JP2020041845A - Radio wave monitoring system, radio wave monitoring processor, radio wave monitoring method, and program - Google Patents

Abstract

To enable the analysis of an interference wave to be performed with relatively high accuracy when specifying the origination source of an interference wave that interferes with a desired wireless signal.SOLUTION: A radio wave monitoring system comprises: a receive unit; a first feature quantity extraction unit for extracting the first feature quantity of a first signal received by the receive unit; an interference determination unit for determining, on the basis of the first feature quantity, the presence of a radio wave interference with a signal from a specific radio wave originating source; a second signal acquisition unit for acquiring a second signal having had the influence of the signal from the specific radio wave originating source removed; a second feature quantity extraction unit for extracting a second feature quantity of the second signal; a discrimination unit for discriminating a candidate for an interference source among radio wave originating sources on the basis of the second feature quantity; a plurality of radio wave sensors for receiving a radio wave having had the influence of the signal from the specific radio wave originating source removed; a position estimation unit for estimating the position of an interference source on the basis of received signals by the plurality of radio wave sensors; and an identification unit for identifying an interference source on the basis of the result of interference source discrimination and the result of interference source position estimation when it is determined by the interference determination unit that there is a radio wave interference.SELECTED DRAWING: Figure 1

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 for identifying the source of radio waves.
For example, Patent Document 1 discloses a radio wave monitoring device for tracking the position of a wireless station to be monitored. This radio wave monitoring device detects the presence or absence of a transmission signal to be monitored from a received signal, and uniquely identifies a radio station of a transmission source from characteristics of the transmission signal. Further, this radio wave monitoring device measures the direction of arrival of the transmission signal, and estimates the position of the radio station of the transmission source from the measurement result. Then, the radio wave monitoring device outputs information in which the identified wireless station (source) is associated with the position of the wireless station.

  Patent Document 2 discloses a radio wave monitoring device for specifying an individual radio station that has emitted a received radio wave without relying on the experience and intuition of a monitor. This radio wave monitoring device receives a radio signal with a plurality of direction information measuring means, measures a direction of arrival, estimates a position of a transmission source based on the direction of arrival, and obtains a radiation source from radio station information registered in advance. And the wireless station information in the vicinity of the estimated position. Further, the radio wave monitoring device reads the identification signal information indicating the radio station of the transmission source based on the radio wave received by the direction information measuring means. The radio monitoring apparatus 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 wireless station, the individual of the wireless station is specified.

JP 2007-248110 A Japanese Patent No. 5472210

  As one of the scenes for specifying the source of the radio wave, there is a scene for specifying the source of the interference wave that interferes with the target wireless signal. In this case, the accuracy of the analysis of the interference wave may be reduced by including the target radio signal in addition to the interference wave in the reception signal used for specifying the transmission source.

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

  According to a first aspect of the present invention, a radio wave monitoring system includes: a receiving unit that receives a radio wave; a first feature amount extracting unit that extracts a first feature amount of a first signal received by the receiving unit; An interference determination unit that determines whether there is radio interference with a signal from a specific radio wave source based on the first characteristic amount, and a second reception signal that is a received signal from which the influence of the signal from the specific radio wave source has been removed. A second signal acquisition unit for acquiring a signal, a second feature amount extraction unit for extracting a second feature amount of the second signal, and identifying a candidate of an interference source among radio wave transmission sources based on the second feature amount An identification unit, a plurality of radio sensors for receiving radio waves from which the influence of the signal from the specific radio wave source has been removed at each of a plurality of positions, and the interference source based on signals received by the plurality of radio sensors. A position estimating unit for estimating a position, and the interference determining unit If it is judged wave interference includes the identification result of the interference source by the identification unit, based on the estimation result of the position of the interference source by the position estimation unit, and a identifying unit for identifying the interference source.

  According to the second aspect of the present invention, the radio wave monitoring and processing device includes: a first feature amount extracting unit configured to extract a first feature amount of a first signal received by a receiving unit; An interference determination unit that determines the presence or absence of radio wave interference with a signal from a specific radio wave source, and a second signal acquisition that obtains a second signal that is a received signal from which the influence of the signal from the specific radio wave source has been removed A second feature amount extracting unit that extracts a second feature amount of the second signal; an identifying unit that identifies a candidate of an interference source 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 a radio wave from which the influence of a signal from the specific radio wave source received by the sensor at each of a plurality of positions has been removed, and the interference determination unit has radio interference. When it is determined, the identification result of the interference source by the identification unit, Based on the estimation result of the position of the interference source by serial position estimation unit, and a identifying unit for identifying the interference source.

  According to a third aspect of the present invention, a radio wave monitoring method includes a step of extracting a first characteristic amount of a first signal received by a receiving unit, and a step of extracting a first characteristic amount from a specific radio wave transmission source based on the first characteristic amount. Determining the presence or absence of radio wave interference with the signal, 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 feature value of the second signal Extracting; and identifying a candidate of an interference source among the radio wave sources based on the second characteristic amount; and a plurality of radio sensors received at a plurality of positions, respectively, from the specific radio wave source. A 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 a step of determining the presence or absence of the radio interference, if it is determined that there is radio interference, the candidate of the interference source and the interference The interference based on the source position estimation result And a step of identifying.

  According to a fourth aspect of the present invention, a program causes a computer to extract a first characteristic amount of a first signal received by a receiving unit, and to specify a specific radio wave transmitting source based on the first characteristic amount. Determining the presence or absence of radio wave interference with a signal from the second signal; obtaining a second signal that is a received signal from which the influence of the signal from the specific radio wave source has been removed; and a second characteristic of the second signal. Extracting the amount, identifying the candidate of the interference source among the radio wave sources based on the second characteristic amount, receiving a plurality of radio sensors at each of a plurality of positions, from the specific radio wave source 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 when it is determined that there is radio interference in the step of determining the presence or absence of the radio interference, the candidate of the interference source, Based on the estimation result of the location of the interference source. Te is a program for executing the steps of identifying the source of interference.

  ADVANTAGE OF THE INVENTION According to this invention, when specifying the source of the interference wave which interferes with the target radio signal, the analysis of the interference wave can be performed with relatively high accuracy.

FIG. 2 is a schematic block diagram illustrating a functional configuration example of a radio wave monitoring system according to the first embodiment. 5 is a flowchart illustrating a first example of a processing procedure in which the radio wave monitoring system according to the first embodiment specifies an interference source. It is a flowchart which shows the 2nd example of the processing procedure which the radio wave monitoring system which concerns on 1st Embodiment specifies an interference source. FIG. 5 is a diagram illustrating an example in which the radio wave monitoring system according to the first embodiment specifies an interference source and does not stop due to an interrupt signal. FIG. 6 is a diagram illustrating an example of a case where the radio wave monitoring system according to the first embodiment specifies an interference source and is interrupted by an interrupt signal. It is a schematic block diagram showing the example of functional composition of the radio wave monitoring system concerning a 2nd embodiment. It is a schematic structure figure showing the example of composition of electric wave sensor 120 concerning a 2nd embodiment. It is a flowchart which shows the 1st example of the processing procedure which the radio wave monitoring system which concerns on 2nd Embodiment specifies an interference source. It is a flowchart which shows the 2nd example of the processing procedure which the radio wave monitoring system which concerns on 2nd Embodiment specifies an interference source. It is a schematic block diagram showing the example of functional composition of the radio wave monitoring system concerning a 3rd embodiment. It is a flowchart which shows the 1st example of the processing procedure which the radio wave monitoring system which concerns on 3rd Embodiment specifies an interference source. It is a flowchart which shows the 2nd example of the processing procedure which the radio wave monitoring system which concerns on 3rd Embodiment specifies an interference source. It is a schematic block diagram showing the example of functional composition of the radio wave monitoring system concerning a 4th embodiment. It is a flowchart which shows the 1st example of the processing procedure which the radio wave monitoring system which concerns on 4th Embodiment specifies an interference source. It is a flow chart which shows the 3rd example of the processing procedure which the electric wave monitoring system concerning a 4th embodiment specifies an interference source. It is a figure showing an example of composition of a radio wave monitoring processor concerning a 5th embodiment. FIG. 14 is a schematic block diagram illustrating a configuration example of a computer according to at least one embodiment.

  Hereinafter, embodiments of the present invention will be described, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of the features described in the embodiments are necessarily essential to the solution of the invention.

<First embodiment>
FIG. 1 is a schematic block diagram illustrating a functional configuration example of the radio wave monitoring system according to the first embodiment. In the configuration shown in FIG. 1, the radio wave monitoring system 1 includes a reception 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, An identification unit 23, a radio wave sensor 31, a position estimation unit 32, and an identification unit 41 are provided.

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

  Hereinafter, a case where the radio wave monitoring system 1 is applied to a factory will be described as an example. In a factory where the communication between the robot and the control device is made wireless, if the communication is interrupted by an interference wave, the radio wave monitoring system 1 can take measures by specifying the interference source. Communication from the terminal device to the server device, such as transmission of control signals from the control device to the robot, such as transmission from the server device to the terminal device, and transmission of sensing data from various sensors and monitors to the control device, etc. And sending to both.

In addition, regarding radio wave interference in a factory, there are generally (1) various radio wave sources in the factory, and (2) it is difficult to predict when an interfering wave will occur intermittently and irregularly and when it will occur. And (3) the interference wave is weak, and it is difficult to identify the interference source. When the radio wave monitoring system 1 specifies the interference source, for example, the interference can be more efficiently performed in a shorter time than when the worker or the like specifies the interference source by trial and error while stopping a part of the equipment in the factory. The source can be identified.
When the interference source is a communication device, it is conceivable to take measures against interference such as using different communication frequencies for the target signal and the interference wave. When the interference source is a device other than the communication device, it is conceivable to take noise countermeasures such as applying a shield to the interference source.

However, the application target of the radio wave monitoring system 1 is not limited to a factory. The radio wave monitoring system 1 can be applied to various situations where radio wave interference can be a problem.
For example, the radio wave monitoring system 1 may be applied to a hospital. It is conceivable to use wireless equipment in hospitals for the purpose of avoiding the obstruction of wiring, such as the use of wireless equipment in operating rooms. In this case, if radio wave interference occurs in the wireless communication, the radio wave monitoring system 1 can take measures by specifying the interference source.

Alternatively, the radio wave monitoring system 1 may be applied to a mobile body such as an automobile. Many electronic devices are mounted on a mobile body such as an automobile, and it is considered that it is difficult to identify an interference source. Also in this case, measures can be taken by the radio wave monitoring system 1 specifying the interference source.
Alternatively, the radio wave monitoring system 1 may be applied to a transportation system such as a subway. In traffic systems, there are electronic devices brought in from outside, such as passenger mobile phones, in addition to electronic devices of the traffic system itself, such as electronic devices mounted on moving objects, and it is considered that it is difficult to identify an interference source. Also in this case, measures can be taken by the radio wave monitoring system 1 specifying the interference source.

The receiving unit 11 receives a radio wave. The signal received by the receiving unit 11 is used to determine the presence or absence of radio wave interference and to identify the interference source when it is determined that there is radio wave interference.
As the receiving unit 11, a receiving device serving as a destination (destination) of a target signal, or a radio wave sensor installed near the receiving device may be used. When the receiving device serving as the destination of the target signal is used as the receiving unit 11, the received signal of the receiving device may be distributed and used for the original processing and the analysis in the radio wave monitoring system 1.

  The radio wave sensor referred to here is a device that receives a radio wave for analysis of the radio wave, such as extraction of a characteristic amount of a radio wave (for example, an amplitude probability distribution, a modulation error parameter, etc. described later) or estimation of the position of a radio wave transmission source. The radio wave sensor may have an analysis function. Alternatively, a radio wave sensor may be configured using a reception device, and a device different from the radio wave sensor may have an 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, a radio wave during normal operation of the receiving device or a radio wave close thereto is acquired. Can be analyzed. In this respect, the interference source can be specified with high accuracy.
The signal received by the receiving unit 11 is called a first signal.

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

  The first feature amount is a feature amount for determining whether or not the target signal is receiving radio wave interference. By using a feature amount having 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. The load on one feature amount extraction unit 12 can be relatively small.

The interference determination unit 13 determines the presence or absence of radio wave interference with a signal (target signal) from a specific radio wave transmission source based on the first characteristic amount. For example, the interference determination unit 13 knows a range of values that the amplitude probability distribution of the target signal takes when there is no radio interference, and the amplitude probability distribution calculated by the first feature amount extraction unit 12 as the first feature amount is It is determined whether or not there is radio wave interference by determining whether or not it is within the range. When the amplitude probability distribution calculated by the first feature amount extraction unit 12 is within this range, the interference determination unit 13 determines that the target signal is not receiving radio wave interference. On the other hand, when the amplitude probability distribution calculated by the first feature value extraction unit 12 is out of this range, the interference determination unit 13 determines that the target signal has received radio wave interference.
As described above, when the amplitude probability distribution is used as the first feature value, the interference determination unit 13 simply determines whether the amplitude probability distribution calculated by the first feature value extraction unit 12 is within a predetermined range. The presence or absence of radio wave interference with the target signal can be determined by simple processing. At this point, 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 value is not limited to the amplitude probability distribution. For example, the first feature value 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 value.

The second signal acquisition unit 21 acquires a reception signal (interference wave) from which the influence of a signal (target signal) from a specific radio wave transmission source has been removed. The signal from which the influence of the target signal has been removed is referred to as 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 for removing the influence of the target signal on the first signal. Alternatively, the second signal acquisition unit 21 may acquire the first signal in a state where the transmission of the target signal is stopped as the second signal. These will be specifically described later.

When the second signal acquisition unit 21 performs correction for removing the influence of the target signal on the first signal, the second signal acquisition unit 21 may acquire the first signal received by the reception unit 11, or may acquire the first signal. A signal corresponding to the first signal may be obtained 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.
The line from the receiving unit 11 to the second signal acquiring unit 21 in FIG. 1 indicates that the second signal acquiring unit 21 may acquire the first signal received by the receiving unit 11. When the second signal acquisition unit 21 does not acquire a signal from the reception unit 11, this line is unnecessary.

The second feature value extraction unit 22 extracts a feature value of the second signal. The feature amount of the second signal is referred to as a second feature amount.
The second feature value extraction unit 22 may extract a modulation error parameter as the second feature value. The modulation error parameter referred to here is a general term for a characteristic amount obtained by performing a modulation analysis on the second signal. The modulation error parameter includes an error vector magnitude (Error Vector Magnitude; EVM), a frequency error, a synchronization correction (Synchronization Correlation), an I / Q offset, and the like. For example, the error vector amplitude is the magnitude of an error (error vector) of a received signal point from an ideal signal point in a constellation. The error vector amplitude is also called error vector strength. The synchronization correction is obtained from the correlation coefficient between the received preamble and the ideal preamble. The I / Q offset is an offset amount of the in-phase component (I) and the quadrature component (Q) of the radio signal caused by carrier feedthrough.
The second feature amount is a feature amount for identifying an interference source by identifying an interference wave. By using a feature amount, such as an error vector strength, which is likely to cause a difference between radio wave sources due to incomplete analog circuit operation or manufacturing variation as the second feature amount, it is possible to identify an interference source with high accuracy. .

The identification unit 23 identifies an interference source candidate among 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. Specifies the radio wave transmission source that matches the most. 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 amounts match.
As a precondition for the identification unit 23 to identify an interference source candidate, it is necessary that radio interference occurs. For this reason, the identification unit 23 specifies an interference source candidate when the interference determination unit 13 determines that there is radio interference.

  As described above, the second feature value extraction unit 22 calculates a modulation error parameter by modulation analysis as the second feature value, and the identification unit 23 uses the modulation error parameter to identify a radio wave transmission source as a candidate for an interference wave. You may do so. Regarding identification of radio wave sources using modulation error parameters 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, one other, "Radiometric Identification of LTE Transmitters", Globecom 2013-Wireless Communications Symposium, 2013 ". The identification unit 23 may identify an interference wave candidate radio wave transmission source based on a modulation error parameter described in any of these documents.

  Alternatively, the identification unit 23 may identify a radio wave transmission source as a candidate for an interference wave using a feature amount based on a time waveform of the radio wave. For this purpose, the second feature value extraction unit 22 may extract a feature value based on the time waveform of the radio wave as the second feature value. "William C. Suski II, 3 others," Using Spectral Fingerprints to Improve Wireless Network Security ", IEEE GLOBECOM 2008, 2008", describes a radio signal source using transient signal characteristics and power spectral density (Power Spectral Density). The identification is described. The identification unit 23 may identify the radio wave source of the interference wave candidate by using the method described in this document.

In order to compare the second feature value extracted by the second feature value extraction unit 22 with the second feature value of a radio wave transmission source in a factory, a hospital, or the like (hereinafter, referred to as a factory), the identification unit 23 includes: The information of the second characteristic 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 in the radio wave monitoring system 1 or from outside the radio wave monitoring system 1.
The identification unit 23 learns, as teacher data, the acquired information of the second feature amount for each radio wave transmission source in the factory, and extracts the second feature amount extracted by the second feature amount extraction unit 22 by using a machine learning algorithm. It may be used for identification. As an identification method in this case, a K-nearest neighbor algorithm (KNN) or a support vector machine (SVM) can be used.

When comparing the amplitude probability distribution with the modulation error parameter, the amplitude probability distribution requires less calculation. In addition, the amplitude probability distribution can measure even a weak radio wave than the modulation error parameter. On the other hand, the modulation error parameter is more likely to be different for each radio wave transmission source than the amplitude probability distribution. Therefore, the modulation error parameter is easier to identify the radio wave transmission source than the amplitude probability distribution.
The interference determination unit 13 determines the presence or absence of radio wave interference with the target signal using the amplitude probability distribution, so that the determination can be made in a relatively short time. On the other hand, it is considered that the identification unit 23 identifies the interference source using the modulation error parameter such as the error vector amplitude, so that the modulation error amount may be different for each radio wave transmission source. Accuracy can be identified.

A plurality of electric wave sensors 31 are arranged in a factory, and receive electric waves at each of a plurality of positions where the electric wave sensors 31 are arranged. Each of the radio sensors 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 so as to form a null point in the arrival direction of the target signal. Alternatively, the radio wave sensor 31 may receive a wireless signal in a state where the transmission of the target signal is stopped.

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

Alternatively, the position estimating unit 32 may create distribution information (map) of the radio wave intensity in the factory based on the radio wave reception status of each of the plurality of radio wave sensors 31. Then, the position estimating unit 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 (accordingly, in an aspect having an area).
As a precondition for the position estimating unit 32 estimating the position of the interference source, it is necessary that radio interference occurs. Therefore, the position estimating unit 32 estimates the position of the interference source when the interference determining unit 13 determines that there is radio interference.

When the interference determination unit 13 determines that there is radio 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. I do.
For example, in the case where the identification unit 23 identifies a plurality of radio wave transmission sources as interference source candidates, the identification unit 41 is the 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. The radio wave transmission source may be identified as the interference source.

  Alternatively, the identification unit 41 may calculate a likelihood (for example, a probability) as 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 a user (person in charge of measures against radio interference) ( For example, display). The user can efficiently check whether the radio wave transmission source is actually the interference source in ascending order of likelihood and take measures.

  As described above, the identification unit 41 identifies an 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 obtain the determination result of the presence or absence of radio wave interference from the interference determination unit 13. Alternatively, the identification unit 41 may obtain the determination result of the presence / absence of radio wave interference via a device other than the interference determination unit 13 such as the identification unit 23.

  When the identification unit 23 identifies only one radio wave transmission source, the identification unit 41 compares the individual of the radio wave transmission source identified by the identification unit 23 with the position estimated by the position estimation unit 32 and outputs the same radio wave transmission source. The source likelihood may be calculated. When the likelihood is equal to or larger than the predetermined threshold, the radio wave 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 transmission source identified by the identification unit 23 and the likelihood calculated by the identification unit 41 to the user.

FIG. 2 is a flowchart illustrating a first example of a processing procedure in which the radio wave monitoring system 1 specifies an interference source. 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 a radio wave. For example, the receiving unit 11 receives a radio wave during a predetermined time slot such as 10 seconds.
After step S111, the process proceeds to step S112.

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

(Step S113)
The interference determination unit 13 determines whether there is radio wave interference with the target signal. For example, as described above, the first feature value extraction unit 12 calculates the amplitude probability distribution as the first feature value, and the interference determination unit 13 determines that the value of the amplitude probability distribution calculated by the first feature value extraction unit 12 is a predetermined value. It is determined whether it is within the 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 interference with the target signal (step S113: NO), the radio wave monitoring system 1 ends the processing in FIG.

(Step S121)
The second signal acquisition unit 21 acquires a second signal. As described above, the second signal is a 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 for removing the influence of the target signal on the first signal. Alternatively, the second signal acquisition unit 21 may acquire the first signal in a state where the transmission of the target signal has stopped as the second signal.

  Interference waves often occur intermittently and irregularly. In order to acquire the second signal including the interference wave, if the interference determination unit 13 determines that there is radio interference, the second signal acquisition unit 21 sets the same time as the reception signal used for the determination by the interference determination unit 13. Preferably, a second signal of the slot is obtained. Therefore, the radio wave monitoring system 1 may include a buffer, and the receiving unit 11 may temporarily store the received signal in the buffer in step S111. Then, the second signal acquisition unit 21 may perform correction for removing the influence of the target signal on the received signal temporarily stored in the buffer.

Alternatively, when the interference wave is generated 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 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 unit 11 may temporarily store the received signal in a buffer.
After step S121, the process proceeds to step S122.

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

(Step S123)
The identification unit 23 identifies an interference source based on the second feature value. As described above, 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 that the second feature amount Identify the best matching radio wave 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 amounts match.
After step S123, the process proceeds to step S124.

(Step S124)
The position estimating unit 32 acquires the received signal of each of the radio wave sensors 31.
After step S124, the process proceeds to step S125.

(Step S125)
The position estimating unit 32 estimates the position of the interference source based on each received signal of the radio wave sensor 31. As described above, the radio wave sensor 31 may receive the interference wave, and the position estimating unit 32 may detect the arrival direction of the interference wave at each of the radio wave sensors 31. Then, the position estimating unit 32 may estimate the position of the interference source based on the direction of arrival of the interference wave at each of the plurality of radio sensors 31 in the manner of triangulation.
Alternatively, the position estimating unit 32 may create distribution information of the radio wave intensity in the factory based on the radio wave reception status of each of the plurality of radio wave sensors 31. Then, the position estimating unit 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 ends the processing in FIG.

FIG. 3 is a flowchart illustrating a second example of a processing procedure in which the radio wave monitoring system 1 specifies an interference source. The radio wave monitoring system 1 repeats, for example, the processing 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 to S232 are the same as steps S121 to 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.
When the interference determination unit 13 determines that there is radio wave interference with the target signal in step S251 (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 interference with the target signal (step S251: NO), the radio wave monitoring system 1 ends the processing in 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 in FIG.

FIG. 3 shows an example in which the processing in step S261 and the processing in step S271 are heavy (the processing load is large). The radio wave monitoring system 1 executes the relatively light steps S231 to S232 and S241 in parallel with the step S221, thereby increasing the efficiency of the processing. In particular, the radio wave monitoring system 1 performs the processing of step S221, the processing of steps S231 to S232, and the processing of step S241 at the same time (parallel processing). Processing time is reduced.
Further, the radio wave monitoring system 1 performs the processing of steps S261 and S271 after the determination of step S251. Thereby, when the interference determination unit 13 determines that there is no radio interference in step S251, the radio wave monitoring system 1 does not perform the processes in steps S261 and S271. In this regard, the load on the radio wave monitoring system 1 can be reduced.

However, the radio wave monitoring system 1 may execute a part or all of the processing of steps S231 and S232 before step S261 (particularly when YES in step S251). The radio wave monitoring system 1 may execute a part or all of the processing of step S241 before step S271 (particularly when YES in step SS251).
If the processing of steps S213 and S232 or the processing of step S241 is heavy, by performing part or all of these processing after step S251, if the interference determination unit 13 determines in step S251 that there is no radio interference, The radio wave monitoring system 1 does not perform these processes. In this regard, 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 interference with 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.
FIG. 4 is a diagram illustrating an example in which the radio wave monitoring system 1 specifies an interference source and does not stop due to an interrupt signal.

In the process of FIG. 4, the receiving unit 11 receives a radio wave (sequence S311) and outputs a received signal (first signal) to the first feature value extracting unit 12 and the second signal acquiring unit 21.
The first feature value extraction unit 12 extracts the first feature value from the signal received from the reception unit 11 (sequence S321). The interference determination unit 13 determines whether there is radio wave interference with the target signal using the first feature value extracted by the first feature value extraction unit 12 (sequence S322). In the example of FIG. 4, the interference determination unit 13 determines that there is radio interference. If it is determined that there is radio interference, the interference determination unit 13 does not output an interrupt signal.

Further, second signal acquisition section 21 acquires a second signal using the reception signal from reception section 11 (sequence S331). FIGS. 4 and 5 illustrate an example in which the second signal acquisition unit 21 performs correction for removing the effect of the target signal on the reception signal from the reception unit 11. Also, when the transmission of the target signal is stopped, the stop of the process using the interrupt signal can be applied.
The second feature value extraction unit 22 extracts a second feature value from the second signal (sequence S332). The identification unit 23 identifies an interference source candidate among the radio wave transmission sources using the second feature amount extracted by the second feature amount extraction unit 22 (sequence S333). The identification unit 23 outputs, to the identification unit 41, information indicating the identified candidate of the interference source (for example, identification information for identifying a radio wave source in a factory).

  The radio wave sensor 31 receives a radio wave (sequence S341). Radio wave sensor 31 outputs the received signal to position estimating unit 32. The position estimating unit 32 estimates the position of the interference source using the received signal of the radio wave sensor 31 (sequence S342). The position estimating unit 32 outputs information indicating the estimated position of the interference source to the identifying 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 illustrating an example of a case in which the radio wave monitoring system 1 specifies an interference source and is interrupted by an interrupt signal.
Sequences S411 and S421 are the same as sequences S311 and S321 in FIG. After the sequence S421, the interference determination unit 13 determines whether there is radio wave interference with the target signal using the first feature value extracted by the first feature value extraction unit 12 (sequence S422). In the example of FIG. 5, the interference determination unit 13 determines that there is no radio interference. When it is determined that there is no radio interference, the interference determination unit 13 outputs an interrupt signal for stopping the identification of the interference source.

  The sequences S431 to S432 are the same as the sequences S331 to S332 in FIG. 4, but in the sequence S432, the second feature amount extraction unit 22 stops extracting the second feature amount in response to the interrupt signal from the interference determination unit 13. I do. Due to the suspension of the extraction of the second feature, the identification unit 23 does not perform the process of identifying the candidate of the interference source (see the sequence S333 in FIG. 3).

Sequences S441 to S442 are the same as sequences S341 to S342 in FIG. 4, but in sequence S442, position estimating unit 32 stops estimating the position of the interference source in response to the interrupt signal from interference determining unit 13.
By stopping the extraction of the second feature value by the second feature value extraction unit 22 in the sequence S432 and stopping the estimation of the position of the interference source by the position estimation unit 32 in the sequence S442, the identification unit 41 identifies the interference source. (See the sequence S351 in FIG. 3).

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

  Similarly, according to the timing at which the interference determination unit 13 determines that there is no radio interference with the target signal, either the reception of the radio wave by the radio wave sensor 31 or the estimation of the position of the interference source by the position estimation unit 32 is stopped by the interrupt processing. It may be. For this purpose, 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 a radio wave. The first feature value extracting unit 12 extracts a first feature value of the first signal received by the receiving unit 11. The interference determining unit 13 determines whether there is radio interference with the target signal based on the first feature value extracted by the first feature value extracting unit 12. The second signal acquisition unit 21 acquires the second signal from which the influence of the target signal has been removed. The second feature value extraction unit 22 extracts a second feature value of the second signal. The identification unit 23 identifies an interference source based on the second feature value extracted by the second feature value extraction unit 22. The plurality of radio sensors 31 receive radio waves from which influence of the target signal has been removed at each of the plurality of positions. The position estimating unit 32 estimates the position of the interference source based on the signals received by the plurality of radio sensors 31. When the interference determination unit 13 determines that there is radio 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. I do.
According to the radio wave monitoring system 1, when specifying the source of an interference wave that interferes with a target wireless signal (target signal), it is possible to remove the influence of the target signal and specify the source. According to the radio wave monitoring system 1, at this point, the analysis of the interference wave can be performed with relatively high accuracy.

Further, the first feature value extraction unit 12 extracts the amplitude probability density as the first feature value. The interference determination unit 13 determines the presence or absence of radio wave interference based on the deviation from the amplitude probability density registered in advance for the target signal (for example, whether or not the target signal is within a predetermined range).
The radio wave monitoring system 1 can determine the presence or absence of radio wave interference with a target signal in a relatively short time by using a feature amount having a relatively small amount of calculation such as an amplitude probability density as the first feature amount, and In addition, the load on the first feature amount extraction unit 12 can be small.

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

Further, the second feature value extraction unit 22 extracts a modulation error parameter such as an error vector amplitude as the second feature value.
The radio wave monitoring system 1 can specify an interference source with high accuracy by using a feature amount, such as an error vector amplitude, in which a difference between radio wave sources is relatively likely to occur as the second feature amount.
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 a frequency error, a synchronization correction, and an I / Q offset.
The second feature value extraction unit 22 may extract a feature value based on the time waveform of the radio wave as the second feature value in addition to or instead of the modulation error parameter.
The radio wave monitoring system 1 can specify an interference source with high accuracy in that a second characteristic amount, which is a characteristic amount based on a time waveform of a radio wave, which is relatively different from each other for each radio wave source, is used. .

<Second embodiment>
In the second embodiment, a first example in which the first embodiment is further embodied will be described.
FIG. 6 is a schematic block diagram illustrating a functional configuration example of the radio wave monitoring system according to the second embodiment. 6, the radio wave monitoring system 2 includes a receiving device 110, a radio wave sensor 120, and a radio wave monitoring processing device 130. The receiving device 110 includes the receiving unit 11. The radio wave sensor 120 includes a receiving unit 121 and a directivity control unit 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, radio wave source information A storage unit 131 and a target signal removing unit 132 are provided.
FIG. 6 shows a target signal source 910 and an interference source 920.
6, the same reference numerals (11, 12, 13, 22, 23, 32, and 41) denote parts having the same functions as those shown in FIG. 1, and a description thereof will be omitted. .

  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 of the radio wave sensors 120, a plurality of receiving units 121 constitute an array antenna. Each of the radio wave sensors 120 measures an arrival direction of an interference wave using an array antenna configured by the receiving unit 121. Existing methods 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 arrival direction of radio waves.

When each of the plurality of radio sensors 120 measures the arrival direction of the interference wave, the position estimating unit 32 can estimate the position of the interference source in the manner of triangulation.
When the radio wave sensor 120 measures the arrival direction of the interference wave, the influence of the target signal is removed so that the measurement can be performed 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 illustrating a configuration example of the radio wave sensor 120. In the configuration illustrated in FIG. 7, the directivity control unit 122 includes a weight adjustment unit 123 and a synthesis unit 124.
Weight adjustment section 123 is provided for each reception section 121 and weights a reception signal of reception section 121. The combining unit 124 combines the received signals with the weight adjustment unit 123 performing weighting. The signal synthesized by the synthesizing unit 124 is expressed as in equation (1).

k (k is a positive integer) indicates the number of receiving units 121 provided in one radio wave sensor 120. x ₁ , x ₂ ,..., x _k indicate received signals of the receiving unit 121. w ₁ , w ₂ ,..., w _k indicate weighting factors by the weight adjustment unit 123.
By adjusting the weighting coefficients w ₁ , w ₂ ,..., W _k by the weight adjusting unit 123 to form a null point of the antenna reception pattern in the arrival direction of the target signal, the influence of the target signal can be removed. For example, an operator who adjusts the radio wave monitoring system 2 sets the weight coefficients w ₁ , w ₂ ,..., W _k by the weight adjustment unit 123 based on the positional relationship between the source of the target signal and the radio wave sensor 120. Set to form a null point. Alternatively, the weight adjustment unit 123 may acquire the position information of the target signal transmission source 910 from the radio wave source information storage unit 131 and automatically set the weight coefficient by the weight adjustment unit 123.
Also, the directivity of the radio wave sensor 120 can be adjusted by adjusting the weight coefficients w ₁ , w ₂ ,..., W _k by the weight adjustment unit 123. From the relationship between the directivity of the radio wave sensor 120 and the radio wave intensity, the arrival direction of the interference wave can be measured.

  The radio wave source information storage unit 131 stores radio wave source information which is information on each of the radio wave transmission sources in the factory. The radio wave source information serves as an information source of a determination criterion for the interference determination unit 13 to determine whether or not there is radio 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 for the identification unit 23 to identify a radio wave transmission source that is a candidate for an interference source using the second feature amount.

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

The radio source information storage unit 131 stores one or more of an ideal amplitude probability distribution, an ideal modulation parameter, and an ideal time waveform in addition to or instead of the information on the wireless standard and the modulation method. You may do so. In this case, the ideal amplitude probability distribution, the ideal modulation parameter, and the ideal time waveform may be theoretical values calculated based on a wireless standard and a modulation method, or may be measured without interference such as interference waves. Measured values. Further, the ideal modulation parameter and the ideal time waveform may be used as teacher data when the identification unit 23 identifies the radio wave source.
The radio wave source information storage unit 131 may further store radio wave transmission source identification information (ID; Identifier) 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 remover 132 performs a correction to remove the effect of the target signal on the received signal (first signal) of the receiver 11 to generate a second signal. For example, the target signal transmission 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 effect of the target signal by performing correction for 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 removing unit 132 performs a correction of subtracting a signal prepared in advance as a stereotype of the target signal from the reception signal of the reception unit 11, so that the effect of the target signal is reduced. May be incompletely removed (ie, reduced).

FIG. 8 is a flowchart illustrating a first example of a processing procedure in which the radio wave monitoring system 2 specifies an interference source. The radio wave monitoring system 2 repeats, for example, the processing 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 determining 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 interference with the target signal (step S513: NO), the radio wave monitoring system 2 ends the processing in FIG.

(Step S521)
Step S521 corresponds to the example of step S121 in FIG. In step S521, the target signal elimination unit 132 performs the correction for removing the influence of the target signal on the reception signal of the reception unit 11, and generates the second signal, as described above.
After step S521, the process proceeds to step S522.
Steps S522 to S523 are the same as steps S122 to S123 in FIG. After step S523, the process proceeds to step S524.

(Step S524)
Each of the radio wave sensors 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 weight coefficient 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 estimating unit 32 measures the angle of arrival of the interference wave. Specifically, each of the radio wave sensors 120 receives a radio wave while changing the directivity of the radio wave sensor 120 itself. The position estimating unit 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 estimating unit 32 estimates the position of the interference source. Specifically, the position estimating unit 32 estimates the position of the interference source based on the principle of triangulation based on the arrival direction 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 ends the processing in FIG.

FIG. 9 is a flowchart illustrating a second example of a processing procedure in which the radio wave monitoring system 2 specifies an interference source. The radio wave monitoring system 2 repeats, for example, the processing 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 to S632 are the same as steps S521 to S522 in FIG.
Steps S641 to S643 are the same as steps S524 to S526 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 interference with the target signal (step S651: NO), the radio wave monitoring system 2 ends the processing in 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 ends the processing in 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 the processes of steps S631 to S632 and S641 to S643, which are relatively light, in parallel with the process of step S621, thereby increasing the efficiency of the process. In particular, the radio wave monitoring system 2 executes the processing of step S621, the processing of steps S631 to S632, and the processing of steps S641 to S643 simultaneously (parallel processing), thereby identifying the interference source after receiving the radio wave. The processing time required to perform is reduced.
Further, 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 interference in step S651, the radio wave monitoring system 2 does not perform the processing in steps S661 and S671. In this regard, the load on the radio wave monitoring system 2 can be reduced.

However, the radio wave monitoring system 2 may execute a part or all of the processing of steps S631 and S632 before step S661 (particularly when YES in step S651). The radio wave monitoring system 2 may execute a part or all of the processing of steps S641 to S643 before step S671 (particularly when YES in step SS651).
When the processing of steps S613 to S632 or the processing of steps S641 to S643 is heavy, the interference determination unit 13 determines that there is no radio interference in step S251 by performing some or all of these processing after step S251. In this case, the radio wave monitoring system 2 does not perform these processes. In this regard, 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 interference with the target signal, an interrupt signal is output to stop the process of identifying the interference source. Good. In the second embodiment, the interference determination unit 13 determines that the target signal removal unit 132 generates the second signal, the second feature amount extraction unit 22 extracts the second feature amount, and the identification unit 23 determines that the interference has occurred. A series of processes (see steps S631 to S632 and S661 in FIG. 9) of the process of identifying the source candidate is interrupted. In addition, the interference determination unit 13 performs a process in which the radio wave sensor 120 forms a null point to receive a signal, the position estimation unit acquires a reception signal of the radio wave sensor 120, estimates an arrival angle of an interference wave, and A series of processes for estimating the position (see steps S641 to S643 and S671 in FIG. 9) is stopped by interruption.

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

Further, the target signal removing unit 132 performs a correction for subtracting a duplicate signal of the target signal from the received signal of the receiving unit 11 to generate a second signal.
Accordingly, the accuracy of the target signal removing unit 132 removing the influence of the target signal from the received signal of the receiving unit 11 is high. In this regard, the radio wave monitoring system 2 can specify the interference source with high accuracy.

  The directivity control unit 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 reception signal of the radio wave sensor 120 can be removed. In this regard, the position estimating unit 32 can estimate the position of the interference source with high accuracy.

<Third embodiment>
In the third embodiment, a second example in which the first embodiment is further embodied will be described.
FIG. 10 is a schematic block diagram illustrating a functional configuration example of a radio wave monitoring system according to the third embodiment. In 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 includes a communication unit 211. The radio wave sensor 120 includes a receiving unit 121 and a directivity control unit 122. The radio wave monitoring and 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, radio wave source information The storage unit 131 includes a wave stop instruction unit 231 and a post-wave signal acquisition unit 232.
FIG. 10 shows a target signal source 910 and an interference source 920.
10, parts having the same functions as those shown in FIG. 6 have 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 reception unit 11 in FIG. The communication unit 211 receives the target signal from the target signal transmission source 910, similarly to the receiving unit 11 in FIGS. In addition, the communication unit 211 transmits a wave stop instruction to stop transmission of the target signal to the target signal source 910.
The stop instruction unit 231 controls the communication unit 211 to transmit a stop instruction for stopping transmission of the target signal to the target signal source 910. This is so that the radio wave monitoring system 3 can specify the interference source without being affected by the target signal. The stop instruction unit 231 causes the communication unit 211 to transmit a stop instruction to the target signal transmission source 911 when the interference determination unit 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 stoppage instructing unit 231 refers to the information (for example, wireless standard, position, ID, etc.) of the radio wave transmission source stored in the radio wave source information storage unit 131 and sends a signal to the target signal transmission source 910 to be stopped. As a result, it is possible to selectively give an appropriate stop instruction.
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 reception signal of the communication unit 211 in a state where the target signal transmission source 910 stops transmitting the target signal according to the stop signal. This signal does not include the target signal. This signal corresponds to an example of the second signal.

  In the configuration of FIG. 10, the position estimating unit 32 can estimate the position of the interference source 920 by using each received signal of the radio wave sensor 120 in a state where the target signal source 910 stops transmitting the target signal. . Therefore, the directivity control unit 122 does not need to form a null point of 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 wave sensor 120 for measuring the arrival direction of the interference wave.

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

(Step S721)
The communication unit 211 transmits a wave stop instruction for stopping transmission of the target signal to the target signal transmission source 910 according to the instruction of the wave stop instruction unit 231. The instruction to stop the wave corresponds to an example of a process for acquiring the second signal. Further, the instruction to stop the wave 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-wave signal acquisition unit 232 acquires the reception signal of 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 to S725 are the same as steps S122 to S124 in FIG.
In comparison with the processing of FIG. 8, since the target signal source 910 stops transmitting the target signal, the directivity control unit 122 does not need to form a null point of the antenna reception pattern in the arrival direction of the target signal. Absent. Therefore, in the processing of FIG. 11, step S524 of FIG. 8 is unnecessary.
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 estimating unit 32 measures the angle of arrival of the interference wave. Specifically, each of the radio wave sensors 120 receives a radio wave while changing its own directivity. The position estimating unit 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 estimating unit 32 estimates the position of the interference source. Specifically, the position estimating unit 32 estimates the position of the interference source based on the principle of triangulation based on the arrival direction of the interference wave for each radio wave sensor 120 obtained in step S726.
After step S727, the process proceeds to step S728.
Step S728 is the same as step S126 in FIG. After step S728, the radio wave monitoring system 3 ends the processing in FIG.

FIG. 12 is a flowchart illustrating a second example of a processing procedure in which the radio wave monitoring system 3 specifies an interference source. The radio wave monitoring system 3 repeats, for example, the processing 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. If the interference determination unit 13 determines that there is no radio interference with the target signal (step S813: NO), the radio wave monitoring system 3 ends the processing in 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 to S833 are the same as steps S722 to S724 in FIG.
Steps S841 to S843 are the same as steps S725 to 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 in FIG.

As described above, the post-wave signal acquisition unit 232 acquires, as the second signal, the reception signal of the communication unit 211 in a state where the specific radio wave transmission source (target signal transmission source 910) is stopped.
Accordingly, in the radio wave monitoring system 3, the post-stop signal acquisition unit 232 can acquire a reception signal that does not include the target signal. In this regard, the radio wave monitoring system 3 can specify the interference source with high accuracy. Further, 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 reception signal that does not include the target signal. At this point, the radio wave monitoring system 3 can also specify the interference source with high accuracy. Further, since it is not necessary to form a null point in the arrival report of the target signal, 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>
In the fourth embodiment, a third example in which the first embodiment is further embodied will be described.
FIG. 13 is a schematic block diagram illustrating a functional configuration example of a radio wave monitoring system according to the fourth embodiment. In the configuration shown in FIG. 13, the radio wave monitoring system 4 includes a communication device 210, a radio wave monitoring and processing device 230, and a radio wave sensor 320. The communication device 210 includes a communication unit 211. The radio wave monitoring and 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, radio wave source information The storage unit 131 includes a wave stop instruction unit 231 and a post-wave signal acquisition unit 232.
FIG. 13 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, and 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 includes an array antenna including a plurality of reception units 121, the radio wave sensor 320 is configured as a reception unit including a single antenna. For this reason, the radio wave sensor 320 measures the radio wave intensity, but cannot measure the direction of arrival (the angle of arrival) of the radio wave.
According to the configuration of the radio wave sensor 320, the position estimating unit 32 estimates the position of the interference source based on the distribution of the radio wave intensity in the factory. For example, the position estimating unit 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 (accordingly, in an aspect having an area).
In other respects, the radio wave monitoring system 4 is the same as the radio wave monitoring system 3.

FIG. 14 is a flowchart illustrating a first example of a processing procedure in which the radio wave monitoring system 4 specifies an interference source. The radio wave monitoring system 4 repeats, for example, the processing 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 interference with the target signal (step S913: NO), the radio wave monitoring system 4 ends the processing in FIG.
Steps S921 to S925 are the same as steps S721 to 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 estimating unit 32 measures the received signal strength at each of the radio wave sensors 320. The position estimating unit 32 creates distribution information (map) of the radio wave intensity in the factory based on the received signal intensity at each of the radio wave sensors 320.
After step S926, the process proceeds to step S927.

(Step S927)
The position estimating unit 32 estimates the position of the interference source. Specifically, the position estimating unit 32 estimates the position where the radio field intensity is maximum as the position of the interference source based on the distribution of the radio field 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 in FIG.

FIG. 15 is a flowchart illustrating a third example of a processing procedure in which the radio wave monitoring system 4 specifies an interference source. 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 interference with the target signal (step S1013: NO), the radio wave monitoring system 4 ends the processing in 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 in FIG.

As described above, the radio wave sensor 320 only needs to be able to measure the radio wave intensity, and does not need to include an array antenna. In the radio wave monitoring system 4, the manufacturing cost and operation cost of the radio wave sensor 320 are relatively low, and in this regard, the manufacturing cost and operation cost of the radio wave monitoring system 4 can be low. Further, since the manufacturing cost and operation cost of the radio wave sensor 320 are relatively low, a large number of radio wave sensors 320 can be arranged in a factory. By arranging many 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 regard, the interference source can be specified with high accuracy.
Further, when the radio wave sensor measures the arrival direction (arrival angle) of a radio wave, it is necessary to have a view between the radio wave transmission source and the radio wave sensor. On the other hand, the radio wave sensor 320 can pick up a reflected wave or the like and include it in the radio wave intensity from a place where the radio wave sensor 320 does not have a line of sight. By using the radio wave sensor 320, the radio wave monitoring system 4 can obtain a distribution of radio wave intensity corresponding to a radio wave from a part with no line of sight even when the line of sight in the factory is not good. According to the radio wave monitoring system 4, at this point, the interference source can be specified 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 illustrating an example of a configuration of a radio wave monitoring processing device according to the fifth embodiment. In the configuration illustrated in FIG. 16, the radio wave monitoring processing device 400 includes a first feature amount extraction unit 411, an interference determination unit 412, a second signal acquisition unit 421, a second feature amount extraction unit 422, and an identification unit 423. , A position estimating unit 431 and an identifying 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. The interference determination unit 412 determines the presence or absence of radio interference with a signal (target signal) from a specific radio wave transmission source based on the first characteristic amount extracted by the first characteristic amount extraction unit 411. The second signal acquisition unit 421 acquires a second signal that is a received signal from which the effect of the target signal has been removed. The second feature value extraction unit 422 extracts a second feature value of the second signal. The identification unit 423 identifies an interference source candidate among radio wave transmission sources based on the second feature value extracted by the second feature value extraction unit 422. The position estimating unit 431 estimates the position of the interference source based on the radio wave from which the influence of the target signal has been removed, received by the plurality of radio sensors at each of the plurality of positions. When the interference determination unit 412 determines that there is radio 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. I do.
According to the radio wave monitoring processing device 400, when specifying the source of the interference wave that interferes with the target signal, the source can be specified by removing the influence of the target signal. According to the radio wave monitoring processing device 400, the analysis of the interference wave can be performed with relatively high accuracy in this regard.

FIG. 17 is a schematic block diagram illustrating a configuration example of a computer according to at least one embodiment. In the configuration illustrated in FIG. 17, the computer 500 includes a CPU 510, a storage device 520, and an interface 530.
When any one or more of the above-described radio wave monitoring systems 1, 2, 3, 4, and the radio wave monitoring processing device 400 are mounted on a computer, the above-described processing units (the first feature amount 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 operations of the target signal removing unit 132, the suspension instruction unit 231 and the post-suspension signal acquisition unit 232 (all or some of them) are stored in the storage device 520 in the form of a program. The CPU 510 reads out a program from the storage device 520 and executes the program to execute the processing of each processing unit. The CPU 510 secures a storage area corresponding to each of the above-described storage units (the radio wave source information storage unit 131) in the storage device 520 according to a 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.

Note that a program for executing all or a part of the processing performed by the radio wave monitoring systems 1, 2, 3, 4, and the radio wave monitoring processing device 400 is recorded on a computer-readable recording medium, and is recorded on the recording medium. The processing of each unit may be performed by causing the computer system to read the recorded program and execute the program. Here, the “computer system” includes an OS and hardware such as peripheral devices.
The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in a computer system. Further, the above-mentioned program may be for realizing a part of the above-mentioned functions, or may be for realizing the above-mentioned functions in combination with a program already recorded in a computer system.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments and includes a design and the like within a range not departing from the gist of the present invention.

1, 2, 3, 4 Radio wave monitoring system 11, 121 Receiving unit 12, 411 First feature amount extracting unit 13, 412 Interference determining unit 21, 421 Second signal acquiring unit 22, 422 Second feature amount extracting 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 and processing device 131 Radio wave source information storage Unit 132 target signal removing 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 amount extraction unit that extracts a first feature amount of a first signal received by the reception unit;
An interference determination unit that determines presence or absence of radio wave interference with 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 reception signal from which an influence of a signal from the specific radio wave transmission source has been removed;
A second feature value extraction unit that extracts a second feature value of the second signal;
An identification unit that identifies a candidate of an interference source among radio wave transmission sources based on the second feature amount;
A plurality of radio sensors that receive radio waves from which the influence of the signal from the specific radio wave source has been removed at each of a plurality of positions,
A position estimating unit that estimates a position of the interference source based on signals received by the plurality of radio sensors,
When the interference determination unit determines that there is radio interference, 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,
Radio monitoring system equipped with. The second signal acquisition unit generates the second signal by removing a component of a signal from the specific radio wave transmission source from a reception signal of the reception unit.
The radio wave monitoring system according to claim 1. The second signal acquisition unit acquires a reception signal of the reception unit in a state where the specific radio wave transmission source is stopped as the second signal,
The radio wave monitoring system according to claim 1. The first feature amount is an amplitude probability density, and the interference determination unit determines presence / absence of radio interference based on a deviation from a previously registered amplitude probability density for a signal from the specific radio wave transmission source.
The radio wave monitoring system according to claim 1. The first feature amount is any one of an amplitude histogram, a moment of a probability distribution, a standard deviation, a skewness, a kurtosis, and a peak coefficient.
The radio wave monitoring system according to claim 1. The second feature value extraction unit extracts a modulation error parameter obtained by modulation analysis as the second feature value;
The radio wave monitoring system according to claim 1. The modulation error parameter is one of an error vector amplitude, a frequency error, a synchronization correction, and an I / Q offset.
The radio wave monitoring system according to claim 6. The second feature value extraction unit extracts a feature value based on a time waveform of a radio wave as the second feature value;
The radio wave monitoring system according to claim 1. The second signal acquisition unit generates a second signal by performing a correction of subtracting a duplicate signal of a signal from the specific radio wave transmission source from a reception signal of the reception unit,
The radio wave monitoring system according to claim 2. Each of the plurality of radio sensors, an antenna reception pattern that forms a null point in the direction of arrival of radio waves from the specific radio wave source is set in the radio sensor itself,
The radio wave monitoring system according to claim 1. A first feature value extracting unit that extracts a first feature value of the first signal received by the receiving unit;
An interference determination unit that determines presence or absence of radio wave interference with 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 reception signal from which an influence of a signal from the specific radio wave transmission source has been removed;
A second feature value extraction unit that extracts a second feature value of the second signal;
An identification unit that identifies a candidate of an interference source among radio wave transmission sources based on the second feature amount;
A plurality of radio wave sensors received at each of a plurality of positions, a position estimating unit that estimates the position of the interference source based on radio waves from which the influence of the signal from the specific radio wave source has been removed,
When the interference determination unit determines that there is radio interference, 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,
A radio wave monitoring and processing device comprising: Extracting a first feature amount of the first signal received by the receiving unit;
A step of determining the presence or absence of radio wave interference with a signal from a specific radio wave transmission source based on the first characteristic amount;
Obtaining 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;
Extracting a second feature value of the second signal;
Identifying a candidate of an interference source among radio wave transmission sources based on the second feature amount;
A step of estimating the position of the interference source based on a radio wave from which the influence of the signal from the specific radio wave source has been removed, wherein the plurality of radio wave sensors have received at each of the plurality of positions,
When it is determined that there is radio interference in the step of determining the presence or absence of the radio interference, a candidate of the interference source, a step of identifying the interference source based on an estimation result of the position of the interference source,
Radio monitoring methods, including. On the computer,
Extracting a first feature amount of the first signal received by the receiving unit;
A step of determining the presence or absence of radio wave interference with a signal from a specific radio wave transmission source based on the first characteristic amount;
Obtaining 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;
Extracting a second feature value of the second signal;
Identifying a candidate of an interference source among radio wave transmission sources based on the second feature amount;
A step of estimating the position of the interference source based on a radio wave from which the influence of the signal from the specific radio wave source has been removed, wherein the plurality of radio wave sensors have received at each of the plurality of positions,
When it is determined that there is radio interference in the step of determining the presence or absence of the radio interference, a candidate of the interference source, a step of identifying the interference source based on an estimation result of the position of the interference source,
A program for executing

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