The present invention addresses the problem of providing a signal process in which a countermeasure against eavesdropping over a physical layer in a wireless communication is performed. An optical signal generation unit 11 generates, as an optical signal, multivalued information that is in a multivalued state and is based on prescribed data. An E/O conversion unit 112 converts the optical signal to an electrical signal. An optical signal amplification unit 12 amplifies the optical signal. An O/E conversion unit 13 converts the optical signal to an electrical signal. A radio wave transmission unit 14 transmits, as a radio wave, the multivalued information converted into the electrical signal. The problem is solved thereby.