WO2023089809A1

WO2023089809A1 - Radio signal observation system, radio signal observation method, and control device

Info

Publication number: WO2023089809A1
Application number: PCT/JP2021/042745
Authority: WO
Inventors: 笑子篠原; 裕介淺井; 泰司鷹取; 純一岩谷; 芳孝清水; 知之山田
Original assignee: 日本電信電話株式会社
Priority date: 2021-11-22
Filing date: 2021-11-22
Publication date: 2023-05-25

Abstract

A radio signal observation system for observing frequency spectra of radio signals comprises: a first spectrum analyzer that observes frequency spectra of radio signals in a first bandwidth; one or multiple second spectrum analyzers that observe frequency spectra of radio signals in a second bandwidth; and a control device that controls the one or more second spectrum analyzers. The control device is configured to execute: processing to calculate, on the basis of information about the frequency spectra observed by the first spectrum analyzer, a specific standby period during which radio signals are not observed by the first spectrum analyzer or a time occupancy is equal to or less than a predetermined value; and processing to select a second bandwidth for each of the one or more second spectrum analyzers so as to perform observation for a specific bandwidth.

Description

Radio signal observation system, radio signal observation method, and control device

The present disclosure relates to technology for observing the frequency spectrum of radio signals.

In recent years, there have been many cases where various wireless communication systems share the same frequency band for operation. For example, in domestic unlicensed bands, it is stipulated that the chassis that performs wireless communication must check the surrounding transmission signal for a certain period of time by carrier sense (or listen-before-talk) before starting transmission. is used as a coexistence technology for

However, when many wireless communication systems coexist in the same frequency band, even if coexistence technology such as carrier sense is used, the frequency utilization efficiency will be lower than when there is no coexistence due to frame collisions. descend. Therefore, in order to maximize frequency utilization efficiency, it is important to appropriately select the channel to be used by grasping the mixture of frequency bands. Also, in order to appropriately select channels when multiple wireless communication systems use the same frequency band, it is possible to observe wireless signals over a wide band using a spectrum analyzer or software defined radio (SDR). It is considered effective (see Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3).

When trying to observe a broadband wireless signal with a spectrum analyzer or SDR, it is necessary to spend more time on one scan than observing a narrowband wireless signal. On the other hand, if a single scan takes a long time, it may not be possible to capture wireless signals with short wireless signal lengths. It is necessary to widen the width (RBW: Resolution Band Width) and execute the scan in a short time.

However, when performing scans many times, it takes a long time to complete the observation because it is necessary to increase the number of scans according to the transmission frequency of the wireless communication system. Further, if the frequency accuracy is lowered, there is a possibility that radio signals transmitted in a narrow band cannot be accurately observed. For example, in heterogeneous wireless systems, there is a maximum bandwidth difference of nearly 40 times in the 920 MHz band, which is difficult to observe accurately at once.

However, using a high-speed, high-dynamic-range spectrum analyzer limits the applicable environment due to cost, availability, and productivity. Non-Patent Document 2 proposes a multi-stage detection method. It will take time. In addition, it is difficult to deal with time-variant frequency usage conditions of a plurality of wireless communication systems.

One object of the present disclosure is to provide a technology capable of appropriately observing broadband radio signals without reducing frequency accuracy. Another object of the present disclosure is to provide a technology capable of flexibly dealing with the case where frequency usage conditions of a plurality of wireless communication systems fluctuate over time.

A first disclosure relates to a radio signal observation system that observes the frequency spectrum of radio signals.
A radio signal observation system according to a first disclosure includes a first spectrum analyzer that observes the frequency spectrum of the radio signal with a first bandwidth, and a second bandwidth narrower than the first bandwidth of the radio signal. One or more second spectrum analyzers that observe the frequency spectrum, and a controller that controls the one or more second spectrum analyzers. Here, the resolution bandwidth of the one or more second spectrum analyzers is set narrower than the resolution bandwidth of the first spectrum analyzer.
The control device performs a process of acquiring spectrum information of the frequency spectrum observed by the first spectrum analyzer, and based on the spectrum information, the radio signal is not observed by the first spectrum analyzer or the radio signal is not observed. a specific band calculation process of calculating a specific band whose time share is equal to or less than a predetermined value; and a selection of selecting the second bandwidth of each of the one or more second spectrum analyzers so as to observe the specific band. is configured to perform a process;

A second disclosure relates to a radio signal observation system having the following characteristics in addition to the radio signal observation system according to the first disclosure.
The selection processing includes the one or more second spectrum analyzers, such that the specific band is frequency-divided or time-divided, and each of the one or more second spectrum analyzers is assigned to the frequency-division or time-division. selecting the second bandwidth for each of .

A third disclosure relates to a radio signal observation system having the following characteristics in addition to the radio signal observation system according to the first or second disclosure.
The control device detects a change in the channel of the radio signal observed by the first spectrum analyzer based on the spectrum information, and in response to the detection of the channel change, the specific band calculation processing and the It is configured to perform selection processing.

A fourth disclosure relates to an unrelated signal observation system according to any one of the first to third disclosures, and further relates to a radio signal observation system having the following features.
The control device is configured to further execute a process of acquiring a frequency band used by a specific wireless terminal. The specific band calculation process includes not using the frequency band to be used as the specific band.

A fifth disclosure relates to a radio signal observation method for observing the frequency spectrum of radio signals using a plurality of spectrum analyzers.
Here, the plurality of spectrum analyzers include a first spectrum analyzer that observes the frequency spectrum of the radio signal with a first bandwidth, and the frequency of the radio signal with a second bandwidth that is narrower than the first bandwidth. and one or more second spectrum analyzers for observing the spectrum. Also, the resolution bandwidth of the first or second spectrum analyzer is set narrower than the resolution bandwidth of the first spectrum analyzer.
A radio signal observation method according to a fifth disclosure acquires spectrum information of the frequency spectrum observed by the first spectrum analyzer, and based on the spectrum information, the radio signal is detected by the first spectrum analyzer. calculating a specific band that is not observed or in which the time occupancy rate of the radio signal is equal to or less than a predetermined value; selecting a width; and

A sixth disclosure relates to a radio signal observation method having the following characteristics in addition to the radio signal observation method according to the fifth disclosure.
Selecting the second bandwidth includes frequency-dividing or time-dividing the specific band, and assigning each of the one or more second spectrum analyzers to the frequency-division or time-division. Selecting the second bandwidth of each of a plurality of second spectrum analyzers.

A seventh disclosure relates to a control device that controls a plurality of spectrum analyzers that observe the frequency spectrum of radio signals.
Here, the plurality of spectrum analyzers include a first spectrum analyzer that observes the frequency spectrum of the radio signal with a first bandwidth, and the frequency of the radio signal with a second bandwidth that is narrower than the first bandwidth. and one or more second spectrum analyzers for observing the spectrum. Also, the resolution bandwidth of the first or second spectrum analyzer is set narrower than the resolution bandwidth of the first spectrum analyzer.
A control device according to a seventh disclosure includes a process of acquiring spectrum information of the frequency spectrum observed by the first spectrum analyzer, and based on the spectrum information, the radio signal is not observed in the first spectrum analyzer. Alternatively, a specific band calculation process for calculating a specific band in which the time occupation ratio of the radio signal is equal to or less than a predetermined value, and the second band of each of the one or more second spectrum analyzers so as to observe the specific band A selection process for selecting a width is performed.

An eighth disclosure relates to a control device having the following characteristics in addition to the control device according to the seventh disclosure.
The selection processing includes the one or more second spectrum analyzers, such that the specific band is frequency-divided or time-divided, and each of the one or more second spectrum analyzers is assigned to the frequency-division or time-division. selecting the second bandwidth for each of .

According to the present disclosure, a first spectrum analyzer observes the frequency spectrum of a broadband, high-time occupancy radio signal, and each of the one or more second spectrum analyzers, in parallel with the first spectrum analyzer, provides a more detailed Observe the frequency spectrum of the radio signal in a narrow band for the specific band that needs to be confirmed. Here, the resolution bandwidth of the second spectrum analyzer is set narrower than the resolution bandwidth of the first spectrum analyzer. As a result, wideband radio signals can be appropriately observed without deteriorating frequency accuracy.

In addition, since each of the one or more second spectrum analyzers does not need to wait for the observation results of the first spectrum analyzer, it is possible to flexibly respond to fluctuations in the frequency usage conditions of a plurality of wireless communication systems. can be done.

1 is a block diagram showing a schematic configuration of a radio signal observation system according to this embodiment; FIG. 1 is a graph showing an example of frequency spectra of radio signals observed by a first spectrum analyzer and one or more second spectrum analyzers; FIG. 4 is a conceptual diagram for explaining an outline of specific band calculation processing; FIG. 10 is a conceptual diagram for explaining an overview of selection processing; It is a block diagram which shows schematic structure of a control apparatus. 4 is a flow chart showing a radio signal observation method realized by the radio signal observation system according to the present embodiment; It is a block diagram which shows schematic structure of the radio signal observation system based on a modification. 4 is a graph showing examples of frequency bands used by specific wireless terminals; 9 is a flowchart showing a radio signal observation method implemented by a radio signal observation system according to a modification;

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, when referring to the number, quantity, amount, range, etc. of each element in the embodiments shown below, unless otherwise specified or the number is clearly specified in principle, the reference The idea according to the present disclosure is not limited to the number. In addition, the configurations and the like described in the embodiments shown below are not necessarily essential to the concept of the present disclosure, unless otherwise specified or clearly specified in principle. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant description thereof will be appropriately simplified or omitted.

1. Overview of Radio Signal Observation System FIG. 1 is a block diagram showing a schematic configuration of a radio signal observation system 10 according to this embodiment. The radio signal observation system 10 includes a first spectrum analyzer 100, one or more second spectrum analyzers 200 (#1-#N), and a controller 300. FIG. Here, N is an integer representing the number of second spectrum analyzers 200 included in the radio signal observation system 10 . However, N=1 may be used. The controller 300 is also communicatively connected to the first spectrum analyzer 100 and one or more second spectrum analyzers 200 . For example, they are electrically connected via a cable. However, information may be transmitted indirectly through a relay device.

Each of the first spectrum analyzer 100 and one or more second spectrum analyzers 200 observes the frequency spectrum of radio signals with a predetermined bandwidth. Hereinafter, the predetermined bandwidth associated with the first spectrum analyzer 100 will be referred to as the "first bandwidth", and the predetermined bandwidth associated with the one or more second spectrum analyzers 200 will be referred to as the "second bandwidth". Here, the second bandwidth may be different for each of the one or more second spectrum analyzers 200 .

Each of the one or more second spectrum analyzers 200 is configured such that the second bandwidth can be selected by the control device 300, which will be described later. For example, each of the one or more second spectrum analyzers 200 acquires a second bandwidth selection request as a control signal output by the control device 300, and updates parameter information defining the second selection width according to the control signal. is configured as In particular, the second bandwidth is selected to be narrower than and contained within the first bandwidth, as described below. That is, the first spectrum analyzer 100 observes the frequency spectrum of the radio signal in a wide band, and the one or more second spectrum analyzers 200 observe the frequency spectrum of the radio signal in a narrow band in parallel with the first spectrum analyzer 100. do.

Note that the first bandwidth may be given as a fixed value, or may be configured so that it can be selected by the control device 300 . Alternatively, an input unit provided in the first spectrum analyzer 100 or an input terminal (switch, touch panel, keyboard, etc.) not shown in FIG. 1 accepts a user's operation, and the first bandwidth is selected according to the operation. It's okay to be.

Each of the first spectrum analyzer 100 and one or a plurality of second spectrum analyzers 200 performs spectrum analysis according to a known sweep method for other parts of the functions described above (algorithms and configurations for observing the frequency spectrum of radio signals). It may be equivalent to the analyzer. That is, the frequency spectrum of the radio signal is observed by executing a scan with a resolution bandwidth (RBW) set for a predetermined bandwidth. It typically includes an attenuator, a local oscillator, a mixer, an IF filter, a detector, and a sweep generator. In particular, each of the first spectrum analyzer 100 and the one or more second spectrum analyzers 200 may be simple spectrum analyzers.

In the radio signal observation system 10 according to this embodiment, the RBW of one or more second spectrum analyzers 200 is set narrower than the RBW of the first spectrum analyzer 100 . That is, the frequency accuracy of one or more second spectrum analyzers 200 is higher than the frequency accuracy of the first spectrum analyzer 100 . The second bandwidth is selected to be narrower than and contained within the first bandwidth, so that the one or more second spectrum analyzers 200 can detect a portion of the first bandwidth. It is possible to observe the frequency spectrum of the radio signal in more detail for the frequency band of .

By the way, in the radio signal observation system 10 according to this embodiment, the second bandwidth is selected to be narrower than the first bandwidth. Therefore, if the RBW of the first spectrum analyzer 100 and the RBW of the one or more second spectrum analyzers 200 are the same, the sweep speed of the first spectrum analyzer 100 is faster than the sweep speed of the one or more second spectrum analyzers 200. slower (the time it takes to scan in the first spectrum analyzer 100 is longer than the time it takes to scan in one or more of the second spectrum analyzers 200). That is, when setting the RBW of the one or more second spectrum analyzers 200 within a range in which the sweep speed of the one or more second spectrum analyzers 200 is not slower than the sweep speed of the first spectrum analyzer 100, the first spectrum analyzer 100 observes the frequency spectrum of broadband, long-occupancy radio signals, and the one or more second spectrum analyzers 200 observes the frequency spectrum of narrow-band, short-occupancy radio signals (eg, short packets).

Note that the RBW of one or more of the second spectrum analyzers may be set as a fixed value, or the control device may 300 may be set. For example, the control device 300 sets the RBW of one or more second spectrum analyzers 200 according to the selected second bandwidth within a range not slower than the sweep speed of the first spectrum analyzer 100 .　

FIG. 2 shows an example of the frequency spectrum of radio signals observed by the first spectrum analyzer 100 and the frequency spectrum of radio signals observed by one or more second spectrum analyzers 200 . FIG. 2 shows graphs of frequency spectra for each of the first spectrum analyzer 100 and one or more second spectrum analyzers 200, with the horizontal axis representing frequency and the vertical axis representing signal strength. Here, for one or a plurality of second spectrum analyzers 200, (A), (B), and (C) show graphs of frequency spectra with different second bandwidths. This is, for example, the frequency spectrum of a radio signal observed on three second spectrum analyzers 200 with mutually different second bandwidths selected. Note that f0, f1, . . . , f10 shown in FIG. 2 indicate frequencies. That is, in FIG. 2, the first bandwidth is f0 or more and f10 or less. In (A), (B), and (C), the respective second bandwidths are divided into band A (f0 or more and f1 or less), band B (f8 or more and f9 or less), and band C (f9 or more and f10 or less). It is an example of the frequency spectrum observed when selected.

As shown in FIG. 2, a first spectrum analyzer 100 observes the frequency spectrum of a radio signal over a wide band, and one or more second spectrum analyzers 200 are arranged in parallel with the first spectrum analyzer 100 over a first bandwidth. Observe the frequency spectrum of the radio signal in the narrow band it contains.

In addition, one or a plurality of second spectrum analyzers 200 observe the frequency spectrum with higher frequency accuracy (RBW narrower than the first spectrum analyzer) than the first spectrum analyzer 100 in the narrow second bandwidth set for each. do. As a result, one or more second spectrum analyzers can observe radio signals that could not be captured by the first spectrum analyzer 100 due to low frequency accuracy, as shown in FIG. 2(A).

The first spectrum analyzer 100 and one or more second spectrum analyzers 200 may be used by a wireless communication terminal to grasp the usage status and interference status of the surrounding frequency band, or the user may It may be used for grasping the usage status and interference status of the surrounding frequency bands. In the former case, for example, the first spectrum analyzer 100 and one or more second spectrum analyzers 200 output observation results of the frequency spectrum of surrounding radio signals to the radio communication terminal. Then, the wireless communication terminal selects a channel according to the usage status and transmits a wireless signal, or grasps the interference status of the wireless signal that is being transmitted. In the latter case, for example, the first spectrum analyzer 100 and the one or more second spectrum analyzers 200 are provided with an input section for accepting user operations and a display section for displaying the frequency spectrum of the observed radio signal. Then, the user sets the first bandwidth and the RBW of the first spectrum analyzer 100 by operating the input section, and by checking the display section, grasps the usage status and interference status of the surrounding frequency bands.

Refer to Figure 1 again. The control device 300 controls one or more second spectrum analyzers 200 . Control by the control device 300 is performed by operating one or more second spectrum analyzers 200 according to the control signal output by the control device 300 . Here, the control signal is generated by a process executed in control device 300 . In particular, the control device 300 executes processing related to selection of the second bandwidth for each of the one or more second spectrum analyzers 200 . The process related to the selection of the second bandwidth executed by the control device 300 is also called "second bandwidth selection process". An outline of the second bandwidth selection process will be described below.

First, in the second bandwidth selection process, information on the frequency spectrum observed by the first spectrum analyzer 100 (hereinafter also referred to as “spectrum information”) is acquired, and based on the spectrum information, the first spectrum analyzer 100 determines whether the radio signal is is not observed or the frequency band in which the time share of the radio signal is equal to or less than a predetermined value is calculated as the specific band (specific band calculation process).

FIG. 3 is a conceptual diagram for explaining the outline of the specific band calculation process. In FIG. 3, (A), (B), (C), (D), and (E) show examples of frequency spectra observed by the first spectrum analyzer 100 in time series in this order. Assume now that the control device 300 acquires spectrum information corresponding to the frequency spectrum shown in FIG. For example, the control device 300 detects a frequency band in which no radio signal is observed or in which the time share of the radio signal is equal to or less than a predetermined value depending on whether the signal strength is equal to or greater than a threshold. In the example shown in FIG. 3, in the frequency band from f0 to f2 and the frequency band from f8 to f10, no radio signal having a signal strength equal to or higher than the threshold is observed. In addition, in the frequency band from f2 to f3, except for (A) and (D), radio signals whose signal strength is equal to or higher than the threshold are observed, and in the frequency band from f6 to f7, only in (C) Radio signals above the threshold have been observed. That is, in the example shown in FIG. 3, the time share of radio signals observed in the frequency band from f2 to f3 is 60%, and the time share of radio signals observed in the frequency band from f6 to f7 is 20%. %. For example, if the predetermined value related to the time share is 50%, in the example shown in FIG. is calculated as a specific band.

It should be noted that the time occupation rate may be given for spectral information acquired at each predetermined cycle, or may be given by recalculating it every time spectral information is acquired.

Next, in the second bandwidth selection process, a second bandwidth is selected for each of the one or more second spectrum analyzers 200 so as to observe a specific band (selection process). Here, the selection processing is performed by frequency-dividing or time-dividing a specific band, and assigning one or more second spectrum analyzers 200 to each of the one or more second spectrum analyzers 200 for the frequency-division or time-division. Select each second bandwidth.

FIG. 4 is a conceptual diagram for explaining the outline of the selection process. In FIG. 4, as in the case described with reference to FIG. 3, it is assumed that the frequency band from f0 to f2, the frequency band from f6 to f7, and the frequency band from f8 to f10 are calculated as specific bands. It is also assumed that the radio signal observation system 10 includes three second spectrum analyzers 200 (#1, #2, #3). In the example shown in FIG. 4, the control device 300, as shown in the upper part of FIG. , band D (from f6 to f7), band E (from f8 to f9), and band F (from f9 to f10). Next, as shown in the lower part of FIG. 4, each band is time-divided and a second bandwidth is selected to be assigned to each of the second spectrum analyzers 200 . For example, for the second spectrum analyzer 200 #1, the control device 300 selects band A as the second bandwidth from time t0 to t1, selects band B as the second bandwidth from time t1 to time t2, and After that, the second bandwidth is selected so as to repeat this.

Note that the control device 300 may be configured to select the second bandwidth by performing only frequency division of a specific band. In this case, the second bandwidth may be selected so as to be equally divided in each of the one or more second spectrum analyzers 200, or the frequency-divided bands may be allocated in descending order of priority. A second bandwidth for each of the second spectrum analyzers 200 may be selected.

The control device 300 outputs a control signal to each of the one or more second spectrum analyzers 200 so as to obtain the second bandwidth selected by the second bandwidth selection process.

By executing the second bandwidth selection process in the control device 300 in this way, the second bandwidth of each of the one or more second spectrum analyzers 200 is selected from the first bandwidth in the first spectrum analyzer 100 as It is included in a specific band in which no radio signal is observed or the time occupation ratio of the radio signal is equal to or less than a predetermined value. That is, according to the radio signal observation system 10 according to the present embodiment, while observing the frequency spectrum of a radio signal with a wide band and a high time occupation ratio with the first spectrum analyzer 100, one or more second spectrum analyzers Each of 200 observes the frequency spectrum of the radio signal in a narrow band for specific bands that require detailed confirmation.

Further, based on the spectrum information, the control device 300 detects a change in the channel of the radio signal observed by the first spectrum analyzer 100, and in response to the detection of the channel change, performs specific band calculation processing and selection processing. configured to run. Here, detection of channel change is performed, for example, by detecting a radio signal in a frequency band in which no radio signal was observed by the first spectrum analyzer 100 . Alternatively, it is performed when the radio signal is no longer detected in the frequency band in which the radio signal was observed by the first spectrum analyzer 100 .

In this way, by performing the specific band calculation process and the selection process in response to the detection of the channel change, unnecessary execution of the second bandwidth selection process can be suppressed. can.

2. Configuration of Control Device The configuration of the control device 300 will be described below. FIG. 5 is a block diagram showing a schematic configuration of the control device 300. As shown in FIG. The control device 300 includes one or more storage devices 310 and one or more processors 320 .

One or more storage devices 310 store a control program 311 executable by one or more processors 320 and control information 312 necessary for processing executed by one or more processors 320 . The one or more storage devices 310 are exemplified by volatile memory, non-volatile memory, HDDs, SSDs, and the like. Information acquired by the control device 300 is stored in one or more storage devices 310 as control information 312 .

The control program 311 includes a program related to execution of the second bandwidth selection process. Examples of the control information 312 include spectrum information acquired from the first spectrum analyzer 100 and parameter information related to the control program 311 (threshold values related to specific band calculation processing, etc.). Note that the control program 311 may be provided through a network.

The one or more processors 320 read the control program 311 and the control information 312 from the one or more storage devices 310 and execute processing according to the control program 311 based on the control information 312 . Thereby, a second bandwidth selection process is performed to generate a control signal for selecting a second bandwidth for each of the one or more second spectrum analyzers 200 .

3. Radio Signal Observation Method Hereinafter, a radio signal observation method implemented by the radio signal observation system 10 according to the present embodiment will be described. FIG. 6 is a flowchart showing a radio signal observation method realized by the radio signal observation system 10 according to this embodiment. The flowchart shown in FIG. 6 is started, for example, after receiving a request to start observation of radio signals by operating the input terminal. Further, each process is executed in each predetermined process cycle.

In step S100, each of the first spectrum analyzer 100 and one or more second spectrum analyzers 200 performs a scan to observe the frequency spectrum of radio signals. Then, control device 300 acquires spectrum information from first spectrum analyzer 100 .

After step S100, proceed to step S200.

At step S200, the control device 300 detects whether or not there is a change in the channel of the radio signal observed by the first spectrum analyzer 100, based on the spectrum information.

If there is a channel change (step S200; Yes), proceed to step S300. If there is no channel change (step S200: No), the process returns to step S100, scans are performed again, and observation is continued.

In step S300, the control device 300 executes specific band calculation processing based on the spectrum information acquired in step S100 to calculate a specific band.

After step S300, proceed to step S400.

In step S400, the control device 300 executes selection processing according to the specific band calculated in step S300, and selects the second bandwidth of each of the one or more second spectrum analyzers 200. Then, control device 300 outputs a control signal to each of one or more second spectrum analyzers 200 so as to achieve the selected second bandwidth.

After step S400, proceed to step S500.

In step S500, each of the first spectrum analyzer 100 and one or more second spectrum analyzers 200 determines whether to end observation. This is determined, for example, by whether or not a request for ending observation has been received by operating the input terminal. If the observation is not to be ended (step S500; No), the process returns to step S100, and the scanning is performed again to continue the observation.

4. Effect As described above, according to the present embodiment, the first spectrum analyzer 100 observes the frequency spectrum of a radio signal with a high time occupation ratio in a wide band, and each of the one or more second spectrum analyzers 200 observes the 1 In parallel with the spectrum analyzer 100, the frequency spectrum of the radio signal is observed in a narrow band for a specific band that requires more detailed confirmation. Here, the RBW of the second spectrum analyzer 200 is narrower than the RBW of the first spectrum analyzer 100 (the frequency accuracy of the second spectrum analyzer 200 is higher than the frequency accuracy of the first spectrum analyzer 100). As a result, wideband radio signals can be properly observed without deteriorating frequency accuracy. Furthermore, it contributes to speeding up the observation of radio signals.

In addition, since each of the one or more second spectrum analyzers 200 does not need to wait for the observation result of the first spectrum analyzer 100, when there is a time variation in the frequency usage of a plurality of wireless communication systems (Fig. 6 (step S200; Yes) (second bandwidth selection process) can be performed flexibly.

5. Modifications The radio signal observation system 10 according to this embodiment may adopt the following modifications. In the following description, portions that overlap with the content described above will be omitted as appropriate.

The control device 300 may be configured so as to acquire the frequency band used by a specific wireless terminal (for example, a wireless LAN terminal) and not use the acquired frequency band as the specific band in the specific band calculation process. Here, the frequency band used can be rephrased as a "channel" used by a specific wireless terminal.

FIG. 7 is a block diagram showing a schematic configuration of the radio signal observation system 10 according to the modification. Compared with the radio signal observation system 10 shown in FIG. 1, the radio signal observation system 10 according to the modification includes a radio communication device 400. In FIG. Control device 300 is connected to wireless communication device 400 so as to be able to communicate with each other.

The wireless communication device 400 is configured to be able to communicate with specific wireless terminals located in the vicinity. Radio communication apparatus 400 acquires a frequency band used by a specific radio terminal through communication. For example, a beacon transmitted by a specific wireless terminal is detected, and a demodulator included in wireless communication apparatus 400 acquires a usable frequency band. Then, the control device 300 acquires the frequency band used by the specific wireless terminal from the wireless communication device 400 .

FIG. 8 shows an example of frequency bands used by specific wireless terminals (wireless terminal A and wireless terminal B). In the example shown in FIG. 8, the frequency band used by wireless terminal A is from near f1 to desired f2, and the frequency band used by wireless terminal B is from near f6 to near f7.

In the specific band calculation process, the control device 300 calculates the specific band so as not to include the available frequency band acquired from the wireless communication device 400 . For example, when the spectrum information is acquired as described in FIG. 3 and the frequency band used as described in FIG. , a frequency band from f0 to f1 and a frequency band from f8 to f10.

FIG. 9 shows a radio signal observation method implemented by the radio signal observation system 10 according to the modification. As shown in FIG. 9, in the radio signal observation method according to the modification, after determining that there is a channel change (step S200; Yes), the control device 300 acquires the frequency band used by a specific radio terminal. (Step S210) is executed. Then, in step S300, control device 300 executes specific band calculation processing based on the spectrum information obtained in step S100 and the frequency band in use obtained in step S210 to calculate a specific band.

By adopting such a modified form, it is possible to grasp in advance the frequency bands in which many wireless terminals exist. Furthermore, although the frequency band does not need to be confirmed because it is used by a large number of wireless terminals, it is a frequency band with a low time occupancy rate and no radio signal is observed by the first spectrum analyzer 100. It is possible to prevent a bandwidth that does not require detailed confirmation from being selected as the second bandwidth.

10 Radio Signal Observation System 100 First Spectrum Analyzer 200 Second Spectrum Analyzer 300 Control Device 310 Storage Device 311 Control Program 312 Control Information 320 Processor 400 Radio Communication Device

Claims

A radio signal observation system for observing the frequency spectrum of radio signals,
a first spectrum analyzer observing the frequency spectrum of the radio signal at a first bandwidth;
one or more second spectrum analyzers observing the frequency spectrum of the radio signal with a second bandwidth narrower than the first bandwidth;
a control device that controls the one or more second spectrum analyzers;
with
The resolution bandwidth of the one or more second spectrum analyzers is set narrower than the resolution bandwidth of the first spectrum analyzer,
The control device is
a process of obtaining spectrum information of the frequency spectrum observed by the first spectrum analyzer;
a specific band calculation process for calculating, based on the spectrum information, a specific band in which the radio signal is not observed in the first spectrum analyzer or in which the time occupation ratio of the radio signal is equal to or less than a predetermined value;
a selection process of selecting the second bandwidth of each of the one or more second spectrum analyzers to observe on the particular band;
A wireless signal observation system, characterized in that it is configured to perform
A wireless signal observation system according to claim 1,
The selection processing includes the one or more second spectrum analyzers, such that the specific band is frequency-divided or time-divided, and each of the one or more second spectrum analyzers is assigned to the frequency-division or time-division. selecting the second bandwidth for each of the wireless signal observation systems.
The radio signal observation system according to claim 1 or claim 2,
The control device detects a change in the channel of the radio signal observed by the first spectrum analyzer based on the spectrum information, and in response to the detection of the channel change, the specific band calculation processing and the A radio signal observation system configured to perform a selection process.
The radio signal observation system according to any one of claims 1 to 3,
The control device is configured to further execute a process of acquiring a frequency band used by a specific wireless terminal,
The radio signal observation system, wherein the specific band calculation process includes not using the frequency band as the specific band.
A radio signal observation method for observing the frequency spectrum of radio signals with a plurality of spectrum analyzers,
The plurality of spectrum analyzers include a first spectrum analyzer that observes the frequency spectrum of the radio signal with a first bandwidth and a second bandwidth that is narrower than the first bandwidth and observes the frequency spectrum of the radio signal. and one or more second spectrum analyzers for
The resolution bandwidth of the one or more second spectrum analyzers is set narrower than the resolution bandwidth of the first spectrum analyzer,
The radio signal observation method includes:
obtaining spectral information of the frequency spectrum observed by the first spectrum analyzer;
calculating, based on the spectrum information, a specific band in which the radio signal is not observed in the first spectrum analyzer or in which the time share of the radio signal is equal to or less than a predetermined value;
selecting the second bandwidth of each of the one or more second spectrum analyzers such that observations are made on the particular band;
A radio signal observation method, comprising:
The radio signal observation method according to claim 5,
Selecting the second bandwidth includes frequency-dividing or time-dividing the specific band, and assigning each of the one or more second spectrum analyzers to the frequency-division or time-division. A radio signal observation method, comprising: selecting the second bandwidth for each of a plurality of second spectrum analyzers.
A control device for controlling a plurality of spectrum analyzers that observe the frequency spectrum of radio signals,
The plurality of spectrum analyzers include a first spectrum analyzer that observes the frequency spectrum of the radio signal with a first bandwidth and a second bandwidth that is narrower than the first bandwidth and observes the frequency spectrum of the radio signal. and one or more second spectrum analyzers for
The resolution bandwidth of the one or more second spectrum analyzers is set narrower than the resolution bandwidth of the first spectrum analyzer,
The control device is
a process of obtaining spectrum information of the frequency spectrum observed by the first spectrum analyzer;
a specific band calculation process for calculating, based on the spectrum information, a specific band in which the radio signal is not observed in the first spectrum analyzer or in which the time occupation ratio of the radio signal is equal to or less than a predetermined value;
a selection process of selecting the second bandwidth of each of the one or more second spectrum analyzers to observe on the particular band;
A control device characterized by performing
A control device according to claim 7,
The selection processing includes the one or more second spectrum analyzers, such that the specific band is frequency-divided or time-divided, and each of the one or more second spectrum analyzers is assigned to the frequency-division or time-division. selecting the second bandwidth for each of .