Radar device, radar operation method, and non-transitory computer-readable recording medium

A radar device comprising:

• a transmission module including
• a transmission-side signal generation unit being a circuit to generate a signal as a transmission-side original signal,
• at least one transmission-side pseudo-random number generation unit, each of the at least one transmission-side pseudo-random number generation unit being a circuit, to generate a transmission-side pseudo-random number sequence formed of a pseudo-random number of one bit or more,
• a transmission-side encryption processing unit being a circuit to receive a true random number sequence formed of a true random number of one bit or more and to generate a transmission-side encryption sequence, which is a signal sequence of encryption, by using the true random number sequence,
• at least one transmission-side modulation code synthesizing unit, each of the at least one transmission-side modulation code synthesizing unit being a circuit, to generate a transmission-side modulation code sequence for use in modulating a signal phase by synthesizing the transmission-side pseudo-random number sequence and the transmission-side encryption sequence, the transmission-side modulation code sequence including a component derived from the transmission-side encryption sequence, and
• at least one phase modulation unit, each of the at least one phase modulation unit being a circuit, to generate a transmission signal by modulating a phase of the transmission-side original signal by using the transmission-side modulation code sequence;
• and
• a reception module including
• a reception-side signal generation unit being a circuit to generate a signal corresponding to the transmission-side original signal as a reception-side original signal,
• at least one reception-side pseudo-random number generation unit, each of the at least one reception-side pseudo-random number generation unit being a circuit, to generate a reception-side pseudo-random number sequence formed of a pseudo-random number of one bit or more,
• a reception-side encryption processing unit being a circuit to receive the true random number sequence and to generate a reception-side encryption sequence, which is a signal sequence of encryption, by using the true random number sequence,
• at least one reception-side modulation code synthesizing unit, each of the at least one reception-side modulation code synthesizing unit being a circuit, to generate a reception-side modulation code sequence, by synthesizing the reception-side pseudo-random number sequence and the reception-side encryption sequence, for use in modulating a signal phase, the reception-side modulation code sequence including a component derived from the reception-side encryption sequence,
• at least one mixer unit, each of the at least one mixer unit being a circuit, to receive a signal as a reception signal and to generate a mixer output signal by mixing the reception-side original signal and the reception signal,
• at least one low-pass filter unit, each of the at least one low-pass filter unit being a circuit, to generate a beat signal by extracting a low frequency wave of the mixer output signal, and
• processing circuitry to demodulate the beat signal by using the reception-side modulation code sequence, wherein
• two said transmission-side modulation code sequences are transmission-side modulation code sequences in which a component derived from the transmission-side encryption sequence disappears by synthesizing two transmission-side modulation code sequences,
• two said reception-side modulation code sequences are reception-side modulation code sequences in which a component derived from the reception-side encryption sequence disappears by synthesizing two reception-side modulation code sequences,
• the number of the at least one transmission-side pseudo-random number generation unit, the number of the at least one reception-side pseudo-random number generation unit, the number of the at least one transmission-side modulation code synthesizing unit, the number of the at least one reception-side modulation code synthesizing unit, and the number of the at least one phase modulation unit each match the number of the at least one transmission antenna, and
• the number of the at least one mixer unit and the number of the at least one low-pass filter unit each match the number of the at least one reception antenna.

A non-transitory computer-readable recording medium recorded with a radar operation program that causes a computer to:

• generate a signal as an original signal;
• generate a pseudo-random number sequence formed of a pseudo-random number of one bit or more;
• generate a true random number sequence formed of a true random number of one bit or more;
• generate a modulation code sequence for use in modulating a signal phase by synthesizing the pseudo-random number sequence and the true random number sequence, the modulation code sequence including a component derived from the true random number sequence;
• and
• generate a transmission signal by modulating a phase of the original signal by using the modulation code sequence, wherein
• the modulation code sequence is a modulation code sequence in which the component derived from the true random number sequence disappears by synthesizing two modulation code sequences.