JP2009162662A - Frequency measuring device, frequency measuring method, frequency measuring program, and data structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frequency measuring device for measuring frequencies of input signals in a wide range. <P>SOLUTION: The frequency measuring device samples the input signals based on sampling frequencies Fs and measures the frequencies of the input signals based on a signal spectrum including a returning component centering Fs/2. The frequency measuring device includes: a first frequency conversion control means (23) for converting the frequency of a second branch signal into a shift frequency shifting Fs/4 frequency; detecting means (12, 13, 32, 33) for detecting the frequencies of each signal spectrum including each returning component by sampling the first and second branch signals respectively; and a first frequency determination control means (14b) for determining the frequencies of the input signals by information (14a) of an emerging pattern about emergence of each signal spectrum including the returning component when the frequencies of the input signals are in one region of each frequency division region dividing a frequency region in each Fs/4 frequency. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a frequency measurement device, a frequency measurement method, a frequency measurement program, and a data structure.

  An example of this type of frequency measurement device is Non-Patent Document 1. The configuration and principle of the frequency measurement device of Non-Patent Document 1 will be described with reference to FIG.

  FIG. 23 is a block diagram illustrating a configuration of the frequency measurement apparatus 1000 of Non-Patent Document 1. As shown in the figure, the frequency measurement apparatus 1000 includes an anti-aliasing filter 1011 that limits the band of a signal component in a specific frequency region of an input signal, and analog signal of the band-limited input signal based on the sampling frequency Fs. A / D converter 1012 for converting the digital signal into digital data, and frequency analysis means 1013 for forming a spectrum of the sampling signal by fast Fourier transform (hereinafter referred to as FFT) and analyzing the frequency of the spectrum to measure the frequency. Composed.

  In such a frequency measuring apparatus 1000, the anti-aliasing filter 1011 is for suppressing (removing) a signal component having a frequency of Fs / 2 or more.

The reason why the anti-aliasing filter 1011 suppresses signal components having a frequency of Fs / 2 or higher in the input signal is as follows.
That is, when the input signal is sampled by the A / D converter 1012, if a signal component having a frequency component of Fs / 2 or higher is included, the signal component of Fs / 2 or higher has a frequency of Fs / 2. It is folded as a center and a folded component is generated in the frequency region of DC (zero frequency) to Fs / 2, and this folded component is added to the signal component in the frequency region of DC to Fs / 2, and in the frequency region of DC to Fs / 2. Accurate signal separation and measurement cannot be performed for signal components. For this reason, the signal component of Fs / 2 or more is removed in advance by the anti-aliasing filter 1011 so that only the signal component of DC to Fs / 2 is obtained.

  The phenomenon in which this aliasing component occurs is called the sampling theorem (or Shannon-Someya's sampling theorem), and the applied sampling frequency Fs is required to be set to at least twice the maximum frequency of the signal to be measured. . The measurable frequency is limited to DC to Fs / 2.

  Moreover, as another example of the frequency measurement device, for example, Patent Literature 1 can be cited. The configuration of this frequency measurement device will be described with reference to FIG.

  FIG. 25 is a block diagram illustrating a configuration of the frequency measurement device disclosed in Patent Document 1. In FIG. As shown in the figure, the frequency measurement apparatus 1100 includes an anti-aliasing filter (LPF_L) 1111 that passes a signal of a frequency L component from a DC component of an analog input signal to a half of the sampling frequency Fs of the A / D converter. A / D converter 1112 that samples the frequency L component that has passed through the anti-alias filter (LPF_L) 1111 and outputs digital data of the frequency L component, and a waveform memory (L) that stores the digital data of the frequency L component 1113.

  Further, the frequency measuring apparatus 1100 includes a low-pass filter (LPF_H) 1121 that passes a signal of a frequency A component from a DC component of an analog input signal to a sampling frequency Fs of the A / D converter, and the low-pass filter An A / D converter 1122 that samples the frequency A component that has passed through the filter (LPF_H) 1121 with a sampling clock common to the frequency L component sampling clock and outputs digital data of the frequency A component; And a waveform memory (H) 1123 for storing digital data.

  Further, the frequency measuring device 1100 includes frequency (L) calculating means 1141 for calculating spectrum data not including the aliasing component of the frequency L component from the digital data in the waveform memory (L) 1113, and the digital in the waveform memory (H) 1123. Frequency is obtained by subtracting the calculated folding component from the spectrum data of the frequency H component including the aliasing component calculated from the data by folding the spectrum data of the calculated frequency L component symmetrically around the sampling frequency Fs / 2. Frequency (H) calculation means 1142 for calculating spectrum data that does not include the H component aliasing component, spectrum data that does not include the aliasing component of the calculated frequency L component, spectrum data that does not include the aliasing component of the frequency H component, Synthesize In which and a synthesizing means 1143 for generating spectrum data which does not include aliasing components having A component.

  In such a frequency measurement apparatus 1100, the first spectrum data not including the aliasing component is extracted by the anti-aliasing filter (LPF_L) 1111 that passes the input signal from DC to Fs / 2.

  On the other hand, the second spectrum data including the aliasing component is extracted by the low-pass filter (LPF_H) 1121 that passes the signal components from DC to Fs.

  Here, as shown in FIG. 26, in the second frequency calculation means 1142 [frequency (H) calculation means], the Fs / 2 to Fs region is cut out from the second spectrum data to obtain the third spectrum. . Next, a fourth spectrum (calculated aliasing component) in which the first spectrum data is expressed symmetrically around the frequency Fs / 2 is obtained. This fourth spectrum has the same characteristics as the folded component (dotted line) in the third spectrum. Therefore, when the fourth spectrum is subtracted from the third spectrum for each corresponding frequency, the difference spectrum of the difference becomes the spectrum component of the frequency H component from which the aliasing component is removed. In this way, the influence of the aliasing component generated in Fs / 2 to Fs by the signal component of DC to Fs / 2 is removed.

Further, as a frequency spectrum display method, for example, Patent Document 2 can be cited.
In one form of Patent Document 2, a resistor divider that distributes an input signal (radio frequency signal RF) into two, two mixers that convert the radio frequency signal RF into an intermediate frequency, and two local signals that supply a local signal Two frequency measurement circuits such as a generation circuit, two low-pass filters, two analog-digital conversion circuits, and two fast Fourier transform circuits that convert digital data from time-level data to frequency-level data are prepared. Then, the level at the same frequency in the frequency-level value data obtained by setting the frequency of the local signal as f1 and the frequency-level value data obtained as the frequency of the local signal as f1 + Δf by the display processing circuit. The values are compared, and a small level value is displayed as a frequency value in the frequency spectrum. Thereby, the interference signal existing outside the band is removed, and the spectrum display of a specific bandwidth is made possible.
For example, when comparing the first spectrum with the frequency f1 (described in FIG. 6 of Patent Document 2) and the second spectrum with the frequency f1 + Δf (described in FIG. 7 of Patent Document 2), the frequency f4 of the first spectrum. 'Is a specific level value, and the level value of the frequency corresponding to the frequency of the second spectrum is 0, so the smaller level value 0 is selected. Similarly, the lower level value 0 is selected at the frequencies of f5 ′, f4 ″, and f5 ″. For this reason, in the spectrum display, the frequency components of f4 ′, f5 ′, f4 ″, and f5 ″ are removed.
In such a form of Patent Document 2, the displayable band is up to fs / 2 (as described in FIG. 8 of Patent Document 2).

In another form of Patent Document 2, the local signal frequency is f1 at the first observation, and the local signal frequency is f1 + Δf (0 <Δf <fs / 4) at the second observation. , Fs: AD sampling frequency), the data of the first and second frequency-level values is obtained.
In the above range of Δf, the local signal frequency may be changed by three or more stages to obtain data of three or more frequency-level values, and the frequency-level obtained by changing the local signal frequency by Δf. The maximum frequency range of 1/2 fs−Δf is expanded by continuously changing the local signal frequency N times, so that the frequency up to the maximum Δf × (N−3) +1/2 fs− A level value can be obtained. Here, N is the number of analog-digital conversions.

Further, as a method for detecting the signal frequency, for example, Patent Document 3 can be cited.
In Patent Document 3, first, a sample data string obtained by sampling a signal whose frequency is unknown at a sampling frequency fs is subjected to an FFT operation with the number of sample points n, and a frequency band A (k · fs / n ± fs / 2n in which a signal frequency exists is obtained. K = 0 to n) are detected.
Next, the sample data string is resampled at the decimation rate D, the resampled data string is subjected to an FFT operation with the number of sample points m, and the peak frequency fp detected in the frequency 0 to fs / 2D region is mapped as a non-inverted spectrum. The frequency (q · fs / D + fp; q = 0, 1, 2,...) And the frequency (q · fs / D−fp) mapped as an inverted spectrum are determined within the range of the frequency band A.
Then, the sample data sequence is thinned out at a predetermined rate to shift the signal frequency upward, and this is resampled at the decimation rate D, and this resampled data sequence is subjected to an FFT operation with the sample point m, and the frequency 0 When the peak frequency fp ′ detected in the region of −fs / 2D is shifted upward from fp, the frequency (q · fs / D + fp) is determined as the signal frequency, and the peak frequency fp ′ is shifted to fp or less. In this case, the frequency (q · fs / D−fp) is determined as the signal frequency.
Chapter 5 of "How to use FFT" (Aiin Takeshi, Nakajima Masayuki, Akiba Publishing) JP 2000-284008 A JP-A-8-233768 JP 2002-236135 A

  However, the frequency measurement device of Non-Patent Document 1 has the following problems.

  That is, in the frequency measuring apparatus 1000, it is conceivable to apply an A / D converter having a high sampling speed as a method of measuring a wider band and a higher frequency signal frequency. In addition to the limitations, generally, the price of the A / D converter depends on the sampling frequency, and an expensive A / D converter is required for realization.

The measurement frequency resolution of the signal calculated by FFT is expressed by the following equation (1) where N is the number of FFT points.
Frequency resolution = N / Fs (1)
This equation (1) shows that the frequency resolution deteriorates as the sampling frequency increases. That is, in an environment where a higher-speed A / D converter is applied, it is necessary to increase the number of FFT points in order to obtain the same frequency resolution. The number of FFT points is defined by the following equation (2).
FFT calculation amount = Nlog ₂ N (2)
As shown in this equation (2), applying a higher-speed A / D converter to increase the frequency resolution and increasing the number of FFT points increases the amount of FFT calculations, and a faster signal for realization. A processing device is required.

  Further, as the characteristics of the anti-aliasing filter 1011, it is required to realize a characteristic having only DC to Fs / 2 as a pass band, but as shown in the characteristic of FIG. 23, it is difficult to realize a filter having an ideal rectangular characteristic. The frequency range that can be actually measured was Fs / 2 or less.

As described above, in the frequency measuring apparatus 1000 of Non-Patent Document 1, the measurable frequency range is limited to DC to Fs / 2 with respect to the sampling frequency Fs, and it is difficult to measure signals having frequencies exceeding this range widely. There was a problem of being.
Further, in order to expand the measurable frequency range, there is a problem that it is necessary to use an expensive high-speed A / D converter and a high-speed signal processing device.

  Further, in the frequency measurement device 1100 of Patent Document 1, when the input signal is present in the frequency region of Fs / 2 to Fs, the spectrum is present in Fs / 2 to Fs, and the loop is reversed. The component spectrum occurs in DC to Fs / 2. For this reason, the frequency measuring device 1100 of Patent Document 1 cannot remove the influence of the aliasing component signal generated in DC to Fs / 2, and when the input signal is in the frequency region of Fs / 2 to Fs, There is a problem that accurate frequency components cannot be measured.

In addition, the frequency measurement device 1100 of Patent Document 1 has a problem that accurate frequency measurement is difficult when an input signal exists in a band exceeding Fs / 2.
Furthermore, two filters having different characteristics are required, and a complicated processing algorithm such as spectrum inversion is required to be applied.

Furthermore, in one form of Patent Document 2, since the displayable frequency is Fs / 2, if an input signal exists in a band exceeding Fs / 2, it is removed as an interference signal, so that accurate frequency measurement is difficult. There was a problem of being.
Further, in another form of Patent Document 2, it is possible to measure a frequency of (1/2) fs or more by changing Δf that is normally fixed. To that end, Δf is changed each time. It is necessary to perform frequency measurement repeatedly. This also increases the amount of calculation and decreases the measurement speed. For example, when the signal exists only for a short time, there is a problem that it is difficult to detect the signal.

  Further, in Patent Document 3, it is necessary to change the mapping fp to fp ′ in order to obtain a non-inverted spectrum, and to perform frequency analysis (FFT) processing each time. In addition, in Patent Document 3, it is necessary to further perform decimation processing for the final frequency determination. This process is to resample at a decimation rate, and is realized by a combination of a filter process for performing decimation and a downsampling process with a specific decimation rate. Therefore, in order to obtain a required frequency analysis result, there is a problem that it is difficult to accurately detect a signal having a long processing time and changing or appearing in a short time.

  The present invention has been made to solve the problems of the above-described technology, and the object thereof is to eliminate the need for an expensive high-speed A / D converter and a high-speed signal processing device. To provide a frequency measurement device, a frequency measurement method, a frequency measurement program, and a data structure that can measure the frequency of an input signal over a wide range and can detect a signal even when the signal exists only in a short time. .

  In order to achieve the above object, the frequency measuring apparatus of the present invention samples an input signal based on the sampling frequency Fs, and includes a signal spectrum including a aliasing component centered on (1/2) Fs of the sampled sampling signal. The frequency measurement device measures the frequency of the input signal based on the first branch signal and the second branch signal of the first branch signal and the second branch signal branching the input signal, and calculates the frequency of the second branch signal as Fs / 4 or (3/4) first frequency conversion control means for performing control for conversion to a shifted frequency shifted by Fs frequency, and sampling each of the first branch signal and the second branch signal, Detecting means for detecting the frequency of each signal spectrum of each sampling signal including the aliasing component of each of the first and second branch signals; and the input signal When the frequency is in any one of the frequency division regions obtained by dividing the frequency region into Fs / 4 frequencies, the combination of the frequency division regions in which the signal spectrums including the aliasing components appear On the basis of the detected appearance pattern of each signal spectrum detected by the detection means, and the appearance pattern information storage means for storing the appearance pattern information to be shown according to each frequency of the input signal. First frequency determination control means for performing control for determining the frequency division region of the input signal corresponding to the detected appearance pattern with reference to the appearance pattern information and outputting it as a measurement frequency .

  The frequency measurement method of the present invention is a frequency measurement method for sampling an input signal based on a sampling frequency and measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal, Control that converts the frequency of each of the other branch signals other than one of the branch signals into a plurality of branched frequencies obtained by branching the input signal into a plurality of different shifted frequencies. A first frequency conversion control step to be performed; and each sampling signal that samples the one branch signal of the frequency of the input signal and each of the other branch signals of the deviation frequency, and includes a folding component of each branch signal A detection step for detecting the frequency of each signal spectrum, and the frequency of the input signal overlaps the frequency domain. In the detection step, the appearance pattern information indicating the combination of the frequency division regions where the signal spectrum including the aliasing component appears when the frequency spectrum is in any one of the frequency division regions divided into And a first frequency determination control step for performing control to determine the frequency division region of the input signal based on the detected detection pattern of each signal spectrum and output as a measurement frequency. Yes.

  The frequency measurement program of the present invention samples an input signal based on a sampling frequency, and causes a computer to execute a process of measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal. Each of the shift frequencies obtained by shifting the frequency of each of the branch signals other than the one of the branch signals by a different frequency among the branch signals obtained by branching the input signal into a plurality of branches. A first frequency conversion control function for performing control for conversion to each of the first and second branch signals having the frequency of the input signal and the other branch signals having the deviation frequency, respectively, and folding the branch signals. Detection system that performs control to detect each frequency of each signal spectrum of each sampling signal including components Each frequency division region in which each signal spectrum including the aliasing component appears when the function and the frequency of the input signal are in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions Control is performed to determine the frequency division region of the input signal and output it as a measurement frequency based on the appearance pattern information indicating the combination of and the detected appearance pattern of each signal spectrum detected by the detection function The computer is configured to execute a function including a first frequency determination control function.

  The data structure of the present invention is used for a computer to perform a process of sampling an input signal based on a sampling frequency and measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal. Each of the signal spectrums including the aliasing component appears when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions. A first structure in which appearance pattern information indicating a combination of the frequency division regions is stored in accordance with each frequency of the input signal, and the first structure is a branch signal in which the computer branches the input signal into a plurality of signals. Each of the other branch signals other than the one branch signal has a different frequency. Control each conversion to each shifted frequency shifted by wave number, sample each of the one branch signal of the frequency of the input signal and each of the other branch signals of the shift frequency, Control is performed to detect the frequency of each signal spectrum of each sampling signal including the aliasing component, and based on the detected appearance pattern of each detected signal spectrum and the appearance pattern information, the frequency division of the input signal It is characterized in that it is used for processing for determining a region and performing control to output it as a measurement frequency.

  According to the present invention, the frequency domain of the input signal is determined by using the aliasing characteristics of the signal by sampling and determining the frequency domain of the input signal from the appearance pattern information based on the signal spectrum of the input signal and the signal spectrum of the normal input signal. Without the need for a high-speed A / D converter or high-speed signal processing device, it is possible to measure the frequency of the input signal over a wide range, and to measure the signal frequency using a simple method that can be determined by referring to the appearance pattern. Therefore, the measurement speed is improved, for example, even when the signal is present only for a short time, even if the signal can be detected, the superior frequency measurement device, the frequency measurement method, which is not available in the related technology, A frequency measurement program and a data structure can be provided.

[Basic configuration of frequency measuring device]
First, the basic configuration of the frequency measurement device of the present invention will be described. A frequency measuring device (for example, reference numeral 1 shown in FIG. 1) samples an input signal based on a sampling frequency Fs, and a signal spectrum including a aliasing component centered on (1/2) Fs of the sampled sampling signal. Is intended to measure the frequency of the input signal based on the above.

  The frequency measuring device deviates the frequency of the second branch signal out of the first branch signal and the second branch signal branched from the input signal by Fs / 4 or (3/4) Fs frequency. The first frequency conversion control means (for example, the configuration including the reference numerals 23 and 21 shown in FIG. 1) that performs control for conversion to the shifted shift frequency is included.

  Further, the frequency measuring device samples each of the first branch signal and the second branch signal, and each signal spectrum of each sampling signal including a folding component of each of the first and second branch signals. The detection means (for example, the structure which consists of the code | symbol 12, the code | symbol 13, the code | symbol 22, the code | symbol 32, the code | symbol 33 shown in FIG. 1, etc.) each comprised is comprised.

  Further, the frequency measurement device may include the signal spectrum including the aliasing component when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region for each Fs / 4 frequency. Appearance pattern information storage means (for example, reference numeral 14a shown in FIG. 1) that stores appearance pattern information indicating a combination of the frequency division regions in which each appears in accordance with each frequency of the input signal.

  Furthermore, the frequency measurement device refers to the appearance pattern information in the appearance pattern information storage unit based on the detection appearance pattern of each signal spectrum detected by the detection unit, and corresponds to the detection appearance pattern. First frequency determination control means (for example, reference numeral 14b shown in FIG. 1) that performs control to determine the frequency division region of the input signal and output it as a measurement frequency is configured.

According to such a frequency measuring apparatus, the signal spectrum of the signal component obtained by shifting the frequency of the second branch signal by the first frequency conversion control means and the detection means, and the first branch signal not shifted. The signal spectrum of the signal component due to.
At this time, each signal spectrum has a folded component, but one of the signal spectra is frequency-shifted in advance, so that each signal spectrum does not overlap in the same frequency region including the folded component. For this reason, according to each frequency of the input signal, by forming an appearance pattern information storage means that defines an appearance pattern of each signal spectrum including the aliasing component, the first frequency determination control means causes the detection means to The frequency of the input signal can be determined based on the detected appearance pattern detected in this way.

  Therefore, it is possible to measure the frequency of the input signal (during Nyquist sampling) in the range from DC to Fs without requiring an expensive high-speed A / D converter or high-speed signal processing device, and the signal folding component. This makes it possible to measure the signal frequency with a simple method that can be determined by referring to the appearance pattern effectively, and the measurement speed is improved, for example, when the signal exists only in a short time. However, the signal can be detected.

  Further, the frequency measurement device uses a second band limiting unit that limits a frequency component outside the pass band of the input signal, with a wide band up to a specific frequency equal to or higher than a sampling frequency among the frequencies of the input signal as a pass band. For example, it can further have a reference 141) shown in FIG. In this case, the first frequency determination control unit is configured to determine the aliasing component due to undersampling based on the first and second branched signals obtained by branching the signal band-limited by the second band-limiting unit. Control for determining the frequency of the input signal from the appearance pattern of each signal spectrum can be performed.

  Furthermore, the frequency measurement device is configured to perform rough measurement based on the third branch signal among the first to third branch signals obtained by branching the signal band-limited by the second band limit unit. Coarse frequency measuring means for measuring the frequency (for example, reference numeral 150 shown in FIG. 12) can be provided.

  Further, the frequency measuring device performs frequency conversion on the second branch signal by the first frequency conversion control means, and is determined based on the first branch signal and the frequency-converted second branch signal. A second frequency for performing control for determining the frequency of the input signal based on the result of precise frequency estimation by the first frequency judgment control means and the result of coarse frequency estimation by the coarse frequency measurement means. It can further have a judgment control means (for example, reference numeral 161 shown in FIG. 12).

  Furthermore, the input is arranged in front of the second band limiting unit, and the input in units of fb × M (M is a positive integer) where fb is a measurable frequency by the second frequency determination control unit. Second frequency conversion control means (for example, reference numeral 242 shown in FIG. 14) for converting the frequency of the signal can be further provided.

  In such a frequency measuring apparatus, the frequency of the input signal exceeding the sampling frequency can be measured by the second band limiting unit, the coarse measurement frequency measuring unit, the frequency determination control unit, and the second frequency conversion control unit. .

An example of a preferred embodiment of the frequency measuring apparatus of the present invention having such a basic configuration will be specifically described below with reference to the drawings.
[First Embodiment]
(Overall configuration of frequency measuring device)
FIG. 1 is a block diagram showing an example of the overall configuration of the frequency measurement device according to the first embodiment of the present invention.
As shown in the figure, the frequency measuring apparatus 1 according to the present embodiment samples an input signal based on a sampling frequency Fs, and a folding component centered on (1/2) Fs of the sampled sampling signal. The frequency of the input signal is measured based on the included signal spectrum, and from the first branch signal and the second branch signal branched from the input signal, from the zero frequency of the first branch signal to the sampling frequency Is the first filter unit 11 that limits the frequency component outside the pass band of the first branch signal, and the analog data of the first branch signal that is band-limited is based on the sampling frequency Fs. The first A / D converter 12 for converting into digital data as a sampling signal and the first A / D converter 12 Configured to include a first frequency calculation means 13 calculates the frequency of the signal spectrum to form a signal spectrum due FFT (fast Fourier transform), the relative sampling signal of the digital data.

  Here, since the first filter unit 11 has a pass band from zero frequency to the sampling frequency, the signal spectrum obtained by the first frequency calculation means 13 is the input signal (first branch signal). Both the signal component and the aliasing component centered on (1/2) Fs of the signal component are included.

  In addition, the frequency measuring apparatus 1 includes a frequency converting unit 23 that performs a process of converting the frequency of the second branch signal into a shifted frequency that is shifted (offset) by Fs / 4 frequency, and the frequency converting unit 23. The second branch signal having the frequency shifted from the zero frequency of the second branch signal having the shifted frequency to the sampling frequency is band-limited to a frequency component outside the pass band of the second branch signal. Filter unit 31 and a second A / D converter for converting analog data of the second branch signal band-limited by the second filter unit 31 into digital data as a sampling signal based on the sampling frequency Fs 32 and the digital data sampling signal converted by the second A / D converter 32 are subjected to a signal spectrum by FFT (Fast Fourier Transform) or the like. Forming a tram configured to include a second frequency calculation means 13 calculates the frequency of the signal spectrum.

  Here, since the second filter unit 31 has a pass band from zero frequency to the sampling frequency, the signal spectrum obtained by the second frequency calculation means 33 is shifted by (1/4) Fs frequency. It includes both the signal component of the second branch signal and the aliasing component centered on (1/2) Fs of the signal component.

Further, in the frequency measuring apparatus 1, sampling clock generating means for generating a clock having a frequency Fs that can supply the sampling frequency Fs to the first A / D converter 12 and the second A / D converter 32, respectively. 22 and a clock frequency dividing means 21 for generating a clock having a frequency of (Fs / 4) based on the clock from the sampling clock generating means 22.
The output of the clock frequency dividing means 21 is supplied to the frequency converting means 23, and the frequency converting means 23 can shift the frequency of the second branch signal by (Fs / 4).

  Further, the frequency measuring device 1 is configured so that when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region for each Fs / 4 frequency, each of the signals including the aliasing component It includes a frequency determination table 14a serving as an appearance pattern information storage unit that stores appearance pattern information indicating a combination of the frequency division regions in which a spectrum appears according to each frequency of the input signal.

  Further, the frequency measuring apparatus 1 includes a signal spectrum including a folding component based on the first branch signal obtained by the first frequency calculation unit 13 and a folding based on the second branch signal obtained by the second frequency calculation unit 33. Control for determining the frequency of the input signal of the corresponding appearance pattern by referring to the frequency determination table 14a based on the combination of both detected appearance patterns of the signal spectrum including the component, and outputting the determination result as the measurement frequency Including a frequency determination control unit 14b.

Next, the appearance pattern of the signal spectrum including the aliasing component will be described together with the data structure of the frequency determination table 14a.
The frequency determination table 14a has a data structure as shown in FIG. This data structure is an example of the “first structure” in the present invention.
Here, the frequency region from the zero frequency to the sampling frequency Fs is divided into blocks for each Fs / 4 frequency, and the divided frequency division regions are sequentially divided into regions I [0 <f ≦ [(3/4 ) Fs]], region II [[(1/4) Fs] <f ≦ [(1/2) Fs]], region III [[Fs / 2] <f ≦ [(3/4) Fs]], Region IV [[(3/4) Fs] <f ≦ Fs].

According to the sampling theorem, the sampling signal after direct A / D conversion of the input signal is folded and has a symmetrical spectrum with respect to Fs / 2.
In this case, since the boundary between the region II and the region III is set to be Fs / 2, when the frequency shift (offset) is not considered, when the frequency of the input signal is in the region II according to the sampling theorem, It is assumed that the folding component (folding signal) of the signal spectrum is generated in the region III. Similarly, when the frequency of the input signal is in region I, the aliasing component (folding signal) of the signal spectrum is generated in region IV. Conversely, when the frequency of the input signal is in region III, the aliasing component (folding signal) of the signal spectrum is generated in region II. Similarly, when the frequency of the input signal is in the region IV, the folded component (folded signal) of the signal spectrum is generated in the region I.

The frequency determination table 14a shown in FIG. 4 is configured to determine the frequency of the input signal while paying attention only to the region I and the region II.
For example, when the frequency f (signal frequency) of the input signal is [Fs / 2] <f ≦ [(3/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is in region II. The signal spectrum that appears and is the output of the second frequency calculation means 33 appears in the region I.

  This is shown in FIGS. 2 and 3. In FIG. 2, when the frequency of the input signal (first branch signal) is in the region III [[Fs / 2] <f ≦ [(3/4) Fs]], it is the output of the first frequency calculation means 13. In the signal spectrum, a signal component of region III and a signal component of region II that is a folding component of the signal component of region III are formed.

  On the other hand, in FIG. 3, when the frequency of the input signal is in the region III [[Fs / 2] <f ≦ [(3/4) Fs]], the second branch signal is converted into (Fs / 4) by the frequency conversion means 23. ) Is the frequency of the region IV shifted (offset). For this reason, the signal spectrum that is the output of the second frequency calculation means 33 is formed with a signal component of the region IV and a signal component of the region I that is a folding component of the signal component of the region IV.

  Therefore, when focusing only on the region I and the region II, the signal spectrum which is the output of the first frequency calculation unit 13 is the signal spectrum whose aliasing component appears in the region II and which is the output of the second frequency calculation unit 33. , The aliasing component appears in region I.

  Similarly, when the frequency f (signal frequency) of the input signal is 0 <f ≦ [(1/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 appears in the region I. The signal spectrum that is the output of the second frequency calculating means 33 appears in the region II.

  This is shown in FIGS. 5 and 6. In FIG. 5, when the frequency of the input signal (first branch signal) is in the region I [0 <f ≦ [(1/4) Fs]], the signal spectrum that is the output of the first frequency calculating means 13 is A signal component of region I and a signal component of region IV that is a folding component of the signal component of region I are formed.

  On the other hand, in FIG. 6, when the frequency of the input signal is in the region I [0 <f ≦ [(1/4) Fs]], the second branch signal is shifted by (Fs / 4) by the frequency conversion means 23. This is the frequency of (offset) region II. For this reason, the signal spectrum that is the output of the second frequency calculation means 33 is formed with a signal component of region II and a signal component of region III that is a folded component of the signal component of region II.

  Therefore, when attention is paid only to the region I and the region II, the signal spectrum which is the output of the first frequency calculation unit 13 is the output of the second frequency calculation unit 33 in which the component of the input signal appears in the region I. In the signal spectrum, the component of the input signal appears in region II.

  Similarly, when the frequency f (signal frequency) of the input signal is [(1/4) Fs] <f ≦ [(1/2) Fs], the signal spectrum which is the output of the first frequency calculation means 13 Appears in region II, and the signal spectrum that is the output of the second frequency calculation means 33 appears in region II.

  This is shown in FIGS. 7 and 8. In FIG. 7, when the frequency of the input signal (first branch signal) is in the region II [[[(1/4) Fs] <f ≦ [(1/2) Fs]], the first frequency calculating means 13 The signal spectrum as an output includes a signal component of region II and a signal component of region III that is a folded component of the signal component of region II.

  On the other hand, in FIG. 8, when the frequency of the input signal is in the region II [[((1/4) Fs] <f ≦ [(1/2) Fs]]], the second branch signal is ( The frequency of the region III is shifted (offset) by Fs / 4). For this reason, the signal spectrum that is the output of the second frequency calculation means 33 is formed with a signal component of region III and a signal component of region II that is a folded component of the signal component of region III.

  Therefore, when attention is paid only to the region I and the region II, the signal spectrum which is the output of the first frequency calculation unit 13 is the output of the second frequency calculation unit 33 with the component of the input signal appearing in the region II. In the signal spectrum, the aliasing component appears in region II.

  Similarly, when the frequency f (signal frequency) of the input signal is [(3/4) Fs] <f ≦ Fs, the signal spectrum that is the output of the first frequency calculation means 13 appears in the region I. The signal spectrum that is the output of the second frequency calculating means 33 appears in the region I.

  This is shown in FIGS. 9 and 10. In FIG. 9, when the frequency of the input signal (first branch signal) is in the region IV [[(3/4) Fs] <f ≦ Fs], the signal spectrum that is the output of the first frequency calculating means 13 is A signal component of region IV and a signal component of region I, which is a folding component of the signal component of region IV, are formed.

  On the other hand, in FIG. 10, when the frequency of the input signal is in the region IV [[(3/4) Fs] <f ≦ Fs], the second branch signal is shifted by (Fs / 4) by the frequency conversion means 23. The frequency of the (offset) region V is obtained. For this reason, the signal spectrum that is the output of the second frequency calculation means 33 is formed by the signal component of the region V, the signal component of the region I and the signal component of the region IV, which are aliasing components of the signal component of the region V. Is done.

  In this way, the position of the detected spectrum differs by frequency offsetting the input signal by (1/4) Fs. The appearance pattern is as shown in FIG. 4 depending on the frequency of the input signal.

  Therefore, when focusing only on the region I and the region II, the signal spectrum which is the output of the first frequency calculation unit 13 is the signal spectrum whose aliasing component appears in the region I and which is the output of the second frequency calculation unit 33. , The aliasing component appears in region I.

  By making the appearance pattern into a table in this way, the signal spectrum that is the output of the first frequency calculation means 13 and the signal spectrum that is the output of the second frequency calculation means 33 are turned components and input signal components. The frequency domain of the corresponding input signal can be determined by determining in which area I and II the area appears.

  That is, for the signal spectrum detection results output from the two first and second frequency calculation means 13 and 33, the frequency determination control unit 14b determines whether or not there is a signal spectrum in the frequency domain I and frequency domain II. 4 is compared with the table shown in FIG. 4, the region of the input signal frequency within DC to Fs is determined, and the frequency is measured.

This makes it possible to measure the frequency of the input signal even if the input signal has a frequency of (1/2) Fs or higher.
At this time, the folding component does not need to be removed. As described above, in the related art, a filter having a passband of zero frequency DC to Fs / 2 is applied to prevent the influence of aliasing, and interference due to a signal of Fs / 2 or more is prevented, and the frequency measurement range is set to zero frequency DC to Limited to Fs / 2. On the other hand, in the present embodiment, since it is not necessary to remove the aliasing component, the first and second filter units 11 and 31 having the pass band from zero frequency DC to Fs are input without using the antialiasing filter. It can be applied to signals.

  Here, the correspondence between the configuration requirements described in the present embodiment and the configuration requirements described in the present invention will be described. According to the frequency determination table 14a of the present embodiment, "appearance pattern information storage means" Can be configured. Further, the “first frequency determination control means” according to the present invention can be configured by the frequency determination control unit 14b of the present embodiment.

  Furthermore, the first A / D converter 12, the first frequency calculation means 13, the sampling clock generation means 22, the second A / D converter 32, and the second frequency calculation means 33 of the present embodiment The “detection means” referred to in the present invention can be configured. Further, the clock frequency dividing means 21 and the frequency converting means 23 of the present embodiment can constitute the “first frequency conversion controlling means” according to the present invention. Furthermore, the first filter unit 11 and the second filter unit 31 of the present embodiment can constitute the “first band limiting unit” according to the present invention.

  The “first frequency conversion control means” sets the frequency of the second branch signal among the first branch signal and the second branch signal obtained by branching the input signal to Fs / 4 or (3/4). ) It is possible to perform control for conversion to a shifted frequency shifted by the Fs frequency. Further, the “detecting means” samples each of the first branch signal and the second branch signal, and each signal spectrum of each sampling signal including each aliasing component of each of the first and second branch signals. Can be detected respectively.

  In addition, the “appearance pattern information storage unit” includes the aliasing component when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region for each Fs / 4 frequency. Appearance pattern information indicating a combination of each frequency division region in which each signal spectrum appears can be stored according to each frequency of the input signal.

  Furthermore, the “first frequency determination control means” refers to the appearance pattern information of the appearance pattern information storage means based on the detection appearance pattern of each signal spectrum detected by the detection means. It is possible to perform control to determine the frequency division region of the input signal corresponding to the pattern and output it as a measurement frequency.

  The “first band limiting means” can band limit frequency components outside the pass band of the first and second branch signals, with a pass band from zero frequency to the sampling frequency. In this case, the “first frequency determination control means” can perform control to determine the frequency of the input signal in each frequency division region equal to or lower than the sampling frequency.

  Further, the “first frequency determination control unit” is configured such that each signal spectrum detected by the detection unit is equal to or less than (½) Fs in each frequency division region from a zero frequency to the sampling frequency Fs. Control for determining the frequency of (1/2) Fs or more of the input signal based on the appearance pattern of the aliasing component of the signal spectrum of (1/2) Fs or more of each sampling signal in each of the frequency division regions. It can be carried out.

The frequency measuring apparatus 1 according to the present embodiment configured as described above generally operates as follows.
First, an input signal is branched into two systems to become a first branch signal and a second branch signal. One first branch signal is input to the first filter unit 11 having a pass band ranging from DC (zero frequency) to Fs (sampling frequency), and is band-limited.

  Subsequently, the first A / D converter 12 performs sampling processing of the filtered signal of the first branch signal based on the clock of the sampling frequency Fs generated by the sampling clock generation means 22.

  Next, the first frequency calculation means 13 detects the signal spectrum for the sampling signal, determines the frequency domain, and calculates the frequency of the signal spectrum. For this frequency calculation processing, FFT is mainly applied.

  On the other hand, the second branch signal is subjected to frequency shift (offset) processing by Fs / 4 by the frequency conversion means 23. The clock signal applied by the frequency converting unit 23 is supplied from the clock dividing unit 21.

The second branch signal subjected to frequency shift (offset) is subjected to band limiting processing by the second filter unit 31 having a pass band ranging from DC (zero frequency) to Fs (sampling frequency).
Furthermore, the second A / D converter 32 performs sampling processing on the second branch signal of the filtered signal that has been band-limited by the second filter unit 31.

  Subsequently, the second frequency calculation and determination means 33 detects the signal spectrum for the sampling signal, determines the frequency domain, and calculates the frequency of the signal spectrum. At this time, the second frequency calculation and determination unit 33 performs the calculation process in the same procedure as the first frequency calculation unit 13.

  As a result, the frequency determination control unit 14b compares each signal spectrum detection area from the first frequency calculation unit 13 and the second frequency calculation unit 33 with the frequency determination table 14a shown in FIG. The frequency domain of the input signal is determined, and based on this, the frequency of the input signal is output.

(About processing procedure)
Next, the present invention can be configured not only as a frequency measurement device but also as a frequency measurement method. Here, a frequency measurement procedure using the frequency measurement apparatus having the above-described configuration will be described with reference to FIG. FIG. 11 is a flowchart illustrating an example of a frequency measurement method.

  The frequency measurement method according to the present embodiment is intended for sampling an input signal based on a sampling frequency and measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal. To do.

  In this frequency measurement method, as a basic configuration, among the branch signals obtained by branching the input signal into a plurality of signals, the frequencies of the other branch signals other than the one branch signal are shifted by different frequencies. A first frequency conversion control step (for example, step S101 shown in FIG. 11) for performing conversion to each of the shifted frequencies, the one branch signal of the frequency of the input signal, and the other of the shift frequency A detection step (for example, step S102 shown in FIG. 11) for detecting the frequency of each signal spectrum of each sampling signal including the aliasing component of each branch signal, and the frequency of the input signal Is in any one of the frequency division regions divided into a plurality of frequency regions, The frequency division region of the input signal is determined based on the appearance pattern information indicating the combination of the frequency division regions where the signal spectrum appears and the detected appearance pattern of each signal spectrum detected in the detection step. And a first frequency determination control step (for example, step S103 shown in FIG. 11) for performing control to output the measurement frequency.

  The frequency measurement method according to the present embodiment uses the aliasing characteristics of the input signal generated by A / D conversion (sampling processing), and the frequency spectrum of the original input signal and the signal obtained by frequency offset of the input signal by 1/4 Fs. By comparing the detection positions, the influence of the aliasing is removed, and the frequency measurement of the input signal from the zero frequency DC to the sampling frequency Fs becomes possible.

More specifically, in the frequency measurement method according to the present embodiment, first, the frequency conversion processing step S101 is performed.
In this frequency conversion processing step S101, at least two systems of first branch signals and second branch signals are formed as input signals, and one of the second branch signals is subjected to sampling frequency Fs by frequency conversion means 23. A process of shifting by 1/4 frequency is performed.

  Next, detection processing step S102 is performed. In this detection processing step S102, the first A / D converter 12 performs sampling processing with the influence of aliasing (folding) on the first branch signal. The sampling frequency of the sampled sampling signal is detected by the first frequency calculation means 13, and the signal spectrum is present in any region on each frequency division region obtained by dividing DC to Fs by Fs / 4 frequency. Detect what to do. Also, the frequency of the signal spectrum is calculated.

  At the same time, the second A / D converter 32 performs a sampling process with an aliasing effect on the second branch signal. The sampled sampled signal is detected by the second frequency calculation means 33, and the signal spectrum is present in any region on each frequency division region obtained by dividing DC to Fs by Fs / 4 frequency. Detect what to do. Also, the frequency of the signal spectrum is calculated.

  Here, in each signal spectrum detected in the detection processing step S102, the effect of the aliasing has a characteristic characteristic depending on the frequency of the input signal because one of the input signals is shifted in frequency (offset).

  Next, the frequency determination control step S103 is performed. In this frequency determination control step S103, a signal spectrum detection appearance pattern composed of the frequency division region of one signal spectrum detected in the detection processing step S102 and the frequency division region of the other signal spectrum, and a frequency determination table 14a. And the frequency position of the input signal is specified and the frequency is determined. This enables frequency measurement of input signals from DC to Fs.

  In addition, between the above step S101 and step S102, the first branch signal is passed through the first filter having a pass bandwidth of DC to Fs, and the second filter having the pass bandwidth of DC to Fs is passed. A first band limiting step for passing the second branch signal after the frequency shift may be provided.

  As described above, according to the present embodiment, the signal folding characteristics of the sampling process are used, and the signal spectrum of the input signal is frequency-shifted and the signal spectrum of the normal input signal is compared. The restriction of the frequency measurement bandwidth due to the influence of the aliasing signal at the time of sampling is relaxed, and the frequency of the input signal can be measured up to the sampling frequency.

  In this way, using the sampling method of digital signal processing technology for the input signal and the frequency conversion method for performing the frequency conversion of the input signal, the spectrum including the aliasing signal by aliasing and the contents of the comparison table are compared and referenced. Thus, it is possible to measure the frequency of the input signal from DC to the sampling frequency.

Further, for example, in Patent Document 2, it is possible to measure a frequency of (1/2) fs or more by changing Δf that is normally fixed. To that end, it is necessary to change Δf each time. Yes, and frequency measurement needs to be performed. This also increases the amount of calculation and decreases the measurement speed. For example, when a signal exists only for a short time, it becomes difficult to detect the signal.
On the other hand, in the present embodiment, the generation position of the spectrum of the signal existing outside the band is specified by comparing the spectrum of the signal of frequency f and the signal of frequency f + Δf with respect to the input signal. At this time, in principle, the frequency characteristics of the aliasing component of the signal are effectively used, and the signal frequency can be measured by a simple method, so that the measurement speed is improved, for example, when the signal exists only for a short time. Even so, the signal can be detected.

Further, for example, in Patent Document 3, it is necessary to change the mapping fp to fp ′ in order to obtain a non-inverted spectrum, and to perform frequency analysis (FFT) processing each time. In addition, in Patent Document 3, it is necessary to further perform decimation processing for the final frequency determination. This process is to resample at a decimation rate, and is realized by a combination of a filter process for performing decimation and a downsampling process with a specific decimation rate. Therefore, in order to obtain a required frequency analysis result, it is difficult to accurately detect a signal having a long processing time and changing or appearing in a short time.
On the other hand, in this embodiment, it is not necessary to change the offset frequency for frequency measurement, and it is not necessary to perform the frequency analysis processing a plurality of times. For this reason, it is possible to accurately detect a signal that changes or appears in a short time.
Further, in principle, the signal frequency measurement can be performed by a simple method by effectively using the appearance characteristic of the folded component of the signal.

Here, some of the blocks (for example, reference numeral 13, reference numeral 33, reference numeral 14b, etc.) in the block diagram shown in FIG. 1 function according to the program by the computer executing various programs stored in an appropriate memory. It may be a software module configuration that indicates an integrated state.
That is, the physical configuration is, for example, one or a plurality of CPUs (or one or a plurality of CPUs and one or a plurality of memories), etc., but the software configuration by each unit (circuit / means) is exhibited by the CPU by controlling the program. A plurality of functions are expressed as components by a plurality of units (means).
When the CPU dynamically expresses a dynamic state (a state in which each procedure constituting the program is executed) executed by the program, each unit (means) is configured in the CPU. In a static state in which the program is not executed, the entire program (or each program part included in the configuration of each unit) that realizes the configuration of each unit is stored in a storage area such as a memory.
The description of each part (means) described above can be interpreted as a computer functionalized by a program together with the function of the program, or a plurality of functions permanently functioning by specific hardware. Naturally, it can be interpreted that the device comprising the electronic circuit block is described. Therefore, these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof, and is not limited to any one.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 12 is a block diagram showing an example of the overall configuration of the frequency measurement device according to the second embodiment of the present invention.

  In the first embodiment described above, the case where the frequency measurement range of the input signal is a frequency from the zero frequency to the sampling frequency Fs has been described. However, in this embodiment, the frequency higher than the sampling frequency Fs can be measured. Is shown.

That is, when the input signal is sampled by the sampling theorem as described above, the input signal is folded.
Sampling methods are broadly divided into oversampling that samples at twice or more the maximum frequency of the input signal and undersampling that samples at or below the maximum frequency of the input signal, and it has been found that aliasing occurs in any sampling method.
Using the characteristics of undersampling, frequency measurement is possible for signals having frequency components higher than the sampling frequency.

FIG. 13 shows spectrum detection characteristics when a signal having a frequency higher than the sampling frequency is input (undersampling condition).
In the example shown in FIG. 13, a signal in the range of [2Fs] <input signal frequency f ≦ [(9/4) Fs] exceeding the sampling frequency Fs is input. It can be seen that an aliased spectrum of the input signal is generated in the spectrum detection range (regions I to IV) described in (1).
That is, by using this result, it is possible to calculate the frequency value of the portion corresponding to DC to Fs in the frequency of the input signal. On the other hand, as the coarse measurement frequency measurement, it is possible to measure the frequency of the input signal by detecting how many times the input signal is in the frequency region and summing the frequency calculation results of both.

  Specifically, as shown in FIG. 12, the frequency measurement apparatus 100 according to the present embodiment includes a first A / D converter 112 having the same configuration as that of the first embodiment, Frequency calculation means 113, sampling clock generation means 122, clock frequency division means 121, frequency conversion means 123, second A / D conversion means 132, second frequency calculation means 133, and frequency determination table In addition to having the first frequency determination control unit 114b, a wideband filter 141 as a third filter unit formed in the previous stage of the frequency conversion unit 123, and an input signal that has passed through the wideband filter 141 is branched. Coarse measurement frequency measuring means 150 for measuring the third branch signal among the first, second and third branch signals, the result of the rough measurement frequency measurement means 150 and the first frequency determination control A second frequency determining unit 161 as a second frequency judgment control means is in the added structure is determined based on the results of 114b.

  Among these, the first A / D converter 112, the first frequency calculation means 113, the sampling clock generation means 122, the clock frequency division means 121, the frequency conversion means 123, and the second A / D conversion. The means 132, the second frequency calculation means 133, the frequency determination table 114a, and the first frequency determination control unit 114b constitute the precise frequency measurement means 110.

  The wideband filter 141 is preferably a filter that maximizes the band (for example, about several hundred MHz) in which the first and second A / D converters 112 and 132 can perform undersampling.

  The rough measurement frequency measurement means 150 includes a third frequency calculation means 151. The third frequency calculation means 151 is a means for measuring the frequency of the input signal by rough measurement, and is the same as the sampling frequency Fs. Has a frequency measurement accuracy of the order.

  For example, an analog method using a discriminator can be used to realize the third frequency calculation unit 151.

  The second frequency determination control unit 161 is a unit that finally determines the frequency of the input signal. The output frequency of the third frequency calculation unit 151 and the frequency output from the first frequency determination control unit 114b The total value of is output.

  Here, the correspondence between the configuration requirements described in the present embodiment and the configuration requirements described in the present invention will be described. By the broadband filter 141 of the present embodiment, the “second band limiting means” according to the present invention is described. Can be configured. Further, the second frequency determination control unit 161 of the present embodiment can constitute the “second frequency determination control means” referred to in the present invention.

  This “second band limiting means” can band limit frequency components outside the pass band of the input signal, with a wide band up to a specific frequency equal to or higher than the sampling frequency among the frequencies of the input signal as a pass band. . In this case, the “first frequency determination control means” is a folded component by undersampling based on the first and second branch signals obtained by branching the signal band-limited by the second band-limiting means. Control for determining the frequency of the input signal can be performed from the appearance pattern of each signal spectrum.

  Further, the coarse measurement frequency measuring means 150 is based on the third branch signal among the first to third branch signals obtained by branching the signal band-limited by the second band limit means. Measurement frequency can be measured.

  Further, the “second frequency determination control means” converts the frequency of the second branch signal by the first frequency conversion control means, and converts the first branch signal and the frequency-converted second branch. Based on the precise frequency estimation result in the first frequency judgment control means determined based on the signal and the rough measurement frequency estimation result in the coarse measurement frequency measurement means, the frequency judgment control of the input signal It can be performed.

  The frequency measuring apparatus 100 having the above-described configuration operates generally as follows. That is, the frequency determined by the first frequency determination control unit 114b of the precise measurement frequency measurement unit 110 (precise measurement frequency f0) and the frequency calculated by the third frequency calculation unit 151 of the coarse measurement frequency measurement unit 150. The (roughly measured frequency f1) is added by the second frequency determination control unit 161.

  For example, as shown in FIG. 13, the spectrum detection region by the third frequency calculation means 151 is the spectrum detection region III shown in FIG. 13, and the frequency (precision) determined by the first frequency determination control unit 114b is shown. When the frequency measurement f0) is in the region I, 2Fs + [(1/4) Fs] = [(9/4) Fs].

  Further, the spectrum detection area II by the third frequency calculation means 151 is the spectrum detection area II shown in FIG. 13, and the frequency (precise measurement frequency f0) determined by the first frequency determination control unit 114b is the area. In the case of I, Fs + [(1/4) Fs] = [(5/4) Fs].

  Here, when implemented as a frequency measurement method in the present embodiment, the following steps may be performed in addition to the steps shown in FIG. 11 of the first embodiment.

  That is, the second band limiting step is performed before the frequency conversion processing step of S101 shown in FIG. In the second band limiting step, the frequency component outside the pass band of each branch signal by the second band limiting unit that sets a wide band up to a specific frequency equal to or higher than the sampling frequency among the frequencies of the input signal. The bandwidth can be limited.

  Thus, in the first frequency determination control step corresponding to the frequency determination control processing step of step S103, undersampling is performed based on each branch signal obtained by branching the signal band-limited in the second band-limiting step. Control for determining the frequency of the input signal can be performed from the appearance pattern of each signal spectrum of the aliasing component.

  Furthermore, after this second band limiting step, before or after steps S101 to S103, a rough measurement frequency measurement step is performed. In this rough measurement frequency measurement step, a rough measurement frequency can be measured based on one of the branch signals among the branch signals obtained by branching the signal band-limited in the second band limit step. it can.

  Then, after the rough measurement frequency measurement step and the first frequency determination control step, a second frequency determination control step is performed. In the second frequency determination control step, each of the branch signals other than the one branch signal and the second branch signal is frequency-converted in the first frequency conversion control step, and the second branch signal and the second branch signal Based on the precise frequency estimation result in the second frequency determination control step determined based on each other branch signal and the coarse frequency estimation result in the coarse frequency measurement step, the input signal Frequency determination control can be performed.

  As described above, according to the present embodiment, it is possible to easily measure the frequency of the input signal exceeding the sampling frequency without using an expensive device while exhibiting the same effects as the first embodiment. It becomes.

  In addition, undersampling processing is applied in sampling processing, and rough measurement frequency measurement is performed, so that measurement of a wideband and high frequency signal frequency exceeding the sampling frequency can be realized inexpensively and easily.

  As a result, it is possible to measure the frequency of a signal spread over a wide band such as an FH (Frequency Hopping) signal, which has been difficult to measure as in the related art, and to improve the device performance of a radio wave monitoring system that requires broadband spectrum monitoring. It can contribute to improvement.

  In this way, using the sampling method of digital signal processing technology for the input signal and the frequency conversion method for performing the frequency conversion of the input signal, the spectrum including the aliasing signal by aliasing and the contents of the comparison table are compared and referenced. Thus, it is possible to measure the frequency of the input signal from DC to the sampling frequency (at the time of Nyquist sampling) and to measure the frequency of the input signal that exceeds the sampling frequency (at the time of undersampling).

Further, for example, in Japanese Patent Application Laid-Open No. 2002-236135, in order to determine a large frame of the signal frequency (described as “frequency band A” in the same publication), the main point is [(1/2) fs]. Determine whether it is a region, a region centered on [(3/2) fs] or a region centered on [(5/2) fs]), and the frequency was calculated by performing an FFT operation. In the above, in order to obtain the mapping fp of the non-inverted spectrum, the decimation processing (filter processing and downsampling processing) and the FFT operation are performed, and further, the decimation processing is performed to change the mapping fp to two fp ′. (Filter processing and down-sampling processing) and FFT calculation had to be performed. Therefore, in order to obtain a required frequency analysis result, it is difficult to accurately detect a signal having a long processing time and changing or appearing in a short time.
On the other hand, in the present embodiment, it is possible to measure the signal frequency by a simple method by effectively using the appearance characteristic of the aliasing component of the signal, and it is not necessary to perform the frequency analysis processing a plurality of times, and the time is short. It is possible to accurately detect a signal that changes or appears in.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Third Embodiment]
Next, a third embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 14 is a block diagram showing an example of the overall configuration of a frequency measurement device according to the third embodiment of the present invention.

  In the second embodiment described above, the measurable frequency range is limited to the band in which the A / D converter can be undersampled. On the other hand, in the third embodiment, when the frequency conversion means in the above embodiment is the first frequency conversion means, measurement can be performed by newly adding the second frequency conversion means. The frequency range can be expanded.

  Specifically, as shown in FIG. 14, the frequency measurement apparatus 200 of the present embodiment includes a first A / D converter 212 having the same configuration as that of the first embodiment, a first Frequency calculation means 213, sampling clock generation means 222, clock frequency division means 221, frequency conversion means 223, second A / D conversion means 232, second frequency calculation means 233, and frequency determination table In addition to having 214a and the first frequency determination control unit 214b, the wideband filter 241 as the third filter unit, which has the same configuration as the second embodiment, and the rough measurement frequency measurement means 250 And a second frequency determination control unit 261 as a second frequency determination control means, and further, a second frequency conversion means 242 unique to the present embodiment is provided in the preceding stage of the broadband filter 241. It has become a pressing configuration.

  Among these, the first A / D converter 212, the first frequency calculation means 213, the sampling clock generation means 222, the clock frequency division means 221, the frequency conversion means 223, and the second A / D conversion. The means 232, the second frequency calculation means 233, the frequency determination table 214a, and the first frequency determination control unit 214b constitute a precise frequency measurement means 210.

The first frequency conversion means 242 can be configured by a frequency conversion circuit or the like. Further, the first frequency conversion unit 242 performs frequency conversion in units of fb × M (M is a positive integer) [Hz], where fb [Hz] is a frequency range that can be measured in the second embodiment. carry out.
Thereby, it is possible to measure the frequency of the input signal up to fb × Nmax (Nmax is the maximum value of N).

  Here, the correspondence between the configuration requirements described in the present embodiment and the configuration requirements described in the present invention will be described. The second frequency conversion means 242 in the present embodiment uses the “second” in the present invention. The frequency conversion control means ”can be configured.

  This “second frequency conversion control means” is arranged in front of the second band limiting means, and fb × M (M is the frequency where fb is a measurable frequency by the second frequency determination control means. , A positive integer) unit, the frequency of the input signal can be converted.

  In addition, when implemented as a frequency measurement method in this embodiment, in addition to the steps shown in FIG. 11 and the steps shown in the second embodiment of the first embodiment, What is necessary is just to implement a step.

  That is, the second frequency conversion control step is performed before the second band limiting step of the second embodiment. In the second frequency conversion control step, fb × M (M is a positive integer) when the measurable frequency in the second frequency determination control step is set to fb before the second band limiting step. The frequency of the input signal in units can be converted.

  As described above, according to the present embodiment, it is possible to measure the frequency of an input signal up to fb × Nmax (Nmax is the maximum value of N) while exhibiting the same operational effects as the first embodiment. It becomes.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Fourth Embodiment]
Next, a fourth embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 14 is a block diagram showing an example of the overall configuration of a frequency measurement device according to the fourth embodiment of the present invention.

  In the present embodiment, an example is shown in which the functions of the frequency measurement apparatuses of the first to third embodiments can be appropriately switched and controlled. That is, the frequency measurement device according to the first embodiment that enables measurement in the frequency domain from DC to Fs, and the frequency measurement device according to the second embodiment that enables measurement above the sampling frequency Fs by undersampling. Further, the function of any one of the frequency measurement devices is appropriately realized by switching control between the frequency measurement device of the third embodiment in which the range of the measurable band is further expanded.

  Specifically, as shown in FIG. 15, the frequency measurement apparatus 300 of the present embodiment includes a first A / D converter 312 having the same configuration as that of the third embodiment, Frequency calculation means 313, sampling clock generation means 322, clock frequency division means 321, frequency conversion means 323, second A / D conversion means 332, second frequency calculation means 333, and frequency determination table 314a, first frequency determination control unit 314b, wideband filter 341, rough measurement frequency measurement unit 350 including third frequency calculation unit 351, and second frequency determination control unit 361, The filter 342 includes a first switching unit 371, a second switching unit 372, a switching control unit 373, and an operation unit 374.

  The first switching unit 371 switches between using the second frequency converting unit 343 and not using it. When used, a frequency measuring device similar to that of the third embodiment is realized, and when not used, a frequency measuring device similar to that of the second embodiment is realized.

  The second switching means 372 uses the wideband filter 341 and uses the first to third branch signals, and the filter 342 uses the first and second branch signals. Switch between two modes. The filter 342 uses DC to Fs as a pass band. Thereby, in the first mode, a frequency measurement device similar to that of the second embodiment is realized, and in the second mode, a frequency measurement device similar to that of the first embodiment is realized.

  The switching control means 373 controls the first switching means 371 and the second switching means 372 based on the operation from the operating means 374, and in the second frequency determination control unit 361, the rough measurement frequency measuring means. Switching control is performed between the case where the measurement result of 350 is added and the case where it is not added. Thereby, in the first mode, a frequency measurement device similar to that of the second embodiment is realized, and in the second mode, a frequency measurement device similar to that of the first embodiment is realized.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Fifth Embodiment]
Next, a fifth embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 16 is an explanatory diagram showing an example of a data structure of a frequency determination table used in the frequency measurement device according to the fifth embodiment of the present invention.

  In the first embodiment described above, the frequency is determined by paying attention to the region I and the region II at the time of the frequency determination. However, the present invention is not limited to this. As described above, the frequency may be determined by paying attention to the region III and the region IV.

  Specifically, in the data structure of the frequency determination table in the frequency measurement apparatus according to the present embodiment, as shown in FIG. 16, the frequency f (signal frequency) of the input signal is 0 <f ≦ [(1/4). Fs], the signal spectrum that is the output of the first frequency calculation means 13 appears in the region IV, and the signal spectrum that is the output of the second frequency calculation means 33 appears in the region III.

  When the frequency f (signal frequency) of the input signal is [(1/4) Fs] <f ≦ [(1/2) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region III and is the output of the second frequency calculation means 33 appears in the region III.

  Furthermore, when the frequency f (signal frequency) of the input signal is [Fs / 2] <f ≦ [(3/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is in region III. The signal spectrum that appears and is the output of the second frequency calculation means 33 appears in the region IV.

  Furthermore, when the frequency f (signal frequency) of the input signal is [(3/4) Fs] <f ≦ [(1/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region IV and is the output of the second frequency calculation means 33 appears in the region IV.

  Even by configuring the data structure of the frequency determination table with such a configuration, the frequency of the input signal can be determined because the appearance pattern of each signal spectrum that appears has characteristics unique to each frequency division region of the input signal. Can do. This data structure is an example of the “first structure” in the present invention.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Sixth Embodiment]
Next, a sixth embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 17 is an explanatory diagram showing an example of a data structure of a frequency determination table used in the frequency measurement device according to the sixth embodiment of the present invention.

  In the first embodiment described above, the frequency is shifted (offset) by (1/4) Fs to shift the frequency. However, in this embodiment, the frequency is shifted by-(1/4) Fs. An example of shifting (offset) is shown.

  Specifically, in the data structure of the frequency determination table in the frequency measurement apparatus according to the present embodiment, as shown in FIG. 17, the frequency f (signal frequency) of the input signal is 0 <f ≦ [(1/4). Fs], the signal spectrum output from the first frequency calculating unit 13 appears in the region I, and the signal spectrum output from the second frequency calculating unit 33 appears in the region I.

  When the frequency f (signal frequency) of the input signal is [(1/4) Fs] <f ≦ [(1/2) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region II and is the output of the second frequency calculation means 33 appears in the region I.

  Furthermore, when the frequency f (signal frequency) of the input signal is [Fs / 2] <f ≦ [(3/4) Fs], the signal spectrum that is the output of the first frequency calculating means 13 is in the region II. The signal spectrum that appears and is the output of the second frequency calculation means 33 appears in the region II.

  Furthermore, when the frequency f (signal frequency) of the input signal is [(3/4) Fs] <f ≦ [(1/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region I and is the output of the second frequency calculation means 33 appears in the region II.

  Even by configuring the data structure of the frequency determination table with such a configuration, the frequency of the input signal can be determined because the appearance pattern of each signal spectrum that appears has characteristics unique to each frequency division region of the input signal. Can do. This data structure is an example of the “first structure” in the present invention.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Seventh Embodiment]
Next, a seventh embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 18 is an explanatory diagram showing an example of a data structure of a frequency determination table used in the frequency measurement device according to the seventh embodiment of the present invention.

  In the above-described sixth embodiment, the frequency is determined by focusing on the region I and the region II at the time of frequency determination with a shift (offset) of − (1/4) Fs. However, the present invention is not limited to this, and the frequency may be determined by paying attention to the region III and the region IV as in the present embodiment.

  Specifically, in the data structure of the frequency determination table in the frequency measurement apparatus of the present embodiment, as shown in FIG. 18, the frequency f (signal frequency) of the input signal is 0 <f ≦ [(1/4) Fs], the signal spectrum output from the first frequency calculation unit 13 appears in the region IV, and the signal spectrum output from the second frequency calculation unit 33 appears in the region IV.

  When the frequency f (signal frequency) of the input signal is [(1/4) Fs] <f ≦ [(1/2) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region III and is the output of the second frequency calculation means 33 appears in the region IV.

  Further, when the frequency f (signal frequency) of the input signal is [Fs / 2] <f ≦ [(3/4) Fs], the signal spectrum that is the output of the first frequency calculating means 13 is in the region IV. The signal spectrum that appears and is the output of the second frequency calculation means 33 appears in the region III.

  Furthermore, when the frequency f (signal frequency) of the input signal is [(3/4) Fs] <f ≦ [(1/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region IV and is the output of the second frequency calculation means 33 appears in the region III.

  Even by configuring the data structure of the frequency determination table with such a configuration, the frequency of the input signal can be determined because the appearance pattern of each signal spectrum that appears has characteristics unique to each frequency division region of the input signal. Can do. This data structure is an example of the “first structure” in the present invention.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Eighth Embodiment]
Next, an eighth embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 19 is an explanatory diagram showing an example of a data structure of a frequency determination table used in the frequency measurement device according to the eighth embodiment of the present invention.

  In the first embodiment described above, the frequency is shifted by (1/4) Fs in order to shift the frequency. However, in this embodiment, the frequency is shifted by (3/4) Fs. An example in the case of (offset) is shown.

  Specifically, in the data structure of the frequency determination table in the frequency measurement apparatus of the present embodiment, as shown in FIG. 19, the frequency f (signal frequency) of the input signal is 0 <f ≦ [(1/4) Fs], the signal spectrum output from the first frequency calculating unit 13 appears in the region I, and the signal spectrum output from the second frequency calculating unit 33 appears in the region I.

  When the frequency f (signal frequency) of the input signal is [(1/4) Fs] <f ≦ [(1/2) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region II and is the output of the second frequency calculation means 33 appears in the region I.

  Furthermore, when the frequency f (signal frequency) of the input signal is [Fs / 2] <f ≦ [(3/4) Fs], the signal spectrum that is the output of the first frequency calculating means 13 is in the region II. The signal spectrum that appears and is the output of the second frequency calculation means 33 appears in the region II.

  Furthermore, when the frequency f (signal frequency) of the input signal is [(3/4) Fs] <f ≦ [(1/4) Fs], the signal spectrum that is the output of the first frequency calculation means 13 is The signal spectrum that appears in the region I and is the output of the second frequency calculation means 33 appears in the region II.

  Even by configuring the data structure of the frequency determination table with such a configuration, the frequency of the input signal can be determined because the appearance pattern of each signal spectrum that appears has characteristics unique to each frequency division region of the input signal. Can do. This data structure is an example of the “first structure” in the present invention.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Ninth Embodiment]
Next, a ninth embodiment according to the present invention will be described with reference to FIGS. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 20 shows spectrum detection characteristics detected when the input signal frequency f is 0 <f ≦ [(1/6) Fs] in each frequency calculation means of the frequency measuring apparatus according to the ninth embodiment of the present invention. It is explanatory drawing which shows an example. FIG. 21 is an explanatory diagram showing an example of a data structure of a frequency determination table used in the frequency measurement device according to the ninth embodiment of the present invention.

  In the first embodiment described above, the input signal is branched into two systems of the first branch signal and the second branch signal, and (1/4) Fs is used to shift the frequency of the second branch signal. In this embodiment, the input signal is branched into three systems of a first branch signal, a second branch signal, and a second branch signal, and the second branch signal is used. Is shifted by (1/6) Fs to shift the frequency of (3), and (1/3) Fs is shifted (offset) to shift the frequency of the third branch signal. An example is shown.

  Specifically, in the frequency measurement device according to the present embodiment, a first frequency conversion unit for performing frequency shift of the first branch signal and a third for performing frequency shift of the second branch signal. Frequency converter, a fourth frequency converter for performing frequency shift of the third branch signal, a first A / D converter for A / D converting the first branch signal, a second A second A / D converter for A / D converting the first branch signal, a third A / D converter for A / D converting the third branch signal, and a first frequency for calculating the frequency of the first branch signal. Frequency calculation means, second frequency calculation means for calculating the frequency of the second branch signal, third frequency calculation means for calculating the frequency of the third branch signal, these first frequency calculation means and second Frequency determination for determining the frequency of the input signal based on the result of the third frequency calculation means and the third frequency calculation means It may have a control unit and a frequency determination table.

  A first filter section for band-limiting a frequency component outside the passband of the first branch signal, with a first passband from a zero frequency of the first branch signal to the sampling frequency; A second filter unit for band-limiting frequency components outside the pass band of the second branch signal, with the second branch signal having a pass band from the zero frequency of the second branch signal to the sampling frequency; A third filter unit that limits the frequency component outside the pass band of the third branch signal with a pass band from the zero frequency of the third branch signal to the sampling frequency may be provided.

  Here, the frequency region from the zero frequency to the sampling frequency Fs is divided into blocks for each Fs / 6 frequency, and the divided frequency division regions are sequentially divided into regions I [0 <f ≦ [(1/6 from the low frequency side. ) Fs]], region II [[(1/6) Fs] <f ≦ [(1/3) Fs]], region III [[((1/3) Fs] <f ≦ [(1/2) Fs ], Region IV [[(1/2) Fs] <f ≦ [(2/3) Fs]], region V [[(2/3) Fs] <f ≦ [(5/6) Fs]] , Region VI [[(5/6) Fs] <f ≦ Fs].

  In this case, since the boundary between the region III and the region IV is set to be Fs / 2, when the frequency shift (offset) is not considered, when the frequency of the input signal is in the region I according to the sampling theorem, It is assumed that the folding component (folding signal) of the signal spectrum is generated in the region VI. Similarly, when the frequency of the input signal is in the region II, the folded component (folded signal) of the signal spectrum is generated in the region V. Further, when the frequency of the input signal is in the region III, the folded component (folded signal) of the signal spectrum is generated in the region IV.

  For example, as shown in FIG. 20, when the frequency f (signal frequency) of the input signal is 0 <f ≦ [(1/6) Fs], the signal spectrum that is the output of the first frequency calculation means is a region. The signal spectrum that appears at I and is the output of the second frequency calculation means shifts from the area I by [(1/6) Fs], and thus appears in the area II and is the output of the third frequency calculation means. Since the signal spectrum shifts from the region I by [(1/3) Fs], it appears in the region III.

  FIG. 21 shows the appearance of each signal spectrum at the output of each frequency calculation means when the frequency f (signal frequency) of the input signal changes stepwise for each [(1/6) Fs]. The data structure of the frequency determination table which showed the pattern is shown.

  For example, when the frequency f (signal frequency) of the input signal is [[(1/6) Fs] <f ≦ [(1/3) Fs]], the signal spectrum that is the output of the first frequency calculating means is The signal spectrum that appears in the region II and is the output of the second frequency calculation means appears in the region III, and the signal spectrum that is the output of the third frequency calculation means appears in the region I.

  Similarly, when the frequency f (signal frequency) of the input signal is [[(1/3) Fs] <f ≦ [(1/2) Fs]], the signal spectrum which is the output of the first frequency calculation means Appears in region III, the signal spectrum that is the output of the second frequency calculation means appears in region I, and the signal spectrum that is the output of the third frequency calculation means appears in region II.

  Similarly, when the frequency f (signal frequency) of the input signal is [[(1/2) Fs] <f ≦ [(2/3) Fs]], the signal spectrum that is the output of the first frequency calculating means. Appears in region III, the signal spectrum that is the output of the second frequency calculating means appears in region II, and the signal spectrum that is the output of the third frequency calculating means appears in region I.

  Similarly, when the frequency f (signal frequency) of the input signal is [[(2/3) Fs] <f ≦ [(5/6) Fs]], the signal spectrum that is the output of the first frequency calculating means. Appears in region II, the signal spectrum that is the output of the second frequency calculation means appears in region I, and the signal spectrum that is the output of the third frequency calculation means appears in region I.

  Similarly, when the frequency f (signal frequency) of the input signal is [[(5/6) Fs] <f ≦ Fs], the signal spectrum that is the output of the first frequency calculation means appears in the region I. The signal spectrum that is the output of the second frequency calculation means appears in region I, and the signal spectrum that is the output of the third frequency calculation means appears in region II.

  Even by configuring the data structure of the frequency determination table with such a configuration, the frequency of the input signal can be determined because the appearance pattern of each signal spectrum that appears has characteristics unique to each frequency division region of the input signal. Can do. This data structure is an example of the “first structure” in the present invention.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Tenth embodiment]
Next, a tenth embodiment according to the present invention will be described with reference to FIG. In the following, description of the substantially similar configuration of the first embodiment will be omitted, and only different parts will be described. FIG. 22 is a flowchart showing an example of an outline of the frequency measurement method of the present invention.

  In the frequency measurement method in the above-described embodiment, the processing is performed in the order of the frequency conversion processing step, the detection processing step, and the frequency determination control processing step. However, in this embodiment, the first branch signal that is not subjected to frequency conversion is processed. You may perform the 1st detection process step which performs a detection, before performing a frequency conversion process step.

  That is, as shown in FIG. 22, in the frequency measurement method for sampling the input signal based on the sampling frequency and measuring the frequency of the input signal based on the signal spectrum including the aliasing component of the sampled sampling signal, A first detection processing step (step) of sampling one of the branch signals among the branch signals obtained by branching the input signal and detecting the frequency of the signal spectrum of the sampling signal including the aliasing component of the branch signal S201) is performed.

  Subsequently, among the branch signals obtained by branching the input signal into a plurality of signals, the respective frequencies of the other branch signals other than the one branch signal are converted into respective shifted frequencies shifted by different frequencies. A frequency conversion processing step (step S202) as a first frequency conversion control step for performing control is performed.

  Then, a second detection processing step of sampling each of the other branch signals having the deviation frequency and detecting the frequency of each signal spectrum of each sampling signal including the aliasing component of each branch signal (step S203). I do.

  Subsequently, each frequency division region in which each signal spectrum including the aliasing component appears when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions. The frequency division region of the input signal is determined and measured based on the appearance pattern information indicating the combination of and the detected appearance pattern of each signal spectrum detected in the first and second detection processing steps. A frequency determination control processing step (step S204) is performed as a first frequency determination control step for performing control to output the frequency.

  Also by such a frequency measurement method, the same operational effects as those of the above-described embodiment can be obtained.

  Other configurations, other steps, and operational effects thereof are the same as those in the first embodiment described above. In the above description, the operation content of each step described above and the components of each unit may be programmed and executed by a computer.

[Various modifications]
Also, although the apparatus and method according to the present invention have been described according to some specific embodiments thereof, the embodiments described in the text of the present invention can be used without departing from the spirit and scope of the present invention. Various modifications are possible.

For example, in the above-described first embodiment, the case of shifting (offset) by 4 / Fs has been described. However, the present invention is not limited to this, and may be offset by other various frequencies.
Specifically, among the first to nth branch signals (n is a positive integer) obtained by branching the input signal into n pieces from the first embodiment and the fifth to ninth embodiments, The frequencies of the second to n-th branch signals are respectively converted into shift frequencies shifted by (1 / 2n) Fs or (1 / 2n) Fs + (1/2) Fs frequency with respect to the sampling frequency Fs. By doing so, the frequency can be determined.

  In particular, the frequency of the second branch signal is converted to a shift frequency shifted by (1 / 2n) Fs or (1 / 2n) Fs + (1/2) Fs frequency, and the frequency of the third branch signal. Is converted to a shifted frequency shifted by 2 (1 / 2n) Fs or 2 (1 / 2n) Fs + (1/2) Fs frequency, and the frequency of the fourth branch signal is converted to 3 (1 / 2n). ) Fs or 3 (1 / 2n) Fs + (1/2) Fs converted to a shifted frequency by frequency,..., (N-2) (1 / 2n) Fs or (n-2) (1 / 2n) Fs + (1/2) Fs is converted to a shifted frequency and the frequency of the nth branch signal is changed to (n-1). ) (1 / 2n) Fs or (n-1) (1 / 2n) Fs + (1/2) Fs It is preferable to convert the frequency to a shifted frequency.

  In this case, when each of the n frequency division regions obtained by dividing the sampling frequency Fs from the zero frequency into n regions is formed, the appearance pattern of each signal spectrum by each branch signal is at each frequency stage of the input signal. It becomes unique and frequency determination can be performed.

  Further, the first frequency conversion control means shifts the frequency of each of the branch signals other than the one of the branch signals out of the branch signals obtained by branching the input signal into a plurality of different frequencies. You may make it perform control which each converts to each deviation frequency.

  In this case, the detection means samples each of the one branch signal of the frequency of the input signal and each of the other branch signals of the deviation frequency, and each signal of each sampling signal including the aliasing component of each branch signal. Each frequency of the spectrum can be detected.

  Further, the first frequency conversion control means may be configured such that each of the signal spectrums including the aliasing component when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions. And determining the frequency division region of the input signal based on the appearance pattern information indicating the combination of the frequency division regions in which each appears and the detected appearance pattern of each signal spectrum detected by the detection means, It is also possible to control to output as a measurement frequency.

  At this time, the appearance pattern information storage means is configured such that when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region, each signal spectrum including the aliasing component is Appearance pattern information indicating a combination of the appearing frequency division regions may be stored according to each frequency of the input signal.

  Further, the first frequency determination control means is configured so that each signal spectrum detected by the detection means is equal to or less than (1/2) Fs in each frequency division region from zero frequency to the sampling frequency Fs. In the frequency division region, control is performed to determine the frequency of (1/2) Fs or more of the input signal based on the appearance pattern of the aliasing component of the signal spectrum of (1/2) Fs or more of each sampling signal. be able to.

Further, the first frequency conversion control means is configured such that the frequency of the second to n-th branch signals among the first to n-th branch signals (n is a positive integer) obtained by branching the input signal into n. Can be converted into a shift frequency shifted by (1 / 2n) Fs or (1 / 2n) Fs + (1/2) Fs frequency with respect to the sampling frequency Fs. At this time, the first frequency determination control means, based on which frequency division region of each frequency division region divided for each Fs / 2n frequency the appearance pattern of each signal spectrum belongs to, Control for determining the frequency of the input signal can be performed.

  The first frequency conversion control means sets the frequency of the second branch signal out of the first branch signal and the second branch signal obtained by branching the input signal to 1/4 of the sampling frequency Fs or The frequency can be converted into a shifted frequency that is shifted by 3/4 frequency, and the first frequency determination control step is configured such that the appearance pattern of each signal spectrum is divided into Fs / 4 frequencies. Control for determining the frequency of the input signal can be performed on the basis of which of the divided regions the frequency division region belongs to.

  Further, the first frequency determination control means may be configured such that the shift and the size of each frequency division region are such that a combination of the appearance patterns corresponding to each frequency of the input signal is not the same at different frequencies. Control for determining the frequency of the input signal can be performed based on the appearance pattern defined in.

  In addition, the frequency measurement method is also intended for sampling an input signal based on a sampling frequency and measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal. it can.

  In the first frequency conversion control step in this frequency measurement method, among the branch signals obtained by branching the input signal into a plurality of frequencies, the frequencies of the other branch signals other than the one branch signal are set to different frequencies. It is possible to perform control for conversion to each shifted frequency.

  In the detection step, each signal spectrum of each sampling signal that samples each of the one branch signal of the frequency of the input signal and each of the other branch signals of the shift frequency and includes a aliasing component of each branch signal. Can be detected respectively.

  Further, in the first frequency determination control step, each signal spectrum including the aliasing component when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions. And determining the frequency division region of the input signal based on the appearance pattern information indicating the combination of the frequency division regions in which each appears and the detected appearance pattern of each signal spectrum detected in the detection step, Control to output as a measurement frequency can be performed.

  In the first frequency determination control step, each signal spectrum detected in the detection step is equal to or less than (1/2) Fs in each frequency division region from zero frequency to the sampling frequency Fs. In the frequency division region, control is performed to determine the frequency of (1/2) Fs or more of the input signal based on the appearance pattern of the aliasing component of the signal spectrum of (1/2) Fs or more of each sampling signal. be able to.

In the first frequency conversion control step, the frequency of the second to n-th branch signals among the first to n-th branch signals (n is a positive integer) obtained by branching the input signal into n. Can be converted into a shift frequency shifted by (1 / 2n) Fs or (1 / 2n) Fs + (1/2) Fs frequency with respect to the sampling frequency Fs. At this time, in the first frequency determination control step, based on which frequency division region of each frequency division region divided for each Fs / 2n frequency the appearance pattern of each signal spectrum belongs to. Control for determining the frequency of the input signal can be performed.

  In the first frequency conversion control step, the frequency of the second branch signal of the first branch signal and the second branch signal branched from the input signal is set to 1/4 of the sampling frequency Fs or It is possible to convert to a shifted frequency shifted by 3/4 frequency. At this time, in the first frequency determination control step, the appearance pattern of each signal spectrum is based on which frequency division region of each frequency division region divided for each Fs / 4 frequency. Control for determining the frequency of the input signal can be performed.

  Further, in the first frequency determination control step, the shift and the size of each frequency division region are such that the combination of the appearance patterns corresponding to each frequency of the input signal is not the same at different frequencies. Control for determining the frequency of the input signal can be performed based on the appearance pattern defined in.

  Further, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like for carrying out the present invention.

  The above-described frequency measurement device may be configured to operate under program control, has a network-related function, and is a desktop, laptop computer, other information device having a wireless / wired communication function, or a similar computer, etc. Any computer can be used, mobile or fixed.

  In that case, the hardware configuration of the frequency measuring device is a display means (screen) for displaying various information, etc., and an operation for operating and inputting data on the display screen (various input fields, etc.) of this display means. Input means (for example, keyboard / mouse), transmission / reception means (communication means) for transmitting / receiving various signals / data, storage means for storing various programs / various data (for example, memory, hard disk, etc.), control of these You may have a control means (for example, CPU etc.) which manages.

(program)
Further, the software program of the present invention that realizes the functions of the above-described embodiments is a program corresponding to the processing unit (processing means), functions, etc. shown in the various block diagrams in each of the above-described embodiments, Each processing program processed in a program corresponding to the processing procedure, processing means, function, etc. shown in the flowchart etc., a program using the data structure shown in the figure, etc., a method generally described in this specification (Step), the entire processing or data of the described processing and data (for example, a frequency determination table).

  Specifically, the frequency measurement program according to the present invention performs processing for sampling an input signal based on a sampling frequency and measuring the frequency of the input signal based on a signal spectrum including a aliasing component of the sampled sampling signal. This is intended for a frequency measurement program to be executed by a computer.

  The frequency measurement program is configured such that, among the branch signals obtained by branching the input signal into a plurality, the respective shift frequencies obtained by shifting the frequencies of the branch signals other than the branch signal by different frequencies. It is possible to cause the computer to execute a function including a first frequency conversion control function (for example, step S101 shown in FIG. 11) for performing control for conversion into each of the above.

  Further, the frequency measurement program samples each of the one branch signal of the frequency of the input signal and each of the other branch signals of the deviation frequency, and each signal of each sampling signal including the aliasing component of each branch signal. It is possible to cause the computer to execute a function including a detection control function (for example, step S102 and step S103 shown in FIG. 11) for performing control for detecting each frequency of the spectrum.

  Further, the frequency measurement program may be configured such that each signal spectrum including the aliasing component appears when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions. Based on the appearance pattern information indicating the combination of the frequency division regions and the detection appearance pattern of each signal spectrum detected by the detection function, the frequency division region of the input signal is determined and output as a measurement frequency It is possible to cause the computer to execute a function including a first frequency determination control function (for example, step S104 shown in FIG. 11) for performing the control.

  In the first frequency determination control function, each signal spectrum detected by the detection control function is equal to or less than (1/2) Fs in each frequency division region from zero frequency to the sampling frequency Fs. Control for determining the frequency of (1/2) Fs or more of the input signal based on the appearance pattern of the aliasing component of the signal spectrum of (1/2) Fs or more of each sampling signal in each of the frequency division regions. It can be carried out.

Furthermore, in the first frequency conversion control function, the frequency of the second to n-th branch signals among the first to n-th branch signals (n is a positive integer) obtained by branching the input signal into n. Can be converted into a shift frequency shifted by (1 / 2n) Fs or (1 / 2n) Fs + (1/2) Fs frequency with respect to the sampling frequency Fs. In this case, in the first frequency determination control function, based on which frequency division region of each frequency division region divided for each Fs / 2n frequency the appearance pattern of each signal spectrum belongs to. Control for determining the frequency of the input signal can be performed.

  In the first frequency conversion control function, the frequency of the second branch signal of the first branch signal and the second branch signal branched from the input signal is set to 1/4 of the sampling frequency Fs or It is possible to convert to a shifted frequency shifted by 3/4 frequency. In this case, in the first frequency determination control function, based on which frequency division region of each frequency division region divided for each Fs / 4 frequency the appearance pattern of each signal spectrum belongs to. Control for determining the frequency of the input signal can be performed.

  Furthermore, in the first frequency determination control function, the shift and the size of each frequency division region are such that the combination of the appearance patterns corresponding to each frequency of the input signal is not the same at different frequencies. Control for determining the frequency of the input signal can also be performed based on the appearance pattern defined in.

  Further, the frequency measurement program causes the computer to further execute a first band limitation control function for performing a band limitation on a frequency component outside the pass band of each branch signal with a pass band from zero frequency to a sampling frequency. You can also In this case, the first frequency determination control function can perform control for determining the frequency of the input signal in each frequency division region equal to or lower than the sampling frequency.

  Further, the frequency measurement program performs control for band-limiting frequency components outside the passband of each branch signal, with a wideband up to a specific frequency equal to or higher than the sampling frequency among the frequencies of the input signal as a passband. The bandwidth limitation control function can be further executed by the computer.

  In the first frequency determination control function, based on each branch signal obtained by branching the signal band-limited by the second band-limit control function, the appearance pattern of each signal spectrum of the aliasing component by undersampling is used. Control for determining the frequency of the input signal can be performed.

  Further, the frequency measurement program is configured to perform rough measurement to measure a rough measurement frequency based on one of the branch signals obtained by branching the signal whose band is limited by the second band limitation control function. The frequency measurement function and the other branch signals other than the one branch signal and the second branch signal are frequency-converted by the first frequency conversion control function, the second branch signal and the other branch signals. On the basis of the precise frequency estimation result in the second frequency determination control function determined based on and the coarse frequency estimation result in the coarse frequency measurement function, the frequency determination control of the input signal is performed. The second frequency determination control function to be performed can be further executed by the computer.

  In addition, the frequency measurement program has fb × M (M is a positive integer), where fb is a measurable frequency by the second frequency determination control function before executing the second band limitation control function. It is also possible to cause the computer to further execute a second frequency conversion control function for performing control for converting the frequency of the input signal in units.

  The program may be in any form such as an object code, a program executed by an interpreter, or script data supplied to the OS. The program can be implemented in a high level procedural or object oriented programming language, or in assembly or machine language as required. In either case, the language may be a compiler or interpreted language. Also included are those in which the above-described frequency measurement program is incorporated in application software that can be operated on a general personal computer or a portable information terminal.

  As a method of supplying the program, it is also possible to provide the program from an external device that is communicably connected to the computer via an electric communication line (whether wired or wireless). For example, the program can be supplied by connecting to a homepage on the Internet using a browser on a computer and downloading the program itself or a compressed file including an automatic installation function from the homepage to a recording medium such as a hard disk. It can also be realized by dividing the program code constituting the program into a plurality of files and downloading each file from a different home page. That is, a server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the scope of the present invention.

  According to the frequency measurement program of the present invention, the frequency measurement program is read from a storage medium such as a ROM storing the control program into a computer (CPU) and executed, or the frequency measurement program is transmitted to the communication means. The above-described frequency measurement device according to the present invention can be realized relatively easily if it is executed after being downloaded via a computer. When the software of the frequency measuring device is embodied as an embodiment of the idea of the invention, it naturally exists and is used on a storage medium storing such software.

  Moreover, the program is the same without any question about the copying stage of the primary copy product, the secondary copy product, etc. If the program is supplied using a communication line, the communication line becomes a transmission medium and the present invention is used.

  In the data structure of the present invention, the computer performs a process of sampling the input signal based on the sampling frequency and measuring the frequency of the input signal based on the signal spectrum including the aliasing component of the sampled sampling signal. It is intended for the data structure used in

  In this data structure, each frequency at which each signal spectrum including the aliasing component appears when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality of frequency regions. A first structure in which appearance pattern information indicating a combination of divided areas is stored in accordance with each frequency of the input signal (for example, various tables in FIGS. 4, 16, 17, 18, 19, and 21). Have

  In the first structure, each of the branch signals obtained by branching the input signal into a plurality of branch signals other than the one branch signal is shifted by a different frequency. Control each conversion to a shift frequency, sample each of the one branch signal of the frequency of the input signal and each of the other branch signals of the shift frequency, and each sampling including the aliasing component of each branch signal Control the detection of each frequency of each signal spectrum of the signal, determine the frequency division region of the input signal based on the detected appearance pattern of each signal spectrum and the appearance pattern information, and measure It is used for processing for performing control to output as a frequency.

(Information recording medium)
Moreover, the structure which recorded the frequency measurement program and the data structure on the information recording medium may be sufficient. An application program including a program is stored in the information recording medium, and a computer can read the application program from the information recording medium and install the application program on the hard disk. Thus, the program can be provided by being recorded on an information recording medium such as a magnetic recording medium, an optical recording medium, or a ROM. Use of an information recording medium in which such a program is recorded in a computer constitutes a convenient information processing apparatus.

  As an information recording medium for supplying the program, for example, ROM, RAM, semiconductor memory such as flash memory and SRAM, and an integrated circuit, or a USB memory, memory card, optical disk, magneto-optical disk, magnetic recording medium and the like including them. Further, flexible disk, CD-ROM, CD-R, CD-RW, FD, DVDROM, HDDVD (HDDVD-R-SL <1 layer>, HDDVD-R-DL <2 layers>, HDDVD-RW) -SL, HDDVD-RW-DL, HDDVD-RAM-SL), DVD ± R-SL, DVD ± R-DL, DVD ± RW-SL, DVD ± RW-DL, DVD-RAM, Blu-Ray Disk <registration Trademark> (BD-R-SL, BD-R-DL, BD-RE-SL, BD-RE-DL), MO It is recorded on a portable medium such as ZIP, magnetic card, magnetic tape, SD card, memory stick, non-volatile memory card, IC card, etc., a storage device such as a hard disk built in a computer system, etc. Good.

  Furthermore, the “information recording medium” is a medium that dynamically holds a program for a short time (transmission medium), such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. Or a transmission wave), a volatile memory inside a computer system serving as a server or a client in that case, and those holding a program for a certain period of time.

  In addition, when an OS running on a computer, an RTOS on a terminal (for example, a mobile phone) performs part or all of the processing, the same functions as those in the above embodiment can be realized and An effect can be obtained.

  Furthermore, the program is encrypted, stored in a recording medium such as a CD-ROM, distributed to the user, and the user who clears the predetermined condition is allowed to download key information for decryption from the homepage via the Internet, and It is also possible to execute the encrypted program by using the key information and install the program on a computer. In this case, the configuration of the present invention may include each component (various means, steps and data) of the program and encryption means for encrypting the program (various means, steps and data).

  Moreover, you may comprise the frequency measurement system by the frequency measurement apparatus of the said embodiment, and the management apparatus formed so that communication with this frequency measurement apparatus was possible. The frequency measurement system in this case is not limited to the client server system, and may be a system based on peer-to-peer (Peer To Peer) communication in which terminals form a network without using a server and transmit / receive data to / from each other. In that case, the management apparatus may be a master terminal in a peer-to-peer system. It is also possible to configure such a “frequency measurement system” as a system integrated with other “information processing systems” as a “system”. The “information processing system” includes an OS and hardware such as peripheral devices.

  Furthermore, as an information processing apparatus in which the above-described program or the like is installed, the server is not limited to a personal computer, for example, but includes various servers, EWS (engineering workstation), medium-sized computers, mainframes, and the like. In addition to the above examples, information terminals include portable information terminals, various mobile terminals, PDAs, mobile phones, wearable information terminals, various (such as portable) televisions, DVD recorders, various acoustic devices and their remote controllers, A configuration that can be used from home appliances equipped with an information communication function, game devices having a network function, and the like may also be used. Or what was improved as an application displayed on these terminals can also be included in the scope of the present invention.

  Further, the program may be for realizing a part of the above-described functions, and further, a program that can realize the above-described functions in combination with a program already recorded in a computer system, a so-called difference file ( Difference program).

  Further, in the present specification, the steps shown in the flowchart include processes that are executed in parallel or individually even if they are not necessarily processed in time series, as well as processes that are executed in time series according to the described procedure. It is a waste. In the implementation, the order in which the program procedures (steps) are executed can be changed. Further, certain procedures (steps) described herein can be implemented, removed, added, or rearranged as a combined procedure (step) as needed for implementation.

  Furthermore, the functions of the program such as each means of the apparatus, each function, and the procedure function of each step may be achieved by dedicated hardware (for example, a dedicated semiconductor circuit). Some of these functions may be processed by hardware, and other functions among all functions may be processed by software. In the case of dedicated hardware, each unit may be formed by an integrated circuit such as an LSI. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. Further, the LSI may include other functional blocks such as a streaming engine. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology.

  Further, in “communication”, wireless communication and wired communication as well as communication in which wireless communication and wired communication are mixed, that is, wireless communication is performed in a certain section and wired communication is performed in another section. There may be. Further, communication from one device to another device may be performed by wired communication, and communication from another device to one device may be performed by wireless communication.

  This communication includes a communication network. As a network constituting the communication network, for example, a cellular phone network (including base stations and switching systems), a public phone network, an IP phone network, an ISDN network, etc. Any hardware configuration such as communication mode using IP protocol), intranet, LAN (including Ethernet: registered trademark, gigabit Ethernet, etc.), WAN, optical fiber communication network, power line communication network, and various dedicated line networks compatible with broadband But you can. In addition to the TCP / IP protocol, the network may be any communication protocol such as a network using various communication protocols, a virtual network constructed in software, or a network including all similar networks. The network is not limited to a wired network, but includes a wireless (including satellite communication, various high-frequency communication means, etc.) network (for example, a single carrier communication system such as a simple telephone system or a cellular phone, W-CDMA, or IEEE 802.11b) Network including a spread spectrum communication system such as a wireless LAN, a multi-carrier communication system such as IEEE802.11a and HiperLAN / 2, etc., or a combination of these may be used. It may be a system connected to a network. Further, the network may take any form such as point-to-point, point-to-multipoint, multipoint-to-multipoint.

  In the communication structure between the management device and the frequency measurement device, the type of interface formed on one or both of them is, for example, a parallel interface, a USB interface, IEEE 1394, a network such as a LAN or WAN, or the like. Or any interface that will be developed in the future.

  Furthermore, among the branch signals, the frequency of each branch signal other than one branch signal is shifted to a different frequency, sampled, and input by the appearance pattern of each signal spectrum including the aliasing component by fast Fourier transform. The method for determining the frequency of the signal is not necessarily limited to an actual apparatus, and it can be easily understood that the method also functions as the method. For this reason, the invention relating to the method is not necessarily limited to a substantial apparatus, and there is no difference that the method is also effective. In this case, a frequency measuring device or the like can be included as an example for realizing the method.

  By the way, such a frequency measurement device may exist alone or may be used in a state where it is incorporated in a certain device (for example, an electronic device). Various embodiments are included. Therefore, it can be changed as appropriate, such as software or hardware. When the software of the frequency measuring device is embodied as an embodiment of the idea of the invention, it naturally exists on a storage medium storing such software, and must be used.

Furthermore, it may be a case where a part is software and a part is realized by hardware, and a part is stored on a storage medium and is read as needed. It may be as a thing. When the present invention is realized by software, a configuration using hardware or an operating system may be used, or may be realized separately from these.
The realization method can call and process a predetermined function in the operating system, or can input from hardware without calling such a function. Even if the program is realized under the intervention of the operating system, it can be understood that the present invention can be implemented only by this program in the process of being recorded and distributed on the medium.
Furthermore, the dependent claims in the method, the program, and the data structure can be configured corresponding to the dependent claims in the apparatus.

  Further, the above embodiments include various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. In other words, examples include a combination of the above-described embodiments or a combination of any of them and any of the modifications. In this case, even if not specifically described in the present embodiment, the obvious effects from the respective configurations disclosed in the embodiments and their modifications are naturally included as the effects of the embodiments. it can. On the contrary, the configuration capable of exhibiting all the effects described in the present embodiment is not necessarily an essential component of the essential features of the present invention. In addition, an embodiment based on a configuration in which some of the configuration requirements are deleted from all the configuration requirements shown in the embodiment, and a technical scope based on the configuration may be an invention.

In addition, the description so far including each of the embodiments and the modifications thereof is intended to facilitate the understanding of the present invention. The embodiments of the invention are merely shown as examples of implementation, are illustrative, not limiting, and can be modified and / or modified as appropriate. The present invention can be implemented in various forms based on its technical idea or its main features, and the technical scope of the present invention should not be construed in a limited manner by each embodiment and its modifications. It will not be.
Therefore, each element disclosed above is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  The present invention can be applied to a device that requires frequency measurement of a signal spread in a wide band or broadband spectrum monitoring.

It is a block diagram which shows an example of a structure of the frequency measurement apparatus by the 1st Embodiment of this invention. 1. Description of an example of a spectrum detection characteristic detected when the input signal frequency f is [Fs / 2] <f ≦ [(3/4) Fs] in the first frequency calculation means of the frequency measuring device of FIG. FIG. 1. Description of an example of a spectrum detection characteristic detected when the input signal frequency f is [Fs / 2] <f ≦ [(3/4) Fs] in the second frequency calculation means of the frequency measuring device of FIG. FIG. It is explanatory drawing which shows an example of the data structure of the frequency determination table of the frequency measurement apparatus of FIG. FIG. 6 is an explanatory diagram showing an example of spectrum detection characteristics detected when the input signal frequency f is 0 <f ≦ [(1/4) Fs] in the first frequency calculation means of the frequency measurement device of FIG. 1. FIG. 6 is an explanatory diagram showing an example of spectrum detection characteristics detected when the input signal frequency f is 0 <f ≦ [(1/4) Fs] in the second frequency calculation means of the frequency measurement device of FIG. 1. An example of spectrum detection characteristics detected when the input signal frequency f is [(1/4) Fs] <f ≦ [(1/2) Fs] in the first frequency calculation means of the frequency measuring apparatus of FIG. It is explanatory drawing which shows. An example of spectrum detection characteristics detected when the input signal frequency f is [(1/4) Fs] <f ≦ [(1/2) Fs] in the second frequency calculation means of the frequency measuring apparatus of FIG. It is explanatory drawing which shows. FIG. 6 is an explanatory diagram showing an example of spectrum detection characteristics detected when the input signal frequency f is [(3/4) Fs] <f ≦ Fs in the first frequency calculation means of the frequency measurement device of FIG. 1. FIG. 6 is an explanatory diagram showing an example of spectrum detection characteristics detected when the input signal frequency f is [(3/4) Fs] <f ≦ Fs in the second frequency calculation means of the frequency measurement device of FIG. 1. It is a flowchart which shows an example of the outline of the frequency measurement method of this invention. It is a block diagram which shows an example of a structure of the frequency measurement apparatus by the 2nd Embodiment of this invention. FIG. 12 is an explanatory diagram showing an example of spectrum detection characteristics detected when the input signal frequency f is [2Fs] <f ≦ [(9/4) Fs] in the frequency measurement device of FIG. 11. It is a block diagram which shows an example of a structure of the frequency measurement apparatus by the 3rd Embodiment of this invention. It is a block diagram which shows an example of a structure of the frequency measurement apparatus by the 4th Embodiment of this invention. It is explanatory drawing which shows an example of the data structure of the frequency determination table of the frequency measuring device by the 5th Embodiment of this invention. It is explanatory drawing which shows an example of the data structure of the frequency determination table of the frequency measuring device by the 6th Embodiment of this invention. It is explanatory drawing which shows an example of the data structure of the frequency determination table of the frequency measuring device by the 7th Embodiment of this invention. It is explanatory drawing which shows an example of the data structure of the frequency determination table of the frequency measuring device by the 8th Embodiment of this invention. An example of spectrum detection characteristics detected when the input signal frequency f is 0 <f ≦ [(1/6) Fs] in each frequency calculation means of the frequency measurement device according to the ninth embodiment of the present invention is shown. It is explanatory drawing. It is explanatory drawing which shows an example of the data structure of the frequency determination table of the frequency measuring device by the 10th Embodiment of this invention. It is a flowchart which shows an example of the outline of the frequency measurement method of this invention. It is a block diagram which shows an example of a structure of the frequency measuring apparatus of related technology. It is explanatory drawing which shows an example of the characteristic of the anti-aliasing filter of the frequency measurement apparatus of FIG. It is a block diagram which shows an example of a structure of the frequency measurement apparatus of another related technique. It is explanatory drawing for demonstrating the process in which the spectrum data in the frequency measuring device of FIG. 25 is calculated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100,200 Frequency measurement apparatus 11 1st filter part 12,112,212 1st A / D converter 13,113,213 First frequency calculation means 14a, 114a, 214a Frequency determination table 14b Frequency determination control Unit 21, 121, 221 Clock dividing unit 22, 122, 222 Sampling clock generating unit 23, 123 Frequency converting unit 31 Second filter unit 32, 132, 232 Second A / D converter 33, 133, 233 First 2 frequency calculation means 110, 210 precise measurement frequency measurement means 114b, 214b first frequency determination control unit 141, 241 wideband filter 150, 250 rough measurement frequency measurement means 151, 251 third frequency calculation means 161, 261 second Frequency determination control unit 223 first frequency conversion means 242 first Frequency conversion means of

1000 Frequency measurement device 1011 Antialias filter 1012 A / D converter 1013 Frequency analysis means 1100 Frequency measurement device 1111 LPF_L
1112 A / D converter 1113 Waveform memory L
1121 LPF_H
1122 A / D converter 1123 Waveform memory H
1130 Sampling clock generation means 1141 Frequency (L) calculation means 1142 Frequency (H) calculation means 1143 Synthesis means

Claims (25)

A frequency measurement device that samples an input signal based on a sampling frequency Fs and measures the frequency of the input signal based on a signal spectrum including a folded component centered on (1/2) Fs of the sampled sampling signal. There,
Of the first branch signal and the second branch signal branched from the input signal, the frequency of the second branch signal is shifted to a shift frequency shifted by Fs / 4 or (3/4) Fs frequency. First frequency conversion control means for performing control for conversion;
Detection means for sampling each of the first branch signal and the second branch signal and detecting the frequency of each signal spectrum of each sampling signal including the aliasing component of each of the first and second branch signals. When,
Each frequency division in which each signal spectrum including the aliasing component appears when the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into Fs / 4 frequencies. Appearance pattern information storage means for storing appearance pattern information indicating a combination of regions according to each frequency of the input signal;
Based on the detected appearance pattern of each signal spectrum detected by the detection means, the frequency division region of the input signal corresponding to the detected appearance pattern is determined by referring to the appearance pattern information of the appearance pattern information storage means. First frequency determination control means for performing control to determine and output as a measurement frequency;
A frequency measurement device comprising: The frequency measurement device according to claim 1,
First band limiting means for band-limiting frequency components outside the pass band of the first and second branch signals, with a pass band from zero frequency to the sampling frequency,
The first frequency determination control means includes
A frequency measurement apparatus that performs control for determining a frequency of the input signal in each frequency division region equal to or lower than the sampling frequency. The frequency measurement device according to claim 1,
The first frequency determination control means includes
Each of the signal spectrums detected by the detection means has a frequency spectrum of (1/2) Fs or less of each frequency division region from zero frequency to the sampling frequency Fs. A frequency measuring apparatus that performs control for determining a frequency of (½) Fs or more of the input signal based on an appearance pattern of a folded component of a signal spectrum of (½) Fs or more. The frequency measurement device according to claim 1,
A second band limiting means for band-limiting a frequency component outside the pass band of the input signal, with a wide band up to a specific frequency equal to or higher than a sampling frequency among the frequencies of the input signal as a pass band;
The first frequency determination control means includes
Based on the first and second branch signals obtained by branching the signal whose band is limited by the second band limiting unit, the frequency of the input signal is determined from the appearance pattern of each signal spectrum of the aliasing component by undersampling. A frequency measurement device that performs control for determining the frequency. The frequency measurement device according to claim 4,
A rough measurement frequency for measuring a rough measurement frequency based on the third branch signal among the first to third branch signals obtained by branching the signal band-limited by the second band limit means. Measuring means;
The first frequency determination is performed on the basis of the first branch signal and the frequency-converted second branch signal by frequency-converting the second branch signal by the first frequency conversion control means. Second frequency determination control means for performing determination control of the frequency of the input signal based on the precise frequency estimation result in the control means and the coarse frequency estimation result in the coarse frequency measurement means;
The frequency measuring device further comprising: The frequency measurement device according to claim 5,
The input signal in units of fb × M (M is a positive integer), where fb is a frequency measurable by the second frequency determination control unit, which is arranged in front of the second band limiting unit. A frequency measuring apparatus further comprising second frequency conversion control means for converting a frequency. A frequency measurement method for sampling an input signal based on a sampling frequency and measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal,
Control that converts the frequency of each of the other branch signals other than one of the branch signals into a plurality of branched frequencies obtained by branching the input signal into a plurality of different shifted frequencies. A first frequency conversion control step to be performed;
The one branch signal of the frequency of the input signal and the other branch signals of the deviation frequency are sampled, and the frequency of each signal spectrum of each sampling signal including the aliasing component of each branch signal is detected. A detection step;
When the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality, the combination of the frequency division regions in which each signal spectrum including the aliasing component appears First frequency control is performed to determine the frequency division region of the input signal based on the appearance pattern information to be shown and the detected appearance pattern of each signal spectrum detected in the detection step, and to output as a measurement frequency A frequency determination control step;
A frequency measurement method comprising: The frequency measurement method according to claim 7,
In the first frequency determination control step,
Each signal spectrum detected in the detection step has a frequency division region of (1/2) Fs or less in each frequency division region from zero frequency to the sampling frequency Fs. A frequency measurement method characterized by performing control to determine a frequency of (1/2) Fs or more of the input signal based on an appearance pattern of a folded component of a signal spectrum of (1/2) Fs or more. The frequency measurement method according to claim 7,
In the first frequency conversion control step,
Of the first to n-th branch signals (n is a positive integer) obtained by branching the input signal into n, the frequency of the second to n-th branch signals is (1 / 2n) with respect to the sampling frequency Fs. ) Fs, or (1 / 2n) Fs + (1/2) Fs, respectively, converted to a shifted frequency,
In the first frequency determination control step,
Control to determine the frequency of the input signal based on which frequency division region of each frequency division region divided for each Fs / 2n frequency the appearance pattern of each signal spectrum belongs to. A characteristic frequency measurement method. The frequency measurement method according to claim 7,
In the first frequency conversion control step,
Of the first branch signal and the second branch signal branched from the input signal, the frequency of the second branch signal is shifted by 1/4 or 3/4 of the sampling frequency Fs. Converted to
In the first frequency determination control step,
Control for determining the frequency of the input signal based on which frequency division region of each frequency division region divided for each Fs / 4 frequency the appearance pattern of each signal spectrum belongs to. A characteristic frequency measurement method. The frequency measurement method according to claim 7,
In the first frequency determination control step,
Based on the appearance pattern defined by the shift and the size of each frequency division region, the combination of the appearance patterns corresponding to each frequency of the input signal is not the same at different frequencies, A frequency measurement method comprising performing control for determining a frequency of an input signal. The frequency measurement method according to claim 7,
A first band limiting step of band-limiting frequency components outside the pass band of each branch signal by each first band limiting means having a pass band from zero frequency to the sampling frequency;
In the first frequency determination control step,
A frequency measurement method comprising performing control to determine a frequency of the input signal in each frequency division region equal to or lower than the sampling frequency. The frequency measurement method according to claim 7,
A second band restriction for band-limiting frequency components outside the pass band of each branch signal by a second band restriction unit having a wide band up to a specific frequency equal to or higher than the sampling frequency among the frequencies of the input signal. And further comprising steps
In the first frequency determination control step,
Control for determining the frequency of the input signal from the appearance pattern of each signal spectrum of the aliasing component due to undersampling is performed based on each branch signal obtained by branching the signal whose band is limited in the second band limiting step. A frequency measurement method characterized by the above. The frequency measurement method according to claim 13,
A rough measurement frequency measurement step for measuring a frequency in rough measurement based on one of the branch signals among the branch signals obtained by branching the signal band-limited in the second band limit step;
The other branch signals other than the one branch signal and the second branch signal are frequency-converted in the first frequency conversion control step, and are determined based on the second branch signal and the other branch signals. A second frequency for performing a determination control of the frequency of the input signal based on the precise frequency estimation result in the second frequency determination control step and the coarse frequency estimation result in the coarse frequency measurement step. A judgment control step;
The frequency measurement method further comprising: The frequency measurement method according to claim 14, wherein
Prior to the second band limiting step, when the measurable frequency in the second frequency determination control step is fb, the frequency of the input signal is converted in units of fb × M (M is a positive integer). The frequency measurement method further comprising a second frequency conversion control step. A frequency measurement program that samples a input signal based on a sampling frequency, and causes a computer to execute a process of measuring the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal,
Control that converts the frequency of each of the other branch signals other than one of the branch signals into a plurality of branched frequencies obtained by branching the input signal into a plurality of different shifted frequencies. A first frequency conversion control function to be performed;
The one branch signal of the frequency of the input signal and the other branch signals of the deviation frequency are sampled, and the frequency of each signal spectrum of each sampling signal including the aliasing component of each branch signal is detected. A detection control function for performing control,
When the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality, the combination of the frequency division regions in which each signal spectrum including the aliasing component appears First frequency control is performed to determine the frequency division region of the input signal based on the appearance pattern information to be displayed and the detected appearance pattern of each signal spectrum detected by the detection function, and to output as a measurement frequency Frequency judgment control function,
A frequency measurement program for causing a computer to execute a function including: The frequency measurement program according to claim 16,
In the first frequency determination control function,
Each signal spectrum detected by the detection control function has a frequency division region of (1/2) Fs or less in each frequency division region from zero frequency to the sampling frequency Fs. A frequency measurement program for performing control for determining a frequency of (1/2) Fs or more of the input signal based on an appearance pattern of a folded component of a signal spectrum of (1/2) Fs or more. The frequency measurement program according to claim 16,
In the first frequency conversion control function,
Of the first to n-th branch signals (n is a positive integer) obtained by branching the input signal into n, the frequency of the second to n-th branch signals is (1 / 2n) with respect to the sampling frequency Fs. ) Fs, or (1 / 2n) Fs + (1/2) Fs, respectively, converted to a shifted frequency,
In the first frequency determination control function,
Control to determine the frequency of the input signal based on which frequency division region of each frequency division region divided for each Fs / 2n frequency the appearance pattern of each signal spectrum belongs to. A featured frequency measurement program. The frequency measurement program according to claim 16,
In the first frequency conversion control function,
Of the first branch signal and the second branch signal branched from the input signal, the frequency of the second branch signal is shifted by 1/4 or 3/4 of the sampling frequency Fs. Converted to
In the first frequency determination control function,
Control for determining the frequency of the input signal based on which frequency division region of each frequency division region divided for each Fs / 4 frequency the appearance pattern of each signal spectrum belongs to. A featured frequency measurement program. The frequency measurement program according to claim 16,
In the first frequency determination control function,
Based on the appearance pattern defined by the shift and the size of each frequency division region, the combination of the appearance patterns corresponding to each frequency of the input signal is not the same at different frequencies, A frequency measurement program for performing control for determining the frequency of an input signal. The frequency measurement program according to claim 16,
A first band limiting control function for performing a band limiting control of frequency components outside the pass band of each branch signal, with a pass band from zero frequency to a sampling frequency,
And let the computer run
In the first frequency determination control function,
A frequency measurement program for performing control for determining the frequency of the input signal in each frequency division region below the sampling frequency. The frequency measurement program according to claim 16,
A second band limitation control function for performing a band limitation control on a frequency component outside the pass band of each branch signal, with a wide band up to a specific frequency equal to or higher than a sampling frequency among the frequencies of the input signal as a pass band,
And let the computer run
In the first frequency determination control function,
Control is performed to determine the frequency of the input signal from the appearance pattern of each signal spectrum of the aliasing component due to undersampling based on each branch signal obtained by branching the signal whose band is limited by the second band limitation control function. A frequency measurement program characterized by that. The frequency measurement program according to claim 22,
A rough measurement frequency measurement function for measuring a frequency in rough measurement based on one of the branch signals among the branch signals obtained by branching the signal band-limited by the second band limit control function;
The other branch signals other than the one branch signal and the second branch signal are frequency-converted by the first frequency conversion control function, and are determined based on the second branch signal and the other branch signals. A second frequency for performing a determination control of the frequency of the input signal based on the precise frequency estimation result in the second frequency judgment control function and the coarse frequency estimation result in the coarse frequency measurement function. A judgment control function;
Is further executed by a computer. The frequency measurement program according to claim 23,
Before executing the second band limitation control function, when the measurable frequency by the second frequency determination control function is fb, the input signal in fb × M (M is a positive integer) unit. A second frequency conversion control function for controlling the frequency conversion;
Further, a frequency measurement program that is executed by a computer. A data structure used by a computer to sample an input signal based on a sampling frequency and measure the frequency of the input signal based on a signal spectrum including a folded component of the sampled sampling signal,
When the frequency of the input signal is in any one of the frequency division regions obtained by dividing the frequency region into a plurality, the combination of the frequency division regions in which each signal spectrum including the aliasing component appears Having a first structure storing appearance pattern information to be indicated according to each frequency of the input signal;
The first structure is:
The computer converts each of the other branch signals other than the one branch signal out of the branch signals obtained by branching the input signal into a plurality of shifted frequencies shifted by different frequencies. Sampling the one branch signal of the frequency of the input signal and each of the other branch signals of the deviation frequency, and each signal spectrum of each sampling signal including the aliasing component of each branch signal. Control to detect each frequency, and to determine the frequency division area of the input signal based on the detected appearance pattern of each detected signal spectrum and the appearance pattern information, and to output as a measurement frequency A data structure characterized by being used for processing to be performed.

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