JP2008151660A - Delay time detection device, delay time detection method, delay time detection machine, and delay time detection program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate a direct wave and a reflection wave from a reception signal in which the direct wave and the reflection wave are mixed, and to detect a delay time difference between the direct wave and the reflection wave, wherein synchronization between a transmission machine 100 and a receiving machine 200 is not required and estimation of the arrival directions of the direct wave and the reflection wave is not required. <P>SOLUTION: In the transmission machine 100, a modulator 130 performs any of amplitude modulation, frequency modulation, and phase modulation, and a transmitter 120 transmits a transmission wave having specific variation in any of the amplitude, the frequency, and the phase via a transmission antenna 110. In the receiving machine 200, a receiver 220 receives as the mixed wave the direct wave from the transmission machine 100, the reflection wave reflected by an object 300 and the other unnecessary waves via a reception antenna 210, a demodulator 230 demodulates the mixed wave, and a delay time detector 240 discriminates the direct wave and the reflection wave having specific variation from the mixed wave, and calculates the time period from the reception time of the direct wave to the reception time of the reflection wave as the delay time difference. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention, for example, synchronizes a transmitter and a receiver in a target detection device that detects a target position using a delay time difference between a delay time of a direct wave from a transmitter and a delay time of a reflected wave from a target. Delay time detection device, delay time detection method, delay time detector, and delay without delay time difference between direct wave and reflected wave from reception signal in which direct wave from transmitter and reflected wave from target are mixed It relates to a time detection program.

A bistatic radar device that receives a direct wave from a transmitter and a reflected wave from a target is mounted on different platforms where the transmitter and the receiver are synchronized, and the reflected wave from a weak target is synchronized. Therefore, it is necessary to receive the direct wave and the reflected wave with separate antennas.
The passive radar device disclosed in Patent Document 1 that solves this problem makes it possible to separate and extract a direct wave and a reflected wave with the same receiving antenna by using a super-resolution algorithm such as MUSIC. However, the passive radar device disclosed in Patent Document 1 performs complicated processing with an antenna device composed of a plurality of element antennas in order to separate and extract the direct wave and the reflected wave, and the arrival of the direct wave and the reflected wave. An azimuth estimation device that estimates the direction is required.

FIG. 12 is a diagram showing a passive radar device disclosed in Patent Document 1. In FIG.
In the figure, 813 is a transmission source, 814 is a target, 815 is an antenna device, 816 is a reception device, 817 is an azimuth estimation device, 818 is a signal separation device, 819 is a correlation processing device, 820 is an integration processing device, and 821 is target detection. A device 822 is a display device.
The passive radar device shown in FIG. 12 receives a direct wave from the transmission source 813 and a reflected wave from the target 814 by the antenna device 815, converts it into a received signal by the receiving device 816, and inputs it to the azimuth estimating device 817. Then, the azimuth estimation device 817 performs complex processing to enable the signal separation device 818 to separate and extract the transmission wave from the transmission source 813 and the reflected wave from the target 814, and performs the direct wave and the reflected wave. It was necessary to estimate the direction of arrival. In addition, the passive radar device needs to include an antenna device 815 including a plurality of element antennas so that the direction estimation device 817 can estimate the arrival directions of the direct wave and the reflected wave.
JP 2002-181925 A

As described above, the conventional bistatic radar apparatus needs to synchronize the transmitter and the receiver and receive the direct wave and the reflected wave with separate antennas, and there is a problem that it cannot be reduced in size.
In addition, a passive radar device that receives a direct wave and a reflected wave with the same receiving antenna is an azimuth estimation device that performs complex processing with a receiving antenna composed of a plurality of element antennas in order to distinguish between the direct wave and the reflected wave. It is necessary to estimate the direction of arrival of the direct wave and the reflected wave.

  The present invention provides, for example, a system for detecting a target position using a delay time difference between a delay time of a direct wave from a transmitter and a delay time of a reflected wave from a target (target detection device). Is not necessary, and it is not necessary to estimate the direction of arrival of the direct wave and reflected wave. The direct wave and reflected wave can be distinguished from the received signal that is a mixture of the direct wave and reflected wave. It is an object of the present invention to provide a delay time detecting device capable of detecting a delay time difference between a wave delay time and a delay time of a reflected wave from a target.

  The delay time detection device of the present invention includes a transmitter that transmits, as a transmission wave, an electromagnetic wave that has been modulated and given a specific change, a reflected wave that is reflected by a target, and a transmission wave that is transmitted from the transmitter. Receiving a hybrid wave including a direct wave directly transmitted without being reflected by a target and a reflected wave based on the transmitted wave transmitted by the transmitter and an unnecessary wave other than the direct wave; Information identifying the direct wave and reflected wave having a specific change given to the transmitted wave by modulation from the hybrid wave and identifying the distance from the reception time of the direct wave to the reception time of the reflected wave It is characterized by having a receiver which calculates as.

According to the present invention, the transmitter transmits a transmission wave having a specific change, so that the receiver does not need to be synchronized with the transmitter and needs to estimate the arrival directions of the direct wave and the reflected wave. And the direct wave and the reflected wave can be distinguished based on whether or not there is a specific change. The receiver (delay time detector) of the present invention can detect the delay time difference between the delay time of the direct wave from the transmitter and the delay time of the reflected wave from the target.
Thereby, the delay time detection apparatus of the present invention having the transmitter and the receiver, and the receiver (delay time detector), for example, use the delay time difference between the direct wave and the reflected wave to set the target position. In the system (target detection device) for detecting the signal, it is possible to eliminate the need for a reception antenna composed of a plurality of element antennas and an azimuth estimation device that performs complicated processing. In other words, according to the present invention, the target detection system (target detection device) can be reduced in size and weight, the costs for manufacturing, installing, and maintaining the target detection system can be reduced, and the time required for the target detection processing can be reduced. can do.

Embodiment 1 FIG.
In the first embodiment, the transmitter gives a specific change to the transmission wave by modulation of at least one of amplitude modulation, frequency modulation, and phase modulation, and whether or not the transmitter receives a specific change depends on whether or not the receiver has a specific change. A mode of discriminating a direct wave and a reflected wave from a target from a hybrid wave including unnecessary waves and detecting a delay time difference between the direct wave and the reflected wave will be described.

FIG. 1 is a block diagram showing a configuration of delay time detection apparatus 199 according to the first embodiment.
In FIG. 1, a delay time detection device 199 (target detection device) includes a transmitter 100 and a receiver 200 (delay time detector, target detection device). The transmitter 100 modulates a transmission antenna 110, a transmitter 120, and a modulation. The receiver 200 includes a receiving antenna 210, a receiver 220, a demodulator 230, a delay time detector 240 (an example of a discriminator), and a target detector 250.
The target object 300 is a target object whose position and distance from the transmitter 100 and the receiver 200 are to be detected.

  In the transmitter 100, the modulator 130 performs modulation to give a specific change (specific pattern) to the electric signal, and the transmitter 120 converts the electric signal modulated by the modulator 130 into an electromagnetic wave (radio wave or light wave) for transmission. The antenna 110 transmits the electromagnetic wave converted by the transmitter 120 as a transmission wave.

  In transmitter 100 in the first embodiment, modulator 130 gives a specific change to an electric signal by modulation, and transmitter 120 converts the electric signal having a specific change into an electromagnetic wave, and the amplitude of the electromagnetic wave and the frequency of the electromagnetic wave. A specific change is given to at least one of the phases of the electromagnetic wave, and the transmission antenna 110 transmits an electromagnetic wave having the specific change as a transmission wave.

  Hereinafter, the process of giving a specific change to the amplitude of the transmission wave by the modulator 130 (and the transmitter 120) is referred to as amplitude modulation, and the process of giving a specific change to the frequency of the transmission wave by the modulator 130 (and the transmitter 120). The frequency modulation is used, and the process of giving a specific change to the phase of the transmission wave by the modulator 130 (and the transmitter 120) is called phase modulation.

In the receiver 200, the receiving antenna 210 is a reflected wave in which the transmission wave transmitted from the transmitter 100 is reflected by the target, or a direct wave or transmitter in which the transmission wave transmitted from the transmitter 100 arrives directly without being reflected by the target. An electromagnetic wave such as a reflected wave based on a transmission wave transmitted by 100 and an unnecessary wave other than a direct wave is received.
In the receiver 200, the receiver 220 converts the electromagnetic wave received by the receiving antenna 210 in a specific time zone into an electrical signal.
Direct waves, reflected waves, and unnecessary waves arrive at the receiving antenna 210 and are received in a specific time zone for which the receiver 220 converts electromagnetic waves into electrical signals. Hereinafter, an electromagnetic wave that is received by the receiving antenna 210 and arrives at a specific time zone and includes a direct wave, a reflected wave, and an unnecessary wave is referred to as a hybrid wave, and an electric signal obtained by converting the hybrid wave is referred to as a hybrid signal.
In the receiver 200, the demodulator 230 demodulates the electrical signal (mixed signal) converted by the receiver 220.
In the receiver 200, the delay time detector 240 discriminates a signal portion corresponding to a direct wave and a signal portion corresponding to a reflected wave from the electrical signal (hybrid signal) demodulated by the demodulator 230 to receive a direct wave. The time from the time to the reception time of the reflected wave is calculated.
In the receiver 200, the target detector 250 determines whether the target 100 is transmitted from the transmitter 100 and the receiver 200 to the target 300 based on the time from the reception time of the direct wave calculated by the delay time detector 240 to the reception time of the reflected wave. The distance and the position of the target 300 are specified.

  The receiver 200 in the first embodiment distinguishes from the hybrid signal a signal portion corresponding to a direct wave having a specific pattern change and a signal portion corresponding to a reflected wave having a specific pattern change. The time from the reception time of the direct wave to the reception time of the reflected wave is used as information for specifying the distance from the target based on the signal interval between the signal portion corresponding to the identified direct wave and the signal portion corresponding to the reflected wave. It is characterized by calculating.

  Hereinafter, the time required for the electromagnetic wave transmitted from the transmitter 100 to reach the receiver 200 is defined as a delay time, which is the difference between the delay time of the direct wave and the delay time of the reflected wave, and the reflected wave from the reception time of the direct wave. The time until the reception time is taken as the delay time difference.

  The receiver 200 in Embodiment 1 can detect the distance from the transmitter 100 and the receiver 200 to the target 300 and the position of the target 300 by calculating the delay time difference. In the delay time detection apparatus 199 of the first embodiment, when the receiver 200 calculates the delay time difference, it is not necessary to synchronize the internal clocks of the transmitter 100 and the receiver 200 to transmit and receive electromagnetic waves. It is not necessary to estimate the arrival directions of direct and reflected waves.

FIG. 2 is a diagram illustrating a positional relationship among the transmitter 100, the receiver 200, and the target object 300.
In the target detection apparatus, for example, the transmitter 100, the receiver 200, and the target object 300 include a transmission wave transmission position A by the transmitter 100 and a reflection wave reception position B by the receiver 200, as shown in FIG. Is a fixed point, a distance aq between the transmission wave transmission position A by the transmitter 100 and the position Q of the target 300 and a distance between the reception position B of the reflected wave by the receiver 200 and the position Q of the target 300 Based on the relationship that the sum of bq forms an ellipsoid P that is equal to the distance corresponding to the delay time of the reflected wave (the distance calculated by multiplying the delay time of the reflected wave by the light wave corresponding to the traveling speed of the electromagnetic wave). The distance (aq + bq) from the transmitter 100 and the receiver 200 to the target 300 and the position Q of the target 300 can be detected.

That is, if the position A of the transmitter 100, the position B of the receiver 200, and the distance corresponding to the delay time of the reflected wave are known, the distance (aq + bq) from the transmitter 100 and the receiver 200 to the target 300 or the target 300 Can be detected.
However, in order to know the delay time of the reflected wave, it is necessary to accurately know the transmission time of the transmission wave by the transmitter 100 and the reception time of the reflected wave by the receiver 200. It is necessary to synchronize the internal clock to transmit and receive electromagnetic waves.
Therefore, in the delay time detection apparatus 199 in each embodiment, for example, the direct wave and the reflected wave can be calculated so that the synchronization between the transmitter 100 and the receiver 200 is unnecessary and the distance corresponding to the delay time of the reflected wave can be calculated. The delay time difference is detected.
Since the reflected wave propagates a distance longer than the direct wave by a distance corresponding to the delay time difference between the direct wave and the reflected wave, the distance corresponding to the delay time of the reflected wave is equal to the direct wave propagation distance (ab). It can be calculated by adding a distance corresponding to the delay time difference from the reflected wave. The propagation distance (ab) of the direct wave is a distance corresponding to the delay time of the direct wave, and is the distance between the position A of the transmitter 100 and the position B of the receiver 200. The distance corresponding to the delay time difference between the direct wave and the reflected wave is a distance calculated by multiplying the delay time difference between the direct wave and the reflected wave by the light wave.

  Further, as described below, in the delay time detection process (target detection process) of the delay time detection apparatus 199 according to the first embodiment, the arrival directions of the direct wave and the reflected wave are not estimated. That is, the delay time detection apparatus 199 according to the first embodiment does not require an antenna apparatus composed of a plurality of element antennas for estimating the arrival directions of the direct wave and the reflected wave and an azimuth estimation apparatus that performs complicated processing. .

FIG. 3 is a diagram illustrating an example of hardware resources of the transmitter 100 and the receiver 200 in the embodiment.
In FIG. 3, the transmitter 100 and the receiver 200 include a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a processor) that executes a program. The CPU 911 is connected to the ROM 913, the RAM 914, the communication board 915, and the magnetic disk device 920 via the bus 912, and controls these hardware devices. The communication board 915 transmits and receives electromagnetic waves using the transmission antenna 110 and the reception antenna 210. Instead of the magnetic disk device 920, another storage device (for example, a semiconductor memory such as a RAM or a flash memory) may be used.
The RAM 914 is an example of a volatile memory. The storage medium of the ROM 913 and the magnetic disk device 920 is an example of a nonvolatile memory. These are examples of a storage device, a storage device, or a storage unit.
The communication board 915 is an example of an input / output device, an input / output device, or an input / output unit. The storage device in which the input / output data is stored is an example of an input / output device, an input / output device, or an input / output unit.

  The magnetic disk device 920 stores an OS 921 (operating system), a program group 923, and a file group 924. The programs in the program group 923 are executed by the CPU 911 and the OS 921.

  The program group 923 stores a program for operating the “˜device” in each embodiment. The program is read and executed by the CPU 911.

In each of the embodiments, the file group 924 includes a modulation scheme used by the modulator 130 and the transmitter 120, a demodulation scheme used by the demodulator 230 and the receiver 220, a specific pattern given to the transmission wave by the modulation, and the transmitter 100. , The position of the receiver 200, the direction of transmission of the transmission wave by the transmitter 100, the time of transmission of the transmission wave by the transmitter 100, the distance from the detected transmitter 100 and the receiver 200 to the target 300, the detected target Information such as the position of the object 300 is stored.
In addition, the arrows in the flowcharts described in each embodiment mainly indicate input / output of (digital / analog) data and (electric) signals, and the data and signal values are the memory of the RAM 914 and the magnetic disk of the magnetic disk device 920. It is recorded on other recording media. Data and signal values are transmitted online via a bus 912, signal lines, cables, or other transmission media.

  In addition, what is described as “˜device” in each embodiment may be “˜unit”, “˜circuit”, “˜device”, “˜equipment”, “˜means”. -Step "," -procedure "," -process "may be used. That is, what is described as “˜device” may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware. Firmware and software are stored as programs on a magnetic disk or other recording medium. The program is read by the CPU 911 and executed by the CPU 911. In other words, the delay time detection program (target detection program) causes the “˜device” to function by a computer. Alternatively, the procedure or method of “˜device” is executed by a computer.

FIG. 4 is a flowchart of the delay time detection process showing the delay time detection method of the delay time detection apparatus 199 in the embodiment.
In order to execute a delay time detection process (target detection process) described below, the transmitter 100 and the receiver 200 use a CPU according to a delay time detection program (target detection program) to set each “˜device”. Control.

<S101 to S102: Modulation processing>
<S101: Signal Change Processing>
First, the modulator 130 of the transmitter 100 modulates the electric signal to give a specific change to the electric signal. At this time, the modulator 130 modulates the electrical signal in order to give a change in the specific pattern to at least one of the amplitude, frequency, and phase of the transmission wave transmitted from the transmitter 100.
<S102: Electrical signal-electromagnetic wave conversion process>
Next, the transmitter 120 of the transmitter 100 converts the electrical signal modulated by the modulator 130 and having a specific change into an electromagnetic wave. When the transmitter 120 converts an electrical signal having a specific change into an electromagnetic wave, the transmitter 120 applies a change corresponding to the specific change of the electrical signal to at least one of the amplitude of the electromagnetic wave, the frequency of the electromagnetic wave, and the phase of the electromagnetic wave.

<S103: Call processing>
Next, the transmission antenna 110 of the transmitter 100 transmits the electromagnetic wave converted by the transmitter 120 as a transmission wave.

(Hybrid wave arrives at receiver 200)
Then, the transmission wave transmitted from the transmitter 100 propagates toward the target 300 and is reflected by the target 300 and as a direct wave that propagates toward the receiver 200 without traveling toward the target 300. To come.
Further, unnecessary waves other than the direct wave and the reflected wave based on the transmission wave transmitted from the transmitter 100 arrive at the receiver 200.

<S104: Reception processing>
Next, the receiving antenna 210 of the receiver 200 receives incoming direct waves, reflected waves, and unnecessary waves. The direct wave and the reflected wave have specific changes (amplitude change, frequency change, phase change) given by the transmitter 100.

<S105 to S106: Demodulation processing>
<S105: Electromagnetic wave-electric signal conversion process>
Next, the receiver 220 of the receiver 200 converts a hybrid wave including a direct wave, a reflected wave, and an unnecessary wave that arrives at the reception antenna 210 and is received in a specific time zone into a hybrid signal. When the receiver 220 converts the hybrid wave into a hybrid signal, the receiver 220 converts at least one of the amplitude change, frequency change, and phase change of the hybrid wave so that the hybrid signal represents the change. The transmitter 100 converts the signal portion corresponding to the time zone when the direct wave arrives at the receiving antenna 210 and the signal portion corresponding to the time zone when the reflected wave arrives at the receiving antenna 210 in the hybrid signal by the conversion of the receiver 220. The specific change you gave will appear.
<S106: Extraction process>
Next, the demodulator 230 of the receiver 200 demodulates the mixed signal converted by the receiver 220 and extracts a change pattern of the mixed signal. For example, the demodulator 230 demodulates the hybrid signal and converts the change pattern of the hybrid signal into digital data.

<S107 to S108: Delay Time Detection Process>
<S107: Identification processing>
Next, the delay time detector 240 of the receiver 200 includes a signal portion corresponding to a direct wave having a specific change given by the transmitter 100 based on the change pattern of the mixed signal extracted by the demodulator 230 and the transmitter 100. A signal portion corresponding to a reflected wave having a given specific change is identified from the hybrid signal. When the delay time detector 240 discriminates between a signal portion corresponding to a direct wave and a signal portion corresponding to a reflected wave, first, a signal portion having a specific change given by the transmitter 100 is extracted from the hybrid signal. By this extraction, two signal parts, a signal part corresponding to a direct wave and a signal part corresponding to a reflected wave, are extracted. Then, the delay time detector 240 discriminates the detected signal portion having the earlier time zone or the stronger signal strength from the detected two signal portions as the signal portion corresponding to the direct wave. The signal part that was not identified as the signal part corresponding to the direct wave among the signal parts, and the signal part with the slower time zone or the signal part with the weaker signal strength is identified as the signal part corresponding to the reflected wave. To do. Since the direct wave arrives directly from the transmitter 100 without passing through the target 300, the arrival time is earlier than the reflected wave and the signal intensity is stronger than the reflected wave because the propagation distance is short.
<S108: Detection Process>
The time corresponding to the signal interval between the signal portion corresponding to the direct wave identified by the delay time detector 240 of the receiver 200 and the signal portion corresponding to the reflected wave is from the reception time of the direct wave to the reception time of the reflected wave. It is calculated as the time. The time from the reception time of the direct wave to the reception time of the reflected wave calculated by the delay time detector 240 indicates a delay time difference between the direct wave and the reflected wave, and the distance from the transmitter 100 and the receiver 200 to the target 300 This is information for specifying the position of the target 300.

<S109: Specific processing>
Further, the target detector 250 of the receiver 200 specifies the distance from the transmitter 100 and the receiver 200 to the target 300 and the position of the target 300 based on the delay time difference calculated by the delay time detector 240. For example, the target detector 250 uses the distance obtained by multiplying the delay time difference by the light wave (the propagation distance difference between the direct wave and the reflected wave, the distance corresponding to the delay time difference between the direct wave and the reflected wave) as the position of the transmitter 100 and the receiver. The transmission distance of the reflected wave (distance corresponding to the delay time of the reflected wave) is added to the distance to the position 200 (distance corresponding to the propagation distance of the direct wave and the delay time of the direct wave). The distance from 200 to the target 300 is calculated. Further, for example, as shown in FIG. 2 described above, the target detector 250 uses the position A of the transmitter 100 and the position B of the receiver 200 as fixed points, and sets the distance aq from the transmitter 100 to the target 300 and the receiver. A formula indicating an ellipsoid P whose sum of the distance bq from 200 to the target 300 is equal to the propagation distance of the reflected wave is calculated as the position Q of the target 300.

  Hereinafter, a specific example of the delay time detection process (S107 to S108) in the first embodiment will be described with reference to the drawings.

FIG. 5 is a diagram illustrating a relationship between a transmission wave, a hybrid wave, and a delay time difference during amplitude modulation in the first embodiment.
For example, the transmitter 100 transmits a transmission wave having a specific change in amplitude as shown in a pulse wave (rectangular wave) in FIG. At this time, the transmitter 100 generates, for example, a transmission wave generated by amplitude modulation by the modulator 130 and the transmitter 120 so that the ratio of the amplitude of the α portion to the amplitude of the β portion has a specific change of 2: 1. To send.
When the unnecessary wave a and the unnecessary wave b reach the receiver 200 together with the direct wave and the reflected wave as shown in the pulse wave of FIG. 5B, the delay time detector 240 has an amplitude ratio of 2: 1. The ones that have (direct wave and reflected wave) are extracted from the hybrid wave. Among the extracted ones, the one with the earlier time (direct wave: t2, reflected wave: t3) and the larger amplitude (intensity / power of electromagnetic wave) The direct wave and the other are identified as the reflected wave, and the time (t3−t2) from the time (t2) of the direct wave to the time (t3) of the reflected wave is calculated as a delay time difference between the direct wave and the reflected wave.
In FIG. 5, the time of the amplitude change point for the direct wave, the reflected wave, and the transmission wave is the time of the wave, but the time of the start point and the time of the end point of each wave may be the time of the wave.
In FIG. 5, the time (t2-t1) from the time (t1) of the transmission wave to the time (t2) of the direct wave indicates the delay time of the direct wave, and the time (t3) of the reflected wave from the time (t1) of the transmission wave. ) (T3-t1) indicates the delay time of the reflected wave.

FIG. 6 is a diagram showing a relationship between a transmission wave, a hybrid wave, and a delay time difference during frequency modulation in the first embodiment.
For example, the transmitter 100 transmits a transmission wave having a specific change in frequency and wavelength, as shown by a pulse wave (sine wave) in FIG.
When the unnecessary wave a and the unnecessary wave b reach the receiver 200 together with the direct wave and the reflected wave as shown in the pulse wave of FIG. 6B, the delay time detector 240 has a specific frequency and wavelength. Extract the thing (direct wave and reflected wave) from the hybrid wave, and the one with the larger time (direct wave: t2, reflected wave: t3) and larger amplitude (electromagnetic wave intensity / power) is extracted directly The wave and the other are identified as reflected waves, and the time (t3-t2) from the time (t2) of the direct wave to the time (t3) of the reflected wave is calculated as a delay time difference between the direct wave and the reflected wave.
In FIG. 6, the time of the start point for the direct wave, the reflected wave, and the transmission wave is the time of the wave, but for each wave, for example, the time of the end point may be the time of the wave.
In FIG. 6, the time (t2-t1) from the time (t1) of the transmission wave to the time (t2) of the direct wave indicates the delay time of the direct wave, and the time (t3) of the reflected wave from the time (t1) of the transmission wave. ) (T3-t1) indicates the delay time of the reflected wave.

FIG. 7 is a diagram showing a relationship between a transmission wave, a hybrid wave, and a delay time difference during phase modulation in the first embodiment.
For example, the transmitter 100 transmits a transmission wave having a specific change in phase as shown by a pulse wave (sine wave) in FIG.
When the unnecessary wave a and the unnecessary wave b reach the receiver 200 together with the direct wave and the reflected wave as shown in the pulse wave of FIG. 7B, the delay time detector 240 has a specific phase ( The direct wave and the reflected wave are extracted from the hybrid wave, and the extracted wave having the earlier time (direct wave: t2, reflected wave: t3) and the larger amplitude (intensity / power of electromagnetic wave) is the direct wave. The other is identified as the reflected wave, and the time (t3−t2) from the time (t2) of the direct wave to the time (t3) of the reflected wave is calculated as a delay time difference between the direct wave and the reflected wave.
In FIG. 7, the time of the start point for the direct wave, the reflected wave, and the transmission wave is the time of the wave. However, for each wave, for example, the time of the end point may be the time of the wave.
In FIG. 7, the time (t2-t1) from the time (t1) of the transmission wave to the time (t2) of the direct wave indicates the delay time of the direct wave, and the time (t3) of the reflected wave from the time (t1) of the transmission wave. ) (T3-t1) indicates the delay time of the reflected wave.

  Delay time detection apparatus 199 according to Embodiment 1 transmits an electromagnetic wave modulated by transmitter 100 and given a specific change as a transmission wave, and receiver 200 is a hybrid including a reflected wave, a direct wave, and an unnecessary wave. A direct wave and a reflected wave having a specific change given to the transmitted wave by modulation by the transmitter 100 are discriminated from the hybrid wave, and the time from the reception time of the direct wave to the reception time of the reflected wave is targeted. It is calculated as information for specifying a distance to an object.

  In particular, the transmitter 100 has at least a specific amplitude modulation that gives a specific change to the amplitude of the electromagnetic wave, a specific frequency modulation that gives a specific change to the frequency of the electromagnetic wave, and a specific phase modulation that gives a specific change to the phase of the electromagnetic wave. At least one of a specific change in amplitude, a specific change in frequency, and a specific change in phase that the receiver 200 has applied to the transmission wave by modulation is performed by performing either modulation. A direct wave and a reflected wave having any specific change are distinguished from the hybrid wave.

  As described above, the delay time detection apparatus 199 according to Embodiment 1 eliminates the need for synchronization between the transmitter 100 and the receiver 200 by using a transmission radio wave modulated by a predetermined method, and also allows direct wave detection. In addition, an expensive receiving antenna and azimuth estimating device for estimating the arrival direction of the reflected wave and the reflected wave are not required, and the delay time difference between the direct wave and the reflected wave can be detected.

  In the first embodiment, amplitude modulation, frequency modulation, and phase modulation have been described as examples of modulation methods. However, other modulation methods may be used. For example, the delay time detection apparatus 199 in the embodiment includes pulse modulation (pulse width modulation, pulse amplitude modulation, pulse density modulation, pulse phase modulation, pulse code modulation) and digital modulation (amplitude shift modulation, phase shift modulation, By applying a specific change to the transmitted wave using frequency shift keying or quadrature amplitude modulation, the delay time difference between the direct wave and the reflected wave is the same as when using amplitude modulation, frequency modulation, or phase modulation, The distance from the transmitter 100 and the receiver 200 to the target 300 and the position of the target 300 may be detected.

Embodiment 2. FIG.
In the second embodiment, the transmitter gives a specific change to the transmission wave by modulation using at least one of pulse compression and chirp compression, and the composite wave received by the receiver is compressed by the compression used by the transmitter. A mode will be described in which a direct wave from a transmitter and a reflected wave from a target are identified from a hybrid wave including unnecessary waves and a delay time difference between the direct wave and the reflected wave is detected by demodulation.
Here, “pulse compression” indicates a pulse compression method using code modulation, and “chirp compression” indicates a pulse compression method using (linear / linear) frequency modulation.
In the following, items different from the first embodiment are mainly described, and items not described are the same as those in the first embodiment.

FIG. 8 is a block diagram showing a configuration of delay time detection apparatus 199 according to the second embodiment.
In FIG. 8, the delay time detection apparatus 199 according to the second embodiment is characterized in that the transmitter 100 includes a modulator 140 with an S / N improvement function. The modulator 140 with an S / N improvement function replaces the modulator 130 having the configuration in the first embodiment (see FIG. 1).
The modulator 140 with an S / N improvement function performs modulation using at least one of pulse compression and chirp compression to give a specific change to a transmission wave transmitted from the transmitter 120 via the transmission antenna 110.
The delay time detection apparatus 199 according to the second embodiment uses an S / N ratio (SNR: SNR) with respect to the delay time detection apparatus 199 according to the first embodiment by using at least one of pulse compression and chirp compression. (Signal to Noise ratio) is improved.

Next, a delay time detection method of the delay time detection apparatus 199 according to the second embodiment will be described with reference to FIG.
In S101, in Embodiment 2, the modulator 130 of the transmitter 100 modulates the electric signal to give a specific change using at least one of pulse compression and chirp compression to the transmission wave transmitted from the transmitter 100. I do. For example, the modulator 130 adds a code for pulse compression to the electric signal, and adds a frequency change band and a pulse width for chirp compression to the electric signal, for example. Pulse compression codes include Barker code, pseudo Barker code, and complementary sequence code.
In S102, in Embodiment 2, when the transmitter 120 of the transmitter 100 converts an electrical signal having a specific change into an electromagnetic wave, the electromagnetic wave is subjected to a specific change using at least one of pulse compression and chirp compression. give.
In S103, as in Embodiment 1, the transmission antenna 110 of the transmitter 100 transmits the electromagnetic wave converted by the transmitter 120 as a transmission wave.

In S104, as in Embodiment 1, the receiving antenna 210 of the receiver 200 receives the incoming mixed wave including the direct wave, the reflected wave, and the unnecessary wave. In the second embodiment, the direct wave and the reflected wave have specific changes based on the compression used by the transmitter 100.
In S105, in Embodiment 2, when the receiver 220 of the receiver 200 converts the hybrid wave into a hybrid signal, the receiver 220 converts the specific change based on the compression used by the transmitter 100 so that the hybrid signal represents the change.
In S <b> 106, in Embodiment 2, the demodulator 230 of the receiver 200 demodulates the mixed signal by the compression used by the transmitter 100. The demodulator 230 of the receiver 200 demodulates the hybrid signal by taking a cross-correlation with the electrical signal of the transmission wave modulated by the modulator 140 with the S / N improvement function of the transmitter 100 and has a specific pattern change. The signal portion corresponding to the direct wave and the signal portion corresponding to the reflected wave are compressed.
In S107, in the second embodiment, the delay time detector 240 of the receiver 200 identifies the compressed direct wave signal portion and the reflected wave signal portion from the hybrid signal.
In S108, as in the first embodiment, the delay time detector 240 of the receiver 200 sets the time corresponding to the signal interval between the signal portion corresponding to the direct wave and the signal portion corresponding to the reflected wave to the direct wave and the reflected wave. It is calculated as the delay time difference.
In S109, as in the first embodiment, the receiving antenna control device 260 of the receiver 200 determines the distance from the transmitter 100 and the receiver 200 to the target 300 and the target based on the delay time difference between the direct wave and the reflected wave. 300 positions are specified.

  Hereinafter, a specific example of the delay time detection process (S107 to S108) in the second embodiment will be described with reference to the drawings.

FIG. 9 is a diagram illustrating a relationship between a transmission wave, a hybrid wave, and a delay time difference during pulse compression in the second embodiment.
For example, the transmitter 100 transmits a transmission wave given a specific code pattern as shown in a pulse wave (rectangular wave) in FIG.
As shown in the pulse wave of FIG. 9B, when the unnecessary wave a and the unnecessary wave b reach the receiver 200 together with the direct wave and the reflected wave, the demodulator 230 and the receiver 220 transmit the wave for each wave. The pulse compression is performed by taking the cross-correlation with the code pattern of the. Due to the pulse compression, only the signal portions of the direct wave and the reflected wave in which the transmission wave and the code pattern are correlated appear as large amplitude as shown in the pulse wave (triangular wave) in FIG. 9C.
The delay time detector 240 extracts a signal portion having a large amplitude (for example, a signal portion having an amplitude larger than a predetermined threshold) from the hybrid wave, and the time (direct wave: t2, reflected wave: t3) among the extracted ones is early. And the one with the larger amplitude (electromagnetic wave intensity / power) is identified as a direct wave and the other as a reflected wave, and the time from the time (t2) of the direct wave to the time (t3) of the reflected wave (t3-t2 ) As a delay time difference between the direct wave and the reflected wave.

FIG. 10 is a diagram illustrating a relationship between a transmission wave, a hybrid wave, and a delay time difference during chirp compression in the second embodiment.
For example, the transmitter 100 transmits a transmission wave given a specific frequency pattern as shown by a pulse wave (sine wave) in FIG.
As shown in the pulse wave of FIG. 10B, when the unnecessary wave a and the unnecessary wave b reach the receiver 200 together with the direct wave and the reflected wave, the demodulator 230 and the receiver 220 transmit the transmitted wave for each wave. Chirp compression is performed by taking a cross-correlation with the frequency pattern of the. By chirp compression, as shown in the pulse wave (sine wave) in FIG. 10C, only the signal portion of the direct wave and the reflected wave in which the transmission wave and the frequency pattern are correlated appears as a large amplitude.
The delay time detector 240 extracts a signal portion having a large amplitude (for example, a signal portion having an amplitude larger than a predetermined threshold) from the hybrid wave, and the time (direct wave: t2, reflected wave: t3) among the extracted ones is early. And the one with the larger amplitude (electromagnetic wave intensity / power) is identified as a direct wave and the other as a reflected wave, and the time from the time (t2) of the direct wave to the time (t3) of the reflected wave (t3-t2 ) As a delay time difference between the direct wave and the reflected wave.

  In the delay time detection apparatus 199 according to the second embodiment, the transmitter 100 performs modulation using at least one of compression of specific pulse compression and specific chirp compression on an electromagnetic wave, and transmits the electromagnetic wave as a transmission wave. The transmitter 200 demodulates the hybrid wave using the compression used by the transmitter 100 for modulation, and distinguishes the direct wave and the reflected wave from the hybrid wave.

  As described above, the delay time detection apparatus 199 according to the second embodiment is such that the transmitter 100 adds a code for pulse compression to the transmission wave, and the receiver 200 performs pulse compression when demodulating the reception wave. The S / N on the receiving side can be earned while reducing the transmission power on the transmitting side. In other words, since the receiver 200 can discriminate between the direct wave and the reflected wave even when the power of the transmission wave of the transmitter 100 is small, the delay time detection apparatus 199 in the second embodiment uses the delay in the first embodiment. In addition to the effect of the time detection device 199, confidentiality can be improved. Further, the delay time detection apparatus 199 according to the second embodiment can improve confidentiality even when chirp compression is used, as in the case where pulse compression is used.

Embodiment 3 FIG.
In the third embodiment, the receiver estimates the arrival direction of the direct wave and the arrival direction of the reflected wave based on the positional relationship with the transmitter and the transmission direction of the transmission wave by the transmitter, and arrives from the estimated direction. A mode for performing reception control for receiving electromagnetic waves will be described.
The method of giving a specific change to the transmitted wave, the method of discriminating between the direct wave and the reflected wave, the method of calculating the delay time difference between the direct wave and the reflected wave, the distance to the target, and the position of the target in the third embodiment The method for specifying the same is the same as in the first and second embodiments.
The following description focuses on matters different from the first embodiment and the second embodiment, and matters not described are the same as those in the first embodiment and the second embodiment.

FIG. 11 is a block diagram showing a configuration of delay time detection apparatus 199 according to the third embodiment.
In FIG. 11, delay time detection apparatus 199 according to Embodiment 3 includes transmitter 100 having transmission antenna control apparatus 160, GPS receiver 170 (Global Positioning System), and information transmission apparatus 180, and receiver 200 controlling reception antenna. It is characterized by having a device 260, a GPS receiver 270, and an information transmission device 280. The modulator 130 may be the modulator 140 with an S / N improvement function as in the second embodiment.
The transmission antenna control device 160 performs transmission beam control for transmitting a transmission wave in a predetermined direction at a predetermined time (time zone), and the reception antenna control device 260 receives an electromagnetic wave coming from a specific direction at a specific time (time zone). Receive beam control is performed. For example, the transmission antenna control device 160 performs transmission beam control by controlling the antenna direction of the transmission antenna 110 and the transmission characteristics of each antenna portion in the transmission antenna 110, and the reception antenna control device 260 performs the antenna direction of the reception antenna 210. The receiving beam control is performed by controlling the receiving characteristics of each antenna portion in the receiving antenna 210.
The GPS receiver 170 and the GPS receiver 270 measure the position of the own device using GPS. However, the transmitter 100 and the receiver 200 may measure the position of the own device using another positioning device (for example, a positioning device using a gyro).
The information transmission device 180 (communication device) and the information transmission device 280 (communication device) are communication devices that perform wired or wireless data communication.

In the transmitter 100, the information transmission device 180 determines the position where the GPS receiver 170 is positioned before the transmitting antenna 110 transmits the transmission wave (the position where the transmitter 100 transmits the transmission wave). The transmission antenna control device 160 transmits to the information transmission device 280 of the receiver 200 the direction / time at which the transmission antenna 110 transmits a transmission wave by transmission beam control. Then, the transmission antenna control device 160 causes the transmission antenna 110 to transmit a transmission wave in a predetermined direction at a predetermined time by transmission beam control.
In the receiver 200, the information transmission device 280 receives from the information transmission device 180 of the transmitter 100 the position where the transmitter 100 exists and the direction and time at which the transmitter 100 transmits a transmission wave. Next, the receiving antenna control device 260 includes the position where the receiver 200 positioned by the GPS receiver 270 (the position where the receiver 200 receives the direct wave and the reflected wave) and the transmitter 100 received by the information transmission device 280. Based on the existing position and the direction / time at which the transmitter 100 transmits the transmission wave, the direction / time at which the direct wave and the reflected wave arrive is calculated. Then, the reception antenna control device 260 performs reception beam control on the reception antenna 210 so as to receive an electromagnetic wave (hybrid wave) coming from the calculated direction at the calculated time.
For example, when the transmitter 100 is located in the north and the receiver 200 is located in the south, and the transmitter 100 transmits a transmission wave in the southwest direction, the reception antenna control device 260 receives the electromagnetic waves coming from the north and the northwest. Receive beam control is performed on the receive antenna 210.
Hereinafter, the receiver 200 discriminates the direct wave and the reflected wave with respect to the hybrid wave received by the reception beam control in the same manner as in the first and second embodiments, and delays the direct wave and the reflected wave. The time difference is calculated, and the distance from the target 300 and the position of the target 300 are specified.

  In Embodiment 3, the receiver 200 acquires the position where the transmitter 100 exists and the direction and time at which the transmitter 100 transmits a transmission wave by the information transmission device 280 communicating with the information transmission device 180. As described above, the position, direction, and time at which the transmitter 100 transmits a transmission wave is determined in advance, and the receiver 200 stores the determined information in a storage device in advance, based on the information stored in advance. The reception beam control may be performed.

  In delay time detection apparatus 199 according to Embodiment 3, transmitter 100 transmits a transmission wave in a predetermined direction at a predetermined position, and receiver 200 receives the position of the receiver itself, the predetermined position of transmitter 100, and the transmitter. 100 is characterized in that it performs reception control so as to receive an electromagnetic wave from a specific direction based on a predetermined direction for transmitting a transmission wave, and receives a hybrid wave.

  As described above, in the delay time detection apparatus 199 according to the third embodiment, the receiver 200 obtains the position of the transmitter 100, the transmission time of the transmission wave, and the transmission beam direction before the transmitter 100 transmits the transmission wave. By controlling the reception beam in a desired direction, radio waves can be received efficiently.

In the first embodiment, the following delay time detection apparatus 199 has been described.
The delay time detection apparatus 199 includes a transmitter 100 and a receiver 200 as described below mounted on an independent platform. The transmitter 100 includes a transmission antenna 110, a transmitter 120, and a modulator 130 for amplitude modulation, frequency modulation, or phase modulation of a transmission wave. The receiver 200 receives a direct wave from the transmitter 100 and a reflected wave from the target, a receiver 220 that converts a hybrid wave including the direct wave and the reflected wave received by the reception antenna into a hybrid signal, A demodulator 230 that demodulates the hybrid signal, and a delay time detector 240 that identifies the direct wave and the reflected wave from the demodulated signal including the demodulated direct wave and the reflected wave and detects a delay time difference between the direct wave and the reflected wave. Is provided.

In the second embodiment, the following delay time detection apparatus 199 has been described.
The delay time detection apparatus 199 includes a transmitter 100 and a receiver 200 as described below mounted on an independent platform. The transmitter 100 includes a transmission antenna 110, a transmitter 120, and a modulator 140 with a modulator S / N improvement function for modulating the transmission wave in order to perform chirp compression of the transmission wave by pulse compression or linear frequency modulation. The receiver 200 receives a direct wave from the transmitter 100 and a reflected wave from the target, and a receiver 220 that converts a hybrid wave including the direct wave and the reflected wave received by the reception antenna 210 into a hybrid signal. A demodulator 230 that demodulates the hybrid signal by pulse compression or chirp compression, and discriminates the direct wave and the reflected wave from the hybrid signal including the demodulated direct wave and the reflected wave to determine the delay time difference between the direct wave and the reflected wave. A delay time detector 240 for detection is provided.

In the third embodiment, the following delay time detection apparatus 199 has been described.
The delay time detection apparatus 199 includes a transmitter 100 and a receiver 200 as described below mounted on an independent platform. The transmitter 100 includes a transmission antenna 110, a transmission antenna control device 160 that performs transmission beam control, a transmitter 120, a modulator 130 in the first embodiment or a modulator 140 with an S / N improvement function in the second embodiment, and position information. A GPS receiver 170 for obtaining information and an information transmission device 180 for transmitting information to and from the receiver 200 are provided. A receiver 200 receives a direct wave and a reflected wave from a target, a receiving antenna 210 that performs reception beam control, and a hybrid signal including a direct wave and a reflected wave received by the receiving antenna 210 as a hybrid signal. Receiver 220 to be converted, demodulator 230 in the first or second embodiment, direct wave and reflected wave are identified from the mixed signal including the demodulated direct wave and reflected wave, and the direct wave and reflected wave are identified. A delay time detector 240 for detecting the delay time difference, a GPS receiver 270 for obtaining position information, and an information transmission device 280 for transmitting information to and from the transmitter 100.

FIG. 2 is a block diagram illustrating a configuration of a delay time detection apparatus 199 according to the first embodiment. The figure which shows the positional relationship of the transmitter 100, the receiver 200, and the target object 300. FIG. 3 is a diagram illustrating an example of hardware resources of a transmitter 100 and a receiver 200 in Embodiment 1. FIG. The flowchart of the delay time detection process which shows the delay time detection method of the delay time detection apparatus 199 in embodiment. FIG. 4 is a diagram illustrating a relationship among a transmission wave, a hybrid wave, and a delay time difference during amplitude modulation in the first embodiment. FIG. 3 is a diagram illustrating a relationship between a transmission wave, a hybrid wave, and a delay time difference during frequency modulation in the first embodiment. FIG. 3 is a diagram illustrating a relationship between a transmission wave, a hybrid wave, and a delay time difference during phase modulation in the first embodiment. FIG. 9 is a block diagram showing a configuration of a delay time detection apparatus 199 according to Embodiment 2. FIG. 10 is a diagram illustrating a relationship between a transmission wave, a hybrid wave, and a delay time difference during pulse compression in the second embodiment. FIG. 10 is a diagram illustrating a relationship among a transmission wave, a hybrid wave, and a delay time difference during chirp compression in the second embodiment. FIG. 10 is a block diagram showing a configuration of a delay time detection apparatus 199 according to Embodiment 3. A passive radar device disclosed in Patent Document 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Transmitter, 110 Transmitting antenna, 120 Transmitter, 130 Modulator, 140 Modulator with S / N improvement function, 160 Transmitting antenna control apparatus, 170 GPS receiver, 180 Information transmission apparatus, 199 Delay time detection apparatus, 200 Reception 210, receiving antenna, 220 receiver, 230 demodulator, 240 delay time detector, 250 target detector, 260 receiving antenna control device, 270 GPS receiver, 280 information transmission device, 300 target object, 813 transmission source, 814 Target, 815 antenna device, 816 receiver, 817 orientation estimation device, 818 signal separation device, 819 correlation processing device, 820 integration processing device, 821 target detection device, 822 display device, 911 CPU, 912 bus, 913 ROM, 914 RAM 915 Communication board, 20 magnetic disk device, 921 OS, 923 programs, 924 files.

Claims (14)

A transmitter that transmits an electromagnetic wave modulated and given a specific change as a transmission wave;
Reflected wave based on a reflected wave reflected by a target transmitted from the transmitter, a direct wave transmitted directly from the transmitter transmitted without being reflected by the target, and a reflected wave transmitted from the transmitter Receiving a hybrid wave including an unnecessary wave other than a direct wave and a direct wave, distinguishing a direct wave and a reflected wave having a specific change given to the transmission wave by modulation by the transmitter from the hybrid wave, A delay time detection apparatus comprising: a receiver that calculates a time from a reception time to a reception time of a reflected wave as information for specifying a distance from a target. The transmitter has at least one of a specific amplitude modulation that gives a specific change to the amplitude of the electromagnetic wave, a specific frequency modulation that gives a specific change to the frequency of the electromagnetic wave, and a specific phase modulation that gives a specific change to the phase of the electromagnetic wave. The electromagnetic wave is transmitted as a transmission wave by modulating
The receiver receives a direct wave and a reflected wave having a specific change of at least one of a specific change in amplitude, a specific change in frequency, and a specific change in phase, which are given to the transmission wave by the transmitter through modulation. The delay time detection apparatus according to claim 1, wherein the delay time detection apparatus is identified from a hybrid wave. The transmitter modulates to give a specific change to the signal, converts the signal having the specific change into an electromagnetic wave, and changes the specific change to at least one of the amplitude of the electromagnetic wave, the frequency of the electromagnetic wave, and the phase of the electromagnetic wave. Giving a corresponding change, transmitting an electromagnetic wave having a change corresponding to the specific change as a transmission wave,
The receiver converts the received mixed wave into a signal, demodulates the mixed wave signal, and discriminates a direct wave signal and a reflected wave signal having a specific change from the mixed wave signal. The delay time detection apparatus according to claim 2. The transmitter performs modulation using at least one of compression of specific pulse compression and specific chirp compression on the electromagnetic wave, and transmits the electromagnetic wave as a transmission wave,
2. The delay time detecting apparatus according to claim 1, wherein the receiver demodulates a hybrid wave using compression used by the transmitter for modulation, and discriminates a direct wave and a reflected wave from the hybrid wave. The transmitter transmits a transmission wave in a predetermined direction at a predetermined position,
The receiver performs a reception control so as to receive an electromagnetic wave from a specific direction based on a position of the receiver itself, a predetermined position of the transmitter, and a predetermined direction in which the transmitter transmits a transmission wave, and performs a mixed wave. The delay time detection apparatus according to claim 1, wherein the delay time detection apparatus receives the delay time. The transmitter communicates with the receiver the position where the transmitter exists and the direction of transmitting the transmission wave before transmitting the transmission wave,
The receiver is based on a position where the receiver is present, a position where the transmitter communicated from the transmitter is present, and a direction in which the transmission wave communicated from the transmitter emits a transmission wave. 5. The delay time detection apparatus according to claim 1, wherein the delay time detection apparatus calculates a direction in which the wave arrives, performs reception control so as to receive electromagnetic waves from the calculated direction, and receives a hybrid wave. Transmits an electromagnetic wave that has been modulated by the transmitter to give a specific change as a transmitted wave,
The reflected wave transmitted from the transmitter by the receiver reflected by the target, the direct wave transmitted directly from the transmitter without being reflected by the target, and the transmitted wave transmitted by the transmitter Receiving a mixed wave including a reflected wave and an unnecessary wave other than a direct wave, and identifying a direct wave and a reflected wave having a specific change given to the transmitted wave by modulation by the transmitter from the mixed wave; A delay time detection method, characterized in that a time from a reception time of a direct wave to a reception time of a reflected wave is calculated as information for specifying a distance from a target. With respect to a transmission wave from a transmitter that transmits a modulated electromagnetic wave having a specific change as a transmission wave, a transmission wave transmitted from the transmitter is reflected by a target and a transmission transmitted from the transmitter A receiver that receives a hybrid wave including a direct wave that the wave has directly reached without being reflected by the target, and a reflected wave based on the transmitted wave transmitted by the transmitter and an unnecessary wave other than the direct wave;
A discriminator for discriminating, from the mixed wave received by the receiver, a direct wave and a reflected wave having a specific change given to the transmission wave by modulation by the transmitter;
A delay time detector comprising: a delay time detector that calculates a time from a reception time of a direct wave to a reception time of a reflected wave as information for specifying a distance from a target based on an identification result of the identifier; Detector. The receiver is at least one of a specific amplitude modulation that gives a specific change to the amplitude of the electromagnetic wave, a specific frequency modulation that gives a specific change to the frequency of the electromagnetic wave, and a specific phase modulation that gives a specific change to the phase of the electromagnetic wave. For the transmission wave from the transmitter that transmits the electromagnetic wave as a transmission wave by modulating the received wave, a hybrid wave including a reflected wave, a direct wave and an unnecessary wave is received,
The discriminator includes a direct wave and a reflected wave having a specific change of at least one of a specific change in amplitude, a specific change in frequency, and a specific change in phase, which the transmitter gives to the transmission wave by modulation. 9. The delay time detector according to claim 8, wherein the delay time detector is identified from a hybrid wave received by the receiver. The delay time detector further comprises a demodulator that demodulates the modulated signal,
The receiver modulates and gives a specific change to the signal, converts the signal giving the specific change into an electromagnetic wave, and changes the specific change to at least one of the amplitude of the electromagnetic wave, the frequency of the electromagnetic wave, and the phase of the electromagnetic wave. Receives mixed waves including reflected waves, direct waves, and unwanted waves with respect to the transmitted waves from transmitters that transmit the electromagnetic waves that give the corresponding changes as the transmitted waves. Convert the received hybrid wave into a signal,
The demodulator demodulates the hybrid wave signal converted by the receiver;
10. The delay time detector according to claim 9, wherein the discriminator discriminates a direct wave signal and a reflected wave signal having a specific change from a hybrid wave signal demodulated by the demodulator. The delay time detector further comprises a demodulator that demodulates the modulated signal,
The receiver performs modulation using a specific pulse compression and / or a specific chirp compression on the electromagnetic wave and directly transmits the electromagnetic wave as a transmission wave to the reflected wave and the reflected wave directly. Receive a hybrid wave that includes waves and unwanted waves,
The demodulator demodulates the hybrid wave received by the receiver using the compression used by the transmitter for modulation;
9. The delay time detector according to claim 8, wherein the discriminator discriminates a direct wave and a reflected wave from a hybrid wave demodulated by the demodulator. The receiver performs a reception control so as to receive an electromagnetic wave from a specific direction based on a position of the receiver itself, a predetermined position of the transmitter, and a predetermined direction in which the transmitter transmits a transmission wave. The delay time detector according to any one of claims 8 to 11, wherein the delay time detector is received. The delay time detector further includes a communicator for receiving the position where the transmitter communicates before the transmitter transmits the transmission wave and the direction of transmitting the transmission wave,
The receiver receives a hybrid wave based on a position where the receiver is present, a position where the transmitter is received by the communication device, and a direction of transmitting the transmission wave of the transmission wave received by the communication device. The delay time detector according to claim 8, wherein a hybrid wave is received by calculating a direction to be received and performing reception control so as to receive an electromagnetic wave from the calculated direction. With respect to a transmission wave from a transmitter that transmits a modulated electromagnetic wave having a specific change as a transmission wave, a transmission wave transmitted from the transmitter is reflected by a target and a transmission transmitted from the transmitter A reception process in which a receiver receives a hybrid wave including a direct wave that has directly arrived without being reflected by a target and a reflected wave based on a transmission wave transmitted by the transmitter and an unnecessary wave other than the direct wave; and
An identification process in which a discriminator discriminates a direct wave and a reflected wave having a specific change given to a transmission wave by modulation by the transmitter from a mixed wave received by the receiver;
Based on the discrimination result of the discriminator, the computer executes a delay time detection process for causing the delay time detector to calculate the time from the reception time of the direct wave to the reception time of the reflected wave as information for specifying the distance from the target. A program for detecting a delay time.

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