JP4988898B2 - Radio wave detection system - Google Patents

Description

  The present invention relates to radio wave detection in a communication system and optimization of a communication frequency by the detected radio wave.

  In a wireless LAN communication system, in order to detect an interference radio wave and establish a good communication state, the intensity of the interference radio wave of a plurality of channels is measured and a channel with the highest S / N ratio is selected (for example, Patent Document 1). Or see 2).

JP 2003-244761 A JP 2004-207986 A

  However, in the conventional radio wave detection system, radio waves are detected in a band that matches the bandwidth of the channel to be used, and thus radio waves of communication systems with different modulation methods and bands may not be reliably detected.

  The present invention has been made to solve the above-described problems, and provides a radio wave detection system that can reliably detect various interference radio waves and can establish an optimum communication state. With the goal.

The radio wave detection system according to the present invention according to the present invention includes an RF amplifier for amplifying a reception signal from an antenna, a mixer for converting the reception signal amplified by the RF amplifier into a reception signal in an intermediate frequency band, and changing the frequency. Detection unit having a local oscillator that oscillates a signal, a band-pass filter that can change the bandwidth of a reception signal that passes through, and an A / D conversion circuit that converts the reception signal that has passed through the band-pass filter into a digital reception intensity signal The local oscillator is controlled so as to oscillate a signal whose frequency scans within a plurality of bands having different bandwidths or bands separated by different frequency shifts, and having the different bandwidths. The band pass filter is configured to pass the received signal in a plurality of bands or in discrete bands with different frequency shifts. Gyoshi, and includes a processing unit for outputting a received strength signal for each said zone, a communication unit that selects an optimum band from the reception strength signal to the communication of each said band received from the processing unit, and the processing unit Is a radio wave that scans a frequency in a plurality of bands obtained by dividing a predetermined frequency band for detecting the radio wave intensity by a predetermined first bandwidth at least for each measurement cycle. A step of measuring the strength, a step of scanning the frequency in a plurality of bands obtained by dividing the second bandwidth different from the first bandwidth and detecting the radio wave strength, and a first frequency deviation within the frequency band. Scanning the frequency in a plurality of separated and separated bands to detect the radio wave intensity, and scanning the frequency in a plurality of separated and separated second frequency deviation bands different from the first frequency deviation within the frequency band. Step to detect the signal strength When executes a step of calculating a maximum field intensity for each band from the radio wave intensity detected by the plurality of measurement cycles including the radio field intensity detected in the measurement cycle, the.

  The radio wave detection system according to the present invention can reliably detect interference radio waves in a band to be used by radio wave detection by a plurality of bands and optimized frequency scanning, and selects an optimal communication band, Communication state can be secured.

1 is a block diagram of a radio wave detection system according to Embodiment 1 of the present invention. It is a conceptual diagram which scans a frequency with the some scanning pattern which the process part which concerns on Embodiment 1 of this invention produces | generates, and detects a field intensity. It is a flowchart which shows the operation | movement which calculates | requires the maximum value of the electromagnetic wave strength for every zone | band performed by the process part which concerns on Embodiment 1 of this invention. It is a conceptual diagram which scans a frequency with another several scanning pattern which a process part produces | generates, and detects a field intensity. It is a flowchart which shows the operation | movement of the first half which calculates | requires the maximum value of the electromagnetic wave intensity for every band performed by the process part which concerns on Embodiment 2 of this invention. It is a flowchart which shows the operation | movement of the second half which calculates | requires the maximum value of the electromagnetic wave intensity for every zone performed by the process part which concerns on Embodiment 2 of this invention.

Hereinafter, preferred embodiments of a radio wave detection system of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram of a radio wave detection system according to Embodiment 1 of the present invention.
As shown in FIG. 1, the radio wave detection system according to Embodiment 1 of the present invention obtains and outputs a received intensity signal 210 from a received signal input from the antenna 1, and is input from the detecting unit 10. Processing unit 20 that processes reception intensity signal 210 to output frequency control signal 220, bandwidth control signal 230, and reception intensity signal 240 for each band, and reception intensity signal 240 for each band that is input from processing unit 20 is optimal for communication. And a communication unit 30 for selecting an appropriate band.

  The detection unit 10 includes an RF amplifier 110 that amplifies the reception signal input from the antenna 1, a mixer 120 that converts the reception signal into a reception signal in the intermediate frequency band, and a local unit that changes the oscillation frequency under the control of the processing unit 20. An oscillator 130, a band-pass filter 140 that changes the frequency width (hereinafter referred to as a bandwidth) of the received signal in the intermediate frequency band under the control of the processing unit 20, and the received signal that has passed through the band-pass filter 140 is digitally converted. And an A / D conversion circuit 150.

Next, the operation of the radio wave detection system according to Embodiment 1 of the present invention will be described.
The RF amplifier 110 amplifies the received signal from the antenna 1 to a level necessary for detection and outputs the amplified signal to the mixer 120.
The mixer 120 converts the received signal from the RF amplifier 110 into a received signal in the intermediate frequency band using the signal from the local oscillator 130 and outputs the received signal to the band pass filter 140.
The band pass filter 140 limits the band of the received signal converted into the intermediate frequency band signal based on the bandwidth control signal 230 from the processing unit 20 and then outputs the band signal to the A / D conversion circuit 150.
The A / D conversion circuit 150 outputs to the processing unit 20 a received intensity signal 210 obtained by digitally converting the band-limited received signal.

The processing unit 20 outputs a frequency control signal 220 to the local oscillator 130 in order to sequentially detect the radio wave intensity from the lower limit value to the upper limit value of the frequency in the preset frequency band.
Also, by outputting a bandwidth control signal 230 for designating the bandwidth of the reception intensity signal 210 to the band pass filter 140, a reception intensity signal in the set band can be obtained. It should be noted that a plurality of scanning patterns can be provided by changing the frequency changing step at the time of frequency scanning while switching the bandwidth to be scanned when the radio wave intensity is detected. The reception intensity signal 240 for each frequency band within the detection frequency range obtained by the above processing is output to the communication unit 30.

  The communication unit 30 is a communication unit that performs wireless communication such as a wireless LAN, and selects a band in which there is no interfering radio wave within a detected frequency band set based on the reception intensity signal 240 for each band received from the processing unit 20. By doing so, the frequency used for communication is changed. At this time, the detection result of the radio wave intensity by the plural scanning patterns by the plural bands at the time of radio wave detection and the plural frequency steps in the reception intensity signal 240 for each band received from the processing unit 20 is integrated, and the radio wave intensity of each frequency band is obtained. judge.

FIG. 2 is a conceptual diagram in which the radio wave intensity is detected by scanning the frequency with a plurality of scanning patterns generated by the processing unit 20.
It has a plurality of measurement modes in which the reception band and the intensity measurement time are set in accordance with the burst wave of the communication method that is assumed to be detected when the radio field intensity is measured.
In the first measurement mode, a predetermined first bandwidth X ₁ is specified, the frequency band for detecting the radio wave intensity is divided into a plurality of bands by the first bandwidth X ₁ , and the center frequency is sequentially increased from the band having the smallest center frequency. The radio wave intensity is detected by changing the frequency within the band while shifting the largest band.
In the second measurement mode, a predetermined second bandwidth X ₂ different from the first bandwidth X ₁ is specified, the frequency band for detecting the radio wave intensity is divided into a plurality of bands by the second bandwidth X ₂ , and the center frequency The radio wave intensity is detected by changing the frequency within the band while sequentially shifting the band of the largest center frequency from the smallest band.
In the third measurement mode, the predetermined third bandwidth X ₃ , the smallest first frequency H _{1 in} the assumed communication method, and the first frequency shift Y ₁ in the assumed communication method are designated, and the first frequency H the third center frequency from the band of the band width X ₃ having a center frequency of ₁ is the first frequency shift amount Y ₁ sequentially increased, most central frequency of the radio wave intensity by changing the frequency of the band while transferred to a large band To detect.
In the fourth measurement mode, a predetermined fourth bandwidth X ₄ , the smallest second frequency H _{2 in} the assumed communication method, the second frequency shift Y ₂ in the assumed communication method are designated, and the second frequency H the center frequency ₂ from the fourth band bandwidth X ₄ having a center frequency and a second frequency shift amount Y ₂ sequentially increased, most central frequency of the radio wave intensity by changing the frequency of the band while transferred to a large band To detect.

  At this time, the detection of the radio field intensity in the first measurement mode and the second measurement mode is performed by setting the optimum bandwidth and detection time for the modulation content of the assumed communication method, and in the third measurement mode and the fourth measurement mode. The detection of the radio field strength of the multiple frequency ranges to be detected by setting the optimal bandwidth, detection time and frequency for the detection assuming the modulation content and frequency of the communication method that changes the assumed frequency sequentially and communicates Corresponds to the communication method.

  Although the concept of radio wave intensity detection in the case of setting four types of measurement modes from the first measurement mode to the fourth measurement mode has been shown, a mode in which further measurement is performed when there are many assumed communication methods within the frequency band to be detected It becomes possible to correspond to many communication systems by adding.

FIG. 3 is a flowchart illustrating an operation for obtaining the maximum value of the radio wave intensity for each band, which is executed by the processing unit 20.
First, in step 101, by dividing a frequency band for detecting a radio wave in a predetermined first bandwidth X ₁ to produce a plurality of bands, the center frequency of the band is measured field intensity of the smallest bandwidth.
Next, at step 102, the value of the radio wave intensity detected at step 101 for A millisecond is stored.
Next, in step 103, the radio field intensity of the band with the next highest center frequency is measured.
Next, at step 104, the value of the radio wave intensity detected at step 103 for A millisecond is stored.

In step 105, it is determined whether or not the center frequency of the band in which the radio wave intensity is measured is the highest. If the center frequency of the band in which the radio wave intensity is measured is not the highest, the process returns to step 103 and the center of the band in which the radio wave intensity is measured. When the frequency is the highest, the process proceeds to step 109.
In step 109, to save the radio wave intensity measured values at a plurality of bands obtained by dividing a frequency band for detecting a radio wave in a first bandwidth X ₁ as data of the first measurement mode, the process proceeds to the measurement of the next measurement mode .

After the end of the first measurement mode, the mode shifts to the second measurement mode.
In step 201, by dividing a frequency band for detecting a radio wave in a predetermined second bandwidth X ₂ to produce a plurality of bands, the center frequency of the band is measured field intensity of the smallest bandwidth.
Next, in step 202, the value of the radio field intensity detected in step 201 for B milliseconds is stored.
Next, in step 203, the radio field intensity of the band with the next highest center frequency is measured.
Next, in step 204, the value of the radio wave intensity detected in step 203 for B milliseconds is stored.

In step 205, it is determined whether or not the center frequency of the band in which the radio wave intensity is measured is the highest. If the center frequency of the band in which the radio wave intensity is measured is not the highest, the process returns to step 203 and the center of the band in which the radio wave intensity is measured. When the frequency is the highest, the process proceeds to step 209.
In step 209, to save the radio wave intensity measured value of the frequency band to detect radio waves in a plurality of bands divided by the second bandwidth X ₂ as data of the second measurement mode, the process proceeds to the measurement of the next measurement mode .

After the measurement in the second measurement mode is completed, the process proceeds to the measurement in the third measurement mode.
In step 301, a first frequency H ₁ is the lower limit of the center frequency, the first frequency H ₁ generates a plurality of center frequencies of the first frequency shift amount Y ₁ as increment, in the frequency band for detecting the radio wave most large center frequency and the upper limit value of the center frequency, the center frequency is a third bandwidth X ₃ at the lower limit value measures the radio wave intensity by scanning the frequency within the band of the bandwidth.
Next, in step 302, the value of the radio wave intensity detected in step 301 for C milliseconds is stored.
Next, in step 303, the center frequency to the first frequency shift amount Y ₁ increases, measures the radio wave intensity by scanning the frequency within the band of the bandwidth X ₃ at its center frequency.
Next, in step 304, the value of the radio wave intensity detected in step 303 for C milliseconds is stored.

In step 305, it is determined whether or not the center frequency of the band whose radio field intensity is measured in step 303 has reached the upper limit value of the center frequency. If the center frequency has not reached the upper limit value, the process returns to step 303, When the upper limit is reached, the process proceeds to step 309.
In step 309, the center frequency to save the radio wave intensity measured value of a band of the first frequency shift amount Y ₁ different bandwidths X ₃ as the data of the third measurement mode, the process proceeds to the measurement of the next measurement mode.

After the measurement in the third measurement mode is completed, the measurement shifts to the measurement in the fourth measurement mode.
First, in step 401, the second frequency H ₂ and the lower limit value of the center frequency, the frequency band to the second frequency H ₂ to produce a plurality of center frequencies of the second frequency shift amount Y ₂ as an incremental, detects the radio wave the greatest center frequency of the inner and upper limit of the center frequency, the center frequency fourth band width X ₄ at the lower limit value measures the radio wave intensity by scanning the frequency within the band of the bandwidth.
Next, in step 402, the value of the radio wave intensity detected in step 401 for D milliseconds is stored.
Next, in step 403, the center frequency second frequency shift amount Y ₂ is increased, and measures the radio wave intensity by scanning the frequency within the band of the bandwidth X ₄ at the center frequency thereof.
Next, in Step 404, the value of the radio wave intensity detected in Step 403 for D milliseconds is stored.

In step 405, it is determined whether or not the center frequency of the band whose radio field intensity is measured in step 403 has reached the upper limit value of the center frequency. If the center frequency has not reached the upper limit value, the process returns to step 403, and the center frequency is When the upper limit is reached, the process proceeds to step 409.
In step 409, the center frequency to save radio wave intensity measured value of a band of the second frequency shift amount Y ₂ different bandwidths X ₄ as data of the fourth measurement mode.

In step 501, the past measurement data is deleted from the measurement data in the first measurement mode to the fourth measurement mode in the past Z cycle, and the remaining measurement data is recorded as past data for one cycle for each cycle. Add cycle measurement data. As a result, the measurement data of the first measurement mode to the fourth measurement mode for the Z period that includes the measurement data of the current period and goes back to the past are stored.
Next, in step 502, the maximum value and the average value for each band are calculated from the data for the past Z cycles from the first measurement mode to the fourth measurement mode.
Next, in step 503, the maximum value and the average value for each band for the past Z periods in the first measurement mode to the fourth measurement mode are output to the communication unit 30.

In the radio wave detection system according to the first embodiment of the present invention, the radio wave intensity is respectively divided at frequencies scanned by a plurality of bands by dividing a frequency band to be used by different bandwidths or frequencies of a plurality of assumed communication methods. Since it is detected, it is possible to reliably detect the interference radio wave within the frequency band to be used.
In addition, since a band not including the frequency of the interference radio wave is selected as the communication band, a good communication state can be ensured.

  In the third measurement mode and the fourth measurement mode, the radio wave intensity is measured in one processing cycle for all frequencies to be detected between the frequency lower limit value and the frequency upper limit value. As shown, the radio wave intensity may be measured for one frequency that is different for each processing cycle.

Embodiment 2. FIG.
The radio wave detection system according to the second embodiment of the present invention is different from the radio wave detection system according to the first embodiment of the present invention in that the processing unit is the same, and the other parts are the same. Is omitted.
5 and 6 are flowcharts showing an operation for obtaining the maximum value of the radio wave intensity for each band, which is executed by the processing unit according to Embodiment 2 of the present invention.
First, in step 101, by dividing a frequency band for detecting a radio wave in a predetermined first bandwidth X ₁ to produce a plurality of bands, the center frequency of the band is measured field intensity of the smallest bandwidth.
Next, at step 102, the value of the radio wave intensity detected at step 101 for A millisecond is stored.
Next, in step 103, the radio field intensity of the band with the next highest center frequency is measured.
Next, at step 104, the value of the radio wave intensity detected at step 103 for A millisecond is stored.

In step 105, it is determined whether or not the center frequency of the band in which the radio wave intensity is measured is the highest. If the center frequency of the band in which the radio wave intensity is measured is not the highest, the process proceeds to step 106, and the center of the band in which the radio wave intensity is measured. When the frequency is the highest, the process proceeds to step 109.
In step 106, it is determined whether the center frequency of the band in which the radio field intensity is measured is an intermittent measurement frequency, and whether the measurement has been skipped continuously for the past L periods. Returning to step 103, if the number of skips in measurement is equal to or less than the past L cycles, the process proceeds to step 107.
In step 107, it is determined whether or not the measured value is continuously greater than or equal to the past N cycles at the frequency, and if the measured value is greater than or equal to N cycles and is greater than or equal to the intensity value MdBm, the process proceeds to step 108. If the measured value is less than the intensity value MdBm for N cycles or more, the process returns to step 103.

In step 108, it records the center frequency of the band that the measurement as an intermittent measurement frequency, skip measurement of this cycle, and change the center frequency to the first bandwidth X ₁ minute higher frequency returns to step 105. The measurement of the frequency at which the radio field intensity equal to or higher than the predetermined radio field intensity is continuously detected by the processing from step 106 to step 108 is skipped by L cycles, and measurement of other frequencies is performed with priority.
In step 109, to save the radio wave intensity measured values at a plurality of bands obtained by dividing a frequency band for detecting a radio wave in a first bandwidth X ₁ as data of the first measurement mode, the process proceeds to the measurement of the next measurement mode .

After the end of the first measurement mode, the mode shifts to the second measurement mode.
In step 201, by dividing a frequency band for detecting a radio wave in a predetermined second bandwidth X ₂ to produce a plurality of bands, the center frequency of the band is measured field intensity of the smallest bandwidth.
Next, in step 202, the value of the radio field intensity detected in step 201 for B milliseconds is stored.
Next, in step 203, the radio field intensity of the band with the next highest center frequency is measured.
Next, in step 204, the value of the radio wave intensity detected in step 203 for B milliseconds is stored.

In step 205, it is determined whether or not the center frequency of the band in which the radio wave intensity is measured is the highest. If the center frequency of the band in which the radio wave intensity is measured is not the highest, the process returns to step 206 and the center of the band in which the radio wave intensity is measured. When the frequency is the highest, the process proceeds to step 209.
In step 206, it is determined whether or not the center frequency of the band in which the radio field intensity is measured is an intermittent measurement frequency, and the measurement has been skipped for the past L periods. If the measurement has been skipped for the past L periods, Returning to step 203, if the number of skips in measurement is equal to or less than the past L cycles, the process proceeds to step 207.
In step 207, it is determined whether or not the measured value is equal to or greater than the intensity value MdBm at the frequency in the past N cycles. If the measured value is equal to or greater than the intensity value MdBm in N cycles, the process proceeds to step 208. If the measured value is less than the intensity value MdBm for N cycles or more, the process returns to step 203.

In step 208, it records the center frequency of the band that the measurement as an intermittent measurement frequency, skip measurement of this cycle, and change the center frequency to the first bandwidth X ₂ minutes high frequency returns to step 205. The measurement of the frequency at which the radio wave intensity equal to or higher than the predetermined radio wave intensity is continuously detected by the processing from step 206 to step 208 is skipped by L cycles, and the measurement of other frequencies is performed with priority.
In step 209, to save the radio wave intensity measured value of the frequency band to detect radio waves in a plurality of bands divided by the second bandwidth X ₂ as data of the second measurement mode, the process proceeds to the measurement of the next measurement mode .

After the measurement in the second measurement mode is completed, the process proceeds to the measurement in the third measurement mode.
In step 301, a first frequency H ₁ is the lower limit of the center frequency, the first frequency H ₁ generates a plurality of center frequencies of the first frequency shift amount Y ₁ as increment, in the frequency band for detecting the radio wave most large center frequency and the upper limit value of the center frequency, the center frequency is a third bandwidth X ₃ at the lower limit value measures the radio wave intensity by scanning the frequency within the band of the bandwidth.
Next, in step 302, the value of the radio wave intensity detected in step 301 for C milliseconds is stored.
Next, in step 303, the center frequency to the first frequency shift amount Y ₁ increases, measures the radio wave intensity by scanning the frequency within the band of the bandwidth X ₃ at its center frequency.
Next, in step 304, the value of the radio wave intensity detected in step 303 for C milliseconds is stored.

In step 305, it is determined whether or not the center frequency of the band whose radio field intensity is measured in step 303 has reached the upper limit value of the center frequency. If the center frequency has not reached the upper limit value, the process proceeds to step 306, where the center frequency is When the upper limit is reached, the process proceeds to step 309.
In step 306, it is determined whether the band at which the radio field intensity is measured has an intermittent measurement frequency at the center frequency and the measurement has been skipped for the past L periods. If the measurement has been skipped for the past L periods, Returning to step 303, if the number of skipped measurements is less than or equal to the past L period, the process proceeds to step 307.
In step 307, it is determined whether or not the measured value is continuously greater than or equal to the intensity value MdBm at the frequency in the past N cycles. If the measured value is continuously greater than or equal to N cycles and the intensity value MdBm, the process proceeds to step 308. If the measured value is less than the intensity value MdBm for N cycles or more, the process returns to step 303.

In step 308, it records the center frequency of the band that the measurement as an intermittent measurement frequency, skip measurement of this cycle, and change the center frequency to the first frequency shift amount Y ₁ large central frequency returns to step 305. The measurement of the frequency at which the radio wave intensity equal to or higher than the predetermined radio wave intensity is continuously detected by the processing from step 306 to step 308 is skipped by L cycles, and the measurement of other frequencies is performed with priority.
In step 309, the center frequency to save the radio wave intensity measured value of a band of the first frequency shift amount Y ₁ different bandwidths X ₃ as the data of the third measurement mode, the process proceeds to the measurement of the next measurement mode.

After the measurement in the third measurement mode is completed, the measurement shifts to the measurement in the fourth measurement mode.
First, in step 401, the second frequency H ₂ and the lower limit value of the center frequency, the frequency band to the second frequency H ₂ to produce a plurality of center frequencies of the second frequency shift amount Y ₂ as an incremental, detects the radio wave the greatest center frequency of the inner and upper limit of the center frequency, the center frequency fourth band width X ₄ at the lower limit value measures the radio wave intensity by scanning the frequency within the band of the bandwidth.
Next, in step 402, the value of the radio wave intensity detected in step 401 for D milliseconds is stored.
Next, in step 403, the center frequency second frequency shift amount Y ₂ is increased, and measures the radio wave intensity by scanning the frequency within the band of the bandwidth X ₄ at the center frequency thereof.
Next, in Step 404, the value of the radio wave intensity detected in Step 403 for D milliseconds is stored.

In step 405, it is determined whether or not the center frequency of the band whose radio field intensity is measured in step 403 has reached the upper limit of the center frequency. If the center frequency has not reached the upper limit, the process proceeds to step 406, where the center frequency is When the upper limit is reached, the process proceeds to step 409.
In step 406, it is determined whether the band whose radio field intensity has been measured has an intermittent measurement frequency at the center frequency and the measurement has been skipped for the past L periods. If the measurement has been skipped for the past L periods, Returning to step 403, if the number of skips in measurement is less than or equal to the past L period, the process proceeds to step 407.
In step 407, it is determined whether or not the measured value is continuously greater than or equal to the intensity value MdBm at the frequency in the past N cycles. If the measured value is continuously greater than or equal to N cycles and the intensity value MdBm, the process proceeds to step 408. If the measured value is less than the intensity value MdBm for N cycles or more, the process returns to step 403.

In step 408, it records the center frequency of the band that the measurement as an intermittent measurement frequency, skip measurement of this cycle, and change the center frequency to the larger center frequency by the second frequency shift amount Y ₂ returns to step 405. The measurement of the frequency at which the radio wave intensity equal to or higher than the predetermined radio wave intensity is continuously detected by the processing from step 406 to step 408 is skipped by L cycles and the measurement of other frequencies is performed with priority.
In step 409, the center frequency to save radio wave intensity measured value of a band of the second frequency shift amount Y ₂ different bandwidths X ₄ as data of the fourth measurement mode.

In step 501, the past measurement data is deleted from the first measurement mode to the fourth measurement mode in the past Z cycle, and the remaining measurement data is re-recorded as one cycle of past data for each cycle. Add measurement data of current cycle. As a result, the measurement data of the first measurement mode to the fourth measurement mode for the Z period that includes the measurement data of the current period and goes back to the past are stored.
Next, in step 502, the maximum value and the average value for each band are calculated from the data for the past Z cycles from the first measurement mode to the fourth measurement mode.
Next, in step 503, the maximum value and the average value for each band for the past Z periods in the first measurement mode to the fourth measurement mode are output to the communication unit 30.

  In the radio wave detection system according to the second embodiment of the present invention, when the same frequency band is higher than a preset intensity for a set period or more, the period is not measured for the specified period. Therefore, the radio wave intensity can be detected efficiently.

  1 antenna, 10 detection unit, 20 processing unit, 30 communication unit, 110 RF amplifier, 120 mixer, 130 local oscillator, 140 band pass filter, 150 A / D conversion circuit, 210 reception intensity signal, 220 frequency control signal, 230 band Width control signal, 240 received signal for each band.

Claims (5)

RF amplifier that amplifies the received signal from the antenna, mixer that converts the received signal amplified by the RF amplifier to a received signal in the intermediate frequency band, a local oscillator that oscillates the signal by changing the frequency, and the band of the received signal that passes through In a radio wave detection system comprising a bandpass filter whose width can be changed, and a detection unit having an A / D conversion circuit that converts a reception signal that has passed through the bandpass filter into a digital reception intensity signal.
The local oscillator is controlled to oscillate a signal whose frequency scans within a plurality of bands of different bandwidths or bands separated by different frequency shifts, and a plurality of bands of the different bandwidths or the different frequencies A processing unit that controls the band-pass filter so as to pass a received signal in a band that is discrete due to deviation, and that outputs a received intensity signal for each band;
A communication unit that selects an optimum band for communication from the received intensity signal for each of the bands received from the processing unit;
Equipped with a,
The processing unit is at least
At each measurement cycle, the radio wave intensity is measured by scanning the frequency in a plurality of bands obtained by dividing a predetermined frequency band for detecting the radio wave intensity by a predetermined first bandwidth. Steps,
Scanning the frequency in a plurality of bands obtained by dividing the second bandwidth different from the first bandwidth to detect the radio field intensity;
Scanning the frequency in a plurality of bands separated and separated by the first frequency shift within the frequency band to detect the radio field intensity;
Scanning the frequency in a plurality of bands separated and separated by a second frequency shift different from the first frequency shift within the frequency band, and detecting the radio field intensity;
Calculating the maximum radio field strength for each band from the radio field intensity detected in a plurality of measurement periods including the radio field intensity detected in the measurement period;
A radio wave detection system characterized by executing .   The radio wave detection system according to claim 1, wherein the communication unit selects an optimum band for performing wireless LAN communication. The processing unit
In the case where the same band is higher than a preset intensity for a preset period or more from the radio field intensity detected in a plurality of measurement periods, a step is performed in which measurement is not performed in the band during the designated period. The radio wave detection system according to claim 1 or 2. Claims 1, characterized in that it comprises a plurality of measurement modes and reception band and intensity measurement time is set to match the burst wave communication method assuming a detection When measuring the radio field intensity to claim 3 The radio wave detection system according to any one of the above. RF amplifier that amplifies the received signal from the antenna, mixer that converts the received signal amplified by the RF amplifier to a received signal in the intermediate frequency band, a local oscillator that oscillates the signal by changing the frequency, and the band of the received signal that passes through A radio wave detection method in a radio wave detection system comprising: a band pass filter capable of changing a width; and a detection unit having an A / D conversion circuit that converts a received signal that has passed through the band pass filter into a digital received intensity signal,
The local oscillator is controlled to oscillate a signal whose frequency scans within a plurality of bands of different bandwidths or bands separated by different frequency shifts, and a plurality of bands of the different bandwidths or the different frequencies A processing step of controlling the band pass filter so as to pass a received signal in a band that is discrete due to a deviation, and outputting a received intensity signal for each band;
A communication step of selecting an optimal band for communication from the received intensity signal for each of the bands received from the processing unit;
With
The above processing steps are at least:
At each measurement cycle, the radio wave intensity is measured by scanning the frequency in a plurality of bands obtained by dividing a predetermined frequency band for detecting the radio wave intensity by a predetermined first bandwidth. Steps,
Scanning the frequency in a plurality of bands obtained by dividing the second bandwidth different from the first bandwidth to detect the radio field intensity;
Scanning the frequency in a plurality of bands separated and separated by the first frequency shift within the frequency band to detect the radio field intensity;
Scanning the frequency in a plurality of bands separated and separated by a second frequency shift different from the first frequency shift within the frequency band, and detecting the radio field intensity;
Calculating the maximum radio field strength for each band from the radio field intensity detected in a plurality of measurement periods including the radio field intensity detected in the measurement period;
A radio wave detection method comprising:

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