Patent ID: 8159297

Claim:
A transmission device comprising: an amplifier that amplifies a transmission signal according to a voltage to be applied; an envelope detector that detects an envelope signal of the transmission signal; a rate decreasing unit that decreases a changing rate of the envelope signal; a voltage controller that changes the voltage applied to the amplifier according to the envelope signal of which changing rate is decreased by the rate decreasing unit; a voltage-control-distortion compensation-coefficient deciding unit that decides a distortion compensation coefficient for compensating for a voltage-control distortion, according to the envelope signal detected by the envelope detector and the envelope signal of which changing rate is decreased by the rate decreasing unit, the voltage-control distortion being a distortion occurring in the amplifier caused by a phase difference between the voltage applied to the amplifier by the voltage controller and the transmission signal input to the amplifier; a distortion compensation-coefficient multiplier that multiplies the transmission signal by the distortion compensation coefficient; a power calculator that calculates a power value of the transmission signal; a nonlinear-distortion compensation-coefficient deciding unit that decides a distortion compensation coefficient for compensating for a nonlinear distortion, according to the power value of the transmission signal, the nonlinear distortion being a distortion occurring in the amplifier caused by nonlinear characteristic of the amplifier; a distortion compensation-coefficient multiplier that multiplies the transmission signal by the distortion compensation coefficient decided by the nonlinear-distortion compensation-coefficient deciding unit; and a distortion compensation-coefficient updating unit that updates the distortion compensation coefficient decided by the voltage-control-distortion compensation-coefficient deciding unit or the distortion compensation coefficient decided by the nonlinear-distortion compensation-coefficient deciding unit.