The device for controling automatic gain and the device for receiving signal and the mathod for receiving signal

An automatic gain controller, a signal receiver, and a signal receiving method are provided to secure accuracy of a size of a signal by controlling a gain by using only a section with a receiving signal when receiving an aperiodic burst signal. A symbol synchronization searcher(206) searches symbol synchronization of a receiving signal and counts the symbol according to the searched symbol synchronization. A symbol section searcher(213) divides the receiving signal of a frequency domain into a symbol section and a noise section. The symbol synchronization searcher includes a counter. The counter counts the number of symbol from the synchronous point searched from the symbol synchronization searcher. A controller calculates the size of the signal of the symbol section about the receiving signal of the frequency domain. The controller produces the size of the signal in the noise section based on the size of the signal of the symbol section. The controller generates the gain control signal according to the size of the signal of the symbol section and the noise section.