Abstract: A group modulator provided a plurality of digitally modulated signals with frequency division multiplex, having a time division multiplexer (11) for multiplexing a plurality of input data (#l through #n). A mapping circuit (12) provides an I-channel signal and a Q-channel signal according to a pattern of the multiplexed signal and the modulation system. A pulse shaping circuit (13) restricts bandwidth of the I-channel signal and the Q-channel signal. A frequency shift circuit (14) shifts frequency of the I-channel signal and the Q-channel signal by the frequency defined by the carrier control signal (i) for each input data. An accumulator (21,22) accumulates each of the I-channel signal and the Q-channel signal of the output of the frequency shift circuit (14) during a predetermined period (T). A D/A converter (31, 32) converts the output of the accumulator from digital form to analog form. A low pass filter (41, 42) is provided at the output of the D/A converter.