at this time sequencer 105 activates reception section 103 and reception section 103 acquires transmission signal step s 3 further sequencer 105 activates delay adjustment section 104 and delay adjustment section 104 eliminates the delay of a demodulation signal with respect to a baseband signal whereby the delay amount of the demodulation signal with respect to the baseband signal is computed step s 4 then delay adjustment section 104 performs delay adjustment for delaying the baseband signal and the demodulation signal by the computed delay amount step s 5 thereafter sequencer 105 determines whether the outputs of the baseband signal and the demodulation signal from delay adjustment section 104 have been brought into a steady state step s 6 when it is determined that the outputs have not been brought into a steady state step s 6 no the processes subsequent to step s 2 are executed when it is determined that the outputs have been brought into a steady state step s 6 yes delay adjustment section 104 stores information of the delay amounts of the baseband signal and the demodulation signal resulting from the delay adjustment in a memory or the like step s 7 thereafter sequencer 105 activates distortion compensation section 101 and distortion compensation section 101 computes a phase difference caused by phase rotation between the baseband signal and the demodulation signal then distortion compensation section 101 adjusts the phase of the.