MULTI-VALUED NUMBER VARIABLE MODEM AND RADIO COMMUNICATION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To eliminate code errors generated accompanying the changeover of a modulation system and to switch the modulation system without hit by providing an amplitude correction means for performing adjustment to a signal point level corresponding to the respective modulation systems. SOLUTION: In a multi-valued number variable modulator 100, the amplitude correction means 130 is inserted between an operating point correction circuit 110 and a digital modulator 120. The amplitude correction means 130 corrects amplitude by using a correction coefficient corresponding to the modulation system specified by modulation system control signals for base band signals outputted from the operating point correction circuit 110 and sends them out to the digital modulator 120. The amplitude correction means 230 of a multi- valued number variable demodulator 200 corrects the amplitude by using the correction coefficient (the inverse number of the correction coefficient in the multi-valued number variable modulator 100) corresponding to the modulation system specified by the modulation system control signals for the base band signals outputted from a digital demodulator 210 and sends them out to an error signal judgement circuit 220.