Automatic gain control apparatus and method in wireless telecommunication system

The present invention relates to an automatic gain control apparatus and method for a wireless communication system for measuring a received signal strength using a preamble symbol (preamble symbol) in a wireless communication system, and automatically adjusts the gain of the amplifier based on the result. The present invention is an automatic gain control apparatus and method, the input after measuring the sample power in samples for the signal to obtain the sample power average value for the unit symbol interval, thus a single frame period with respect to the sample the power mean value obtained in the wireless communication system and then detects the maximum value for a, characterized in that for performing automatic gain control on the basis and calculating the gain adjustment value thereto.