To prevent deterioration of the transmitting spectrum when the trans mission is started by inputting a training signal in place of a modulated signal to carry out a training operation.

A digital signal string showing a complex modulated signal which is inputted from an input terminal 101 is supplied to the address of a RAM 103 via a switch 115 that is controlled by a controller 118. The RAM 103 outputs the compensation data whose address is designated by a modulated signal. An adder 104 adds together the modulated signal and the compensation data, and this addition result is turned into an original signal waveform via an amplifier 111. The output of the adder 104 is converted into an analog signal by a D/A converter zoo, and the carrier signal sent from an oscillator 110 undergoes the quadrature modulation 108 and is outputted through an antenna. When the controller 118 designates a training operation, a switch 116 is connected to a termination circuit 119. Then the output training signal of a training signal generator 117 updates the RAM 103 in place of the input signal of the terminal 101.