A transmission device (10) includes: a series/parallel converter (11); an MSK modulator (31) for modulating a signal on a channel basis; a D/A converter (13); a frequency converter (14a) for conversion into different carrier frequencies; a synchronization circuit (32); an amplifier (15); a multiplexer (16) for multiplexing amplification signals; and an antenna (19). A reception device (20) includes: an antenna (21); a demultiplexer (22); a frequency converter (23) for converting signal demultiplexed on a channel basis into a baseband frequency; a low-pass filter (33) for removing a higher-harmonic component of the signal; an A/D converter (24); a digital filter (36) for extracting a main wave component from the digital signal; a sampling point detection circuit (35a) for detecting a sampling point from the main wave component; an MSK demodulator (34a) for reproducing and demodulating a symbol point based on detection information by an interpolation process; and a parallel/series converter (26) for restoring an original signal from the demodulated signal.