JP2011257311A - Measurement instrument, measurement method, and measurement program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate evaluation based on statistics of an amplitude by calculating statistics of only a component of amplitude variation due to a factor to be evaluated.SOLUTION: A measurement instrument includes: input means for entering an amplitude of an electromagnetic wave to be transmitted; amplitude variation correction means which performs correction to reduce a specific amplitude variation from the input amplitude; amplitude statistic calculation means which calculates statistics of the corrected amplitude; and output means for outputting statistics of the amplitude obtained by the calculation.

Description

The present invention relates to a technique for measuring an electromagnetic environment.

  Various proposals have been made as methods for measuring the environment of electromagnetic waves. For example, Patent Document 1 proposes a measuring apparatus that measures an electromagnetic environment such as an amplitude probability distribution, estimates communication quality from the measurement result, and classifies the electromagnetic environment at an observation location. Patent Document 2 proposes a measuring device for obtaining a statistical value of noise amplitude data in order to evaluate the bit error rate characteristics. Patent Document 3 proposes a radio station that measures the spectrum and direction of arrival of electromagnetic waves and transmits measurement results, and a remote monitoring system that constantly monitors electromagnetic waves at a center station that remotely operates them. Here, when evaluating electromagnetic interference or electromagnetic environment based on amplitude statistics such as amplitude probability distribution, if electromagnetic interference or noise occurs, the amplitude will fluctuate and the amplitude statistics will change. Electromagnetic interference and the like can be evaluated by changing the amplitude statistic.

JP 09-218230 A JP 2007-010490 A JP 2004-015202 A

  However, when an attempt is made to evaluate electromagnetic interference or electromagnetic environment based on amplitude statistics such as an amplitude probability distribution, amplitude fluctuations may also occur due to causes other than electromagnetic interference or noise, such as fading. That is, the fluctuation of the amplitude of the electromagnetic wave also changes due to a factor (for example, fading) other than the change in amplitude due to the factor that should be evaluated originally. As described above, since the amplitude statistic also changes due to changes other than the factors to be evaluated, there is a problem that it is difficult to evaluate electromagnetic interference in the amplitude statistic. In calculating the amplitude statistic, a filter has been applied to the waveform in order to obtain a specific frequency. However, adjusting the amplitude, which is the size of the waveform, changes the statistic. It was not done to give.

  The present invention has been made in view of such a situation. A measuring apparatus, a measuring method, and a measuring program for calculating a statistic of only an amplitude fluctuation component due to a factor to be evaluated and facilitating an evaluation based on the amplitude statistic. I will provide a.

  In order to solve the above-described problem, the present invention is corrected by an input unit that inputs the amplitude of an electromagnetic wave to be transmitted, an amplitude variation correction unit that corrects a specific amplitude variation from the input amplitude, and a correction. A measurement apparatus comprising: an amplitude statistic calculating unit that calculates an amplitude statistic based on an amplitude; and an output unit that outputs an amplitude statistic obtained by the calculation.

  The present invention also provides a condition input means for inputting conditions for measuring the electromagnetic wave to be transmitted, an input means for inputting the amplitude of the electromagnetic wave according to the condition input by the condition input means, and a specific factor based on the input amplitude. Amplitude fluctuation correcting means for performing correction for reducing amplitude fluctuation, amplitude statistic calculating means for calculating amplitude statistic based on the corrected amplitude, and evaluation based on the amplitude statistic obtained by calculation are determined. A measurement apparatus comprising: an evaluation unit; and an output unit that outputs an evaluation result.

  The present invention also includes a step of inputting an amplitude of an electromagnetic wave to be transmitted, a step of performing a correction for reducing a specific amplitude fluctuation from the input amplitude, and calculating an amplitude statistic based on the corrected amplitude. And a step of outputting an amplitude statistic obtained by calculation.

  The present invention also includes a step of inputting conditions for measuring the electromagnetic wave to be transmitted, a step of inputting the amplitude of the electromagnetic wave according to the condition input by the condition input means, and an amplitude variation of a specific factor from the input amplitude. Performing a reduction correction, calculating an amplitude statistic based on the corrected amplitude, determining an evaluation based on the amplitude statistic obtained by the calculation, and outputting an evaluation result And a measuring method characterized by comprising:

  The present invention also includes a step of inputting the amplitude of an electromagnetic wave to be transmitted to a computer, a step of performing correction to reduce a specific amplitude fluctuation from the input amplitude, and an amplitude statistic based on the corrected amplitude. And a step of outputting a statistic of amplitude obtained by the calculation.

  The present invention also includes a step of inputting a measurement condition of an electromagnetic wave to be transmitted to a computer, a step of inputting the amplitude of the electromagnetic wave according to the condition input by the condition input means, and a specific factor based on the input amplitude. A step of performing correction to reduce amplitude fluctuation, a step of calculating an amplitude statistic based on the corrected amplitude, a step of determining an evaluation based on the amplitude statistic obtained by the calculation, and outputting an evaluation result And a measuring program for executing the step.

  As described above, according to the present invention, by calculating an amplitude statistic after reducing a specific amplitude variation, a change in the statistic due to a factor that should not be evaluated is reduced, and an original amplitude statistic is calculated. Can be evaluated by changes in By correcting the amplitude, it becomes possible to calculate the statistic only for the component of the amplitude variation due to the factor to be evaluated, and the evaluation based on the amplitude statistic can be facilitated.

It is a block diagram showing the structure of the measuring apparatus by the 1st Embodiment of this invention. It is a block diagram showing the structure of the input means by the 1st Embodiment of this invention. It is a block diagram showing the structure of the amplitude fluctuation correction means by the 1st Embodiment of this invention. It is a block diagram showing the structure of the amplitude fluctuation correction means by the 1st Embodiment of this invention. It is a block diagram showing the structure of the amplitude statistic calculation means by the 1st Embodiment of this invention. It is a flowchart which shows the operation example of the measuring apparatus by the 1st Embodiment of this invention. It is a block diagram showing the structure of the measuring apparatus by the 2nd Embodiment of this invention. It is a block diagram showing the structure of the amplitude fluctuation correction means by the 2nd Embodiment of this invention. It is a block diagram showing the structure of the evaluation means by the 2nd Embodiment of this invention. It is a flowchart which shows the operation example of the measuring apparatus by the 2nd Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a configuration of a measuring apparatus 100 according to the first embodiment of the present invention. The measuring apparatus 100 according to the present embodiment includes an input unit 101, an amplitude variation correction unit 102, an amplitude statistic calculation unit 103, and an output unit 104.
The input means 101 is means for receiving an electromagnetic wave and inputting a waveform. This means is a means for receiving an electromagnetic wave and outputting an amplitude, like a general receiver. Further, a means using a measuring instrument capable of measuring amplitude such as a spectrum analyzer may be used. Further, it may be a means for inputting the waveform and amplitude data received by a separate apparatus and outputting the amplitude.

  Specifically, the input means 101 can be configured as shown in FIG. The input unit 101 includes, for example, an antenna 401, a band pass filter 402, an amplifier 403, a frequency converter 404, an A / D converter 405, and an amplitude calculation 406. The antenna 401 receives an electromagnetic wave to be transmitted. The received electromagnetic wave is transmitted through the band pass filter 402 and a signal is output. The amplifier 403 amplifies the output signal. The frequency converter 404 converts the amplified signal from radio frequency to baseband to obtain an I / Q (in-phase / quadrature) waveform. The configuration of the antenna 401 to the frequency converter 404 is the same as that of a receiver having a general I / Q demodulator. The A / D converter 405 converts the I / Q waveform into a digital signal. The amplitude calculation 406 obtains the amplitude of the signal by adding the square of the I phase and the square of the Q phase to obtain the square root of the signal converted into the digital signal.

  The amplitude fluctuation correcting unit 102 is a unit that outputs an amplitude obtained by reducing a specific amplitude fluctuation from the amplitude input from the input unit 101. Here, as an example, the factor to be evaluated is the generation and intensity of interference waves (noise and other communication waves) that interfere with the damage waves (communication waves that are originally intended to be received). On the other hand, the factor that should not be evaluated is the amplitude fluctuation due to fading. At this time, the amplitude fluctuation due to the interference wave is caused by the phase difference between the damage wave and the interference wave. This fluctuation occurs due to a frequency difference between the damage wave and the interference wave, or a change in the signal of the damage wave and the interference wave. Therefore, the amplitude fluctuation is a fluctuation having a high frequency component (for example, several hundred Hz or more). However, the amplitude fluctuation due to fading occurs due to the movement of the sender or the fluctuation of the surrounding environment, and therefore, the fluctuation of the low frequency component (for example, several tens of Hz or less). As described above, the characteristics of the amplitude variation of the factor to be evaluated are different from the characteristics of the amplitude variation of the factor that should not be evaluated.

  Therefore, the amplitude fluctuation correcting unit 102 operates so as to separate the amplitude fluctuations having different characteristics from each other and cancel a factor that should not be evaluated. As shown in FIG. 3, the amplitude fluctuation correcting unit 102 includes a filter unit 201 and a correcting unit 202. The amplitude input to the amplitude fluctuation correction unit 102 is input to the filter unit 201 and the correction unit 202. The filter means 201 separates specific amplitude fluctuations. In this embodiment, the frequency of the factor that should not be evaluated differs from the frequency of the factor that should be evaluated. Since the fluctuation frequency of the factor that should not be evaluated is lower than the factor that should be evaluated, the amplitude that fluctuates at the low frequency can be separated by the low-pass filter that passes the low frequency. The correction unit 202 corrects the input amplitude based on the amplitude separated by the filter unit 201. In the present embodiment, the amplification factor is adjusted by multiplying the reciprocal of the separated amplitude by the input amplitude, and the amplitude fluctuation of a factor that should not be evaluated is reduced.

Further, as the amplitude fluctuation correcting means 102, specifically, a band pass filter 501 may be applied as shown in FIG.
Although the low-pass filter is used in the filter unit 201 here, a high-pass filter or a band-pass filter may be used in accordance with the characteristics of factors that should not be evaluated.
Further, the amplitude fluctuation correcting means 102 may be an auto gain controller that follows amplitude fluctuation due to a factor that should not be evaluated.
Further, the amplitude fluctuation correcting unit 102 may be a filter (for example, a low-pass filter, a high-pass filter, a band stop filter, or the like) that reduces a frequency component of a specific amplitude fluctuation.

  Returning to FIG. 1, the amplitude statistic calculation means 103 calculates the amplitude statistic. Here, the amplitude statistic calculation means 103 calculates the amplitude probability distribution as the amplitude statistic. The amplitude probability distribution represents a time probability exceeding a certain amplitude value as a function of the value. It can be obtained by counting the time when the input amplitude exceeds. As an example, an amplitude probability distribution creation method described in a patent document (Japanese Patent Laid-Open No. 2008-39762) can be applied. The amplitude statistic calculation means 103 is not limited to the amplitude probability distribution, but may be one of statistical values such as an amplitude histogram, average value, standard deviation, skewness, kurtosis, peak coefficient, and moment of probability distribution. Multiple calculations may be performed and output.

Specifically, the amplitude statistic calculation means 103 can be configured as shown in FIG. Here, the amplitude statistic calculation unit 103 includes a CPU 601 and a storage device 602. Based on the input information, the amplitude statistic calculation means 103 calculates an average value, standard deviation, skewness indicating the object of distribution, and kurtosis indicating the spread of the distribution.
The output unit 104 is a unit that outputs the statistic calculated by the amplitude statistic calculation unit 103. For example, the output unit 104 outputs the calculated value as a numerical value or a graph. Specifically, the output unit 104 is an output unit such as a display or a printer.

  Next, a specific operation example of the measurement apparatus 100 according to the present embodiment will be described. FIG. 6 is a flowchart showing an operation example of the measurement apparatus 100 according to the present embodiment. Here, it is assumed that the amplitude variation of the factor to be evaluated is amplitude variation due to digital modulation, and the amplitude variation of the factor that should not be evaluated is amplitude variation due to influence other than digital modulation. Digital modulation is performed with a transmission frequency of 260 MHz, π / 4 shift QPSK modulation, and a symbol rate of 32 kHz.

  When receiving the transmitted electromagnetic wave, the input unit 101 converts the received electromagnetic wave into a digital signal and obtains the amplitude of the signal (step S1). Then, the amplitude variation correcting means 102 passes the component by digital modulation at a symbol rate of 32 kHz out of the signal input to 101 (step S2). Here, for example, a band-pass filter that passes a 32 kHz component is applied as the amplitude fluctuation correcting unit 102. The amplitude statistic calculation means 103 is based on the information of the signal that has passed through the amplitude fluctuation correction means 102, and is an average value that is a statistic, a standard deviation, a skewness that indicates the object of distribution, and a kurtosis that indicates the degree of spread of the distribution Amplitude statistics such as are calculated (step S3). Then, the output unit 104 outputs the statistic calculated by the amplitude statistic calculation unit 103 (step S4).

<Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 7 is a block diagram showing the measuring apparatus 300 according to the present embodiment. The measuring apparatus 300 includes an amplitude input unit 301, an amplitude fluctuation correction unit 302, an amplitude statistic calculation unit 303, an output unit 304, an evaluation unit 305, a condition input unit 306, and a database 307. Here, among the units included in the measurement apparatus 300, the units having the same names as the units included in the measurement apparatus 100 in the first embodiment have the same configuration, and therefore, characteristic points in the present embodiment will be described below. To do.

  The condition input means 306 receives measurement conditions (for example, setting values such as the frequency to be measured and the type of reference data). Specifically, the condition input unit 306 is an input device such as a keyboard or an operation panel. This input device accepts input of measurement conditions from the user. The condition input unit 306 stores the input condition in the database 307. The amplitude input unit 301 measures the amplitude according to the conditions set by the condition input unit 306. For example, the electromagnetic wave is received by the receiver at the frequency set in the condition input means 306, and the amplitude is output.

  The database 307 stores the coefficient of the filter used by the amplitude variation correcting unit 302 and information on the statistic used as the reference used by the evaluating unit 305. The filter coefficient is, for example, a filter coefficient that can extract low-speed amplitude fluctuations caused by fading at each measurement frequency. In addition, the reference statistic information is, for example, a histogram and a similarity reference value when there is no interference in each modulation method.

  The amplitude fluctuation correcting unit 302 reduces a specific amplitude fluctuation. At this time, the amplitude fluctuation correcting unit 302 reads and uses parameters used by the amplitude fluctuation correcting unit 302 from the conditions input to the condition input unit 306 and stored in the database 307. For example, the amplitude fluctuation correcting unit 302 reads out the frequency to be reduced from the database 307 based on the input measurement frequency, and sets the filter characteristics. Based on the parameters, similarly to the amplitude fluctuation correction unit 102 in the first embodiment, the amplitude fluctuation of factors that should not be evaluated is reduced by a method such as adjustment of an amplification factor or a filter.

Specifically, the amplitude fluctuation correcting unit 302 can be configured as shown in FIG. The amplitude fluctuation correcting unit 302 includes, for example, a delay 701, a low-pass filter 702, an inverse operation 703, and a multiplication operation 704. The amplitude fluctuation correction unit 302 reads the low-pass filter coefficient stored in the database 307 in accordance with the measurement frequency that is the condition input to the condition input unit 306, and sets the filter. As a result, the output from the amplitude input means 301 passes through the delay 701 and the low-pass filter 702. The delay 701 generates the same delay as that generated by the low-pass filter 702 and the reciprocal calculation 703. The low-pass filter 702 performs filtering with a set coefficient. The reciprocal operation 703 turns the filtered amplitude into a reciprocal. Multiplication operation 704 multiplies the output of delay 701 and the output of reciprocal operation 703 and outputs the result.
In the amplitude fluctuation correcting unit 302, the low-pass filter 702 extracts fluctuations caused by fading. Further, by multiplying the reciprocal of the extracted fluctuation (dividing by the extracted fluctuation), the amplitude fluctuation due to fading is corrected.

The amplitude statistic calculation means 303 calculates an amplitude statistic. The amplitude statistic calculation unit 303 is the same as the amplitude statistic calculation unit 103 of the first embodiment.
The evaluation unit 305 evaluates the amplitude statistic calculated by the amplitude statistic calculation unit 303. In addition, the evaluation unit 305 reads the reference value stored in the database 307. The evaluation unit 305 compares the read reference value with the result of the statistic calculated by the amplitude statistic calculation unit 303 for evaluation. For example, the evaluation unit 305 compares the output of the amplitude statistic calculation unit 303 with the reference value stored in the database 307, and outputs a predetermined warning message if it is far from the reference value.

  Specifically, as shown in FIG. 9, the evaluation unit 305 can be configured by a similarity calculation unit 801 and a determination unit 802. The similarity calculation 801 reads out from the database 307 a modulation method histogram that is a reference when there is no interference. The similarity calculation 801 calculates the similarity between the reference modulation method histogram read from the database 307 and the histogram output from the statistic calculation unit 303. As the similarity calculation, for example, a distance function including Euclidean distance, a correlation coefficient, or the like is used. The determination unit 802 determines whether the similarity obtained in the similarity calculation 801 is larger or smaller than the similarity reference value in the database 307. With this evaluation means 305, the presence or absence of interference can be determined. If there is interference in the received signal, the amplitude histogram changes due to the interference. Therefore, the shape is different from the histogram when there is no interference. Therefore, the change of the histogram is calculated by calculating the similarity. The determination unit 802 determines that the degree of change is greater than the reference similarity, and detects interference.

  Next, a specific operation example of the measurement apparatus 300 according to the present embodiment will be described. FIG. 6 is a flowchart showing an operation example of the measurement apparatus 100 according to the present embodiment. Here, the factor that should not be evaluated is amplitude fluctuation due to fading. The evaluation target is detection of an interference wave that interferes with communication.

  First, a condition is input to the condition input means 306 (step S10). For example, conditions such as a measurement frequency of 260 MHz and a reference modulation method being QPSK are input. The amplitude input unit 301 receives an electromagnetic wave according to the frequency condition input to the condition input unit 306 (step S11). The amplitude fluctuation correcting unit 302 corrects the amplitude fluctuation of the received electromagnetic wave (step S12). The amplitude statistic calculation unit 303 calculates the amplitude statistic (step S13). For example, the amplitude statistic calculation unit 303 calculates an appearance probability for each amplitude size, and obtains an amplitude histogram.

  Then, the evaluation unit 305 evaluates the statistic obtained by the amplitude statistic calculation unit 303 (step S14). For example, the evaluation unit 305 calculates the similarity between the reference modulation scheme histogram and the histogram output from the statistic calculation unit 303 based on the Euclidean distance. Then, the calculated similarity is compared with the reference value of the similarity stored in the database 307 to determine the magnitude. The output unit 304 outputs the evaluation result from the evaluation unit 305.

Thus, according to the present invention, by calculating the amplitude statistic after reducing a specific amplitude variation, the change in the statistic due to a factor that should not be evaluated is reduced, and the change in the original amplitude statistic is reduced. Can be evaluated. Further, by correcting the amplitude, it becomes possible to calculate only the statistic of the component of the amplitude variation due to the factor to be evaluated, and the evaluation based on the statistic of the amplitude can be facilitated.
The measuring apparatus and method disclosed herein, and these control programs can be used for a measuring apparatus that measures the state of an electromagnetic wave environment based on an amplitude statistic, and an electromagnetic wave environment determination apparatus such as electromagnetic wave interference or modulation means determination. .

  A program for executing at least a part of the processing of each component of the measuring apparatus according to the present invention by computer control and causing the computer to execute the above processing according to the above-described procedure includes a semiconductor memory, a CD, and the like. -You may store and distribute to computer-readable recording media, such as ROM and a magnetic tape. A computer including at least a microcomputer, a personal computer, and a general-purpose computer may read the program from the recording medium and execute a part of the processing.

DESCRIPTION OF SYMBOLS 100 Measuring apparatus 101 Input means 102 Amplitude fluctuation correction means 103 Amplitude statistic calculation means 104 Output means 201 Filter means 202 Correction means 300 Measuring apparatus 301 Amplitude input means 302 Amplitude fluctuation correction means 303 Amplitude statistic calculation means 304 Output means 305 Evaluation means 306 Condition input means 307 Database 401 Antenna 402 Band pass filter 403 Amplifier 404 Frequency converter 405 A / D converter 406 Amplitude calculation 501 Band pass filter 601 CPU
602 Storage device 701 Delay 702 Low-pass filter 703 Reciprocal operation 704 Multiplication operation 801 Similarity calculation 802 Determination unit

Claims (9)

Input means for inputting the amplitude of the electromagnetic wave to be transmitted;
Amplitude fluctuation correcting means for performing correction to reduce a specific amplitude fluctuation from the inputted amplitude;
An amplitude statistic calculating means for calculating an amplitude statistic based on the corrected amplitude;
An output means for outputting a statistic of the amplitude obtained by calculation;
A measuring apparatus comprising: Condition input means for inputting the conditions for measuring the electromagnetic wave transmitted;
Input means for inputting the amplitude of the electromagnetic wave according to the condition input by the condition input means;
Amplitude fluctuation correction means for performing correction to reduce the amplitude fluctuation of a specific factor from the inputted amplitude;
An amplitude statistic calculating means for calculating an amplitude statistic based on the corrected amplitude;
An evaluation means for determining an evaluation based on a statistic of the amplitude obtained by calculation;
Output means for outputting the evaluation result;
A measuring apparatus comprising: The measurement apparatus according to claim 1, wherein the amplitude fluctuation correcting unit performs correction by reducing or passing a specific frequency component of the amplitude fluctuation. The amplitude fluctuation correcting means includes
Filter means for reducing or passing specific frequency components;
Correction means for correcting the amplitude reduced or passed by the filter means;
The measuring apparatus according to claim 1, comprising: The amplitude fluctuation correcting means includes
Filter means for reducing or passing specific frequency components;
Correction means for correcting the amplitude reduced or passed by the filter means by multiplying by the inverse of the amplitude;
The measuring apparatus according to claim 1, comprising: Inputting the amplitude of the electromagnetic wave to be transmitted;
Performing a correction to reduce a specific amplitude variation from the input amplitude;
Calculating an amplitude statistic based on the corrected amplitude;
Outputting a statistic of the amplitude obtained by calculation;
A measurement method comprising: Inputting the measurement conditions of the electromagnetic wave to be transmitted;
Inputting the amplitude of the electromagnetic wave according to the condition input by the condition input means;
Performing correction to reduce amplitude fluctuation of a specific factor from the inputted amplitude;
Calculating an amplitude statistic based on the corrected amplitude;
Determining an evaluation based on a statistic of the amplitude determined by calculation;
Outputting the evaluation result; and
A measurement method comprising: On the computer,
Inputting the amplitude of the electromagnetic wave to be transmitted;
Performing a correction to reduce a specific amplitude variation from the input amplitude;
Calculating an amplitude statistic based on the corrected amplitude;
Outputting a statistic of the amplitude obtained by calculation;
A measurement program that executes On the computer,
Inputting the measurement conditions of the electromagnetic wave to be transmitted;
Inputting the amplitude of the electromagnetic wave according to the condition input by the condition input means;
Performing correction to reduce amplitude fluctuation of a specific factor from the inputted amplitude;
Calculating an amplitude statistic based on the corrected amplitude;
Determining an evaluation based on a statistic of the amplitude determined by calculation;
Outputting the evaluation result; and
A measurement program that executes

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