A power correction value generating unit determines a power correction value for minimizing an error, from a reference output power value of a carrier multiplexed signal, generating due to peak power suppression under a carrier setting based on the carrier setting relating to either one or both of the number of carrier signals and frequency arrangement, and peak suppression setting. An output power error correcting unit corrects a signal gain before or after the carrier signals are multiplexed, using the power correction value obtained by the power correction value generating unit. In an apparatus performing peak suppression according to an input limitation power of the power amplifier, it is possible to always obtain a desirable transmission (output) power even when the number of carriers or carrier frequency arrangement varies.