Radar device, radar operating procedures and radar operating program

Abstract

Radar device (10), comprising: a signal generation unit (100) for generating a signal as an original signal; at least one unit (102) for generating pseudorandom numbers in order to generate a pseudorandom number sequence formed from a pseudorandom number of one bit or more; a unit (101) for generating true random numbers, in order to generate a true random number sequence formed from a true random number of one bit or more; at least one modulation code synthesis unit (103) for generating a modulation code sequence for use in modulating a signal phase by synthesizing the pseudorandom number sequence and the true random number sequence, wherein the modulation code sequence includes a component derived from the true random number sequence; and at least one phase modulation unit (104) for generating a transmit 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 real random number sequence disappears by synthesizing two modulation code sequences; still comprehensive: at least one transmitting antenna (105) for converting the transmit signal into a transmitting wave and for transmitting the transmitting wave; at least one receiving antenna (106) for receiving a receiving wave corresponding to the transmitting wave and for converting the receiving wave into a receiving signal; at least one mixer unit (107) for generating a mixer output signal by mixing the original signal and the received signal; at least one low-pass filter unit (108) for generating a beat signal by extracting a low-frequency wave from the mixer output signal; and a demodulation unit (121) for demodulating the beat signal by using the modulation code sequence, wherein the number of at least one unit (102) for generating pseudorandom numbers, the number of at least one modulation code synthesis unit (103) and the number of at least one phase modulation unit (104) each match the number of at least one transmitting antenna (105), and the number of at least one mixer unit (107) and the number of at least one low-pass filter unit (108) each match the number of at least one receiving antenna (106); characterized by the fact that either: The unit (101, 316) generates a true random number of one bit by converting an extreme value of the beat signal into a binary number; or: the radar device (10, 30) comprises a plurality of low-pass filter units (108, 308), and the unit (101, 316) for generating true random numbers generates random number bits, wherein each of the random number bits is generated using each of the beat signals corresponding to each of the plurality of low-pass filter units (108, 308), and a true random number of one bit is generated by performing an exclusive OR operation or an exclusive NOR operation using the generated random number bits.

Description

field of technology

[0001] The present disclosure relates to a radar device, a radar operating method and a radar operating program. State of the art

[0002] A radar is a device that emits electrical waves toward a target and measures the waves reflected from the target, thereby determining the relative distance between the radar and the target, the target's relative speed, or similar parameters. A frequency-modulated continuous wave (FMCW) system is one such radar system, and it is inexpensive yet excellent in its ability to measure distance and speed. In particular, a fast FMCW system has a higher resolution than a conventional slow FMCW system. A fast FMCW system is one in which the sweep time of a chirp signal is relatively short, that is, a few microseconds.

[0003] A radar using a MIMO (Multiple Input Multiple Output) system can measure an angle and improve angular resolution. A MIMO system utilizes multiple transmitting and receiving antennas.

[0004] Furthermore, there is a method for modulating a phase to avoid mutual interference of transmitted waves from multiple transmitting antennas. A well-known technique involves modulating the phase by assigning each element of a highly autocorrelated pseudorandom number sequence, such as an M-sequence or Gold sequence, to 0 or π.

[0005] Deception is a danger when operating radar. Deception is an attack in which a false measurement is generated by introducing an external electrical wave, disguised as a reflected wave, into the radar. Non-patent literature 1 discloses, as a countermeasure to deception, a measurement system for modulating a chirp of a slow FMCW radar by using a relatively simple pseudorandom number to detect an attack by using the frequency and amplitude of a beat signal. The slow FMCW radar is a radar that utilizes a slow FMCW system.

[0006] Patent document 1 describes a vehicle radar detection system using a high-rate random number generator. Patent document 2 discloses a radar sensor with two-dimensional beam steering and an L-, U-, or T-shaped structure for installation in the area of ​​the front radiator of an automobile. Patent document 3 relates to the deletion of signal residues that arise during the demodulation of a received signal. List of cited documents Patent literature Patent literature 1: Printed document US 9575160 B1 Patent literature 2: Publication DE 10 2017 200 383 A1 Patent Literature 3: Printed Publication US 2017 / 0160380 A1 Non-patented literature

[0007] Non-Patent Literature 1: Suzuki, Nashimoto, et al.: “Randomizing Chirp Signal in Frequency Modulated Continuous Wave Radar,” SCIS2018, 2018 Symposium on Cryptography and Information Security, Niigata, Japan, Jan. 23-26, 2018, The Institute of Electronics, Information and Communication Engineers. Outline of the invention: Technical task

[0008] To determine whether deception is present, the slow FMCW radar must change (modulate) the edge of an FMCW signal upwards or downwards.

[0009] Fast FMCW radar must process a multitude of waveforms in aggregate to measure a target's position or speed. Fast FMCW radar is a radar that utilizes a fast FMCW system. When a fast FMCW radar detects deception, the frequency of a beat signal changes in a manner similar to that of slow radar, corresponding to the edge of an FMCW signal. This can interfere with the measurement of the target's position, speed, or other parameters.

[0010] Furthermore, since the pseudorandom number sequence, such as an M-sequence or Gold sequence, which is conventionally used to modulate a phase in MIMO radar, does not exhibit many variations, it is known that the next appearing value can be guessed when observing in the middle. MIMO radar is a radar that utilizes a MIMO system.

[0011] Consequently, relatively simple interference countermeasures do not serve as countermeasures against deception attacks, such as guessing a sequence used for phase modulation.

[0012] An object of the present invention is to provide a radar device capable of reducing the risk of guessing the sequence used for phase modulation, wherein the radar device incorporates measures that do not impair the measurement of the target's position, velocity, or the like. The radar device of the present disclosure is typically a radar device employing a fast FMCW system. Technical solution

[0013] To solve this technical problem, radar devices according to the independent claims and a radar operating method comprising the use of a radar device according to one of the independent claims are proposed. Individual embodiments are described in the dependent claims. Advantageous effects of the invention

[0014] According to the radar device of the present disclosure, it is possible to provide a radar device that is able to reduce the risk of guessing the sequence used for phase modulation, wherein the radar device has implemented measures that do not impair the measurement of the position, speed or the like of the target. Brief description of the drawings Fig. Figure 1 illustrates an example of a structure of a radar device 10 according to embodiment 1. Fig. Figure 2 illustrates an example of a hardware structure of a signal processing device 110 according to embodiment 1. Fig. Figure 3 is a flowchart illustrating the operation of the radar device 10 according to embodiment 1. Fig. Figure 4 is a diagram illustrating a process in which a transmit signal S105 is generated according to embodiment 1. Fig. Figure 5 is a diagram describing the operation of a demodulation unit 121 according to embodiment 1. Fig. Figure 6 illustrates an example of a structure of the radar device 10 according to a modification example of embodiment 1. Fig. Figure 7 illustrates an example of a structure of the signal processing device 110 according to the modification example of embodiment 1. Fig. Figure 8 is a flowchart illustrating the operation of the radar device 10 according to the modification example of embodiment 1. Fig. Figure 9 illustrates an example of a structure of a radar device 20 according to a modification example of embodiment 1. Fig. Figure 10 illustrates an example of a hardware structure of a computer 200 according to the modification example of embodiment 1. Fig. Figure 11 is a diagram describing an example of a process in which a unit 225 for generating true random numbers generates a random number according to the modification example of embodiment 1. Fig. Figure 12 is a flowchart illustrating the operation of unit 225 for generating true random numbers according to the modification example of embodiment 1. Fig. Figure 13 illustrates an example of the structure of the signal processing device 110 according to a modification example of embodiment 1. Fig. Figure 14 illustrates an example of a structure of a radar device 30 according to embodiment 2. Fig. Figure 15 is a flowchart illustrating the operation of the radar device 30 according to embodiment 2. Fig. Figure 16 illustrates an example of a structure of a radar device 40 according to a modification example of embodiment 2. Fig. Figure 17 illustrates an example of a hardware structure of a receiver control computer 410 according to the modification example of embodiment 2. Fig. Figure 18 illustrates an example of a hardware structure of a transmit control computer 400 according to the modification example of embodiment 2. Description of embodiments Embodiment form 1.

[0015] The present embodiment is described in detail below with reference to the drawings. ***Description of the structure***

[0016] A radar device 10 according to the present embodiment typically employs a fast FMCW (Frequency Modulated Continuous Wave) system and also employs a MIMO (Multiple Input Multiple Output) system. The MIMO system is a system that utilizes a plurality of transmitting antennas and a plurality of receiving antennas.

[0017] Fig. Figure 1 illustrates an example of the structure of the radar device 10 according to the present embodiment. Black circles in this drawing indicate that a plurality of lines are connected to each other at contact with the black circles. If no black circle is shown at a point where a plurality of lines intersect, the plurality of lines are not connected.

[0018] As illustrated in this drawing, the radar device 10 has a transmitting unit 15 and a receiving unit 16.

[0019] The transmitting unit 15 comprises a signal generation unit 100, a unit 101 for generating true random numbers, a plurality of units 102 for generating pseudorandom numbers, a plurality of modulation code synthesis units 103, a plurality of phase modulation units 104, and a plurality of transmitting antennas 105. In this drawing, all transmitting antennas 105 are designated as "105-1" and "105-2" for identification purposes. The same applies to the plurality of other components included in each radar device described herein.

[0020] The number of units 102 for generating pseudorandom numbers, the number of modulation code synthesis units 103 and the number of phase modulation units 104 each correspond to the number of transmitting antennas 105.

[0021] The signal generation unit 100, the true random number generation unit 101, the pseudorandom number generation unit 102, the modulation code synthesis units 103, and the phase modulation units 104 each typically consist of a circuit. A circuit can implement a plurality of components of the radar device 10. Alternatively, a plurality of circuits can implement a component of the radar device 10. Each component described as comprising a circuit can include a computer. Each computer described in the description can be composed of a plurality of computers. The computer can optionally convert a digital signal to an analog signal and, if necessary, convert an analog signal to a digital signal.

[0022] The signal generation unit 100 generates a signal as an original signal S101.

[0023] Unit 101 for generating true random numbers generates a true random number sequence S102, formed from true random numbers of one bit or more.

[0024] The Unit 101 for generating true random numbers can generate a true random number of one bit by converting an extreme value of a beat signal S110 into a binary number. The Unit 101 for generating true random numbers can generate a true random number of one bit by generating random number bits, each corresponding to a plurality of LPF Unit 108, using the beat signals S110, each corresponding to the plurality of LPF Unit 108, and performing an exclusive OR operation or an exclusive NOR operation using the generated random number bits.

[0025] Unit 102 for generating pseudorandom numbers generates a pseudorandom number sequence S103, formed from pseudorandom numbers of one bit or more.

[0026] The modulation code synthesis unit 103 synthesizes a pseudorandom number sequence S103 and a true random number sequence S102 to generate a modulation code sequence S104 for use in signal phase modulation and containing components derived from the true random number sequence S102. The components derived from the true random number sequence S102 are influences of the true random number sequence S102 contained within the elements. The modulation code sequence S104 is the modulation code sequence S104 itself, so two modulation code sequences S104 are synthesized to cause the components derived from the true random number sequence S102 to disappear. The modulation code sequences S104 can be the same or different from each other.

[0027] It should be noted that a system for synthesizing the pseudorandom number sequence S103 and the true random number sequence S102, as well as a system for synthesizing two modulation code sequences S104, may be different.

[0028] The modulation code synthesis unit 103 can generate a modulation code sequence by performing an exclusive OR operation or an exclusive NOR operation.

[0029] An element of a sequence refers to a minimal unit that configures the sequence. As a concrete example, the sequence is formed from an array. In this example, an element of a sequence is an element of an array.

[0030] The phase modulation unit 104 generates a transmit signal S105 by modulating the phase of the original signal S101 by using the modulation code sequence S104.

[0031] The transmitting antenna 105 converts the transmit signal S105 into a transmit wave S106 and transmits the transmit wave S106.

[0032] The receiving unit 16 comprises a plurality of receiving antennas 106, a plurality of mixer units 107, a plurality of LPF (low-pass filter) units 108, a plurality of ADC (analog-to-digital converter) units 109, and a signal processing device 110. The LPF units are also referred to as low-pass filter units.

[0033] The number of mixer units 107, the number of LPF units 108 and the number of ADC units 109 each correspond to the number of receiving antennas 106.

[0034] The mixer units 107, the LPF units 108 and the ADC units 109 typically each consist of a circuit.

[0035] The receiving antenna 106 receives a receiving wave S107 corresponding to the transmitting wave S106 and converts the receiving wave S107 into a receiving signal S108.

[0036] The mixer unit 107 generates a mixer output signal S109 by mixing the original signal S101 and the received signal S108.

[0037] The LPF unit 108 generates the beat signal S110 by extracting a low frequency wave from the mixer output signal S109.

[0038] The original signal S101 is a signal generated by the signal generation unit 100. The true random number sequence S102 is a sequence formed from signals generated by unit 101 to generate true random numbers. The pseudorandom number sequence S103 is a sequence formed from signals generated by unit 102 to generate pseudorandom numbers. The modulation code sequence S104 is a sequence formed from signals generated by the modulation code synthesis unit 103, which synthesizes the true random number sequence S102 and the pseudorandom number sequence S103. The transmit signal S105 is a signal obtained by the phase modulation unit 104, which modulates the original signal S101 using the modulation code sequence S104.

[0039] It should be noted that with regard to the bits that configure the true random number sequence S102, it is assumed that each is not significantly larger than the other in terms of the number of bits whose values ​​are 0 and the number of bits whose values ​​are 1.

[0040] The transmitting wave S106 is a signal sent by the transmitting antenna 105. The receiving wave S107 is the transmitted wave S106 reflected by a target 11 and is a signal that reaches the receiving antenna 106.

[0041] The number of transmitting waves S106 corresponds to the number of transmitting antennas 105. A maximum value for the number of receiving waves S107 corresponds to a number obtained by multiplying the number of transmitting antennas 105 by the number of receiving antennas 106. For example, as in Fig. 1. The radar device 10 comprises two transmitting antennas 105 and four receiving antennas 106, and a maximum of eight receiving waves S107 exist. The transmitting antenna 105 and the receiving antenna 106 can be configured as one antenna.

[0042] The received signal S108 is a signal generated by the receiving antenna 106 using the receiving wave S107. The received signal S108 corresponds to the transmitted signal S105. The mixer output signal S109 is a signal received by the mixer unit 107, which performs mixing using the original signal S101 and the received signal S108. The beat signal S110 is a signal received by the LPF unit 108, which performs filtering. A digital signal S111 is a signal received by the ADC unit 109, which performs digitization.

[0043] Fig. Figure 2 illustrates an example of a hardware structure of a signal processing device 110. The signal processing device 110 is a general computer.

[0044] As illustrated in this drawing, the signal processing device 110 comprises a processor 111, a digital signal interface 112, and a memory 113 as hardware. The hardware components contained in the signal processing device 110 are each connected via signal lines.

[0045] As illustrated in this drawing, the signal processing device 110 has a demodulation unit 121 and a target measurement unit 122 as functional components.

[0046] The processor 111 is an IC (integrated circuit) that executes an arithmetic operating process and controls hardware contained in the signal processing device 110. As a specific example, the processor 111 is a CPU (central processing unit), a DSP (digital signal processor), or a GPU (graphics processing unit).

[0047] The digital signal interface 112 is, as a concrete example, a serial communication interface. Specific examples of serial communication interfaces include SPI (Serial Peripheral Interface), UART (Universal Asynchronous Receiver / Transmitter), and I2C (Inter-Integrated Circuit). The digital signal interface 112 is used to connect the signal processing device 110 and external hardware. The external hardware includes the modulation code synthesis unit 103 and the ADC unit 109.

[0048] Memory 113 consists of at least one volatile memory device and one non-volatile memory device. The volatile memory device is, as a concrete example, RAM (Random Access Memory). The non-volatile memory device is, as a concrete example, ROM (Read Only Memory), an HDD (Hard Disk Drive), or flash memory.

[0049] A cache, which the processor 111 has, etc., can be contained in memory 113.

[0050] The demodulation unit 121 demodulates the beat signal S110 by using the modulation code sequence S104.

[0051] The functions of the demodulation unit 121 and the target measurement unit 122 are implemented by a program. The program is stored in memory 113 and is executed in processor 111.

[0052] Each program described in the description can be stored on a non-volatile storage medium in a way that is readable by a computer. A concrete example of a non-volatile storage medium is an optical disk or flash memory.

[0053] A radar operating program is a general term for a program used to operate any radar device described in the description. The radar operating program may be provided as a software product. ***Functional Description***

[0054] The operating sequence of radar device 10 corresponds to a radar operating procedure. Furthermore, a program for achieving the operation of radar device 10 corresponds to the radar operating program.

[0055] Fig. Figure 3 is a flowchart illustrating an example of the operation of radar device 10. The operation of radar device 10 is described with reference to this drawing.

[0056] Unit 101, the true random number generator, generates a true random number sequence S102 and sends it to the modulation code synthesis unit 103. The true random number sequence S102 is a sequence formed from true random numbers. These true random numbers can include a complex pseudorandom number. A complex pseudorandom number is a pseudorandom number whose random value is difficult to guess. A concrete example of a complex pseudorandom number is a random number generated using a Mersenne twister or a PCG (permuted congruential generator).

[0057] Unit 101, for generating true random numbers, is, for example, a ring oscillator with an odd number of oscillators connected in a beaded chain configuration. The true random number sequence S102, for example, is a sequence of "1, 1, 1, 0, 0, ...".

[0058] Unit 102, for generating pseudorandom numbers, generates a pseudorandom number sequence S103 and sends the pseudorandom number sequence S103 to the modulation code synthesis unit 103. The pseudorandom number sequence S103 is a sequence formed from pseudorandom numbers.

[0059] Unit 102, used for generating pseudorandom numbers, is, for example, an M-sequence or Gold-sequence generator. The pseudorandom number sequence S103 is a sequence of bits, for example, "1, 0, 1, 0, 1, ...".

[0060] The modulation code synthesis unit 103 generates a modulation code sequence S104 using the true random number sequence S102 and the pseudorandom number sequence S103 and sends the modulation code sequence S104 to the phase modulation unit 104 and the demodulation unit 121. The sequence lengths of the true random number sequence S102, the pseudorandom number sequence S103, and the modulation code sequence S104 are all the same. The sequence length represents the number of elements the sequence contains. For example, the modulation code sequence S104 is a sequence consisting of one-bit elements, "0, 1, 0, 0, 1, ...". Hereafter, it is assumed that each element of the modulation code sequence S104 is one bit.

[0061] The modulation code synthesis unit 103 synthesizes the true random number sequence S102 and the pseudorandom number sequence S103 by using, as a concrete example, an XOR or XNOR operation. The XOR operation is also known as exclusive disjunction. The XNOR operation is also known as the negation of an exclusive disjunction.

[0062] As a concrete example, how in Fig. Figure 1 illustrates a case where two units 102 are available for generating pseudorandom numbers. Let the true random number sequence S102 be r. Let the pseudorandom number sequence S103 generated by unit 102-1 be m1. Let the pseudorandom number sequence S103 generated by unit 102-2 be m2.

[0063] If the modulation code synthesis unit 103 synthesizes r and m1 and r and m2 respectively using an XOR operation, the modulation code sequence S104 can be represented as XOR(r, m1) and XOR(r, m2), respectively. In this case, each element of the modulation code sequence S104 receives an influence from the real random number sequence S102. That is, the modulation code sequence S104 contains components derived from the real random number sequence S102.

[0064] Expression (1) indicates that both are synthesized by performing an XOR operation. From the last term of expression (1), r vanishes. That is, both XOR(r,m1) and XOR(r,m2) are the modulation code sequence S104 in which components derived from the true random number sequence S102 vanish by synthesizing two modulation code sequences S104. Note that expression (1) corresponds to a case where demodulation is performed using a modulation code sequence S104 that differs from the modulation code sequence S104 used for modulation. XOR(XOR(r,m1),XOR(r,m2))=XOR(XOR(m1,m2),XOR(r,r))=XOR(m1,m2)

[0065] The signal generation unit 100 sends the original signal S101 to the phase modulation unit 104 and the mixer unit 107.

[0066] The phase modulation unit 104 generates the transmit signal S105 by phase modulation of the original signal S101 using the modulation code sequence S104 and sends the transmit signal S105 to the transmitting antenna 105.

[0067] As a concrete example, the phase modulation unit 104 converts the modulation code sequence S104 into a phase by taking the phase modulation amount as 0 when the bit indicates 0, and as π when the bit indicates 1. The following description is based on the fundamental assumption that the phase modulation unit 104 converts the modulation code sequence S104 into a phase, as in this example.

[0068] Fig. Figure 4 illustrates an example of a process in which the transmit signal S105 is generated.

[0069] The modulation code synthesis unit 103 generates the modulation code sequence S104 by synthesizing the true random number sequence S102 and the pseudorandom number sequence S103 by using an exclusive OR.

[0070] The phase modulation unit 104 generates the transmitted signal S105 by performing phase modulation of the original signal S101 using the modulation code sequence S104. The phase modulation unit 104 takes the phase modulation amount to be 0 if the bit of the modulation code sequence S104 indicates 0, and takes the phase modulation amount to be π if the bit of the modulation code sequence S104 indicates 1.

[0071] The transmitting antenna 105 sends the transmission wave S106 to the outside world. The transmission wave S106 is reflected by target 11.

[0072] The receiving antenna 106 receives the receiving wave S107. The receiving antenna 106 converts the receiving wave S107 into the receiving signal S108 and sends the receiving signal S108 to the mixer unit 107.

[0073] The mixer unit 107 generates the mixer output signal S109 by performing mixing using the received signal S108 and the original signal S101 and sends the mixer output signal S109 to the LPF unit 108. Mixing is the multiplication of signals. Mixing is represented as expression (2). cosfst⋅cosfrt=[cos{(fs−fr)t}+cos{(fs+fr)t}] / 2 f s represents the frequency of the original signal S101. r represents the frequency of the received signal S108. cos represents a sine function. t represents time. f s and f r typically represent frequencies that change over time. A concrete example is f s and f rFrequencies corresponding to chirp signals. It is subsequently assumed that f s and f r These are frequencies that correspond to chirp signals.

[0074] The LPF unit 108 extracts a low-frequency wave from the mixer output signal S109. The LPF unit 108 considers a wave to be a low-frequency wave if the frequency (f s -f r ) is, and does not consider a wave to be a low-frequency wave if the frequency (f s +f r ) is.

[0075] The beat signal S110 is a signal extracted from the LPF unit 108. The beat signal S110 can be expressed as cos{(f s -f r )t} / 2 of expression (2) is represented. That is, the beat signal S110 is a signal with information about a frequency difference between the original signal S101 and the received signal S108. The LPF unit 108 sends the beat signal S110 to the ADC unit 109.

[0076] The ADC unit 109 generates the digital signal S111 by converting the beat signal S110 as an analog signal into a digital signal and sends the digital signal S111 to the demodulation unit 121.

[0077] The demodulation unit 121 demodulates the digital signal S111 using the modulation code sequence S104, thereby generating a demodulation signal. The demodulation signal is sent to the target measurement unit 122.

[0078] The digital signal S111 contains information about the multitude of transmit waves S106, which are sent by the multitude of transmitting antennas 105. The demodulation unit 121 demodulates the digital signal S111 by extracting, from the digital signal S111, the transmit wave S106, which was sent by a transmitting antenna 105. Given that a phase shift due to phase modulation is contained in the beat signal S110, the digital signal S111 is represented as expression (3). Each term in expression (3) corresponds to a unit of chirp signals. ∑(i=1 to N)cos{fbit+ϕi} ϕ i represents an amount of phase modulation by the phase modulation unit 104-i. f bi N represents the frequency of the beat signal S110, which corresponds to the transmitting antenna 105-i. N represents a total number of transmitting antennas 105.

[0079] For example, as in Fig. 1, assuming that two transmitting antennas 105 are present. When the demodulation unit 121 performs demodulation using the modulation code sequence S104-1, the demodulated signal is represented as expression (4). cos{fb1t+2ϕ1}+cos{fb2t+ϕ1+ϕ2}=cos{fb1t}+cos{fb2t+ϕ1+ϕ2}

[0080] Here ϕ applies i = {0, π}. Consequently, cos{2ϕ1} = 1 and sin{2ϕ1} = 0. Therefore, cos{f b1 t+2ϕ1} = cos{f b1 t}.

[0081] Modulation and demodulation correspond to phase inversion. If the phase is inverted by 2π, the phase is inverted once. That is, inverting the phase by 2π is identical to not inverting the phase. Consequently, demodulation is equivalent to performing an XOR operation on a bit sequence when ϕ i = {0, π}. Consequently, it can be assumed that the components ϕ1+ϕ2 in cos{f b2The expression (4) t+ϕ1+ϕ2} corresponds to the result obtained by performing an XOR operation on an element of the modulation code sequence S104-1 and an element of the modulation code sequence S104-2. While both ϕ1 and ϕ2 are generated based on the true random sequence S102 when the demodulation unit 121 demodulates the digital signal S111, the components of the true random sequence S102 contained in the digital signal S111 are mutually canceled out. That is, it can be assumed that ϕ1 and ϕ2 were each generated based on the pseudorandom sequence S103.That is, if the unit 102 generates a sequence with high autocorrelation as the pseudorandom number sequence S103, the results obtained by the demodulation unit 121 by integrating a signal into a region of a cycle unit (referred to as a sweep unit in FMCW radars) of the pseudorandom number sequence S103 are such that cos{f. b1 t}-components mutually reinforced and cos{f b2 The components of t+ϕ1+ϕ2} are mutually weakened. A sequence with high autocorrelation is, as a concrete example, an M-sequence or a Gold-sequence.

[0082] Using the property in which the cos{f b1 Since the t} components are mutually strengthened, the demodulation unit 121 can measure the cos{f b1 Remove the t} components.

[0083] Fig. Figure 5 is a diagram illustrating an example of the operation of radar device 121.

[0084] It should be noted that the demodulation unit 121 takes a total number of signals that are demodulated by a cycle unit of the pseudorandom number sequence S103. The cos{f b1 The t-components correspond to a signal obtained by demodulation using a correct modulation code sequence. The correct modulation code sequence is modulation code sequence S104, which is used by phase modulation unit 104 when the transmit signal S105 is generated according to the digital signal S111. The cos{f b2The t+ϕ1+ϕ2 components correspond to a signal obtained by demodulation using a faulty modulation code sequence. When demodulation unit 121 performs demodulation using the faulty modulation code sequence, the signal phases are often not identical. Thus, demodulation unit 121 cannot obtain the result with stacked signals, but instead obtains the result with mutually attenuated signals.

[0085] Based on the demodulation signal, the target measurement unit 122 calculates a distance from the radar device 10 to the target 11, a speed of the target 11 and an angle formed by the radar device 10 and the target 11.

[0086] It should be noted that in the above description, the genuine random number sequence S102 is deleted from the demodulation signal. Therefore, modulation using the genuine random number sequence S102 does not affect the measurement of distance, speed, and angle by the target measuring unit 122. ***Description of the effects of embodiment 1***

[0087] As described above, the radar device 10 according to the present embodiment incorporates the MIMO system and the FMCW system and develops a signal sequence for use in modulation, thereby achieving the following effects.

[0088] The modulation code synthesis unit 103 generates the modulation code sequence S104 based on the true random number sequence S102 and the pseudorandom number sequence S103. The phase modulation unit 104 generates the transmitted signal S105 by modulating the phase of the original signal S101 using the modulation code sequence S104. The pseudorandom number sequences S103 for use by the respective phase modulation units 104 are generated by the different units 102 for generating pseudorandom numbers. Thus, the respective phase modulation units 104 normally generate the transmitted signals S105, which are different from one another. Therefore, the transmitted waves S106 sent by the respective transmitting antennas 105 are normally different from one another. Thus, the radar device 10 can normally prevent the multitude of transmitted waves S106 from interfering with each other.

[0089] The demodulation unit 121 performs demodulation using the modulation code sequence S104. Here, the components based on the true random number sequence S102 are deleted. Therefore, the modulation using the true random number sequence S102 does not affect the measurement of the position, speed, or similar parameters of the target 11 by the target measurement unit 122.

[0090] Even if an attacker detects the pseudorandom number sequence S103 by observing the transmitted waves S106, he cannot guess the true random number sequence S102. Consequently, the attacker cannot guess the modulation code sequence S104. Thus, according to the radar device 10 of the present embodiment, the risk of a deception attack can be reduced. ***Other structures***<Modifikationsbeispiel 1>

[0091] The radar device 10 can comprise at least one transmitting antenna 105 and one receiving antenna 106. In the case of a transmitting antenna 105, the number of units 102 for generating pseudorandom numbers, the number of modulation code synthesis units 103, and the number of phase modulation units 104 can each be one. In the case of a receiving antenna 106, the number of mixer units 107, the number of LPF units 108, and the number of ADC units 109 can each be one.

[0092] That is, the radar device 10 can comprise at least one of each component that is described as being included multiple times in the present embodiment. <Modifikationsbeispiel 2>

[0093] The following points, which differ from the embodiment described above, are described with reference to the drawings.

[0094] Fig. Figure 6 illustrates an example of the structure of the radar device 10 according to the present modification example. With reference to this drawing, differences between the radar device 10 according to the present embodiment and the radar device 10 according to the present modification example are described.

[0095] It should be noted that the mixer unit 107 can correspond to each phase modulation unit 104. That is, the number of mixer units 107 can be a number obtained by multiplying the number of phase modulation units 104 by the number of receiving antennas 106.

[0096] Fig. Figure 7 illustrates an example of the structure of the signal processing device 110 according to the present modification example. The signal processing device 110 does not include the demodulation unit 121.

[0097] Fig. Figure 8 is a flowchart illustrating an example of the operation of the radar device 10 according to the present modification example. With reference to this drawing, differences between the operation of the radar device 10 according to the present embodiment and the operation of the radar device 10 according to the present modification example are described.

[0098] The signal generation unit 100 does not send the original signal S101 to the mixer unit 107.

[0099] The modulation code synthesis unit 103 does not send the modulation code sequence S104 to the signal processing device 110.

[0100] The phase modulation unit 104 also sends the transmit signal S105 to the mixer unit 107.

[0101] The mixer unit 107 receives the transmit signal S105 instead of the original signal S101 and generates a mixer output signal S109 by mixing the transmit signal S105 and the receive signal S108. The mixer output signal S109 is a signal obtained by demodulating the receive signal S108.

[0102] When mixer unit 107 receives a large number of transmitted signals S105, it mixes each transmitted signal S105 with the received signal S108. In this case, the number of mixer output signals S109 generated by mixer unit 107 corresponds to the number of transmitted signals S105 received by mixer unit 107. Then, LPF unit 108 generates the beat signal S110 corresponding to each mixer output signal S109, and ADC unit 109 generates the digital signal S111 corresponding to each beat signal S110.

[0103] In this case, too, the radar device 10 can comprise a mixer unit 107 for a receiving antenna 106 or a plurality of mixer units 107 for a receiving antenna 106. As a specific example, if the radar device 10 comprises a mixer unit 107 for a receiving antenna 106, the mixer unit 107 switches the transmit signal S105 for use in mixing at predetermined time intervals. If the radar device 10 comprises a plurality of mixer units 107 for a receiving antenna 106, as a specific example, the number of transmit signals S105 and the number of mixer units 107 are equal, and each mixer unit 107 corresponds to each distinct transmit signal S105.

[0104] The signal processing device 110 does not receive the modulation code sequence S104.

[0105] The target measurement unit 122 uses the digital signal S111 instead of a demodulation signal.

[0106] As described above, according to the present modification example, the mixer unit 107 performs demodulation using the transmitted signal S105. The mixer unit 107 thus performs mixing and demodulation simultaneously. Consequently, the signal processing device 110 does not need to include the demodulation unit 121. Therefore, the radar device 10 does not need to retain the modulation code sequence S104. Furthermore, according to the present modification example, the signal processing device 110 can be one intended for use in a standard radar device. <Modifikationsbeispiel 3>

[0107] Fig. Figure 9 illustrates an example of the structure of a radar device 20. The radar device 20 is a device that has a different structure than the radar device 10 and implements some of the functions of the radar device 10 using a computer.

[0108] The radar device 20 consists of a transmitter unit 25 and a receiver unit 26. The transmitter unit 25 and the receiver unit 26 share and use a computer 200.

[0109] The transmitting unit 25 is formed from a signal generation unit 201, a plurality of phase modulation units 202 and a plurality of transmitting antennas 203.

[0110] The signal generation unit 201 is equivalent to the signal generation unit 100. The phase modulation unit 202 is equivalent to the phase modulation unit 104. The transmitting antenna 203 is equivalent to the transmitting antenna 105.

[0111] The number of phase modulation units 202 corresponds to the number of transmitting antennas 203.

[0112] The receiving unit 26 is formed from a plurality of receiving antennas 204, a plurality of mixer units 205, a plurality of LPF units 206 and a plurality of ADC units 207.

[0113] The receiving antenna 204 is equivalent to the receiving antenna 106. The mixer unit 205 is equivalent to the mixer unit 107. The LPF unit 206 is equivalent to the LPF unit 108. The ADC unit 207 is equivalent to the ADC unit 109.

[0114] The number of mixer units 205, the number of LPF units 206 and the number of ADC units 207 each correspond to the number of receiving antennas 204.

[0115] An original signal S201 is similar to the original signal S101. A modulation code sequence S204 is a sequence formed from signals generated by the computer 200. The modulation code sequence S204 can be an analog signal sequence. A transmit signal S205 is similar to the transmit signal S105.

[0116] A transmitting wave S206 is similar to a transmitting wave S106. A receiving wave S207 is similar to a receiving wave S107.

[0117] A received signal S208 is similar to a received signal S108. A mixer output signal S209 is similar to a mixer output signal S109. A beat signal S210 is similar to a beat signal S110. A digital signal S211 is similar to a digital signal S111.

[0118] Fig. Figure 10 illustrates an example of the hardware structure of the Computer 200. The Computer 200 is a general-purpose computer.

[0119] The computer 200 comprises a processor 211, a digital signal interface 212 and a memory 213 as hardware.

[0120] The computer 200 comprises a demodulation unit 221, a target measurement unit 222, a unit 223 for generating pseudorandom numbers, a modulation code generation unit 224 and a unit 225 for generating real random numbers as functional components.

[0121] Processor 211 is equivalent to processor 111. Digital signal interface 212 is equivalent to digital signal interface 112. Digital signal interface 212 is used to connect phase modulation units 202, ADC units 207, and computer 200. Memory 213 is equivalent to memory 113.

[0122] The demodulation unit 221, the target measurement unit 222, the unit 223 for generating pseudorandom numbers, the modulation code generation unit 224, and the unit 225 for generating true random numbers are implemented by a program. The program is stored in memory 213 and is executed in processor 211.

[0123] The operation of radar device 20 is described.

[0124] The operation of radar device 20 is similar to the operation of radar device 10. The operation of radar device 20 is similar to the operation shown in the flowchart of Fig. 3, wherein the unit 101 for generating true random numbers is designated as the unit 225 for generating true random numbers, the unit 102 for generating pseudorandom numbers is designated as the unit 223 for generating pseudorandom numbers, the modulation code synthesis unit 103 is designated as the modulation code generation unit 224, the signal generation unit 100 is designated as the signal generation unit 201, the phase modulation units 104 are designated as the phase modulation units 202, the transmitting antennas 105 are designated as the transmitting antennas 203, the mixer units 107 are designated as the mixer units 205, the receiving antennas 106 are designated as the receiving antennas 204, the target 11 is designated as a target 21, the LPF units 108 are designated as the LPF units 206, the ADC units 109 are designated as the ADC units 207,The demodulation unit 121 is designated as the demodulation unit 221, and the target measurement unit 122 is designated as the target measurement unit 222.

[0125] The unit 225 for generating true random numbers can generate a true random number sequence using the digital signal S211 of the ADC unit 207.

[0126] Fig. Figure 11 is a diagram illustrating an example of a process in which unit 225 generates a true random number sequence from the digital signal S211. The digital signal S211, shown in the middle of this diagram, is obtained by digitizing the beat signal S210 and is a signal formed from a sine wave (hereinafter referred to as a sine wave signal).

[0127] It should be noted that, as a concrete example, the unit 225 generates a random number from the digital signal S211 using a peak value of the sine wave signal for the random number.

[0128] In a graph of the digital signal S211 from Fig. In section 11, a symbol ∇ is given for a vertex of the sine wave. A histogram generated by collecting vertices of the sine wave for a sweep is shown in a lower part of Fig. Figure 11 illustrates this. In this histogram, it can be observed that the values ​​vary sufficiently and no significant distortion of the values ​​is observed. Consequently, the Unit 225 can use the peak values ​​of the sine wave, as in this example, to generate a truly random number.

[0129] Fig. Figure 12 illustrates a flowchart that demonstrates an example of a procedure in which the unit 225 generates a random sequence of one bit from the digital signal S211 to generate true random numbers. (Step S11: Process of capturing the vertex)

[0130] The unit 225 for generating true random numbers detects a vertex from the digital signal S211.

[0131] As a concrete example, if a large number of vertices are present in the digital signal S211, as in Fig. As observed in 11, the unit 225 takes a maximum value, a minimum value, an average value, or a median of the number of vertices as a vertex to generate a true random number. An extremum is a general term consisting of a maximum value, a minimum value, a maximum value, and a minimum value of the digital signal S211. (Step S12: Process of generating the sequence)

[0132] The Unit 225, used for generating true random numbers, produces a one-bit sequence using the value of the detected vertex. The one-bit sequence is a sequence formed from the signals of a single bit.

[0133] As a concrete example, Unit 225 uses a procedure to generate a true random number, assigning 0 or 1 according to whether the vertex value is even or not, a procedure to generate a one-bit random number by taking the vertex value as a seed or starting value of a pseudorandom function, or a procedure to generate a hash value corresponding to the vertex value by using a hash function and taking a specific bit value of the generated hash value. (Step S13: Data verification process)

[0134] When the unit 225 for generating true random numbers finishes the process for all digital signals S211 corresponding to all receiving antennas 204, the unit 225 for generating true random numbers returns to step S11. Otherwise, the unit 225 for generating true random numbers continues with step S14. (Step S14: Process of selecting random numbers)

[0135] The unit 225 for generating true random numbers selects a random number of one bit from the one-bit sequence generated in step S12.

[0136] As a concrete example, the Unit 225 uses a method of cyclic reference to the digital signal S211-i (i = 1, 2, 3, ..., 1, 2, ...) or a method of applying the result of the XOR operation to all random numbers to generate true random numbers.

[0137] As described above, the Unit 225 can generate a one-bit random number from signals of a chirp.

[0138] The effects of radar device 20 are equivalent to the effects of radar device 10. <Modifikationsbeispiel 4>

[0139] In the present embodiment, the case has been described in which each functional component of the signal processing device 110 is implemented by software. As a modification example, however, each functional component can be implemented by hardware.

[0140] Fig. Figure 13 illustrates an example of a hardware structure of the signal processing device 110 according to the present modification example.

[0141] If each functional component is implemented by hardware, as illustrated in this drawing, the signal processing device 110 comprises an electronic circuit 114 instead of the processor 111. Alternatively, although not shown, the signal processing device 110 comprises an electronic circuit 114 instead of the processor 111 and the memory 113. The electronic circuit 114 is a dedicated electronic circuit that implements the function of all the functional components (and the memory 113). The electronic circuit can be referred to as a processing circuit.

[0142] The electronic circuit 114 is assumed to be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA (Gate Array), an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0143] Each functional component can be implemented by a single electronic circuit 114, or each functional component can be implemented by being distributed across a multitude of electronic circuits 114. Alternatively, part of each functional component can be implemented by hardware and the remaining functional components can be implemented by software.

[0144] The processor 111, the memory 113, and the electronic circuit 114 described above are collectively referred to as the "processing circuit." That is, the function of each functional component of the signal processing device 110 is implemented by processing circuits.

[0145] Like the signal processing device 110, the computer 200 can include an electronic circuit in place of the processor 211 or in place of the processor 211 and the memory 213. Design 2.

[0146] The following points, which differ from the embodiment described above, are described with reference to the drawings.

[0147] A radar device 30 according to the present embodiment is a radar device that incorporates both the fast FMCW system and the MIMO system. The radar device 30 comprises a hardware component whose function is to transmit signals and a hardware component whose function is to receive signals. These two hardware components are distinct from one another. ***Description of the structure***

[0148] Fig. Figure 14 illustrates an example of the structure of radar device 30.

[0149] As illustrated in this drawing, the radar device 30 has a transmitting module 31 and a receiving module 32.

[0150] The transmitting module 31 comprises a signal generation unit 300, an encryption processing unit 301, a plurality of units 302 for generating pseudorandom numbers, a plurality of modulation code synthesis units 303, a plurality of phase modulation units 304 and a plurality of transmitting antennas 305.

[0151] Signal generation unit 300 is equivalent to signal generation unit 100. Encryption processing unit 301 typically consists of a circuit. Pseudorandom number generation unit 302 is equivalent to pseudorandom number generation unit 102. Modulation code synthesis unit 303 is equivalent to modulation code synthesis unit 103. Phase modulation unit 304 is equivalent to phase modulation unit 104. Transmitting antenna 305 is equivalent to transmitting antenna 105.

[0152] The number of units 302 for generating pseudorandom numbers, the number of modulation code synthesis units 303 and the number of phase modulation units 304 each correspond to the number of transmitting antennas 305.

[0153] The signal generation unit 300 is also referred to as a transmit-side signal generation unit. An original signal S301 is also referred to as a transmit-side original signal. The signal generation unit 300 generates a signal as the original signal S301.

[0154] The signal generation unit 300 synchronizes the original signal S301 with an original signal S312 using a synchronization signal S313. As a concrete example, the signal generation unit 300 makes the original signal S301 identical to the original signal S312 at a specific time.

[0155] The encryption processing unit 301 is also referred to as a send-side encryption processing unit. An encryption sequence S303 is also referred to as a send-side encryption sequence. The encryption processing unit 301 receives a true random number sequence S316 and generates the encryption sequence S303, which is a signal sequence for encryption, using the true random number sequence S316. The true random number sequence S316 is formed from true random numbers of one bit or more. The encryption sequence is a sequence that relates to an encryption algorithm. The encryption sequence can be a sequence obtained by encrypting plaintext.

[0156] The Unit 302 for generating pseudorandom numbers is also referred to as a transmit-side unit for generating pseudorandom numbers. A pseudorandom number sequence S302 is also referred to as a transmit-side pseudorandom number sequence. The Unit 302 for generating pseudorandom numbers generates the pseudorandom number sequence S302, formed from pseudorandom numbers of one bit or more.

[0157] The Modulation Code Synthesis Unit 303 is also referred to as a transmit-side Modulation Code Synthesis Unit. A Modulation Code Sequence S304 is also referred to as a transmit-side Modulation Code Sequence. The Modulation Code Synthesis Unit 303 generates the Modulation Code Sequence S304 based on the pseudorandom number sequence S302 and the encryption sequence S303. The Modulation Code Sequence S304 is similar to the Modulation Code Sequence S104. However, instead of components derived from the true random number sequence S102, the Modulation Code S304 contains components derived from the encryption sequence S303.

[0158] The phase modulation unit 304 generates a transmit signal S305 by modulating the phase of the original signal S301 by using the modulation code sequence S304.

[0159] The signal generation unit 300 and the encryption processing unit 301 each include a communication interface (IF) for communication with the receiver module 32. The communication interface is, as a concrete example, a Wi-Fi (registered trademark) or Ethernet (registered trademark) module.

[0160] The receiver module 32 comprises a plurality of receiving antennas 306, a plurality of mixer units 307, a plurality of LPF units 308, a plurality of ADC units 309, a signal processing device 310, a signal generation unit 311, a synchronization signal generation unit 312, an encryption processing unit 313, a plurality of modulation code synthesis units 314, a plurality of units 315 for generating pseudorandom numbers and a unit 316 for generating true random numbers.

[0161] The receiving antenna 306 is equivalent to the receiving antenna 106. The mixer unit 307 is equivalent to the mixer unit 107. The LPF unit 308 is equivalent to the LPF unit 108. The ADC unit 309 is equivalent to the ADC unit 109. The signal processing device 310 is equivalent to the signal processing device 110. The signal generation unit 311 is equivalent to the signal generation unit 100. The synchronization signal generation unit 312 typically consists of a circuit. The encryption processing unit 313 is equivalent to the encryption processing unit 301. The modulation code synthesis unit 314 is equivalent to the modulation code synthesis unit 103. The pseudorandom number generation unit 315 is equivalent to the pseudorandom number generation unit 102. The true random number generation unit 316 is equivalent to the true random number generation unit 101.

[0162] The number of mixer units 307, the number of LPF units 308 and the number of ADC units 309 each correspond to the number of receiving antennas 306.

[0163] The number of modulation code synthesis units 314 and the number of units 315 for generating pseudorandom numbers each correspond to the number of transmitting antennas 305.

[0164] The mixer unit 307 receives a signal as a receive signal S308 and generates a mixer output signal S309 by mixing the original signal S312 and the receive signal S308.

[0165] The LPF unit 308 generates a beat signal S310 by extracting a low frequency wave from the mixer output signal S309.

[0166] The signal generation unit 311 is also referred to as a receiver-side signal generation unit. The original signal S312 is also referred to as a receiver-side original signal. The signal generation unit 311 generates a signal corresponding to the original signal S301 as the original signal S312.

[0167] The signal generation unit 311 synchronizes the original signal S312 with an original signal S301 using a synchronization signal S313.

[0168] The synchronization signal generation unit 312 generates a synchronization signal S313 for use in signal synchronization and sends the synchronization signal S313 to the transmitting module 31.

[0169] The encryption processing unit 313 is also referred to as a receive-side encryption processing unit. An encryption sequence S317 is also referred to as a receive-side encryption sequence. The encryption processing unit 313 receives a true random number sequence S316 and generates the encryption sequence S317, which is a signal sequence of encryption, using the true random number sequence S316.

[0170] The modulation code synthesis unit 314 is also referred to as a receive-side modulation code synthesis unit. A modulation code sequence S315 is also referred to as a receive-side modulation code sequence. The modulation code synthesis unit 314 generates the modulation code sequence S315 by synthesizing a pseudorandom number sequence S314 and the encryption sequence S317. The modulation code sequence S315 is similar to the modulation code sequence S304.

[0171] The unit 315 for generating pseudorandom numbers is also referred to as a receiving unit for generating pseudorandom numbers. The pseudorandom number sequence S314 is also referred to as a receiving pseudorandom number sequence.

[0172] Unit 316 for generating true random numbers generates a true random number sequence S316 and sends the true random number sequence S316 to the transmitting module 31.

[0173] The synchronization signal generation unit 312 and the unit 316 for generating true random numbers each include a communication interface for communication with the transmitter module 31.

[0174] The original signal S301 is similar to the original signal S101. The pseudorandom number sequence S302 is similar to the pseudorandom number sequence S103. The encryption sequence S303 is a sequence formed from signals generated by the encryption processing unit 301. The modulation code sequence S304 is a sequence formed from signals generated by the modulation code synthesis unit 303. The transmit signal S305 is a sequence formed from signals generated by the phase modulation unit 304. A transmit wave S306 is similar to the transmit wave S106.

[0175] A received wave S307 is similar to a received wave S107. The received signal S308 is similar to a received signal S108. The mixer output signal S309 is similar to a mixer output signal S109. The beat signal S310 is similar to a beat signal S110. A digital signal S311 is similar to a digital signal S111. The original signal S312 is a signal generated by the signal generation unit 311. The synchronization signal S313 is a synchronization signal generated by the signal generation unit 312. The synchronization signal S313 is used to synchronize the transmit module 31 and the receive module 32. The pseudorandom number sequence S314 is a sequence formed from signals generated by the unit 315 for the generation of pseudorandom numbers. The modulation code sequence S315 is a sequence formed from signals generated by the modulation code synthesis unit 314.The true random number sequence S316 is a sequence formed from signals generated by the Unit 316 for generating true random numbers. The encryption sequence S317 is a sequence formed from signals generated by the Encryption Processing Unit 313.

[0176] One difference between radar device 10 and radar device 30 is that the transmitting module 31 and the receiving module 32 are separate hardware components. Thus, transmitting module 31 and receiving module 32 each comprise elements corresponding to the signal generation unit 100, the pseudorandom number generation units 102, and the modulation code synthesis units 103. Furthermore, transmitting module 31 and receiving module 32 share the true random number sequence S316.

[0177] The synchronization signal generation unit 312 controls the signal generation unit 300 and the signal generation unit 311 to coordinate signal transmission times, thereby synchronizing the transmit module 31 and the receive module 32.

[0178] Instead of the receiver module 32, the transmitter module 31 can include at least one of the unit 316 for generating true random numbers and the synchronization signal generation unit 312.

[0179] The internal structure of the signal processing device 310 is similar to that of the signal processing device 110. Consequently, the description of the signal processing device 310 is omitted.

[0180] The radar device 30 can be a radar device comprising the transmitting module 31 and the receiving module 32. Alternatively, the radar device 30 can be configured from a variety of radar devices at different positions, such as a bisstatic radar or a multistatic radar. ***Functional Description***

[0181] Fig. Figure 15 is a flowchart illustrating an example of the operation of radar device 30. The operation of radar device 30 is described with reference to this drawing.

[0182] The true random number generator unit 316 generates the true random number sequence S316 and sends the true random number sequence S316 to the encryption processing unit 301 and the encryption processing unit 313. This allows the encryption processing unit 301 and the encryption processing unit 313 to share the true random number sequence S316.

[0183] The true random number generation unit 316 can perform the operation described in this paragraph once at the time the radar device 30 is started, or it can perform the operation described in this paragraph repeatedly at predetermined time intervals, such as each individual sweep. Alternatively, the true random number generation unit 316 can perform the operation described in this paragraph if the demodulation unit 121 fails as a pulse during demodulation.

[0184] The encryption processing unit 301 generates the encryption sequence S303 by encrypting plaintext M using the true random number sequence S316 and sends the encryption sequence S303 to the modulation code synthesis unit 303. The encryption processing unit 313 generates the encryption sequence S317 by encrypting plaintext M using the true random number sequence S316 and sends the encryption sequence S317 to the modulation code synthesis unit 314. The plaintext M can be any plaintext and can be generated in any way. The plaintext is unencrypted data. The encryption sequence S303 and the encryption sequence S317 are identical. The encryption processing unit 301 and the encryption processing unit 313 share the plaintext M.

[0185] When generating the encryption sequences S303 and S317 for the first time, the encryption processing unit 301 and the encryption processing unit 313 use a pre-shared initial value as a concrete example. The encryption processing unit 301 and the encryption processing unit 313 can share the true random number sequence S316 as a secret key.

[0186] The Encryption Processing Unit 301 and the Encryption Processing Unit 313 generate a signal sequence that is difficult for attackers to guess.

[0187] As a concrete example, the 301 and 313 encryption processing units each use block encryption or stream encryption as their encryption algorithm. Block encryption is, as a concrete example, AES (Advanced Encryption Standard) or Camellia (registered trademark). Stream encryption is, as a concrete example, KCipher (registered trademark)-2.

[0188] As another concrete example, encryption processing unit 301 generates the encryption sequence S303 using the procedure described above or the like, performs an XOR operation on the generated encryption sequence S303 and the genuine random number sequence S316, executes a hash function using the result of the XOR operation, and accepts the result of the hash function execution as the encryption sequence S303. In this example, encryption processing unit 313 generates the encryption sequence S317 by executing a process similar to the process performed by encryption processing unit 301 that generated the encryption sequence S303. In this example, encryption processing unit 301 and encryption processing unit 313 share the hash function.

[0189] The unit 302 for generating pseudorandom numbers generates the pseudorandom number sequence S302 and sends the pseudorandom number sequence S302 to the modulation code synthesis unit 303.

[0190] The unit 315 for generating pseudorandom numbers generates the pseudorandom number sequence S314 and sends the pseudorandom number sequence S314 to the modulation code synthesis unit 314.

[0191] The modulation code synthesis unit 303 generates the modulation code sequence S304 by using the encryption sequence S303 and the pseudorandom number sequence S302 and sends the modulation code sequence S304 to the phase modulation unit 304.

[0192] The modulation code synthesis unit 314 generates the modulation code sequence S315 by using the encryption sequence S317 and the pseudorandom number sequence S314 and sends the modulation code sequence S315 to the demodulation unit 121.

[0193] As with the modulation code synthesis unit 103, the modulation code synthesis unit 303 and the modulation code synthesis unit 314 each synthesize signal sequences.

[0194] The synchronization signal generation unit 312 sends the synchronization signal S313 to each of the signal generation units 300 and 311. One purpose of the transmission of the synchronization signal S313 by the synchronization signal generation unit 312 is to correct a synchronization shift between the signal generation unit 300 and the signal generation unit 311, which operate based on different oscillators. The signal generated by the signal generation unit 300 and the signal generated by the signal generation unit 311 are typically identical.

[0195] It should be noted that the timing at which the synchronization signal generation unit 312 sends the synchronization signal S313 can be arbitrary. As a concrete example, the synchronization signal generation unit 312 sends the synchronization signal S313 with every chirp or every sweep.

[0196] The signal generation unit 300 generates the original signal S301 and sends the original signal S301 to the phase modulation unit 304. Similarly, the signal generation unit 311 generates the original signal S312 and sends the original signal S312 to the mixer unit 307.

[0197] The phase modulation unit 304 generates the transmit signal S305 by performing phase modulation on the original signal S301 using the modulation code sequence S304 and sends the transmit signal S305 to the transmitting antenna 305.

[0198] As with the phase modulation unit 104, the phase modulation unit 304 performs phase modulation of the original signal S301.

[0199] The transmitting antenna 305 sends the transmission wave S306 to the outside world. The transmission wave S306 is reflected by a target 33.

[0200] The receiving antenna 306 receives the received wave S307. The receiving antenna 306 converts the received wave S307 into the received signal S308 and sends the received signal S308 to the mixer unit 307.

[0201] The mixer unit 307 generates the mixer output signal S309 by performing mixing using the received signal S308 and the original signal S312 and sends the mixer output signal S309 to the LPF unit 308.

[0202] The LPF unit 308 generates the beat signal S310 by extracting a low frequency wave from the mixer output signal S309 and sends the beat signal S310 to the ADC unit 309.

[0203] The ADC unit 309 generates the digital signal S311 by converting the beat signal S310 as an analog signal into a digital signal and sends the digital signal S311 to the demodulation unit 121.

[0204] The demodulation unit 121 demodulates the digital signal S311 using the modulation code sequence S315, thereby generating a demodulation signal. The demodulation signal is sent to the target measurement unit 122.

[0205] As with the demodulation unit 121 of the radar device 10, the demodulation unit 121 of the radar device 30 demodulates the digital signal S311. ***Description of the effects of embodiment 2***

[0206] The radar device 30 according to the present embodiment has the following effects in addition to effects equivalent to those of the radar device 10 according to embodiment 1.

[0207] The transmitting module 31 includes the encryption processing unit 301, and the receiving module 32 includes the encryption processing unit 313. The encryption processing unit 301 and the encryption processing unit 313 each generate an encrypted signal sequence. This enables the radar device 30 to reduce the number of communication attempts required to split the genuine random number sequence S316.

[0208] In the fast FMCW system, the sweep time for a unit's chirp is short. According to the present embodiment, the transmit module 31 and the receive module 32 can be processed separately. Thus, the risk of process delay due to time spent communicating to share the true random number sequence S316 is relatively low. Therefore, the present embodiment is particularly effective in radar devices employing the fast FMCW system. ***Other structures***<Modifikationsbeispiel 5>

[0209] When the encryption sequence S303 and the encryption sequence S317 are first generated, the encryption processing unit 301 and the encryption processing unit 313 may not use a pre-shared initial value.

[0210] In the present modification example, encryption processing unit 301 and encryption processing unit 313 share a random number generation algorithm and generate a random number sequence by taking the real random number sequence S316 as a seed. Encryption processing unit 301 adopts the random number sequence as the encryption sequence S303. Encryption processing unit 313 adopts the random number sequence as the encryption sequence S317. <Modifikationsbeispiel 6>

[0211] The unit 316 for generating true random numbers can encrypt the true random number sequence S316.

[0212] In the present modification example, as a concrete example, the encryption processing unit 301 and the encryption processing unit 313 share a decryption key for decoding unit 316 to generate true random numbers and decrypt the encrypted true random number sequence S316 using the decryption key. In this example, the modulation code synthesis unit 303 uses the true random number sequence S316 instead of the encryption sequence S303, and the modulation code synthesis unit 314 uses the true random number sequence S316 instead of the encryption sequence S317. That is, the encryption sequence S303 and the encryption sequence S317 can each contain the true random number sequence S316. <Modifikationsbeispiel 7>

[0213] Fig. Figure 16 illustrates an example of the structure of a radar device 40. The radar device 40 has a different structure than the radar device 30.

[0214] The relationship between radar device 40 and radar device 30 is similar to the relationship between radar device 20 and radar device 10. That is, radar device 40 is a device that implements some of the functions of radar device 30 using computers.

[0215] As illustrated in this drawing, the radar device 40 comprises a transmitting module 41 and a receiving module 42 as hardware.

[0216] The transmitter module 41 comprises a transmitter control computer 400, a signal generation unit 401, a plurality of phase modulation units 404, and a plurality of transmitting antennas 405. The number of phase modulation units 404 corresponds to the number of phase modulation units 405.

[0217] The signal generation unit 401 is equivalent to the signal generation unit 100. The phase modulation unit 404 is equivalent to the phase modulation unit 104. The transmitting antenna 405 is equivalent to the transmitting antenna 105.

[0218] The receiver module 42 comprises a signal generation unit 402, a variety of receiving antennas 406, a variety of mixer units 407, a variety of LPF units 408, a variety of ADC units 409 and a receiver control computer 410.

[0219] The signal generation unit 402 is equivalent to the signal generation unit 100. The receiving antenna 406 is equivalent to the receiving antenna 106. The mixer unit 407 is equivalent to the mixer unit 107. The LPF unit 408 is equivalent to the LPF unit 108. The ADC unit 409 is equivalent to the ADC unit 109.

[0220] An original signal S401 is similar to the original signal S301. A modulation code sequence S404 is a sequence formed from signals generated by the transmit control computer 400. A transmit signal S405 is similar to the transmit signal S305. A transmit wave S406 is similar to the transmit wave S306. The number of transmit waves S406 corresponds to the number of transmit antennas 405.

[0221] A received wave S407 is similar to a received wave S307. A maximum value of the number of received waves S407 corresponds to a number obtained by multiplying the number of transmitting antennas 405 by the number of receiving antennas 406. A received signal S408 is similar to a received signal S308. A mixer output signal S409 is similar to a mixer output signal S309. A beat signal S410 is similar to a beat signal S310. A digital signal S411 is similar to a digital signal S311. An original signal S412 is similar to an original signal S312. A synchronization signal S413 is a signal generated by the receive control computer 410. A true random number sequence S416 is a sequence formed from signals generated by the receive control computer 410.

[0222] Fig. Figure 17 illustrates an example of a hardware structure of the receiver control computer 410. The receiver computer 410 is a general-purpose computer.

[0223] As illustrated in this drawing, the receiver control computer 410 comprises a processor 411, a digital signal interface 412, an analog signal interface 413 and a memory 414 as hardware.

[0224] In addition, the receiver control computer 410 includes a demodulation unit 421, a target measurement unit 422, a unit 423 for generating pseudorandom numbers, a modulation code generation unit 424, an encryption processing unit 425, a synchronization signal generation unit 426 and a unit 427 for generating true random numbers as functional components.

[0225] The 411 processor is equivalent to the 111 processor. The 414 memory is equivalent to the 113 memory.

[0226] The digital signal interface 412 is equivalent to the digital signal interface 112. The digital signal interface 412 is used to connect the ADC unit 409 and the receiver control computer 410.

[0227] Analog signal interface 413 is, for example, a digital-to-analog converter (DAC). Analog signal interface 413 is used to connect the receiver control computer 410 and external hardware. It is assumed that the synchronization signal S413 is input to signal generation unit 401 and signal generation unit 402. Thus, the external hardware comprises signal generation unit 401 and signal generation unit 402. The synchronization signal S413 can be, for example, a reset signal, enable signal, or trigger signal.

[0228] As with the signal processing device 110, the receiving control computer 410 can comprise an electronic circuit in place of the processor 411 or in place of the processor 411 and the memory 414.

[0229] The demodulation unit 421, the target measurement unit 422, the unit 423 for generating pseudorandom numbers, the modulation code generation unit 424, the encryption processing unit 425, the synchronization signal generation unit 426, and the unit 427 for generating true random numbers are implemented by a program. The program is stored in memory 414 and is executed by processor 411.

[0230] Fig. Figure 18 illustrates an example of a hardware structure of the transmitting control computer 400. The transmitting control computer 400 is a general-purpose computer.

[0231] As illustrated in this drawing, the transmitting control computer 400 comprises a processor 431, a digital signal interface 432 and a memory 433 as hardware.

[0232] Furthermore, the transmitting control computer 400 includes a unit 441 for generating pseudorandom numbers, a modulation code generation unit 442 and an encryption processing unit 443 as functional components.

[0233] The 431 processor is equivalent to the 111 processor. The 433 memory is equivalent to the 113 memory.

[0234] The 432 digital signal interface is equivalent to the 112 digital signal interface. The 432 digital signal interface is used to connect the 400 transmit control computer and the 404 phase modulation units.

[0235] As with the signal processing device 110, the transmit control computer 400 can comprise an electronic circuit in place of the processor 431 or in place of the processor 431 and the memory 433.

[0236] Unit 441 for generating pseudorandom numbers, the modulation code generation unit 442, and the encryption processing unit 443 are implemented by a program. The program is stored in memory 433 and is executed by processor 431.

[0237] The operation of radar device 40 is described. The operation of radar device 40 is similar to the operation of radar device 30. The functioning of radar device 40 is similar to the functioning shown in the flowchart of Fig.15, wherein the true random number generation unit 316 is designated as the true random number generation unit 427, the encryption processing unit 301 as the encryption processing unit 443, the encryption processing unit 313 as the encryption processing unit 425, the pseudorandom number generation unit 302 as the pseudorandom number generation unit 441, the pseudorandom number generation unit 315 as the pseudorandom number generation unit 423, the modulation code synthesis unit 303 as the modulation code generation unit 442, the modulation code synthesis unit 314 as the modulation code generation unit 424, the synchronization signal generation unit 312 as the synchronization signal generation unit 426, the signal generation unit 300 as the signal generation unit 401, the signal generation unit 311 as the signal generation unit 402,the phase modulation units 304 as the phase modulation units 404, the transmitting antennas 305 as the transmitting antennas 405, the target 33 as a target 43, the receiving antennas 306 as the receiving antennas 406, the mixer units 307 as the mixer units 407, the LPF units 308 as the LPF units 408, the ADC units 309 as the ADC units 409, the demodulation unit 121 as the demodulation unit 421 and the target measurement unit 122 as the target measurement unit 422.

[0238] The Unit 427 for generating true random numbers can perform a process similar to that of the Unit 225 for generating true random numbers, thereby generating the true random number sequence S416 using the digital signal S411. *** Other versions ***

[0239] It is possible to freely combine the embodiments described above, to modify any component in any embodiment, or to omit any component in any embodiment.

[0240] It should be noted that the embodiments described above are by their nature preferred examples and are not intended to limit the present disclosure, its applications and the scope of its uses.

[0241] Furthermore, embodiments are not limited to those described in embodiments 1 and 2 and can be modified differently if necessary. Reference symbol list

[0242] 10, 20, 30, 40: Radar device; 11, 21, 33, 43: Target; 31, 41: Transmit module; 32, 42: Receive module; 15, 25: Transmit unit; 16, 26: Receive unit; 100, 201, 300, 311, 401, 402: Signal generation unit; 101, 316: True random number generation unit; 102, 302, 315: Pseudorandom number generation unit; 103, 303, 314: Modulation code synthesis unit; 104, 202, 304, 404: Phase modulation unit; 105, 203, 305, 405: Transmitting antenna; 106, 204, 306, 406: Receiving antenna; 107, 205, 307, 407: Mixer unit; 108, 206, 308, 408: LPF unit; 109, 207, 309, 409: ADC unit; 110, 310: Signal processing device; 200: Computer; 301, 313: Encryption processing unit; 312: Synchronization signal generation unit; 400: Transmit control computer; 410: Receive control computer; 111, 211, 411, 431: Processor; 112, 212, 412, 432: Digital signal interface; 113, 213, 414, 433: Memory; 114: electronic circuit; 413: analog signal interface;121, 221, 421: Demodulation unit; 122, 222, 422: Target measurement unit; 223, 423, 441: Pseudorandom number generation unit; 224, 424, 442: Modulation code generation unit; 225, 427: True random number generation unit; 425, 443: Encryption processing unit; 426: Synchronization signal generation unit; S101, S201, S301, S312, S401, S412: Original signal; S102, S316, S416: True random number sequence; S103, S302, S314: Pseudorandom number sequence; S104, S204, S304, S315, S404: Modulation code sequence; S105, S205, S305, S405: Transmit signal; S106, S206, S306, S406: Transmit wave; S107, S207, S307, S407: Receive wave; S108, S208, S308, S408: Receive signal; S109, S209, S309, S409: Mixer output signal; S110, S210, S310, S410: Beat signal; S111, S211, S311, S411: Digital signal; S303, S317: Encryption sequence; S313, S413: Synchronization signal;

Claims

[1] Radar device (10), comprising: a signal generation unit (100) for generating a signal as an original signal; at least one unit (102) for generating pseudorandom numbers in order to generate a pseudorandom number sequence formed from a pseudorandom number of one bit or more; a unit (101) for generating true random numbers, in order to generate a true random number sequence formed from a true random number of one bit or more; at least one modulation code synthesis unit (103) for generating a modulation code sequence for use in modulating a signal phase by synthesizing the pseudorandom number sequence and the true random number sequence, wherein the modulation code sequence includes a component derived from the true random number sequence; and at least one phase modulation unit (104) for generating a transmit 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 real random number sequence disappears by synthesizing two modulation code sequences; still comprehensive: at least one transmitting antenna (105) for converting the transmit signal into a transmitting wave and for transmitting the transmitting wave; at least one receiving antenna (106) for receiving a receiving wave corresponding to the transmitting wave and for converting the receiving wave into a receiving signal; at least one mixer unit (107) for generating a mixer output signal by mixing the original signal and the received signal; at least one low-pass filter unit (108) for generating a beat signal by extracting a low-frequency wave from the mixer output signal; and a demodulation unit (121) for demodulating the beat signal by using the modulation code sequence, wherein the number of at least one unit (102) for generating pseudorandom numbers, the number of at least one modulation code synthesis unit (103) and the number of at least one phase modulation unit (104) each match the number of at least one transmitting antenna (105), and the number of at least one mixer unit (107) and the number of at least one low-pass filter unit (108) each match the number of at least one receiving antenna (106); characterized by , that either: The unit (101, 316) generates a true random number of one bit by converting an extreme value of the beat signal into a binary number; or: the radar device (10, 30) comprises a plurality of low-pass filter units (108, 308), and the unit (101, 316) for generating true random numbers generates random number bits, wherein each of the random number bits is generated using each of the beat signals corresponding to each of the plurality of low-pass filter units (108, 308), and a true random number of one bit is generated by performing an exclusive OR operation or an exclusive NOR operation using the generated random number bits. [2] Radar device (10), comprising: a signal generation unit (100) for generating a signal as an original signal; at least one unit (102) for generating pseudorandom numbers in order to generate a pseudorandom number sequence formed from a pseudorandom number of one bit or more; a unit (101) for generating true random numbers, in order to generate a true random number sequence formed from a true random number of one bit or more; at least one modulation code synthesis unit (103) for generating a modulation code sequence for use in modulating a signal phase by synthesizing the pseudorandom number sequence and the true random number sequence, wherein the modulation code sequence includes a component derived from the true random number sequence; and at least one phase modulation unit (104) for generating a transmit 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 real random number sequence disappears by synthesizing two modulation code sequences; still comprehensive: at least one transmitting antenna (105) for converting the transmit signal into a transmitting wave and for transmitting the transmitting wave; at least one receiving antenna (106) for receiving a receiving wave corresponding to the transmitting wave and for converting the receiving wave into a receiving signal; at least one mixer unit (107) for generating a mixer output signal by mixing the transmit signal and the receive signal; and at least one low-pass filter unit (108) for generating a beat signal by extracting a low-frequency wave from the mixer output signal; wherein the number of at least one unit (102) for generating pseudorandom numbers, the number of at least one modulation code synthesis unit (103) and the number of at least one phase modulation unit (104) each match the number of at least one transmitting antenna (105), and the number of at least one mixer unit (107) and the number of at least one low-pass filter unit (108) each match the number of at least one receiving antenna (106); characterized by , that either: The unit (101, 316) generates a true random number of one bit by converting an extreme value of the beat signal into a binary number; or: the radar device (10, 30) comprises a plurality of low-pass filter units (108, 308), and the unit (101, 316) for generating true random numbers generates random number bits, wherein each of the random number bits is generated using each of the beat signals corresponding to each of the plurality of low-pass filter units (108, 308), and a true random number of one bit is generated by performing an exclusive OR operation or an exclusive NOR operation using the generated random number bits. [3] Radar device (10) according to claim 1 or 2, wherein the modulation code synthesis unit (103) generates the modulation code sequence by performing an exclusive OR operation or an exclusive NOR operation. [4] Radar device (30), comprising: a transmitter module (31) which features: a transmit-side signal generation unit (300) for generating a signal as a transmit-side original signal; at least one transmit-side unit (302) for generating pseudorandom numbers in order to generate a transmit-side pseudorandom number sequence formed from a pseudorandom number of one bit or more, a transmit-side encryption processing unit (301) for receiving a true random sequence formed from a true random number of one bit or more, and for generating a transmit-side encryption sequence, which is a signal sequence of encryption, by using the true random sequence, at least one transmit-side modulation code synthesis unit (303) for generating a transmit-side modulation code sequence for use in modulating a signal phase by synthesizing the transmit-side pseudorandom number sequence and the transmit-side encryption sequence, wherein the transmit-side modulation code sequence comprises a component derived from the transmit-side encryption sequence; and at least one phase modulation unit (304) for generating a transmit signal by modulating a phase of the transmit-side original signal by using the transmit-side modulation code sequence; and a receiving module (32) which includes: a receiving signal generation unit (311) for generating a signal corresponding to the transmitting original signal as a receiving original signal, at least one receiving unit (315) for generating pseudorandom numbers in order to generate a receiving pseudorandom number sequence formed from a pseudorandom number of one bit or more, a receiving encryption processing unit (313) for receiving the genuine random number sequence and for generating a receiving encryption sequence, which is a signal sequence of encryption, by using the genuine random number sequence, at least one receive-side modulation code synthesis unit (314) for generating a receive-side modulation code sequence by synthesizing the receive-side pseudorandom number sequence and the receive-side encryption sequence, for use in modulating a signal phase, wherein the receive-side modulation code sequence has a component derived from the receive-side encryption sequence, at least one mixer unit (307) for receiving a signal as a receive signal and for generating a mixer output signal by mixing the original receive signal and the receive signal, at least one low-pass filter unit (308) for generating a beat signal by extracting a low-frequency wave from the mixer output signal, and a demodulation unit (121) for demodulating the beat signal by using the receiver-side modulation code sequence, wherein two of the transmit-side modulation code sequences are transmit-side modulation code sequences in which a component derived from the transmit-side encryption sequence disappears by synthesizing two transmit-side modulation code sequences, two of the receiving modulation code sequences are receiving modulation code sequences in which a component derived from the receiving encryption sequence disappears by synthesizing two receiving modulation code sequences, the number of at least one transmitting unit (302) for generating pseudorandom numbers, the number of at least one receiving unit (315) for generating pseudorandom numbers, the number of at least one transmitting modulation code synthesis unit (303), the number of at least one receiving modulation code synthesis unit (314) and the number of at least one phase modulation unit (304) each match the number of at least one transmitting antenna (305), and the number of at least one mixer unit (307) and the number of at least one low-pass filter unit (308) each match the number of at least one receiving antenna (306); wherein the receiving module (32) comprises a unit (316) for generating true random numbers in order to generate the true random number sequence and to send the true random number sequence to the transmitting module (31); characterized by , that either: The unit (101, 316) generates a true random number of one bit by converting an extreme value of the beat signal into a binary number; or: the radar device (10, 30) comprises a plurality of low-pass filter units (108, 308), and the unit (101, 316) for generating true random numbers generates random number bits, wherein each of the random number bits is generated using each of the beat signals corresponding to each of the plurality of low-pass filter units (108, 308), and a true random number of one bit is generated by performing an exclusive OR operation or an exclusive NOR operation using the generated random number bits. [5] Radar device (30) according to claim 4, wherein the receiving module (32) comprises a synchronization signal generation unit (312) for generating a synchronization signal for use in signal synchronization and for sending the synchronization signal to the transmitting module (31), the transmit-side signal generation unit (300) synchronizes the transmit-side original signal signal with the receive-side original signal using the synchronization signal, and The receiving signal generation unit (311) synchronizes the receiving original signal with the transmitting original signal using the synchronization signal. [6] Radar device (30) according to claim 4 or 5, wherein the transmit-side modulation code synthesis unit (303) generates the transmit-side modulation code sequence by performing an exclusive OR operation or an exclusive NOR operation, and the receiving modulation code synthesis unit (314) generates the receiving modulation code sequence by performing an exclusive OR operation or an exclusive NOR operation. [7] Radar operating method comprising using the radar device (10) according to any one of claims 1 to 3 for: Generate, by the signal generation unit (100), the signal as the original signal; Generate, by which at least one unit (102) is used to generate pseudorandom numbers, the pseudorandom number sequence; Generate, by the unit (101) for generating true random numbers, the true random number sequence; Generating, by which at least one modulation code synthesis unit (103) of the modulation code sequence for use in modulating the signal phase; and Generating, by means of at least one phase modulation unit (104), of the transmitted signal by modulating the phase of the original signal by using the modulation code sequence. [8] Radar operating program that instructs a computer: to generate a signal as an original signal; to generate a pseudorandom sequence of numbers formed from a pseudorandom number of one bit or more; to generate a true random sequence of numbers, formed from a true random number of one bit or more; to generate a modulation code sequence for use in modulating a signal phase by synthesizing the pseudorandom number sequence and the true random number sequence, wherein the modulation code sequence includes a component derived from the true random number sequence; and to generate a transmitted signal by modulating a phase of the original signal using the modulation code sequence, wherein the modulation code sequence is a modulation code sequence in which the component derived from the real random number sequence disappears by synthesizing two modulation code sequences; where the radar operating program instructs the computer to: either: to generate a true random number of one bit by converting an extreme value of a beat signal into a binary number; or: to generate random number bits, wherein each of the random number bits is generated using beat signals, each corresponding to a plurality of the low-pass filter units (108, 308), and to generate a true random number of one bit by performing an exclusive OR operation or an exclusive NOR operation using the generated random number bits.

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