JP7131218B2 - Radio wave monitoring system, radio wave monitoring processing device, radio wave monitoring method and program - Google Patents

Description

The present invention relates to a radio wave monitoring system, a radio wave monitoring processing device, a radio wave monitoring method, and a program.

Several techniques have been proposed in relation to the identification of the source of radio waves.
For example, Patent Literature 1 describes a radio wave monitoring device for tracking the position of a radio station to be monitored. This radio wave monitoring apparatus detects the presence or absence of a transmission signal to be monitored from the received signal, and uniquely identifies the source radio station from the characteristics of the transmission signal. Also, this radio wave monitoring device measures the direction of arrival of the transmission signal and estimates the position of the source radio station from the measurement result. Then, the radio wave monitoring apparatus outputs information that associates the identified radio station (source) with the position of the radio station.

Further, Patent Literature 2 describes a radio wave monitoring apparatus for identifying an individual radio station that has emitted a received radio wave without relying on the experience and intuition of the monitor. This radio wave monitoring apparatus receives radio signals with a plurality of azimuth information measuring means, measures arrival azimuths, estimates the position of a transmission source based on the arrival azimuths, and determines the transmission source from pre-registered radio station information. and search for wireless station information in its vicinity. Also, this radio wave monitoring device reads and interprets identification signal information representing the source radio station based on the radio waves received by the azimuth information measuring means. Then, this radio wave monitoring device searches the obtained radio station information, selects a radio station having the same value as the read identification signal information, and associates the selected radio station with the emission source position estimation information. Then, by classifying the position of the emission source for each radio station, an individual radio station is specified.

JP 2007-248110 A Japanese Patent No. 5472210

One of the scenes for specifying the source of radio waves is the scene for specifying the source of interference waves that interfere with a target radio signal. In this case, the received signal used to identify the transmission source includes the target radio signal in addition to the interference wave, which may reduce the analysis accuracy of the interference wave.

An object of the present invention is to provide a radio wave monitoring system, a radio wave monitoring processing apparatus, a radio wave monitoring method, and a program that can solve the above-described problems.

According to a first aspect of the present invention, a radio wave monitoring system includes a receiving unit that receives radio waves, a first feature amount extracting unit that extracts a first feature amount of a first signal received by the receiving unit, and an interference determination unit that determines presence or absence of radio wave interference with respect to a signal from a specific radio wave transmission source based on a first feature amount; a second signal acquisition unit that acquires a signal; a second feature extraction unit that extracts a second feature of the second signal; and a candidate for an interference source among radio wave transmission sources based on the second feature. a plurality of radio wave sensors that receive radio waves from which the influence of the signal from the specific radio wave transmission source is removed at each of a plurality of positions; and the interference source based on the signals received by the plurality of radio wave sensors. A position estimating unit that estimates a position, and when the interference determining unit determines that there is radio wave interference, based on the identification result of the interference source by the identifying unit and the estimation result of the position of the interference source by the position estimating unit. , and an identification unit for identifying the interference source.

According to the second aspect of the present invention, the radio wave monitoring processing device includes a first feature extraction unit for extracting a first feature of the first signal received by the receiver, and based on the first feature, An interference determination unit that determines whether or not there is radio wave interference with a signal from a specific radio wave transmission source, and a second signal acquisition that acquires a second signal that is a received signal from which the influence of the signal from the specific radio wave transmission source has been removed. a second feature extraction unit for extracting a second feature of the second signal; an identification unit for identifying interference source candidates among radio wave transmission sources based on the second feature; and a plurality of radio waves a position estimating unit for estimating the position of the interference source based on radio waves from which the influence of the signal from the specific radio wave source is removed, which are received by the sensor at each of a plurality of positions; an identification unit that identifies the interference source based on the identification result of the interference source by the identification unit and the estimation result of the position of the interference source by the position estimation unit when it is determined that

According to a third aspect of the present invention, a radio wave monitoring method includes the steps of: extracting a first characteristic quantity of a first signal received by a receiving unit; obtaining a second signal, which is a received signal from which the influence of the signal from the specific radio wave source has been removed; and a second characteristic quantity of the second signal. a step of identifying a candidate interference source among the radio wave transmission sources based on the second feature quantity; When it is determined that there is radio wave interference in the step of estimating the position of the interference source based on the radio wave from which the influence of the signal has been removed and the step of determining the presence or absence of the radio wave interference, the candidate for the interference source and the interference and identifying the interfering source based on the estimation of the location of the source.

According to the fourth aspect of the present invention, the program causes the computer to extract a first characteristic quantity of the first signal received by the receiving unit; obtaining a second signal that is a received signal from which the influence of the signal from the specific radio source has been removed; and a second characteristic of the second signal identifying a candidate interference source among the radio wave transmission sources based on the second characteristic quantity; When it is determined that there is radio wave interference in the step of estimating the position of the interference source based on the radio wave from which the influence of the signal of is removed, and the step of determining the presence or absence of the radio wave interference, the interference source candidate, and identifying the interference source based on the result of estimating the position of the interference source.

According to the present invention, it is possible to analyze the interference waves with relatively high accuracy when identifying the source of the interference waves that interfere with the target radio signal.

1 is a schematic block diagram showing a functional configuration example of a radio wave monitoring system according to a first embodiment; FIG. 4 is a flow chart showing a first example of a processing procedure for identifying an interference source by the radio wave monitoring system according to the first embodiment; 7 is a flow chart showing a second example of a processing procedure for identifying an interference source by the radio wave monitoring system according to the first embodiment; FIG. 10 is a diagram showing an example of a case where the process of identifying an interference source by the radio wave monitoring system according to the first embodiment is not interrupted by an interrupt signal; FIG. 4 is a diagram showing an example of a case where the process of identifying an interference source by the radio wave monitoring system according to the first embodiment is interrupted by an interrupt signal; FIG. 11 is a schematic block diagram showing an example functional configuration of a radio wave monitoring system according to a second embodiment; FIG. 3 is a schematic configuration diagram showing a configuration example of a radio wave sensor 120 according to a second embodiment; 9 is a flow chart showing a first example of a processing procedure for specifying an interference source by the radio wave monitoring system according to the second embodiment; 9 is a flow chart showing a second example of a processing procedure for specifying an interference source by the radio wave monitoring system according to the second embodiment; FIG. 11 is a schematic block diagram showing a functional configuration example of a radio wave monitoring system according to a third embodiment; FIG. 11 is a flow chart showing a first example of a processing procedure for specifying an interference source by the radio wave monitoring system according to the third embodiment; FIG. FIG. 11 is a flowchart showing a second example of a processing procedure for specifying an interference source by the radio wave monitoring system according to the third embodiment; FIG. FIG. 11 is a schematic block diagram showing an example of functional configuration of a radio wave monitoring system according to a fourth embodiment; FIG. 11 is a flow chart showing a first example of a processing procedure for specifying an interference source by the radio wave monitoring system according to the fourth embodiment; FIG. FIG. 14 is a flow chart showing a third example of a processing procedure for specifying an interference source by the radio wave monitoring system according to the fourth embodiment; FIG. FIG. 12 is a diagram showing an example of the configuration of a radio wave monitoring processing device according to a fifth embodiment; 1 is a schematic block diagram illustrating an example configuration of a computer according to at least one embodiment; FIG.

Embodiments of the present invention will be described below, but the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention.

<First embodiment>
FIG. 1 is a schematic block diagram showing a functional configuration example of a radio wave monitoring system according to the first embodiment. With the configuration shown in FIG. 1, the radio wave monitoring system 1 includes a receiving unit 11, a first feature amount extraction unit 12, an interference determination unit 13, a second signal acquisition unit 21, a second feature amount extraction unit 22, It includes an identification unit 23 , a radio wave sensor 31 , a position estimation unit 32 and an identification unit 41 .

The radio wave monitoring system 1 is a system for identifying the source of interference waves. A source of interference waves is called an interference source. A radio signal to be protected from interference waves is called a target signal. A target signal may be referred to as a signal from a specific radio source. The source of the target signal may be referred to as a specific radio wave source.

A case where the radio wave monitoring system 1 is applied to a factory will be described below as an example. In a factory where communication between robots and control devices is wireless, if communication is cut off due to interference waves, the radio wave monitoring system 1 identifies the source of the interference, making it possible to take countermeasures. Communication in the factory includes transmission of control signals from the control device to the robot, so to speak, transmission from the server device to the terminal device, and transmission of sensing data from various sensors, monitors, etc. to the control device, so to speak, from the terminal device to the server device. and sending to

Regarding radio wave interference in factories, generally speaking, (1) there are various sources of radio wave transmission in the factory, and (2) interference waves occur intermittently and irregularly, making it difficult to predict when they will occur. and (3) the interference wave is weak, making it difficult to identify the interference source. By identifying the interference source by the radio wave monitoring system 1, the interference can be efficiently detected in a short time, for example, compared to the case where a person such as a worker identifies the interference source by trial and error while stopping a part of the equipment in the factory. source can be identified.
When the interference source is a communication device, it is conceivable to take countermeasures against interference, such as using different communication frequencies for the target signal and the interference wave. If the interference source is a device other than the communication device, it is conceivable to take noise countermeasures such as shielding the interference source.

However, the application target of the radio wave monitoring system 1 is not limited to factories. The radio wave monitoring system 1 can be applied to various situations where radio wave interference can become a problem.
For example, the radio wave monitoring system 1 may be applied to hospitals. It is conceivable to make equipment in hospitals wireless for the purpose of avoiding wiring becoming a hindrance, such as making equipment in operating rooms wireless. At that time, if radio wave interference occurs in wireless communication, the radio wave monitoring system 1 identifies the source of the interference, so that countermeasures can be taken.

Alternatively, the radio wave monitoring system 1 may be applied to mobile objects such as automobiles. Mobile objects such as automobiles are equipped with many electronic devices, and it may be difficult to identify the source of interference. In this case as well, the radio wave monitoring system 1 can identify the interference source to take countermeasures.
Alternatively, the radio wave monitoring system 1 may be applied to a transportation system such as a subway. In the transportation system, in addition to the electronic devices of the transportation system itself, such as electronic devices mounted on moving bodies, there are also electronic devices brought in from the outside, such as the mobile phones of passengers, and it is thought that it is difficult to identify the source of interference. In this case as well, the radio wave monitoring system 1 can identify the interference source to take countermeasures.

The receiving unit 11 receives radio waves. The signal received by the receiver 11 is used to determine whether or not there is radio wave interference, and to identify the source of interference when it is determined that there is radio wave interference.
As the receiving unit 11, a receiving device that is the destination (destination) of the target signal or a radio wave sensor installed near the receiving device may be used. When the receiving device, which is the destination of the target signal, is used as the receiving unit 11, the received signal of this receiving device may be divided between the original processing and the analysis in the radio wave monitoring system 1 for use.

The radio wave sensor here is a device that receives radio waves for analyzing radio waves such as extraction of characteristic quantities of radio waves (for example, amplitude probability distribution, modulation error parameter, etc., which will be described later) or estimation of the position of a radio wave transmission source. The radio wave sensor may have an analysis function. Alternatively, the radio wave sensor may be configured using the receiving device, and a device other than the radio wave sensor may have the analysis function.

By using the receiving device that is the destination of the target signal or a radio wave sensor installed near the receiving device as the receiving unit 11, the radio wave during normal operation of this receiving device or a radio wave close to it is acquired. can be analyzed using In this respect, it is possible to identify the interference source with high accuracy.
A signal received by the receiver 11 is referred to as a first signal.

The first feature quantity extraction unit 12 extracts the feature quantity of the first signal. As described above, the first signal is the signal received by the receiver 11 . A feature amount of the first signal is referred to as a first feature amount.
The first feature quantity extraction unit 12 may calculate an amplitude probability distribution (APD) as the first feature quantity. The amplitude probability distribution is the time rate at which the instantaneous amplitude of the signal to be measured exceeds a certain amplitude threshold within a certain measurement time.

The first feature amount is a feature amount for determining whether or not the target signal is subject to radio wave interference. By using a feature amount with a relatively small amount of calculation, such as an amplitude probability distribution, as the first feature amount, the first feature amount extraction unit 12 can calculate the first feature amount in a relatively short time. 1 The load on the feature quantity extraction unit 12 can be relatively small.

The interference determination unit 13 determines whether or not there is radio wave interference with respect to a signal (target signal) from a specific radio wave transmission source based on the first feature amount. For example, the interference determination unit 13 knows the range of values that the amplitude probability distribution of the target signal takes when there is no radio wave interference, and the amplitude probability distribution calculated as the first feature value by the first feature value extraction unit 12 is this value. The presence or absence of radio wave interference is determined by determining whether or not it is within the range. When the amplitude probability distribution calculated by the first feature quantity extraction unit 12 is within this range, the interference determination unit 13 determines that the target signal is not subject to radio wave interference. On the other hand, when the amplitude probability distribution calculated by the first feature quantity extraction unit 12 is outside this range, the interference determination unit 13 determines that the target signal is subject to radio wave interference.
Thus, when the amplitude probability distribution is used as the first feature amount, the interference determination unit 13 simply determines whether or not the amplitude probability distribution calculated by the first feature amount extraction unit 12 is within a predetermined range. With simple processing, it is possible to determine the presence or absence of radio wave interference with respect to the target signal. In this respect, the interference determination unit 13 can determine the presence or absence of radio wave interference with the target signal in a short time, and the load on the interference determination unit 13 can be reduced.
However, the first feature amount is not limited to the amplitude probability distribution. For example, the first feature quantity extraction unit 12 may calculate statistics such as an amplitude histogram, moment of probability distribution, standard deviation, skewness, kurtosis, and peak coefficient as the first feature quantity.

The second signal acquisition unit 21 acquires a received signal (interference wave) from which the influence of a signal (target signal) from a specific radio wave source has been removed. A signal from which the influence of the target signal has been removed is called a second signal. The removal of the influence of the target signal here may be complete removal or incomplete removal (that is, reduction).
The second signal acquisition unit 21 may generate the second signal by performing correction to remove the influence of the target signal from the first signal. Alternatively, the second signal acquisition unit 21 may acquire the first signal in a state where transmission of the target signal is stopped as the second signal. These will be specifically described later.

When the second signal acquisition unit 21 corrects the first signal to remove the influence of the target signal, the first signal received by the reception unit 11 may be acquired. A signal corresponding to the first signal may be acquired from a receiving unit or a receiving device other than the above. Alternatively, the second signal acquisition unit 21 itself may acquire a signal corresponding to the first signal.
A line from the receiver 11 to the second signal acquirer 21 in FIG. 1 indicates that the second signal acquirer 21 may acquire the first signal received by the receiver 11 . This line is unnecessary when the second signal acquisition unit 21 does not acquire a signal from the reception unit 11 .

The second feature quantity extraction unit 22 extracts the feature quantity of the second signal. A feature amount of the second signal is referred to as a second feature amount.
The second feature quantity extraction unit 22 may extract the modulation error parameter as the second feature quantity. The modulation error parameter here is a general term for feature amounts obtained by modulation analysis of the second signal. Modulation error parameters include error vector magnitude (EVM), frequency error, synchronization correction, I/Q offset, and the like. For example, the error vector amplitude is the magnitude of the error (error vector) of the received signal points in the constellation from the ideal signal points. Error vector amplitude is also referred to as error vector strength. A synchronization correction is obtained from the correlation coefficient between the received preamble and the ideal preamble. I/Q offset is the amount of offset between the in-phase (I) and quadrature (Q) components of a radio signal caused by carrier feedthrough.
The second feature quantity is a feature quantity for identifying the interference source by identifying the interference wave. The interference source can be identified with a high degree of accuracy by using, as the second feature value, a feature value such as error vector strength that is likely to vary from one radio source to another due to imperfections in analog circuit operation and manufacturing variations. .

The identification unit 23 identifies interference source candidates among the radio wave transmission sources based on the second feature amount. Specifically, the identification unit 23 compares the second feature amount calculated by the second feature amount extraction unit 22 with the information of the second feature amount for each radio wave transmission source in the factory, and determines the second feature amount identifies the radio source with the best match. Alternatively, the identification unit 23 may specify a plurality of radio wave transmission sources, such as specifying a predetermined number of radio wave transmission sources in the order in which the second feature values match.
As a precondition for the identification unit 23 to identify interference source candidates, radio wave interference must occur. Therefore, the identifying unit 23 identifies the interference source candidate when the interference determining unit 13 determines that there is radio wave interference.

As described above, the second feature amount extraction unit 22 calculates the modulation error parameter by modulation analysis as the second feature amount, and the identification unit 23 uses the modulation error parameter to identify the radio wave source of the interference wave candidate. You may do so. Regarding identification of radio source using modulation error parameter by modulation analysis, ``Vladimir Brik, 3 others, "Wireless device identification with radiometric signatures", MobiCom '08 Proceedings of the 14th ACM international conference on Mobile computing and networking, p. 116-127, 2008" and Frederic Demers et al., "Radiometric Identification of LTE Transmitters", Globecom 2013 - Wireless Communications Symposium, 2013. The identification unit 23 may identify the radio wave source of the interference wave candidate based on the modulation error parameter described in any of these documents.

Alternatively, the identification unit 23 may identify the radio wave transmission source as a candidate for the interference wave using a feature value based on the time waveform of the radio wave. For this reason, the second feature quantity extraction unit 22 may extract a feature quantity based on the time waveform of radio waves as the second feature quantity. In "William C. Suski II, et al., "Using Spectral Fingerprints to Improve Wireless Network Security", IEEE GLOBECOM 2008, 2008", there is a discussion of radio wave source using transient signal characteristics and Power Spectral Density. Identification is described. The identification unit 23 may use the method described in this document to identify radio wave sources that are candidates for interference waves.

In order to compare the second feature amount extracted by the second feature amount extraction unit 22 with the second feature amount of a radio wave transmission source such as a factory or a hospital (hereinafter represented by the factory), the identification unit 23 Information on the second feature amount for each radio wave transmission source in the factory may be stored in advance. Alternatively, the identification unit 23 may acquire the information of the second feature amount for each radio wave transmission source in the factory from another part within the radio wave monitoring system 1 or from the outside of the radio wave monitoring system 1 .
The identification unit 23 learns the acquired information of the second feature amount for each radio wave transmission source in the factory as teacher data, and the second feature amount extracted by the second feature amount extraction unit 22 is subjected to a machine learning algorithm. can be identified using As an identification method in this case, a k-nearest neighbor algorithm (KNN) or a support vector machine (SVM) can be used.

Comparing the amplitude probability distribution and the modulation error parameter, the amplitude probability distribution requires less calculation. In addition, the amplitude probability distribution can be used to measure weaker radio waves than the modulation error parameter. On the other hand, the modulation error parameter is more likely to differ from one radio source to another than the amplitude probability distribution. Therefore, the modulation error parameter is easier to identify the radio wave source than the amplitude probability distribution.
The interference judgment unit 13 judges the presence or absence of radio wave interference with respect to the target signal using the amplitude probability distribution, so that the judgment can be made in a relatively short period of time. On the other hand, since the identification unit 23 identifies the interference source using modulation error parameters such as error vector amplitude, it is conceivable that the amount of modulation error differs for each radio wave transmission source. can be identified with precision.

A plurality of radio wave sensors 31 are arranged in the factory, and each of the plurality of positions where the radio wave sensors 31 are arranged receives radio waves. Each radio wave sensor 31 acquires a received signal from which the influence of the target signal has been removed or reduced.
For example, the radio wave sensor 31 may be configured using an array antenna, and the antenna pattern of the array antenna may be set to form a null point in the arrival direction of the target signal. Alternatively, the radio wave sensor 31 may receive the radio signal while the transmission of the target signal is stopped.

The position estimator 32 estimates the position of the interference source based on the signals received by the plurality of radio wave sensors 31 .
For example, the radio wave sensor 31 may receive the interference wave, and the position estimator 32 may detect the direction of arrival of the interference wave at each of the radio wave sensors 31 . Then, the position estimator 32 may estimate the position of the interference source by triangulation based on the direction of arrival of the interference wave in each of the plurality of radio wave sensors 31 .

Alternatively, the position estimating unit 32 may create distribution information (map) of radio field intensity in the factory based on the radio wave reception status of each of the plurality of radio wave sensors 31 . Then, the position estimator 32 may estimate the position where the radio wave intensity is maximum as the position of the interference source. In this case, the position where the radio wave intensity is maximum may be indicated by a pinpoint, or may be indicated as a region (thus, in a manner having an area).
As a precondition for the position estimating unit 32 to estimate the position of the interference source, radio wave interference must occur. Therefore, the position estimation unit 32 estimates the position of the interference source when the interference determination unit 13 determines that there is radio wave interference.

When the interference determination unit 13 determines that there is radio wave interference, the identification unit 41 identifies the interference source based on the identification result of the interference source by the identification unit 23 and the estimation result of the position of the interference source by the position estimation unit 32. do.
For example, when the identification unit 23 identifies a plurality of radio wave transmission sources that are interference source candidates, the identification unit 41 selects the radio wave transmission source that is closest to the position estimated by the position estimation unit 32 among the plurality of radio wave transmission sources identified by the identification unit 23. Radio wave sources may be identified as sources of interference.

Alternatively, the identification unit 41 may calculate the likelihood (for example, probability) of being an interference source for each radio wave transmission source identified by the identification unit 23 . For example, the radio wave monitoring system 1 presents information indicating the radio wave transmission sources identified by the identification unit 23 and the likelihood that each of these radio wave transmission sources is an interference source to the user (person in charge of radio interference countermeasures) ( display). The user can efficiently confirm whether or not the radio wave transmission source is actually the interference source, for example, by confirming in descending order of likelihood, and can take countermeasures.

As described above, the identification unit 41 identifies the interference source when the interference determination unit 13 determines that there is radio wave interference. The identification unit 41 may be connected to the interference determination unit 13 and directly acquire the determination result of the presence or absence of radio wave interference from the interference determination unit 13 . Alternatively, the identification unit 41 may acquire the radio wave interference determination result via a device such as the identification unit 23 other than the interference determination unit 13 .

When the identification unit 23 identifies only one radio wave transmission source, the identification unit 41 compares the individual radio wave transmission source identified by the identification unit 23 with the position estimated by the position estimation unit 32 to identify the same radio wave transmission source. Alternatively, the likelihood of the source may be calculated. When this likelihood is equal to or greater than a predetermined threshold, the radio monitoring system 1 may present information indicating the radio wave transmission source identified by the identification unit 23 to the user. Alternatively, the radio wave monitoring system 1 may present information indicating the radio wave source identified by the identification unit 23 and the likelihood calculated by the identification unit 41 to the user.

FIG. 2 is a flow chart showing a first example of a processing procedure for specifying an interference source by the radio wave monitoring system 1. As shown in FIG. The radio wave monitoring system 1 repeats, for example, the process of FIG. 2 at predetermined time intervals.
(Step S111)
The receiving unit 11 receives radio waves. For example, the receiver 11 receives radio waves for a predetermined time slot such as 10 seconds.
After step S111, the process proceeds to step S112.

(Step S112)
The first feature quantity extraction unit 12 extracts a first feature quantity. As described above, the first feature amount is the feature amount of the signal (first signal) received by the receiver 11 .
After step S112, the process proceeds to step S113.

(Step S113)
The interference determination unit 13 determines whether or not there is radio wave interference with the target signal. For example, as described above, the first feature amount extraction unit 12 calculates the amplitude probability distribution as the first feature amount, and the interference determination unit 13 determines that the value of the amplitude probability distribution calculated by the first feature amount extraction unit 12 is a predetermined value. Determine if it is within range.
If the interference determination unit 13 determines that there is radio wave interference with the target signal (step S113: YES), the process proceeds to step S121.
When the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S113: NO), the radio wave monitoring system 1 terminates the processing of FIG.

(Step S121)
The second signal acquisition section 21 acquires the second signal. As described above, the second signal is the signal from which the influence of the target signal has been removed. The second signal acquisition unit 21 may generate the second signal by performing correction to remove the influence of the target signal from the first signal. Alternatively, the second signal acquisition unit 21 may acquire the first signal in a state where transmission of the target signal is stopped as the second signal.

Interference waves often occur intermittently and irregularly. In order to acquire the second signal containing the interference wave, when the interference determination unit 13 determines that there is radio wave interference, the second signal acquisition unit 21 acquires the same time as the received signal used for the determination by the interference determination unit 13. It is preferable to obtain the second signal of the slot. Therefore, the radio wave monitoring system 1 may be provided with a buffer, and the receiving section 11 may temporarily store the received signal in the buffer in step S111. Then, the second signal acquisition unit 21 may correct the received signal temporarily stored in the buffer to remove the influence of the target signal.

Alternatively, when interference waves continue to occur for a relatively long time, the time slot is set to be slightly longer such as 10 seconds, and when the interference determination unit 13 determines that there is radio wave interference, the second signal acquisition unit 21 However, the second signal may be obtained from the received signal in the remaining time of the same time slot. Also in this case, if necessary for processing, the receiving section 11 may temporarily store the received signal in the buffer.
After step S121, the process proceeds to step S122.

(Step S122)
The second feature quantity extraction unit 22 acquires a second feature quantity. As described above, the second feature quantity is the feature quantity of the second signal.
After step S122, the process proceeds to step S123.

(Step S123)
The identification unit 23 identifies the interference source based on the second feature amount. As described above, the identification unit 23 compares the second feature amount calculated by the second feature amount extraction unit 22 with information on the second feature amount for each radio wave transmission source in the factory, and determines that the second feature amount is Identify the best matching radio source. Alternatively, the identification unit 23 may specify a plurality of radio wave transmission sources, such as specifying a predetermined number of radio wave transmission sources in the order in which the second feature values match.
After step S123, the process proceeds to step S124.

(Step S124)
The position estimator 32 acquires each reception signal of the radio wave sensor 31 .
After step S124, the process proceeds to step S125.

(Step S125)
The position estimator 32 estimates the position of the interference source based on the signals received by the radio wave sensor 31 . As described above, the radio wave sensor 31 may receive the interference wave, and the position estimator 32 may detect the direction of arrival of the interference wave at each of the radio wave sensors 31 . Then, the position estimator 32 may estimate the position of the interference source by triangulation based on the direction of arrival of the interference wave in each of the plurality of radio wave sensors 31 .
Alternatively, the position estimating unit 32 may create distribution information of radio field intensity in the factory based on the radio wave reception status of each of the plurality of radio wave sensors 31 . Then, the position estimator 32 may estimate the position where the radio wave intensity is maximum as the position of the interference source.
After step S125, the process proceeds to step S126.

(Step S126)
The identification unit 41 identifies the interference source based on the identification result of the interference source by the identification unit 23 and the estimation result of the position of the interference source by the position estimation unit 32 .
The radio wave monitoring system 1 presents the interference source identified by the identification unit 41 to the user.
After step S126, the radio wave monitoring system 1 terminates the processing of FIG.

FIG. 3 is a flow chart showing a second example of a processing procedure for the radio wave monitoring system 1 to identify an interference source. The radio wave monitoring system 1 repeats, for example, the process of FIG. 3 at predetermined time intervals.
Step S211 is the same as step S111 in FIG. After step S211, the radio wave monitoring system 1 executes steps S221, S231, and S241 in parallel.
Step S221 is the same as step S112 in FIG. Steps S231-S232 are the same as steps S121-S122 in FIG. Step S241 is the same as step S124 in FIG.

After steps S221, S232, and S241, the process proceeds to step S251. Step S251 is the same as step S113 in FIG.
In step S251, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S251: YES), the radio wave monitoring system 1 executes steps S261 and S271 in parallel. In step S251, when the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S251: NO), the radio wave monitoring system 1 ends the processing of FIG.

Step S261 is the same as step S123 in FIG.
Step S271 is the same as step S125 in FIG.
After steps S261 and S271, the process proceeds to step S281.
Step S281 is the same as step S126 in FIG.
After step S281, the radio wave monitoring system 1 ends the processing of FIG.

FIG. 3 shows an example in which the processing of step S261 and the processing of step S271 are heavy (the processing load is large). The radio wave monitoring system 1 executes relatively light processes of steps S231 to S232 and S241 in parallel with the process of step S221, thereby improving the efficiency of the process. In particular, the radio wave monitoring system 1 simultaneously executes (parallel processing) the processing of step S221, the processing of steps S231 to S232, and the processing of step S241, so that from the reception of the radio wave to the identification of the interference source. processing time is shortened.
Also, the radio wave monitoring system 1 performs the processing of steps S261 and S271 after the determination of step S251. Accordingly, when the interference determination unit 13 determines that there is no radio wave interference in step S251, the radio wave monitoring system 1 does not perform the processes of steps S261 and S271. In this respect, the load on the radio wave monitoring system 1 can be reduced.

However, the radio wave monitoring system 1 may perform part or all of the processing of steps S231 and S232 before step S261 (particularly if YES in step S251). The radio wave monitoring system 1 may execute part or all of the processing of step S241 before step S271 (especially when YES in step SS251).
If the processing of steps S213 and S232 or the processing of step S241 is heavy, some or all of these processes are performed after step S251. The radio wave monitoring system 1 does not perform these processes. In this respect, the load on the radio wave monitoring system 1 can be reduced.

Alternatively, when the interference determination unit 13 determines that there is no radio wave interference with respect to the target signal, an interrupt signal may be output to stop the process of identifying the interference source. This point will be described with reference to FIGS. 4 and 5. FIG.
FIG. 4 is a diagram showing an example of a case where the process of identifying an interference source by the radio wave monitoring system 1 is not interrupted by an interrupt signal.

In the process of FIG. 4, the receiver 11 receives radio waves (sequence S311) and outputs a received signal (first signal) to the first feature extractor 12 and the second signal acquirer .
The first feature amount extraction unit 12 extracts the first feature amount from the received signal from the reception unit 11 (sequence S321). The interference determination unit 13 uses the first feature extracted by the first feature extraction unit 12 to determine whether or not there is radio wave interference with the target signal (sequence S322). In the example of FIG. 4, the interference determination unit 13 determines that there is radio wave interference. When it is determined that there is radio wave interference, the interference determination unit 13 does not output an interrupt signal.

Also, the second signal acquiring unit 21 acquires the second signal using the received signal from the receiving unit 11 (sequence S331). FIGS. 4 and 5 illustrate an example in which the second signal acquisition unit 21 corrects the reception signal from the reception unit 11 to remove the influence of the target signal. Also when the transmission of the target signal is to be stopped, the interruption of processing using the interrupt signal can be applied.
The second feature quantity extraction unit 22 extracts the second feature quantity from the second signal (sequence S332). The identifying unit 23 uses the second feature amount extracted by the second feature amount extracting unit 22 to identify the interference source candidate among the radio wave transmission sources (sequence S333). The identification unit 23 outputs to the identification unit 41 information indicating the specified candidate for the interference source (for example, identification information for identifying the radio wave transmission source in the factory).

Further, the radio wave sensor 31 receives radio waves (sequence S341). The radio wave sensor 31 outputs the received signal to the position estimator 32 . The position estimation unit 32 estimates the position of the interference source using the signal received by the radio wave sensor 31 (sequence S342). The position estimation unit 32 outputs information indicating the estimated position of the interference source to the identification unit 41 .

The identification unit 41 identifies the interference source based on the identification result of the interference source by the identification unit 23 and the estimation result of the position of the interference source by the position estimation unit 32 (sequence S351).

FIG. 5 is a diagram showing an example of a case where the process of identifying an interference source by the radio wave monitoring system 1 is interrupted by an interrupt signal.
Sequences S411 and S421 are similar to sequences S311 and S321 in FIG. After the sequence S421, the interference determination unit 13 uses the first feature extracted by the first feature extraction unit 12 to determine whether or not there is radio wave interference with the target signal (sequence S422). In the example of FIG. 5, the interference determination unit 13 determines that there is no radio wave interference. When it is determined that there is no radio wave interference, the interference determination unit 13 outputs an interrupt signal for stopping the identification of the interference source.

Sequences S431 to S432 are the same as sequences S331 to S332 in FIG. do. By canceling the extraction of the second feature quantity, the identifying unit 23 does not perform the process of identifying the interference source candidate (see sequence S333 in FIG. 3).

Sequences S441 to S442 are the same as sequences S341 to S342 in FIG.
Identification of the interference source by the identification unit 41 by stopping extraction of the second feature amount by the second feature amount extraction unit 22 in sequence S432 and stopping estimation of the position of the interference source by the position estimation unit 32 in sequence S442. (See sequence S351 in FIG. 3) is also canceled.

The processing to be stopped by the interrupt signal from the interference determination unit 13 is not limited to the extraction of the second feature amount by the second feature amount extraction unit 22 and the estimation of the position of the interference source by the position estimation unit 32 .
Acquisition of the second signal by the second signal acquisition unit 21, extraction of the second feature amount by the second feature amount extraction unit 22, and identification according to the timing at which the interference determination unit 13 determines that there is no radio wave interference with the target signal Any of the identification of interference source candidates by the unit 23 may be interrupted by an interrupt process. Therefore, the interference determination unit 13 may transmit an interrupt signal to all of the second signal acquisition unit 21 , the second feature amount extraction unit 22 and the identification unit 23 .

Similarly, depending on the timing at which the interference determination unit 13 determines that there is no radio wave interference with the target signal, either the reception of radio waves by the radio wave sensor 31 or the estimation of the position of the interference source by the position estimation unit 32 is interrupted by interrupt processing. can be Therefore, the interference determination unit 13 may transmit an interrupt signal to both the radio wave sensor 31 and the position estimation unit 32 .

As described above, the receiving unit 11 receives radio waves. The first feature quantity extraction unit 12 extracts the first feature quantity of the first signal received by the reception unit 11 . The interference determination unit 13 determines whether or not there is radio wave interference with the target signal based on the first feature amount extracted by the first feature amount extraction unit 12 . A second signal acquisition unit 21 acquires a second signal from which the influence of the target signal has been removed. The second feature quantity extraction unit 22 extracts the second feature quantity of the second signal. The identification unit 23 identifies the interference source based on the second feature amount extracted by the second feature amount extraction unit 22 . The plurality of radio wave sensors 31 receive radio waves from which the influence of the target signal has been removed at each of the plurality of positions. The position estimator 32 estimates the position of the interference source based on the signals received by the plurality of radio wave sensors 31 . When the interference determination unit 13 determines that there is radio wave interference, the identification unit 41 identifies the interference source based on the identification result of the interference source by the identification unit 23 and the estimation result of the position of the interference source by the position estimation unit 32. do.
According to the radio wave monitoring system 1, when identifying the source of an interference wave that interferes with a target radio signal (target signal), the source can be identified by removing the influence of the target signal. In this respect, the radio wave monitoring system 1 can analyze interference waves with relatively high accuracy.

Also, the first feature quantity extraction unit 12 extracts the amplitude probability density as the first feature quantity. The interference determination unit 13 determines the presence or absence of radio wave interference based on the deviation of the target signal from the amplitude probability density registered in advance (for example, whether it is within a predetermined range).
The radio wave monitoring system 1 can determine the presence or absence of radio wave interference with respect to the target signal in a relatively short time by using a feature amount with a relatively small amount of calculation, such as the amplitude probability density, as the first feature amount, and , the load on the first feature quantity extraction unit 12 can be reduced.

Further, the first feature quantity extraction unit 12 extracts any one of amplitude histogram, moment of probability distribution, standard deviation, skewness, kurtosis, and peak coefficient as the first feature quantity.
The radio wave monitoring system 1 uses, as the first feature amount, a feature amount with a relatively small amount of calculation, such as an amplitude histogram, moment of probability distribution, standard deviation, skewness, kurtosis, or peak coefficient. can be determined in a relatively short time, and the load on the first feature quantity extraction unit 12 can be reduced.

Also, the second feature quantity extraction unit 22 extracts a modulation error parameter such as an error vector amplitude as a second feature quantity.
The radio wave monitoring system 1 uses, as the second feature value, a feature value such as the error vector amplitude that is relatively likely to differ between radio wave transmission sources, so that the interference source can be identified with high accuracy.
The modulation error parameter extracted by the second feature amount extraction unit 22 is not limited to the error vector amplitude, and may be any one of frequency error, synchronization correction, and I/Q offset.
The second feature amount extraction unit 22 may extract, as the second feature amount, a feature amount based on the time waveform of radio waves in addition to or instead of the modulation error parameter.
The radio wave monitoring system 1 uses, as the second feature amount, a feature amount based on the time waveform of the radio wave, which is relatively likely to differ from one radio wave transmission source to another, so that the interference source can be identified with high accuracy. .

<Second embodiment>
2nd Embodiment shows the 1st example which further actualized 1st Embodiment.
FIG. 6 is a schematic block diagram showing a functional configuration example of the radio wave monitoring system according to the second embodiment. With the configuration shown in FIG. 6 , the radio wave monitoring system 2 includes a receiver 110 , a radio wave sensor 120 , and a radio wave monitoring processing device 130 . The receiving device 110 includes a receiving section 11 . The radio wave sensor 120 includes a receiver 121 and a directivity controller 122 . The radio wave monitoring processing device 130 includes a first feature amount extraction unit 12, an interference determination unit 13, a second feature amount extraction unit 22, an identification unit 23, a position estimation unit 32, an identification unit 41, and radio wave source information. A storage unit 131 and a target signal removal unit 132 are provided.
FIG. 6 also shows a target signal source 910 and an interference source 920 .
6, the same reference numerals (11, 12, 13, 22, 23, 32, 41) are attached to the parts having the same functions as those shown in FIG. .

The radio wave sensor 120 corresponds to an example of the radio wave sensor 31 in FIG. The radio wave monitoring system 2 includes a plurality of radio wave sensors 120, and in each radio wave sensor 120, a plurality of receivers 121 constitute an array antenna. Each radio wave sensor 120 measures the direction of arrival of the interference wave using the array antenna formed by the receiving section 121 . Existing techniques such as PoA (Power of Arrival) or AoA (Angle of Arrival) can be used as a method for the radio wave sensor 120 to measure the direction of arrival of radio waves.

Each of the plurality of radio wave sensors 120 measures the direction of arrival of the interference wave, so that the position estimator 32 can estimate the position of the interference source by triangulation.
The influence of the target signal is removed so that the radio wave sensor 120 can measure the direction of arrival of the interference wave with high accuracy. Specifically, the radio wave sensor 120 removes the influence of the target signal on the received signal by forming a null point of the antenna reception pattern in the arrival direction of the target signal.

FIG. 7 is a schematic configuration diagram showing a configuration example of the radio wave sensor 120. As shown in FIG. In the configuration shown in FIG. 7 , directivity control section 122 includes weight adjustment section 123 and synthesis section 124 .
Weight adjustment section 123 is provided for each reception section 121 and weights the received signal of reception section 121 . Combining section 124 combines the received signals with weighting by weight adjusting section 123 . A signal synthesized by the synthesizing unit 124 is represented by Equation (1).

k (k is a positive integer) indicates the number of receivers 121 included in one radio wave sensor 120 . x ₁ , _{x 2} , . w ₁ , _{w 2} , .
By adjusting the weight _coefficients w ₁ , w ₂ , . For example, an operator who adjusts the radio wave monitoring system 2 adjusts the weight _coefficients w ₁ , w ₂ , . Set to form a null point. Alternatively, the weight adjustment section 123 may acquire the position information of the target signal transmission source 910 from the radio wave source information storage section 131 and automatically set the weighting coefficient by the weight adjustment section 123 .
Also, the directivity of the radio wave sensor 120 can be adjusted by adjusting the weighting _coefficients w ₁ , w ₂ , . The direction of arrival of the interference wave can be measured from the relationship between the directivity of the radio wave sensor 120 and the radio wave intensity.

The radio wave source information storage unit 131 stores radio wave source information, which is information regarding each radio wave transmission source in the factory. The radio wave source information is an information source of a criterion for the interference determination unit 13 to determine the presence or absence of radio wave interference with the target signal based on the first feature amount. Further, the radio wave source information serves as an information source of the second feature amount for each radio wave transmission source so that the identifying unit 23 uses the second feature amount to identify the radio wave transmission source that is a candidate for the interference source.

The radio wave source information storage unit 131 stores, for each radio wave transmission source, radio standard (WLAN, Bluetooth (registered trademark), Zigbee (registered trademark), etc.), frequency, modulation method (QPSK, 16QAM, 64QAM, etc.), It stores the output power and the position coordinates of the radio wave source.
An ideal amplitude probability distribution and ideal modulation parameters can be obtained from the radio standard and modulation scheme indicated in the radio wave source information. The ideal amplitude probability distribution is an amplitude probability distribution in an ideal state without communication failures such as interference waves. The ideal modulation parameters are the constellation, frequency, preamble, etc. in an ideal state without communication failures such as interference waves.

The radio wave source information storage unit 131 stores one or more of the ideal amplitude probability distribution, the ideal modulation parameter, and the ideal time waveform in addition to or instead of the information on the radio standard and modulation scheme. You may do so. The ideal amplitude probability distribution, ideal modulation parameter, and ideal time waveform in this case may be theoretical values calculated based on the wireless standard and modulation method, or may be measured in the absence of obstacles such as interference waves. It may be a measured value. Also, the ideal modulation parameter and the ideal time waveform may be used as teacher data when the identification unit 23 identifies the radio wave transmission source.
The radio wave source information storage unit 131 may further store identification information (ID: Identifier) of the radio wave transmission source such as a MAC address.

The target signal removal unit 132 corresponds to an example of the second signal acquisition unit in FIG. The target signal removal unit 132 corrects the reception signal (first signal) of the reception unit 11 to remove the influence of the target signal to generate a second signal. For example, the target signal source 910 may temporarily transmit a signal of a specific pattern as the target signal. Then, the target signal removing unit 132 may remove the influence of the target signal by performing correction by subtracting the replica signal of the target signal from the received signal of the receiving unit 11 .

Alternatively, during normal operation of the target signal transmission source 910, the target signal removal unit 132 performs a correction by subtracting a signal prepared in advance as a stereotype of the target signal from the received signal of the reception unit 11, thereby reducing the influence of the target signal. may be incompletely removed (ie, reduced).

FIG. 8 is a flow chart showing a first example of a processing procedure for the radio wave monitoring system 2 to identify the interference source. The radio wave monitoring system 2 repeats, for example, the process of FIG. 8 at predetermined time intervals.
Steps S511 to S513 in FIG. 8 are the same as steps S111 to S113 in FIG.
In step S513, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S513: YES), the process proceeds to step S521. When the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S513: NO), the radio wave monitoring system 2 terminates the processing of FIG.

(Step S521)
Step S521 corresponds to the example of step S121 in FIG. In step S521, the target signal removing unit 132 generates the second signal by correcting the reception signal of the receiving unit 11 to remove the influence of the target signal, as described above.
After step S521, the process proceeds to step S522.
Steps S522-S523 are the same as steps S122-S123 in FIG. After step S523, the process proceeds to step S524.

(Step S524)
Each radio wave sensor 120 forms a null point in the arrival direction of the target signal. For example, an operator who adjusts the radio wave monitoring system 2 adjusts the weighting factor for the received signal as described above based on the positional relationship between the source of the target signal and the radio wave sensor 120 . Thereby, the radio wave sensor 120 forms a null point in the arrival direction of the target signal.
After step S524, the process proceeds to step S525.
Step S525 is the same as step S124 in FIG. After step S525, the process proceeds to step S526.

Steps S526 and S527 correspond to the example of step S125 in FIG.
(Step S526)
The position estimator 32 measures the arrival angle of interference waves. Specifically, each radio wave sensor 120 receives radio waves while changing the directivity of the radio wave sensor 120 itself. The position estimator 32 detects the arrival angle of the interference wave for each radio sensor 120 based on the relationship between the directivity of the radio sensor 120 and the received signal strength.
After step S526, the process proceeds to step S527.

(Step S527)
The position estimator 32 estimates the position of the interference source. Specifically, the position estimating unit 32 estimates the position of the interference source by the principle of triangulation based on the direction of arrival of the interference wave for each radio wave sensor 120 obtained in step S526.
After step S527, the process proceeds to step S528.
Step S528 is the same as step S126 in FIG. After step S528, the radio wave monitoring system 2 terminates the processing of FIG.

FIG. 9 is a flow chart showing a second example of a processing procedure for the radio wave monitoring system 2 to identify the interference source. The radio wave monitoring system 2 repeats, for example, the process of FIG. 9 at predetermined time intervals.
Step S611 is the same as step S511 in FIG. After step S611, the radio wave monitoring system 2 executes steps S621, S631, and S641 in parallel.
Step S621 is the same as step S512 in FIG.
Steps S631-S632 are the same as steps S521-S522 in FIG.
Steps S641-S643 are the same as steps S524-526 in FIG.

After steps S621, S632, and S643, the process proceeds to step S651. Step S651 is the same as step S513 in FIG.
In step S651, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S651: YES), the radio wave monitoring system 2 executes steps S661 and S671 in parallel. In step S651, when the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S651: NO), the radio wave monitoring system 2 ends the processing of FIG.

Step S661 is the same as step S523 in FIG.
Step S671 is the same as step S527 in FIG.
After steps S661 and S671, the process proceeds to step S681.
Step S681 is the same as step S628 in FIG.
After step S681, the radio wave monitoring system 2 terminates the processing of FIG.

FIG. 9 shows an example in which the processing in step S661 and the processing in step S671 are heavy. The radio wave monitoring system 2 executes relatively light processing of steps S631 to S632 and S641 to S643 in parallel with the processing of step S621, thereby improving the efficiency of the processing. In particular, the radio wave monitoring system 2 simultaneously executes (parallel processing) the processing of step S621, the processing of steps S631 to S632, and the processing of steps S641 to S643, thereby identifying the interference source after receiving radio waves. processing time is shortened.
Also, the radio wave monitoring system 2 performs the processing of steps S661 and S671 after the determination of step S651. Accordingly, when the interference determination unit 13 determines that there is no radio wave interference in step S651, the radio wave monitoring system 2 does not perform the processes of steps S661 and S671. In this respect, the load on the radio wave monitoring system 2 can be reduced.

However, the radio wave monitoring system 2 may execute part or all of the processing of steps S631 and S632 before step S661 (particularly if YES in step S651). The radio wave monitoring system 2 may execute part or all of the processing of steps S641 to S643 before step S671 (particularly if YES in step SS651).
If the processing of steps S613 to S632 or the processing of steps S641 to S643 is heavy, some or all of these processes are performed after step S251, so that the interference determination unit 13 determines that there is no radio interference in step S251. In this case, the radio wave monitoring system 2 does not perform these processes. In this respect, the load on the radio wave monitoring system 2 can be reduced.

As described with reference to FIGS. 4 and 5, when the interference determination unit 13 determines that there is no radio wave interference with the target signal, an interrupt signal may be output to stop the process of identifying the interference source. good. In the second embodiment, the interference determination unit 13 performs processing for the target signal removal unit 132 to generate the second signal, processing for the second feature amount extraction unit 22 to extract the second feature amount, and processing for the identification unit 23 to perform interference detection. A series of processes for identifying source candidates (see steps S631 to S632 and S661 in FIG. 9) are stopped by an interrupt. Further, the interference determination unit 13 performs processing for the radio wave sensor 120 to form a null point and receives a signal, and the position estimation unit acquires the received signal of the radio wave sensor 120, estimates the angle of arrival of the interference wave, and determines the position of the interference source. A series of processes for estimating the position (see steps S641 to S643 and S671 in FIG. 9) are stopped by an interrupt.

As described above, the target signal removing unit 132 removes the component of the signal (target signal) from the specific radio wave source from the signal received by the receiving unit 11 to generate the second signal.
As a result, the radio wave monitoring system 2 can identify the interference source without stopping the target signal.

Further, the target signal removing unit 132 performs correction by subtracting the copy signal of the target signal from the received signal of the receiving unit 11 to generate a second signal.
As a result, the target signal removing unit 132 removes the influence of the target signal from the received signal of the receiving unit 11 with high accuracy. In this respect, the radio wave monitoring system 2 can identify the interference source with high accuracy.

Further, directivity control section 122 sets an antenna reception pattern that forms a null point in the arrival direction of the target signal. Thereby, the influence of the target signal on the signal received by the radio wave sensor 120 can be eliminated. In this respect, the position estimator 32 can estimate the position of the interference source with high accuracy.

<Third Embodiment>
The third embodiment shows a second example that further embodies the first embodiment.
FIG. 10 is a schematic block diagram showing a functional configuration example of a radio wave monitoring system according to the third embodiment. With the configuration shown in FIG. 10 , the radio wave monitoring system 3 includes a radio wave sensor 120 , a communication device 210 , and a radio wave monitoring processing device 230 . The communication device 210 has a communication unit 211 . The radio wave sensor 120 includes a receiver 121 and a directivity controller 122 . The radio wave monitoring processing device 230 includes a first feature amount extraction unit 12, an interference determination unit 13, a second feature amount extraction unit 22, an identification unit 23, a position estimation unit 32, an identification unit 41, and radio wave source information. It includes a storage unit 131 , a wave stop instruction unit 231 , and a wave stop signal acquisition unit 232 .
FIG. 10 also shows a target signal source 910 and an interference source 920 .
10, the same reference numerals (12, 13, 22, 23, 32, 41, 120, 121, 122, 131, 910, 920) and the description is omitted.

The communication unit 211 corresponds to an example of the receiving unit 11 in FIG. The communication unit 211 receives the target signal from the target signal transmission source 910, like the receiving unit 11 in FIGS. 1 and 6 . In addition, the communication unit 211 transmits to the target signal transmission source 910 a wave stop instruction instructing to stop transmission of the target signal.
The wave stop instruction unit 231 controls the communication unit 211 to transmit a wave stop instruction instructing to stop transmission of the target signal to the target signal transmission source 910 . This is so that the radio wave monitoring system 3 can identify the interference source without being affected by the target signal. Wave stop instruction section 231 causes communication section 211 to transmit a wave stop instruction to target signal transmission source 911 when interference determination section 13 determines that there is radio wave interference.

The wave stop instruction unit 231 may be connected to the radio wave source information storage unit 131 . The wave stop instructing unit 231 refers to the radio wave transmission source information (for example, wireless standard, position, ID, etc.) stored in the radio wave source information storage unit 131, and instructs the target signal transmission source 910 to be stopped. Then, an appropriate stop instruction can be given selectively.
The post-stop signal acquisition unit 232 corresponds to an example of the second signal acquisition unit 21 in FIG. The post-stop signal acquisition unit 232 acquires the signal received by the communication unit 211 while the target signal transmission source 910 stops transmitting the target signal in accordance with the wave stop instruction. This signal does not contain the target signal. This signal corresponds to an example of the second signal.

In the configuration of FIG. 10, the position estimator 32 can estimate the position of the interference source 920 using the signals received by the radio wave sensors 120 while the target signal transmission source 910 has stopped transmitting the target signal. . Therefore, directivity control section 122 does not need to form a null point in the antenna reception pattern in order to remove the influence of the target signal. The directivity control unit 122 adjusts the directivity of the radio sensor 120 to measure the direction of arrival of interference waves.

FIG. 11 is a flow chart showing a first example of a processing procedure for the radio wave monitoring system 3 to identify the interference source. The radio wave monitoring system 3 repeats, for example, the process of FIG. 11 at predetermined time intervals.
Steps S711 to S713 in FIG. 11 are the same as steps S111 to S113 in FIG.
In step S713, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S713: YES), the process proceeds to step S721. When the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S713: NO), the radio wave monitoring system 3 terminates the processing of FIG.

(Step S721)
The communication unit 211 transmits a stop wave instruction instructing stop transmission of the target signal to the target signal transmission source 910 according to the instruction from the wave stop instruction unit 231 . The stop instruction corresponds to an example of processing for acquiring the second signal. Furthermore, the wave stop instruction corresponds to an example of processing in which the radio wave sensor 31 receives a signal from which the influence of the target signal has been removed.
After step S721, the process proceeds to step S722.

(Step S722)
Step S722 corresponds to the example of step S121 in FIG. In step S722, the post-stop signal acquisition unit 232 acquires the signal received by the communication unit 211 after the target signal transmission source 910 stops transmitting the target signal. This signal corresponds to an example of the second signal.
After step S722, the process proceeds to step S723.

Steps S723-S725 are the same as steps S122-S124 in FIG.
In comparison with the processing of FIG. 8, since the target signal transmission source 910 has stopped transmitting the target signal, the directivity control section 122 does not need to form the null point of the antenna reception pattern in the arrival direction of the target signal. do not have. Therefore, step S524 of FIG. 8 is unnecessary in the process of FIG.
After step S725, the process proceeds to step S726.

Steps S726 and S727 correspond to the example of step S125 in FIG.
(Step S726)
The position estimator 32 measures the arrival angle of interference waves. Specifically, each of radio wave sensors 120 receives radio waves while changing its own directivity. The position estimator 32 detects the arrival angle of the interference wave for each radio sensor 120 based on the relationship between the directivity of the radio sensor 120 and the received signal strength.
After step S726, the process proceeds to step S727.

(Step S727)
The position estimator 32 estimates the position of the interference source. Specifically, the position estimation unit 32 estimates the position of the interference source based on the principle of triangulation based on the direction of arrival of the interference wave for each radio sensor 120 obtained in step S726.
After step S727, the process proceeds to step S728.
Step S728 is similar to step S126 in FIG. After step S728, the radio wave monitoring system 3 terminates the processing of FIG.

FIG. 12 is a flow chart showing a second example of a processing procedure for the radio wave monitoring system 3 to identify the interference source. The radio wave monitoring system 3 repeats, for example, the process of FIG. 12 at predetermined time intervals.
Steps S811 to S813 are the same as steps S711 to S713 in FIG.
In step S813, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S813: YES), the process proceeds to step S821. When the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S813: NO), the radio wave monitoring system 3 terminates the processing of FIG.

Step S821 is the same as step S721 in FIG. After step S821, the radio wave monitoring system 3 executes steps S831 and S841 in parallel.
Steps S831-S833 are the same as steps S722-S724 in FIG.
Steps S841-S843 are the same as steps S725-S727 in FIG.

After steps S833 and S843, the process proceeds to step S851. Step S851 is the same as step S728 in FIG.
After step S851, the radio wave monitoring system 3 ends the processing of FIG.

As described above, the post-stop signal acquisition unit 232 acquires, as the second signal, the signal received by the communication unit 211 while the specific radio wave transmission source (target signal transmission source 910) is stopped.
As a result, in the radio monitoring system 3, the post-stop signal acquisition unit 232 can acquire a received signal that does not include the target signal. In this respect, the radio wave monitoring system 3 can identify the interference source with high accuracy. In addition, since there is no need to perform correction for removing the target signal from the received signal, the processing of the radio wave monitoring system 3 is simple, and the processing load of the radio wave monitoring system 3 can be relatively small.
The radio wave sensor 320 can also acquire a received signal that does not contain the target signal. In this respect as well, the radio wave monitoring system 3 can identify the interference source with high accuracy. In addition, since it is not necessary to form a null point in the target signal arrival report, the processing of the directivity control unit 122 is simple, and the processing load of the directivity control unit 122 can be relatively small.

<Fourth Embodiment>
The fourth embodiment shows a third example that further embodies the first embodiment.
FIG. 13 is a schematic block diagram showing a functional configuration example of the radio wave monitoring system according to the fourth embodiment. With the configuration shown in FIG. 13 , the radio wave monitoring system 4 includes a communication device 210 , a radio wave monitoring processing device 230 , and a radio wave sensor 320 . The communication device 210 has a communication unit 211 . The radio wave monitoring processing device 230 includes a first feature amount extraction unit 12, an interference determination unit 13, a second feature amount extraction unit 22, an identification unit 23, a position estimation unit 32, an identification unit 41, and radio wave source information. It includes a storage unit 131 , a wave stop instruction unit 231 , and a wave stop signal acquisition unit 232 .
FIG. 13 also shows a target signal source 910 and an interference source 920 .
13, the same reference numerals (12, 13, 22, 23, 32, 41, 131, 210, 211, 230, 231, 232, 910, 920), and the description is omitted.

The radio wave sensor 320 corresponds to an example of the radio wave sensor 31 in FIG. While each of the radio wave sensors 120 in FIG. 10 has an array antenna with a plurality of receiving sections 121, the radio wave sensor 320 is configured as a receiving section having a single antenna. Therefore, the radio wave sensor 320 measures the radio wave intensity, but cannot measure the arrival direction (arrival angle) of the radio wave.
Depending on the configuration of the radio wave sensor 320, the position estimator 32 estimates the position of the interference source based on the distribution of radio wave intensity in the factory. For example, the position estimator 32 may estimate the position where the radio wave intensity is maximum as the position of the interference source. In this case, the position where the radio wave intensity is maximum may be indicated by a pinpoint, or may be indicated as a region (thus, in a manner having an area).
Otherwise, the radio wave monitoring system 4 is the same as the radio wave monitoring system 3 .

FIG. 14 is a flow chart showing a first example of a processing procedure for the radio wave monitoring system 4 to identify an interference source. The radio wave monitoring system 4 repeats, for example, the process of FIG. 14 at predetermined time intervals.
Steps S911 to S913 in FIG. 14 are the same as steps S711 to S713 in FIG.

In step S913, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S913: YES), the process proceeds to step S921. When the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S913: NO), the radio wave monitoring system 4 terminates the processing of FIG.
Steps S921-S925 are the same as steps S721-S725 in FIG. After step S925, the process proceeds to step S926.

Steps S926 and S927 correspond to the example of step S125 in FIG.
(Step S926)
The position estimator 32 measures the received signal strength at each of the radio wave sensors 320 . The position estimator 32 creates distribution information (map) of radio wave intensity in the factory based on the received signal intensity of each of the radio wave sensors 320 .
After step S926, the process proceeds to step S927.

(Step S927)
The position estimator 32 estimates the position of the interference source. Specifically, the position estimating unit 32 estimates the position where the radio wave intensity is maximum as the position of the interference source based on the distribution of the radio wave intensity in the factory obtained in step S926.
After step S927, the process proceeds to step S928.
Step S928 is the same as step S728 in FIG. After step S928, the radio wave monitoring system 4 ends the processing of FIG.

FIG. 15 is a flow chart showing a third example of a processing procedure for specifying an interference source by the radio wave monitoring system 4. In FIG. The radio wave monitoring system 4 repeats, for example, the process of FIG. 15 at predetermined time intervals.
Steps S1011 to S1013 are the same as steps S911 to S913 in FIG.
In step S1013, when the interference determination unit 13 determines that there is radio wave interference with the target signal (step S1013: YES), the process proceeds to step S1021. When the interference determination unit 13 determines that there is no radio wave interference with the target signal (step S1013: NO), the radio wave monitoring system 4 terminates the processing of FIG.

Step S1021 is the same as step S921 in FIG. After step S1021, the radio wave monitoring system 4 executes steps S1031 and S1041 in parallel.
Steps S1031 to S1033 are the same as steps S922 to S924 in FIG.
Steps S1041 to S1043 are the same as steps S925 to S927 in FIG.

After steps S1033 and S1043, the process proceeds to step S1051. Step S1051 is the same as step S928 in FIG.
After step S1051, the radio wave monitoring system 4 ends the processing of FIG.

As described above, the radio wave sensor 320 does not need to be equipped with an array antenna as long as it can measure the radio wave intensity. In the radio wave monitoring system 4, the manufacturing cost and operating cost of the radio wave sensor 320 are relatively low. Also, since the radio wave sensor 320 has relatively low manufacturing and operating costs, a large number of radio wave sensors 320 can be arranged in the factory. By arranging a large number of radio wave sensors 320 in the factory, the radio wave monitoring system 4 can measure the radio wave intensity in the factory with high accuracy, and in this respect, can identify the interference source with high accuracy.
Further, when a radio wave sensor measures the arrival direction (arrival angle) of radio waves, it is necessary to have a line of sight between the radio wave source and the radio wave sensor. On the other hand, the radio wave sensor 320 can pick up reflected waves and the like from radio waves from places where the radio wave sensor 320 itself has no line of sight, and include them in the radio wave intensity. In the radio wave monitoring system 4, by using the radio wave sensor 320, even if the line of sight in the factory is not good, it is possible to obtain the distribution of the radio wave intensity corresponding to the radio wave from the part without line of sight. In this regard, the radio wave monitoring system 4 can identify the interference source with high accuracy.

<Fifth Embodiment>
In the fifth embodiment, an example of the configuration of the radio wave monitoring processing device will be described.
FIG. 16 is a diagram showing an example of the configuration of a radio wave monitoring processing device according to the fifth embodiment. With the configuration shown in FIG. 16 , the radio wave monitoring processing device 400 includes a first feature extraction unit 411, an interference determination unit 412, a second signal acquisition unit 421, a second feature extraction unit 422, and an identification unit 423. , a position estimation unit 431 and an identification unit 441 .
With such a configuration, the first feature amount extraction unit 411 extracts the first feature amount of the first signal received by the reception unit. Based on the first feature amount extracted by the first feature amount extraction section 411, the interference determination section 412 determines whether or not there is radio wave interference with respect to a signal (target signal) from a specific radio wave transmission source. The second signal acquisition unit 421 acquires the second signal, which is the received signal from which the influence of the target signal has been removed. The second feature quantity extraction unit 422 extracts the second feature quantity of the second signal. The identification unit 423 identifies interference source candidates among the radio wave transmission sources based on the second feature amount extracted by the second feature amount extraction unit 422 . The position estimator 431 estimates the position of the interference source based on the radio waves from which the effects of the target signal are removed, which are received by the plurality of radio wave sensors at each of the plurality of positions. When the interference determination unit 412 determines that there is radio wave interference, the identification unit 441 identifies the interference source based on the identification result of the interference source by the identification unit 423 and the estimation result of the position of the interference source by the position estimation unit 431. do.
According to the radio wave monitoring processing apparatus 400, when identifying the source of the interference wave that interferes with the target signal, it is possible to remove the influence of the target signal. In this regard, the radio wave monitoring processing device 400 can analyze interference waves with relatively high accuracy.

FIG. 17 is a schematic block diagram illustrating an example configuration of a computer according to at least one embodiment. With the configuration shown in FIG. 17 , computer 500 includes CPU 510 , storage device 520 , and interface 530 .
When any one or more of the radio wave monitoring systems 1, 2, 3, and 4 and the radio wave monitoring processing device 400 described above are implemented in a computer, each of the above-described processing units (the first feature quantity extraction units 12 and 411, Interference determination units 13 and 412, second signal acquisition units 21 and 421, second feature amount extraction units 22 and 422, identification units 23 and 423, position estimation units 32 and 431, identification units 41 and 441, directivity control unit 122 , the target signal removal unit 132, the wave termination instruction unit 231, and the wave termination signal acquisition unit 232) are stored in the storage device 520 in the form of a program. The CPU 510 reads a program from the storage device 520 and executes it, thereby executing the processing of each processing unit. In addition, the CPU 510 secures storage areas corresponding to the above-described storage units (radio wave source information storage unit 131) in the storage device 520 according to the program. The functions of the receiving units 11 and 121 and the communication unit 211 are executed by the CPU 50 controlling a communication device as the interface 530 according to a program.

A program for executing all or part of the processing performed by the radio wave monitoring systems 1, 2, 3, and 4 and the radio wave monitoring processing device 400 is recorded on a computer-readable recording medium, and the program is stored on this recording medium. Each part may be processed by reading the recorded program into a computer system and executing it. It should be noted that the "computer system" referred to here includes hardware such as an OS and peripheral devices.
The term "computer-readable recording medium" refers to portable media such as flexible discs, magneto-optical discs, ROMs and CD-ROMs, and storage devices such as hard discs incorporated in computer systems. Further, the program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design and the like are included within the scope of the gist of the present invention.

1, 2, 3, 4 Radio wave monitoring system 11, 121 Receiving unit 12, 411 First feature quantity extraction unit 13, 412 Interference determination unit 21, 421 Second signal acquisition unit 22, 422 Second feature quantity extraction unit 23, 423 Identification unit 31, 320 Radio wave sensor 32, 431 Position estimation unit 41, 441 Identification unit 110 Receiving device 120 Radio wave sensor 122 Directivity control unit 123 Weight adjustment unit 124 Combining unit 130, 230, 400 Radio wave monitoring processing device 131 Radio wave source information storage Unit 132 Target signal removal unit 210 Communication device 211 Communication unit 231 Wave stop instruction unit 232 Signal acquisition unit after wave stop

Claims (13)

a receiver for receiving radio waves;
a first feature quantity extraction unit for extracting a first feature quantity of the first signal received by the receiving unit;
an interference determination unit that determines the presence or absence of radio wave interference with respect to a signal from a specific radio wave transmission source based on the first feature amount;
a second signal acquisition unit that acquires a second signal that is a received signal from which the influence of the signal from the specific radio wave source is removed;
a second feature extraction unit that extracts a second feature of the second signal;
an identification unit that identifies interference source candidates among radio wave transmission sources based on the second feature amount;
a plurality of radio wave sensors that receive radio waves from which the influence of the signal from the specific radio wave source is removed at each of a plurality of positions;
a position estimating unit that estimates the position of the interference source based on the signals received by the plurality of radio wave sensors;
When the interference determination unit determines that there is radio wave interference, the identification unit identifies the interference source based on the identification result of the interference source by the identification unit and the estimation result of the position of the interference source by the position estimation unit. When,
radio wave monitoring system. The second signal acquisition unit generates the second signal by removing a signal component from the specific radio wave source from the signal received by the receiving unit.
The radio wave monitoring system according to claim 1. The second signal acquisition unit acquires, as the second signal, the signal received by the reception unit in a state where the specific radio wave transmission source is stopped.
The radio wave monitoring system according to claim 1. The first feature amount is an amplitude probability density, and the interference determination unit determines the presence or absence of radio interference based on a deviation from a pre-registered amplitude probability density for the signal from the specific radio wave transmission source.
The radio wave monitoring system according to any one of claims 1 to 3. The first feature amount is an amplitude histogram, moment of probability distribution, standard deviation, skewness, kurtosis, peak coefficient,
The radio wave monitoring system according to any one of claims 1 to 3. The second feature quantity extraction unit extracts a modulation error parameter obtained by modulation analysis as the second feature quantity,
The radio wave monitoring system according to any one of claims 1 to 5. The modulation error parameter is either error vector amplitude, frequency error, synchronization correction, or I/Q offset.
The radio wave monitoring system according to claim 6. The second feature quantity extraction unit extracts a feature quantity based on a time waveform of radio waves as the second feature quantity,
The radio wave monitoring system according to any one of claims 1 to 7. The second signal acquisition unit generates the second signal by performing correction by subtracting a duplicate signal of the signal from the specific radio wave source from the signal received by the reception unit.
The radio wave monitoring system according to claim 2. Each of the plurality of radio wave sensors sets itself an antenna reception pattern that forms a null point in the direction of arrival of radio waves from the specific radio wave source.
The radio wave monitoring system according to any one of claims 1 to 9. a first feature extraction unit that extracts a first feature of the first signal received by the receiver;
an interference determination unit that determines the presence or absence of radio wave interference with respect to a signal from a specific radio wave transmission source based on the first feature amount;
a second signal acquisition unit that acquires a second signal that is a received signal from which the influence of the signal from the specific radio wave source is removed;
a second feature extraction unit that extracts a second feature of the second signal;
an identification unit that identifies interference source candidates among radio wave transmission sources based on the second feature amount;
a position estimating unit for estimating the position of the interference source based on the radio waves from which the influence of the signal from the specific radio wave source is removed, which are received by the plurality of radio wave sensors at each of the plurality of positions;
When the interference determination unit determines that there is radio wave interference, the identification unit identifies the interference source based on the identification result of the interference source by the identification unit and the estimation result of the position of the interference source by the position estimation unit. When,
A radio wave monitoring processing device. a step of extracting a first feature quantity of the first signal received by the receiving unit;
a step of determining the presence or absence of radio wave interference with respect to a signal from a specific radio wave transmission source based on the first feature amount;
obtaining a second signal, which is a received signal from which the influence of the signal from the specific radio wave source has been removed;
extracting a second feature quantity of the second signal;
a step of identifying a candidate interference source among radio wave transmission sources based on the second feature quantity;
a step of estimating the position of the interference source based on radio waves received by a plurality of radio wave sensors at each of a plurality of positions and from which the influence of the signal from the specific radio wave source is removed;
If it is determined that there is radio interference in the step of determining the presence or absence of radio wave interference, a step of identifying the interference source based on the candidate for the interference source and the estimation result of the position of the interference source;
A radio wave monitoring method comprising: to the computer,
a step of extracting a first feature quantity of the first signal received by the receiving unit;
a step of determining the presence or absence of radio wave interference with respect to a signal from a specific radio wave transmission source based on the first feature amount;
obtaining a second signal, which is a received signal from which the influence of the signal from the specific radio wave source has been removed;
extracting a second feature quantity of the second signal;
a step of identifying a candidate interference source among radio wave transmission sources based on the second feature quantity;
a step of estimating the position of the interference source based on radio waves received by a plurality of radio wave sensors at each of a plurality of positions and from which the influence of the signal from the specific radio wave source is removed;
If it is determined that there is radio interference in the step of determining the presence or absence of radio wave interference, a step of identifying the interference source based on the candidate for the interference source and the estimation result of the position of the interference source;
program to run the

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