JP7707033B2 - Radio wave emission source monitoring device and radio wave emission source monitoring method - Google Patents

Description

This embodiment of the invention relates to a radio wave emission source monitoring device and a radio wave emission source monitoring method.

In recent years, there has been progress in the development of radio wave emission source monitoring devices that perform a desired wave detection process on a received signal and an arrival direction estimation process to estimate the arrival direction of the desired wave relative to the radio wave emission source. However, in real space, interference waves exist in addition to the desired wave, so when detecting the desired wave, if there is an interference wave with a large signal strength, it becomes difficult to detect the desired wave. Furthermore, in the arrival direction estimation process, there are cases where the arrival direction cannot be estimated correctly due to the influence of an interference wave with a large signal strength.

In contrast, conventional radio wave source monitoring devices do not have an effective means for removing interference waves that is worth the cost. As a result, even in environments where interference waves are present, the detection process for the desired wave and the estimation of the direction of arrival are performed without taking measures to remove the interference waves, and the presence of interference waves has a negative impact on the accuracy of the detection process for the desired wave and the estimation of the direction of arrival.

Patent No. 6629978

As described above, conventional radio wave source monitoring devices do not have an effective means to eliminate interference waves that is commensurate with the cost, and the presence of interference waves has a negative impact on the detection process of the desired wave and the accuracy of estimating the direction of arrival.

The object of the present invention is to provide a radio wave source monitoring device and a radio wave source monitoring method that can relatively easily suppress interference wave components with a desired wave, thereby improving the accuracy of detecting the desired wave and estimating the direction of arrival.

In order to solve the above problems, the radio wave emission source monitoring device of the embodiment receives arriving waves in a wideband by a wideband receiving unit, receives the arriving waves in a narrowband by a narrowband receiving unit, detects a desired wave signal emitted from a radio wave emission source to be monitored from the signal received by the wideband signal processing unit , and when the desired wave signal is detected by the wideband signal processing unit, detects the desired wave signal from the signal received by the narrowband signal processing unit to estimate the direction of arrival from the target to be monitored , detects a portion determined to be the interference wave from at least one of the signal received in the wideband and the signal received in the narrowband based on requirements for determining that the desired wave signal is an interference wave and removes that portion, and detects the desired wave signal from the signal from which the interference wave has been removed .

FIG. 1 is a block diagram showing the configuration of a radio wave emission source monitoring device according to the first embodiment. FIG. 2 is a flow chart showing a process flow of the radio wave emission source monitoring device shown in FIG. FIG. 3 is a block diagram showing the configuration of a radio wave emission source monitoring device according to the second embodiment. FIG. 4 is a flow chart showing a process flow of the radio wave emission source monitoring device shown in FIG. FIG. 5 is a block diagram showing the configuration of a radio wave emission source monitoring device according to the third embodiment. FIG. 6 is a flow chart showing the flow of processing by the radio wave emission source monitoring device shown in FIG.

Hereinafter, an embodiment will be described with reference to the drawings.
(First embodiment)
Fig. 1 is a block diagram showing the configuration of a radio wave emission source monitoring device according to the first embodiment. In Fig. 1, the radio wave emission source to be monitored (e.g., an unmanned aerial vehicle, etc.) transmits, for example, IQ data as a communication signal in the same frequency band as the commonly used Wi-Fi. For this reason, the Wi-Fi communication device becomes an interference wave source.

The radio wave emission source monitoring device shown in FIG. 1 includes an antenna unit 11, a switching unit 12, a broadband receiving unit 13, a broadband signal processing unit 14A, a narrowband receiving unit 15, a narrowband signal processing unit 16, and a post-processing unit 17.

The antenna unit 11 is composed of an array antenna and captures incoming radio waves within its coverage area. The switching unit 12 selects broadband output in the initial state, and switches to narrowband output in response to a switching instruction. The broadband receiving unit 13 receives incoming broadband radio waves through the antenna unit 11 in response to the selection of broadband output by the switching unit 12. The broadband signal processing unit 14A performs interference wave blanking processing on the broadband signal received by the broadband receiving unit 13, analyzes the processing output to determine whether it contains radio waves from the desired monitoring target, and if so, instructs the switching unit 12 to switch from broadband output to narrowband output.

The narrowband receiver 15 receives narrowband radio waves through the antenna 11 in response to the selection of the narrowband output. The narrowband signal processor 16 analyzes the narrowband signal received by the narrowband receiver 15 to estimate the direction of arrival of the radio waves from the monitored object. The post-processor 17 displays the result of the estimation of the direction of arrival of the radio waves obtained by the narrowband signal processor 16, transmits information to related devices, etc.

In the above configuration, a series of processing operations will be described with reference to FIG.
In the actual environment in which the radio wave emission source monitoring device is placed, there are interference waves in addition to the desired wave signal. For example, the interference wave is a Wi-Fi signal transmitted from a wireless LAN access point. When the signal strength of the interference wave is relatively small, the effect on the detection of the desired wave and the estimation of the direction of arrival is tolerable. On the other hand, when the signal strength of the interference wave becomes relatively large, the effect on the detection of the desired wave cannot be ignored. Therefore, a process of removing the interference wave by blanking is performed.

Figure 2 is a flow chart showing the process flow of the radio wave emission source monitoring device shown in Figure 1. First, when monitoring is started, incoming radio waves are received in a wide band by selecting the wideband system output (step S1). Next, parameters for detecting the radio waves to be monitored are set (step S2), blanking process (step S3), and signal detection process (step S4) are executed in that order. Here, it is determined whether the parameter has reached a preset number of changes (step S5), and if not, the process returns to step S2 to set other parameters, and blanking process (step S3) and signal detection process (step S4) are executed in that order.

If it is determined in step S5 that the number of parameter changes has reached a specified value, the parameters for detecting the desired signal are selected (step S6), and the narrowband output is selected to receive the incoming radio waves in a narrowband (step S7). Next, parameters with stricter threshold conditions are set (step S8), the desired signal is detected and the direction of arrival is estimated (step S9), and post-processing such as displaying the estimated result of the radio wave direction of arrival and transmitting information to related devices is performed (step S10), and the series of processes is terminated.

Here, the signal detection process for the desired radio wave involves, for example, storing the characteristics of the signal to be detected in advance, such as the center frequency, spectrum shape, and signal length, and comparing the characteristics of the received signal, such as the center frequency, spectrum shape, and signal length, to determine whether the signal is the desired signal.

The above-mentioned interference wave blanking process can be performed in three ways: by removing the portion of the signal whose strength exceeds a threshold; by counting the signal length in the time direction and removing the portion if it is determined to be an interference wave; or by analyzing the spectrum of the received signal and removing the portion if it is determined to be an interference wave based on the analysis results.

In addition, the above parameters are selected by performing interference blanking processing on a wideband signal, performing analysis processing on the interference blanking processed signal to determine the effectiveness of the interference blanking processing, and repeating this process by changing the parameters related to the interference blanking to select appropriate parameters, thereby making it possible to automate the interference blanking processing.

According to the radio wave emission source monitoring device of the above embodiment, interference wave blanking processing based on multiple parameters is performed on the received wideband signal to detect the radio wave signal to be monitored, and then the parameters for detecting the desired radio wave signal are reset to estimate the direction of arrival from the narrowband signal. Therefore, when detecting the desired wave, even if an interference wave with a high signal strength is present, the desired wave can be reliably detected, and the direction of arrival estimation processing can also correctly estimate the direction of arrival without being affected by the interference wave with a high signal strength.

Second Embodiment
FIG. 3 is a block diagram showing the configuration of a radio wave emission source monitoring device according to the second embodiment, and FIG. 4 is a flowchart showing the flow of processing by the radio wave emission source monitoring device shown in FIG.

In this embodiment, as shown in FIG. 3, a broadband signal processing unit 14 that does not include interference wave blanking processing is used instead of a broadband signal processing unit 14A that includes interference wave blanking processing, and a narrowband signal processing unit 16A that includes interference wave blanking processing is used instead of a narrowband signal processing unit 16 that does not include interference wave blanking processing.

That is, as shown in FIG. 4, in the wideband system, after receiving a wideband signal (step S1), signal detection processing (step S4) is performed directly without performing interference wave blanking processing, and in the narrowband system, after receiving a narrowband signal (step S7), parameters with stricter threshold conditions are set (step S8), interference wave blanking processing is performed (step S11), and the system proceeds to arrival direction estimation processing (step S9) and post-processing (step S10).

As described above, the radio wave emission source monitoring device of this embodiment detects the radio wave signal to be monitored based on multiple parameters for the received wideband signal, and when the parameters for detecting the desired radio wave signal are reset, interference wave blanking processing is performed on the received narrowband signal to estimate the direction of arrival. Therefore, as with the first embodiment, when detecting the desired wave, even if an interference wave with a high signal strength is present, the desired wave can be reliably detected, and the direction of arrival estimation processing can also correctly estimate the direction of arrival without being affected by the interference wave with a high signal strength.

In this embodiment, the method of interference wave blanking processing and automation of interference wave blanking processing by parameter selection are the same as in the first embodiment.

Third Embodiment
FIG. 5 is a block diagram showing the configuration of a radio wave emission source monitoring device according to the third embodiment, and FIG. 6 is a flowchart showing the flow of processing by the radio wave emission source monitoring device shown in FIG.

In this embodiment, as shown in FIG. 5, a wideband signal processing unit 14A including interference wave blanking processing and a narrowband signal processing unit 16A including interference wave blanking processing are used, and as shown in FIG. 6, interference wave blanking processing (steps S3 and S11) is performed in each of the wideband and narrowband systems, and then signal detection processing (step S4) and arrival direction estimation processing (step S9) are performed.

As described above, the radio wave emission source monitoring device according to this embodiment performs interference wave blanking processing in the signal processing of the wideband signal system and the narrowband system, and executes signal detection and estimation of the direction of arrival. Therefore, as with the first and second embodiments, when detecting a desired wave, even if an interference wave with a high signal strength is present, the desired wave can be reliably detected, and the direction of arrival estimation process can also correctly estimate the direction of arrival without being affected by the interference wave with a high signal strength.

In this embodiment, the method of interference wave blanking processing and automation of interference wave blanking processing by parameter selection are the same as in the first embodiment.

In the above embodiment, communication from a small unmanned aerial vehicle is assumed as an example of a desired wave, but this is not limited to a small unmanned aerial vehicle. Also, Wi-Fi is assumed as an interference wave, but this is not limited to Wi-Fi. Also, the configurations of each embodiment may be applied independently or in combination with other embodiments.

The present invention is not limited to the above-described embodiments as they are, and in the implementation stage, the components can be modified and embodied without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be deleted from all of the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined.

11...antenna unit, 12...switching unit, 13...broadband receiving unit, 14...broadband signal processing unit, 14A...broadband signal processing unit (including interference wave blanking processing), 15...narrowband receiving unit, 16...narrowband signal processing unit, 16A...narrowband signal processing unit (including interference wave blanking processing), 17...post-processing unit.

Claims (6)

a wideband receiving unit that receives an incoming wave in a wideband;
a narrowband receiver that receives the incoming wave in a narrowband;
a broadband signal processing unit that detects a desired wave signal emitted from a radio wave emission source to be monitored from the signal received by the broadband receiving unit;
a narrowband signal processing unit that detects the desired wave signal from the signal received by the narrowband receiving unit when the desired wave signal is detected by the wideband signal processing unit, and estimates the direction of arrival from the monitored object ,
At least one of the wideband signal processing unit and the narrowband signal processing unit is equipped with blanking processing that detects parts of the signals received in the respective bands that are determined to be interference waves based on requirements for determining that the signals are interference waves with respect to the desired wave signal and removes the parts, and the radio wave emission source monitoring device detects the desired wave signal from the signal from which the interference waves have been removed . The radio wave source monitoring device according to claim 1, wherein the blanking process of the interference wave removes the part of the received signal whose strength exceeds a threshold value. The radio wave source monitoring device according to claim 1, wherein the blanking process of the interference wave counts the signal length of the received signal in the time direction and removes the part that is determined to be an interference wave. The radio wave source monitoring device according to claim 1, wherein the blanking process of the interference wave is performed by analyzing the spectrum of the received signal, and removing the part that is determined to be an interference wave from the analysis results. The radio wave emission source monitoring device according to claim 1, in which the blanking process of the interference wave is automated by switching between multiple parameters and judging the effectiveness of the blanking process through the analysis process for each, changing the parameters related to the blanking process and repeating this process, and selecting the appropriate parameters. Receives incoming waves in a wide band,
receiving the incoming wave in a narrow band;
Detecting a desired wave signal emitted from a radio wave emission source to be monitored from the wideband received signal;
A radio wave monitoring method for estimating a direction of arrival from a monitoring target by detecting a signal of the desired wave from a signal received in the narrow band when the signal of the desired wave is detected from the signal received in the wide band,
A method for monitoring a radio wave emission source, comprising: detecting a portion of a signal received in the wide band or in the narrow band that is determined to be an interference wave based on requirements for determining that the signal is an interference wave with respect to the desired wave signal; removing the portion; and detecting the desired wave signal from the signal from which the interference wave has been removed .

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