number;
• the first number corresponds to the number of valid frames belonged to the first signal block;
• if the first number is not smaller than the predefined number, then the discontinuous transmission detection module determines that the first signal block is not in the discontinuous transmission mode, otherwise the discontinuous transmission detection module determines that the first signal block is in the discontinuous transmission mode;
• a gain control module connected to the receiver module and the discontinuous transmission detection module for adjusting the gain value used by the receiver module;
• wherein after receiving the first frame of the first signal block, the gain control module updates the gain value according to the power level of the baseband signal corresponding to the first frame;
• then the receiver module uses the updated gain value for amplifying the RF signal corresponding to a second frame when receiving the second frame;
• and if the discontinuous transmission detection module determines that the first signal block is in the discontinuous transmission mode, the gain control module resumes the gain value according to the power level of the baseband signal corresponding to a third frame that belongs to a third signal block sent before the first signal block and the third signal block is not in the discontinuous transmission mode.

An automatic gain control apparatus applied in a wireless receiver, the wireless receiver 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 receiver having a receiver module for amplifying a received RF signal corresponding to a first frame with a gain value and down converting the RF signal to generate a baseband signal, the wireless transmitter having a discontinuous transmission mode, the apparatus comprising:

• a discontinuous transmission detection module connected to the receiver module for determining whether a first signal block is in the discontinuous transmission mode or not, wherein the first signal block contains the first frame, wherein the discontinuous transmission detection module determines whether a first signal block is in the discontinuous transmission mode or not by comparing a first number with a predefined number;
• the first number corresponds to the number of valid frames belonged to the first signal block;
• if the first number is not smaller than the predefined number, then the discontinuous transmission detection module determines that the first signal block is not in the discontinuous transmission mode, otherwise the discontinuous transmission detection module determines that the first signal block is in the discontinuous transmission mode;
• a gain control module connected to the receiver module and the discontinuous transmission detection module for adjusting the gain value used by the receiver module;
• wherein after receiving the first frame of the first signal block, the gain control module updates the gain value according to the power level of the baseband signal corresponding to the first frame;
• then the receiver module uses the updated gain value for amplifying the RF signal corresponding to a second frame when receiving the second frame;
• and if the discontinuous transmission detection module determines that the first signal block is in the discontinuous transmission mode, the gain control module resumes the gain value according to the power level of the baseband signal corresponding to a third frame that belongs to a third signal block sent before the first signal block and the third signal block is not in the discontinuous transmission mode.