In transmitting first information necessary for gaining synchronism of transmission signal and second information which is the other information by determining a break of a single modulation unit with a simple structure and processing prior to Fourier transformation on the side receiving a signal transmitted as a multi-carrier signal, a transmission symbol stream is expanded on a frequency axis. With a predetermined frequency position (for example, 0 kHz) as reference, a transmission symbol stream symmetrical is generated on the frequency axis and then, the transmission symbol stream symmetrical on the frequency axis is Fourier-transformed and transmitted.