The peak-index calculator 301 calculates a peak index as an indication of PAR in accordance with gain factors ² of channels. The coefficient selector 302 includes a lookup table storing therein fitting coefficients X and Y each categorized in accordance with a combination of ², and selects coefficients X and Y each having a value determined in accordance with a combination of the gain factors ². The power-reduction calculator 303 calculates a reduction in maximum signal-transmission power in accordance with both the peak index and the selected coefficients X and Y. The TXAGC calculator 304 controls maximum signal-transmission power in accordance with the calculated reduction.
