JP5674607B2 - Radio frequency signal identification device - Google Patents

Description

  The present invention relates to a radio frequency signal identification device for identifying a radio frequency signal.

  In a conventional radio frequency signal identification device, when an unknown radio frequency signal feature pattern is input, a large number of known verification signal feature patterns are sequentially input to the verification means, and whether or not they match sequentially. (For example, refer to Patent Document 1).

Japanese Patent No. 4675216

  However, in such a radio frequency signal identification device, as the number of verification signal feature patterns increases, more calculations are required for verification of unknown signals, which reduces the amount of calculation and processing time. The problem to be solved still remained from the viewpoint of shortening the time.

  The present invention has been made to solve the above-described problems. It is an object of the present invention to obtain a radio frequency signal identification device capable of reducing the amount of calculation for collation and shortening the time required for collation. Objective.

An apparatus for identifying a radio frequency signal according to the present invention comprises: a radio frequency signal feature extracting unit that extracts a radio frequency signal feature pattern that is a waveform of an instantaneous frequency based on the radio frequency signal; and a record storage that records a verification signal feature pattern. And a matching means for matching the radio frequency signal feature pattern extracted by the radio frequency signal feature extracting means with the matching signal feature pattern recorded by the recording storage means to identify the radio frequency signal. The signal identification apparatus includes a collation control unit that obtains a rough feature with a smaller amount of data from a radio frequency signal feature pattern, and a control information record storage unit that saves the rough feature. When the frequency signal feature pattern is extracted, the matching control means obtains the approximate feature of the extracted radio frequency signal feature pattern and Based on the general feature of the control information record storage means, a matching signal feature pattern that matches the general feature is determined, and the matching means checks only the matching signal feature pattern that matches the new radio frequency signal feature pattern and the general feature. It is what I did.

  In the radio frequency signal identification device of the present invention, when a new radio frequency signal feature pattern is extracted, only the matching signal feature pattern that matches the general feature of the radio frequency signal feature pattern is checked. Therefore, it is possible to reduce the amount of calculation for the purpose and the time required for collation.

It is a block diagram which shows the identification device of the radio frequency signal by Embodiment 1 of this invention. It is explanatory drawing which shows an example of the schematic characteristic of the identification device of the radio frequency signal by Embodiment 1 of this invention.

Embodiment 1 FIG.
1 is a block diagram showing a radio frequency signal identification device according to Embodiment 1 of the present invention.
The radio frequency signal identification apparatus shown in the figure includes an A / D converter (A / D) 1, radio frequency signal feature extraction means 2, verification control means 3, control information record storage means 4, verification means 5, and record storage means 6. It has.

  The A / D converter 1 receives the received radio frequency signal SR and converts it into a digital signal. The radio frequency signal feature extracting means 2 is a means for receiving the digitized radio frequency signal SR and outputting the radio frequency signal feature pattern CP of the signal portion SRP including the amplitude changing portion AC. 21, an instantaneous frequency extraction unit 22, and a signal feature pattern output unit 23.

  The signal extraction means 21 is means for receiving the digitized unknown radio frequency signal SR and extracting the signal portion SRP in the signal extraction period. The instantaneous frequency extracting unit 22 includes a phase change extracting unit 221, an approximate line segment fitting unit 222, and an approximate line segment gradient extracting unit 223. The phase change extraction unit 221 receives the signal portion SRP extracted by the signal extraction unit 21 and extracts a phase change Pθ with respect to time t in the signal extraction period. The phase change extraction unit 221 obtains the phase θ of all cycles of the signal portion SRP using, for example, fast Fourier transform, and extracts the phase change Pθ with respect to time t.

  The approximate line fitting means 222 receives the phase change Pθ and applies the approximate line segment to the phase change Pθ. The approximate line segment fitting means 222 performs approximate line segment fitting using a moving window. The approximate line segment fitting means 222 applies an approximate line segment that approximates the phase change of each portion of the phase change Pθ included in the moving window while sequentially moving the moving window in the time axis direction.

  The approximate line segment gradient extracting unit 223 extracts the gradient of each approximate line segment fitted by the approximate line segment fitting unit 222. The gradient of this approximate line segment indicates the instantaneous frequency f of the signal portion SRP.

  The signal feature pattern output unit 23 includes an instantaneous frequency characteristic extraction unit 231. The instantaneous frequency characteristic extraction unit 231 extracts the instantaneous frequency characteristic Pf in the signal portion SRP. This instantaneous frequency characteristic Pf indicates a change in the instantaneous frequency f with respect to the signal extraction period. Then, the signal feature pattern output means 23 outputs the instantaneous frequency characteristic Pf as the radio frequency signal feature pattern CP.

  The collation control means 3 receives the radio frequency signal feature pattern CP output from the radio frequency signal feature extraction means 2 and obtains its outline feature, and the obtained outline feature as control information is stored in the control information record storage means 4 Save with the wireless device name or its identification number. When the radio frequency signal feature extraction unit 2 outputs the radio frequency signal feature pattern CP from the new radio frequency signal SR, the matching control unit 3 calculates the summary information, and the matching signal feature pattern CPref having the matching summary information. Are sequentially input from the record storage means 6 to the verification means 5.

  The matching unit 5 includes an L2 norm calculation unit 51 and an identity determination unit 52. The L2 norm calculation unit 51 includes a pattern difference L2 norm that is a difference between the radio frequency signal feature pattern CP and the matching signal feature pattern CPref. Calculate PDL. The identity determination unit 52 determines the identity between the unknown radio frequency signal feature pattern CP and the known matching signal feature pattern CPref based on the size of the pattern difference L2 norm PDL calculated by the L2 norm calculation unit 51. Note that the recording storage unit 6 and the control information recording storage unit 4 may be realized by using physically the same device.

  The A / D converter 1, the radio frequency signal feature extraction means 2, the collation means 5 and the record storage means 6 use known configurations described in Patent Document 1, but these means have equivalent functions. Other means having

  An example of the collation control means 3 averages a plurality of relative frequency samples with respect to the center frequency in a certain time domain, obtains a sequence of average codes in each area as a rough feature, and uses the control information record storage means 4 as control information. And the wireless device name or the identification number. That is, the radio frequency signal SR is a signal obtained by modulating a radio frequency carrier wave as shown in, for example, Patent Document 1 based on the modulation signal, and the outline feature is the center of the signal in a plurality of predetermined time domains. A plurality of relative frequency samples with respect to frequencies are averaged, and a sequence of average codes in each region is used.

  FIG. 2 is a part of an instantaneous frequency characteristic pattern obtained by receiving actual signals transmitted by four individual transmitters of the same type, and plots a sample of the relative frequency with respect to the center frequency against the relative number of the sample. ing. All these signals are decoded into the same information bit string, and the relative numbers correspond to the same time domain. The partial areas indicated by shading indicate time areas each including eight relative frequencies. When the relative frequencies are averaged in each time domain, a code string +-++-++-is obtained for the individuals 1 and 2. The code string +++++ is obtained for the individuals 3 and 4 by the same processing. These code strings are stored in the control information recording storage unit 4 together with their wireless device names or their identification numbers as general features.

When the radio frequency signal feature extraction unit 2 outputs the radio frequency signal feature pattern CP from the new radio frequency signal SR, the collation control unit 3 uses the average frequency code string as a schematic feature of the radio frequency signal feature pattern CP. Ask. Next, control information that matches the obtained code string is obtained from the control information recording / storing means 4, and the matching signal feature pattern CPref of the wireless device or identification number that matches the control information is taken out from the recording / storing means 6 and the matching means 5 Output to.
As a result, in the matching means 5, the L2 norm calculation means 51 calculates the pattern difference L2 norm PDL with only the matching signal feature pattern CPref having the same approximate feature, and the identity determination means 52 determines the pattern difference L2 norm PDL. Based on the above, identity is determined.

  For example, when the general feature is a code string +-++-++-, the matching signal feature pattern CPref corresponding to the individual 1 and the individual 2 is output to the matching unit 5. Matching is performed only with the CP and the matching signal feature pattern CPref of the individuals 1 and 2. When the general feature is a code string +++++-+, a matching signal feature pattern CPref corresponding to the individual 3 and the individual 4 is output to the matching unit 5, and the matching unit 5 checks the matching of the individuals 3 and 4. Collation is performed only with the signal feature pattern CPref.

  With this configuration, the radio frequency signal feature pattern CP of the new radio frequency signal SR does not match the code sequence that is a general feature, that is, the identity determination is performed with the matching signal feature pattern CPref having a large pattern difference L2 norm PDL. Therefore, it is possible to reduce the amount of calculation for collation or to shorten the time for collation, which has a remarkable effect that has not been achieved in the past.

  Another example of the schematic feature of the collation control means 3 is that control information is recorded as control information on the duration from the rising part to the falling part of the signal extracted by the signal extracting means 21 together with its wireless device name or its identification number. Save in the storage means 4. That is, the radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on the modulation signal. Based on the modulation, the rising portion where the amplitude increases from approximately zero to the peak value, and the amplitude is approximately zero from the peak value. The signal duration from the rising edge to the falling edge of the signal is used as a general feature.

  When the radio frequency signal feature extraction unit 2 outputs the radio frequency signal feature pattern CP from the new radio frequency signal SR, the collation control unit 3 obtains the duration by the above processing, and is recorded in the record storage unit 6. Of the matching signal feature patterns CPref, matching signal feature patterns CPref having the same duration are sequentially input to the matching means 5. With this configuration, the radio frequency signal feature pattern CP of the new radio frequency signal SR does not match the approximate pulse duration, that is, the identity difference between the pattern difference L2 norm PDL and the collation signal feature pattern CPref is large. Since the implementation is avoided, there is an unprecedented remarkable effect of reducing the amount of calculation for collation or shortening the time for collation.

  Further, another example of the collation control unit 3 is to store the distribution of the instantaneous frequency characteristic extracted by the instantaneous frequency characteristic extraction unit 231 in the control information record storage unit 4 together with the wireless device name or the identification number. . When the radio frequency signal feature extraction unit 2 outputs the radio frequency signal feature pattern CP from the new radio frequency signal SR, the collation control unit 3 obtains the distribution of instantaneous frequency characteristics by the above processing, and the control information record storage unit 4 The matching signal feature pattern CPref having the same instantaneous frequency characteristic distribution among the known matching signal feature patterns CPref is sequentially input to the matching means 5 on the basis of the control information recorded in. With this configuration, the new radio frequency signal feature pattern CP and the distribution of the instantaneous frequency characteristic that is a general feature do not match, that is, the identity determination with the matching signal feature pattern CPref having a large pattern difference L2 norm PDL can be performed. Since this is avoided, there is an unprecedented remarkable effect of reducing the amount of calculation for collation or shortening the time for collation.

As described above, according to the radio frequency signal identification device of the first embodiment, the radio frequency signal feature extraction unit that extracts the radio frequency signal feature pattern that is the waveform of the instantaneous frequency based on the radio frequency signal, and the collation A record storage unit for recording a signal feature pattern, a radio frequency signal feature pattern extracted by the radio frequency signal feature extraction unit and a verification signal feature pattern recorded by the record storage unit are collated to identify a radio frequency signal A radio frequency signal identification device comprising a matching means, comprising: a matching control means for obtaining a rough feature having a smaller amount of data from a radio frequency signal feature pattern; and a control information record saving means for saving the rough feature, When a new radio frequency signal feature pattern is extracted by the signal feature extraction means, the matching control means performs an outline of the extracted radio frequency signal feature pattern. A feature is obtained, and a matching signal feature pattern that matches the approximate feature is determined based on the approximate feature of the control information record storage unit, and the matching unit uses a matching signal feature that matches the new radio frequency signal feature pattern and the approximate feature. Since only the pattern is collated, the amount of calculation for collation can be reduced, and the time required for collation can be shortened.

  Further, according to the radio frequency signal identification device of the first embodiment, the radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on the modulation signal, and the center frequency of the signal in a plurality of predetermined time domains. Since a plurality of relative frequency samples are averaged and a sequence of average codes in each region is used as an approximate feature, the amount of computation and collation time are reduced while avoiding the complexity of the device configuration. Can be achieved.

  In addition, according to the radio frequency signal identification device of the first embodiment, the radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on the modulation signal, and the amplitude of the radio frequency signal is approximately zero to a peak value based on the modulation. And the rising portion of which the amplitude decreases from the peak value to almost zero, and the signal duration from the rising edge of the signal to the falling edge is used as a rough feature. It is possible to reduce the amount of calculation and shorten the verification time while avoiding complexity.

  Further, according to the radio frequency signal identification device of the first embodiment, the radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on the modulation signal, and the distribution of the instantaneous frequency of the signal is used as a schematic feature. Therefore, it is possible to reduce the amount of calculation and shorten the collation time while avoiding the complicated configuration of the apparatus.

  In the present invention, any constituent element of the embodiment can be modified or any constituent element of the embodiment can be omitted within the scope of the invention.

  1 A / D converter, 2 radio frequency signal feature extraction means, 3 collation control means, 4 control information record storage means, 5 collation means, and 6 record storage means.

Claims (4)

Based on the radio frequency signal, the radio frequency signal feature extracting means for extracting the radio frequency signal feature pattern which is the waveform of the instantaneous frequency, the record storage means for recording the verification signal feature pattern, and the radio frequency signal feature extracting means extract the radio frequency signal feature pattern. In the radio frequency signal identification device, the radio frequency signal feature pattern is collated with the collation signal feature pattern recorded by the record storage unit, and the radio frequency signal is identified.
Collation control means for obtaining a rough feature with a smaller amount of data from the radio frequency signal feature pattern;
Control information record storage means for storing the general features,
When a new radio frequency signal feature pattern is extracted by the radio frequency signal feature extraction unit, the collation control unit obtains a schematic feature of the extracted radio frequency signal feature pattern, and the control information record storage unit Based on the outline feature, a matching signal feature pattern that matches the outline feature is determined, and the matching means checks only the matching signal feature pattern that matches the new radio frequency signal feature pattern and the outline feature. A radio frequency signal identification device.   The radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on the modulation signal, and averages a plurality of relative frequency samples with respect to the center frequency of the signal in a plurality of predetermined time domains, and calculates an average in each domain. 2. The radio frequency signal identification apparatus according to claim 1, wherein a sequence of codes is used as a schematic feature.   The radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on the modulation signal. Based on the modulation, the rising portion where the amplitude increases from approximately zero to the peak value, and the amplitude from the peak value to approximately zero. 2. The radio frequency signal identification apparatus according to claim 1, further comprising: a signal duration time from a rising edge to a falling edge of the signal including a falling portion that decreases.   2. The radio frequency signal identification apparatus according to claim 1, wherein the radio frequency signal is a signal obtained by modulating a radio frequency carrier wave based on a modulation signal, and the distribution of the instantaneous frequency of the signal is used as a schematic feature.

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