JP4383214B2 - Radio system identification method and identification apparatus - Google Patents

Description

The present invention relates to a radio system identification method and a radio system identification device for identifying a wireless system for transmitting and receiving the radio signal by using the feature of the radio signal out extraction.

  In recent years, with the development of mobile phones, mobile phones, wireless LANs, RFIGs, etc., various types of various wireless systems (systems) have been proposed, developed, and commercialized. When using various commercialized wireless systems, the user selects one of the wireless systems, acquires a terminal corresponding to the wireless system, and registers and uses the terminal. Normally, when used for one wireless system, the other systems other than the wireless system cannot be used because the method is different.

  Conventionally, from the user's standpoint, a method has been studied in which a wireless system can be arbitrarily selected and used from any of a variety of wireless systems so that communication with multiple wireless systems can be performed. Yes. As such a method, it is conceivable that a terminal is provided with a plurality of wireless system hardware to enable communication including data transmission and to manually switch the communication state. More generally speaking, as a method for selecting an optimum radio system, as will be described later, (1) a method for identifying a frequency band as a narrow band by electric field strength, (2) a method for demodulating, and (3) calculating a periodic frequency. Three methods have been proposed.

  In view of cost, it is actually difficult to configure a terminal so that a plurality of wireless system hardware is provided and the communication state is manually switched.

  In addition, the conventional method of selecting the optimum wireless system by identifying with the electric field strength of (1) is the simplest method. However, since there is a frequency overlap between a microwave oven found in the 2.4 GHz band and the like and a wireless LAN, Bluetooth (registered trademark), etc., there is a problem that it is difficult to identify only by the electric field strength. is there.

  The “demodulating method” in (2) is the method that can identify the system most reliably. However, at present when there are a large number of radio systems, a demodulator for each radio system must be provided, which increases the processing time and the scale of hardware, which is not practical. Furthermore, it cannot be realized unless the detailed part of the method is a publicly disclosed wireless method.

  The most advanced signal feature extraction method for specifying a wireless system uses the periodic steadiness of (3) above, and is a method for estimating the modulation method of a wireless signal based on the calculated periodic frequency. In this method, the frequency spectrum is obtained from the data after autocorrelation of the received signal, and the feature is extracted. However, since the feature extraction method based on the periodic frequency obtains the autocorrelation of the radio signal, the number of calculation processes becomes enormous. As a result, there is a problem that the calculation time becomes long and the hardware configuration related to the processing circuit increases. Furthermore, a high sampling frequency is required, high speed hardware is required, and a memory capacity is increased.

  Next, Patent Document 1 and Non-Patent Document 1 can be cited as publicly known documents related to the present invention.

  Patent Document 1 discloses a wireless communication system and the like. This wireless communication system is a system that can be used regardless of differences in communication methods and can relax the circumstances restricted by regions, etc., when communication methods are restricted due to restrictions in the regions. The wireless communication system includes a wireless signal feature extracting unit that extracts a feature of a wireless signal from a wireless signal received by a wireless receiving unit, and the communication procedure processing unit is configured to switch a demodulation method based on the feature of the wireless signal. ing. However, in the above wireless communication system, the wireless communication feature extraction unit is simply described as “extract features from the frequency, modulation, etc. of the received wireless signal and identify the communication method from the extracted features”. There is no specific configuration of the radio signal feature extraction unit.

Further, Non-Patent Document 1 includes the content of page 120 in the article “Explore radio waves with shared technology, find interference and adapt radio” (pages 116 to 123). Signal feature extraction techniques are described. Here, a technique for discriminating a modulation method by a characteristic value of a periodic frequency due to periodic stationarity is introduced.
JP 2002-9657 A Nikkei Electronics 2003, 3-17, 116-123

  The problem of the present invention is that, in the current wireless communication technology environment in which various wireless systems are widely used, the wireless signal has high practicality, high speed, and reliability with a simple device configuration in terms of hardware and software. For example, to develop a technique for identifying a wireless system.

SUMMARY OF THE INVENTION In view of the above problems, in the current wireless communication technologies use environment quotient iodide have been various wireless systems have been utilized, and to identify reliable radio signals by a simple apparatus construction It is an object of the present invention to provide a practical radio system identification method and radio system identification apparatus that enable identification of a radio system.
Still another object of the present invention is to provide a wireless system having a configuration for rapidly processing detection data by restoring a baseband signal, and thereby identifying a wireless system by identifying a wireless signal at high speed. To provide a specifying method and a wireless system specifying device.

  In order to achieve the above object, the present invention is configured as follows.

A wireless system specifying method according to the present invention (corresponding to claim 1) is as follows:
From the received radio signal, a first frequency spectrum analysis is performed to obtain a peak frequency of the frequency spectrum related to the radio signal as a center frequency, and the base frequency is obtained by performing quasi-synchronous detection processing using the center frequency as a reference frequency. ,
Obtaining frequency spectrum data related to the baseband signal from the baseband signal by the second frequency spectrum analysis method, obtaining a peak frequency or bandwidth indicating characteristics of the frequency spectrum related to the baseband signal,
Based on the acquired peak frequency value or bandwidth value, the wireless system of the wireless signal is specified by referring to the wireless system data prepared in advance in the memory.

The wireless system specifying device according to the present invention (corresponding to claim 2)
A wireless system identification device for identifying a wireless system of a wireless signal received by a receiver,
A peak frequency of a frequency spectrum related to the radio signal is obtained as a center frequency from the received radio signal by first frequency spectrum analysis, and a baseband signal is obtained by performing quasi-synchronous detection processing using the center frequency as a reference frequency. Baseband signal acquisition means;
Second frequency spectrum calculation means for acquiring frequency spectrum data related to the baseband signal from the baseband signal acquired by the baseband signal acquisition means by a second frequency spectrum analysis method;
Means for detecting a peak frequency or bandwidth indicating characteristics of a frequency spectrum related to the baseband signal;
And determining means for identifying the radio system of the radio signal by referring to the data of the radio system prepared in advance in the memory based on the detected peak frequency value or bandwidth value.
A radio system specifying device according to the present invention (corresponding to claim 3), in the above configuration, the receiver includes a down converter that generates an intermediate frequency signal from the radio signal, and the baseband signal acquisition means includes the intermediate frequency signal. A first frequency spectrum calculating means for calculating a frequency spectrum related to the radio signal from, a center frequency detecting means for detecting a center frequency of the frequency spectrum related to the radio signal, and an occupied bandwidth at the center frequency of the frequency spectrum related to the radio signal. A first occupied bandwidth detecting means for detecting is provided, and a baseband signal is acquired based on the center frequency and the occupied bandwidth.
Furthermore, in the wireless system specifying device (corresponding to claim 4) according to the present invention, in the above configuration, the center frequency detecting means detects the peak frequency of the frequency spectrum related to the wireless signal as the center frequency, and detects the first occupied bandwidth. The means calculates the occupied bandwidth from the peak frequency of the frequency spectrum related to the radio signal, calculates a thinning rate based on the occupied bandwidth, and performs data thinning by the baseband signal acquisition means to reduce the number of data. Features.

  The present invention has the following effects. Since the characteristics of the radio signal are extracted based on the waveform of the baseband signal restored from the received radio signal, it is possible to extract the characteristics of the radio signal without performing demodulation processing specific to the radio signal. It is possible to identify the wireless system that transmits and receives the wireless signal. In addition, without changing hardware and software (algorithm) for each wireless system, it is possible to easily extract and identify features of a wireless signal at high speed, and to specify a wireless system that transmits and receives the wireless signal.

  Furthermore, since the radio system is specified based on the frequency spectrum parameters in the restored baseband signal waveform, when the frequency spectrum is obtained, digital signal processing is performed and the number of data is reduced by decimation. Since the spectrum can be analyzed, the number of data can be reduced, and when a frequency spectrum calculation method such as FFT (Fast Fourier Transform) is employed, the number of operations can be reduced and the processing time can be increased.

  Further, by thinning out, the resolution of the frequency spectrum can be made finer than in the case of the same number of FFT operations (same circuit scale). Further, by reducing the thinning rate for low-speed wireless signals and reducing the thinning rate for high-speed wireless signals, it is possible to obtain the optimum resolution for the system. The thinning rate is calculated from the spectrum bandwidth at the intermediate frequency (IF). With a circuit configuration of the same scale, it is possible to improve the frequency spectrum resolution and extract more detailed features. Further, since the reference frequency for detection is calculated from the spectrum of the intermediate frequency (IF), the identification process can be performed without worrying about the frequency error from the wireless system standard. The performance of components such as frequency transmitters can be configured with general-purpose products, and costs can be reduced.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.

  A wireless system identification device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a basic circuit configuration of the radio system specifying device, FIG. 2 shows a detailed circuit configuration of the radio system specifying device, and FIG. 3 shows a specific circuit configuration of the radio system specifying device.

  In FIG. 1, a radio system specifying device 10 detects a baseband signal by detecting an antenna 11 that receives a radio wave E1 related to a radio signal, a receiver 12, and a signal (intermediate frequency signal) output from the receiver 12. It comprises a detector 13 to be extracted and a wireless system specifying unit 14 that specifies a wireless system based on the waveform of the baseband signal restored by the detector 13. The radio wave E1 received by the antenna 11 includes a radio signal SIG1 made by a radio system used in an arbitrary radio system. The receiver 12 receives the radio signal SIG1 through the antenna 11, performs predetermined processing on the radio signal, and then sends the obtained intermediate frequency signal to the detector 13. The detector 13 extracts the baseband signal SIG2 from the input intermediate frequency signal and supplies the baseband signal SIG2 to the wireless system specifying unit 14.

  The radio system specifying unit 14 includes a second frequency spectrum calculating unit 15 that calculates the frequency spectrum of the baseband signal SIG2, and a peak frequency and a bandwidth of the frequency spectrum in the waveform calculated by the second frequency spectrum calculating unit 15. And the like, and a determination unit 17 that identifies the wireless system transmitted based on the parameters of the frequency spectrum extracted by the feature extraction unit 16. Since the detector 13 includes a first frequency spectrum calculation unit 18 as shown in FIG. 2, the frequency spectrum calculation unit in the radio system identification unit 14 is referred to as a “second frequency spectrum calculation unit”. To do.

  As described above, the baseband signal SIG2 is extracted by the detector 13 based on the radio signal SIG1 received by the antenna 11 and the receiver 12, and the characteristics of the radio signal SIG1 are extracted based on the frequency spectrum of the baseband signal SIG2. Is done. The wireless system identification unit 14 identifies a wireless system that transmits and receives the wireless signal based on the characteristics of the extracted wireless signal SIG1 by the determination unit 17, and outputs the identification result.

  In the above, the actual configuration of the receiver 12 is as shown in FIG. The receiver 12 includes a down converter (frequency reduction circuit) 24 and an A / D converter 25. In the receiver 12, the radio signal received by the antenna 11 is converted into an intermediate frequency signal (IF signal) by the down converter 24, and this intermediate frequency signal is sampled by the A / D converter 25 to obtain the digital intermediate frequency signal. Generate. The intermediate frequency signal is supplied to the detector 13 as a signal SIG14, and the detector 13 extracts the baseband signal from the intermediate frequency signal.

  Next, detailed circuit configurations of the detector 13 and the wireless system identification device 10 will be described with reference to FIG.

  The detector 13 includes a first frequency spectrum calculation unit 18, a center frequency detection unit 19, a first occupied bandwidth detection unit 20, and a detection unit 21. The first frequency spectrum calculation unit 18 applies frequency spectrum analysis processing such as FFT (Fast Fourier Transform) to the digital intermediate frequency signal (sampling data) SIG 14 sent from the receiver 12 to obtain frequency spectrum data. Thereafter, the signal SIG11 related to the frequency spectrum data is output to the center frequency detector 19 and the first occupied bandwidth detector 20. The center frequency detector 19 detects the peak frequency of the frequency spectrum as the center frequency, and supplies the signal SIG12 related to the center frequency to the detector 21 as the reference frequency. The center frequency may be a center frequency obtained by obtaining a bandwidth. The first occupied bandwidth detection unit 20 acquires parameters such as a thinning rate and supplies a signal SIG 13 related to the parameters to the detection unit 21. The detector 21 uses the center frequency obtained from the signal SIG12 as a reference frequency and obtains a baseband signal based on the intermediate frequency signal SIG14 supplied from the receiver 12 and the parameters of the signal SIG13. The band signal SIG2 is supplied to the second frequency spectrum calculation unit 15 of the wireless system identification unit 14. It should be noted that the frequency and the occupied bandwidth determined in advance may be used without obtaining the detection frequency using the frequency spectrum analysis method.

  Further, in detail, as shown in FIG. 2, the radio system specifying unit 14 includes the second frequency spectrum calculation unit 15, the feature extraction unit 16 including a peak frequency detection unit 22 and a second occupied bandwidth detection unit 23. And the determination unit 17. Details of the operation of the wireless system identification unit 14 will be described later.

  The configuration of the detector 13 and the configuration of the radio system specifying unit 14 shown in FIG. 2 are each shown by a block circuit, but actually, it is constituted by an arithmetic unit 28 as shown in FIG. The arithmetic unit 28 includes a DSP (Digital Signal Processor) 26 and a RAM 27. Therefore, the functions of the detector 13 and the wireless system specifying unit 14 are realized by software. Each block element of the detector 13 and the wireless system specification 14 shown in FIG. 2 is a functional element realized by software.

  Next, an operation process for specifying a wireless system by the wireless system specifying device 10 will be described. The process of identifying the wireless system is described with reference to the flowchart shown in FIG. 4 and the spectrum diagram of the intermediate frequency signal (A) and the spectrum diagram of the baseband signal (B) shown in FIGS. The

  The operations of the receiver 12 and the detector 13 are as described above. According to the flowchart of FIG. 4, the down-conversion process by the down converter 4 (step S11), the sampling process by the A / D converter 25 (step S12), the frequency analysis process by the first frequency spectrum calculation unit 18 (step S13), A parameter acquisition process (step S14) by the first bandwidth detection unit 20, a quasi-synchronous detection process (step S15) by the detection unit 21, and a baseband signal acquisition process (step S16) are performed.

  The identification of the wireless system according to the present embodiment is realized as a practical means by acquiring a signal of an intermediate frequency (IF) from a wireless signal and using a technique for performing frequency analysis on the signal of the intermediate frequency. By obtaining a frequency spectrum at the intermediate frequency (IF), parameters (center frequency + occupied bandwidth) necessary for feature extraction are obtained from the frequency spectrum. If these parameters are used, there is an advantage that the influence of the frequency error can be reduced. Therefore, in specifying the wireless system according to the present embodiment, it is hardly necessary to consider the influence of the frequency error.

  The first occupied bandwidth detection unit 20 calculates the occupied bandwidth at the center frequency based on the signal SIG15 from the center frequency detection unit 19. The signal SIG13 from the first occupied bandwidth detection unit 20 is used for the bandwidth of a low-pass filter (LPF) that uses the bandwidth in quasi-synchronous detection and the setting of the thinning rate in the decimation process. Therefore, the spectrum analysis in the second frequency detector 15 can be performed in a short calculation time. Furthermore, more detailed feature extraction is possible by improving the resolution of the frequency spectrum with a circuit configuration of the same scale.

  The center frequency is used as a reference frequency in the quasi-synchronous detection process (step S15). Therefore, as described above, the detection unit 21 of the detector 13 performs quasi-synchronous detection using the reference frequency (step S15), extracts the baseband signal SIG2 (step S16), and the second of the radio system identification unit 14 It outputs to the frequency spectrum calculation unit 15.

  The second frequency spectrum calculation unit 15 uses the baseband signal SIG2 to obtain frequency spectrum data SIG21 by a frequency spectrum analysis method such as FFT (Fast Fourier Transform), and the peak frequency detection unit 22 and the second occupied bandwidth Output to the detection unit 23. The peak frequency detection unit 22 detects the center frequency of the peak of the frequency spectrum given from the second frequency spectrum calculation unit 15 (step S17), and outputs a signal SIG22 related to the peak center frequency to the determination unit 17. The second occupied bandwidth detection unit 23 acquires parameters such as the occupied bandwidth (step S18), and outputs a signal SIG23 related to the parameters to the determination unit 17.

  The determination unit 17 stores in advance a table indicating the peak frequency and occupied bandwidth of the frequency spectrum of the baseband signal in each wireless system in the memory (RAM 27), and by referring to the table, the base unit A corresponding wireless system is specified based on the information on the peak frequency and occupied bandwidth of the frequency spectrum of the band signal (step S19).

  As described above, the radio system specifying device 10 detects the received radio signal and restores and extracts the baseband signal. Signal features are extracted from the frequency spectrum of the baseband signal. Since this frequency spectrum includes information such as the transmission rate of the baseband signal and the spread chip rate bandwidth, it is possible to identify the radio system from these parameters.

  Next, description will be added with reference to the spectrum diagrams (A) and (B) shown in FIGS. Various examples of the frequency spectrum related to the intermediate frequency signal SIG14 are shown in FIGS. 5 to 8A, and examples of the frequency spectrum related to the baseband signal SIG2 are shown in FIGS. Here, FIG. 5 is based on radio waves of a PHS mobile phone, FIG. 6 is based on radio waves of a PDC mobile phone, and FIG. 7 is based on radio waves of a CDMA mobile phone. FIG. 8 is based on electromagnetic waves emitted from the microwave oven.

  5A to 8B, the horizontal axis represents frequency (MHz) and the vertical axis represents signal level (dB). In the spectrum shown in FIG. 5A, a peak P10 is seen, and a bandwidth calculation for center frequency detection thinning for quasi-synchronous detection is performed from this peak P10. In the spectrum shown in FIG. 6A, a peak P11 is seen, a reference frequency for quasi-synchronous detection is calculated from the peak P11, and a low-pass filter used for quasi-synchronous detection from the bandwidth of the peak P11 The decimation rate is calculated in the decimation process of the detection unit. In the spectrum shown in FIG. 7A, a peak P12 is seen, a reference frequency for quasi-synchronous detection is calculated from this peak P12, and a low-pass filter and detection used in quasi-synchronous detection from the bandwidth of the peak P12. The decimation rate is calculated in the decimation process. In the spectrum shown in FIG. 8A, a peak P13 is seen, a reference frequency for quasi-synchronous detection is calculated from the peak P13, and a low-pass filter used for quasi-synchronous detection from the bandwidth of the peak P13 The decimation rate is calculated in the decimation process of the detection unit.

  Next, in FIG. 5B to FIG. 8B, the horizontal axis represents frequency (MHz), and the vertical axis represents signal level (dB). In the spectrum shown in FIG. 5B, a peak P20 is seen. The frequency corresponding to this peak P20 is 192 kHz. It is apparent from the wireless system standard that the symbol rate of the PHS system is 192 kHz. From this, it is possible to recognize the wireless signal of peak P20 as a PHS wireless system. That is, it can be specified that a wireless system having this characteristic is a PHS system. In the spectrum shown in FIG. 6B, a peak P21 is seen. The frequency corresponding to this peak P21 is 21 kHz. It is apparent from the radio system standard that the symbol rate of the PDC system is 21 kHz. Therefore, the wireless signal at the peak P21 can be recognized as a PDC wireless system. That is, it can be specified that a wireless system having this characteristic is a PDC system.

  In the spectrum shown in FIG. 7B, the bandwidth W is 1.3 MHz. From this bandwidth W, it can be confirmed that the target wireless system has a transmission rate of up to 1.3 MHz, and further adopts a spread modulation scheme. In the case of a CDMA wireless system, direct spread modulation with a chip rate of 1.3 MHz is employed. Further, since this spread signal is longer than the burst frame length, it has a feature that a specific spectrum cannot be confirmed up to the chip rate band. A feature of the CDMA wireless system is that it has a bandwidth up to a chip rate of 1.3 MHz. Therefore, a system having this characteristic can be specified as the CDMA system.

  Further, in the spectrum shown in FIG. 8B, a peak P22 is seen near a frequency of 0 Hz. From this, it can be confirmed that this signal is not from the wireless system or has a very low transmission rate. Here, in the case of a microwave oven, a signal is not transmitted, and a signal is generated by turning on and off a pulse of about 10 ms. For this reason, the frequency spectrum of the baseband signal related to the radio wave from the microwave oven has a peak at about 100 Hz. Therefore, it can be specified that a signal having this characteristic is not from a wireless system.

  As described above, the determination unit 17 stores a table showing the peak frequency and occupied bandwidth of the frequency spectrum related to the baseband signal, so that the wireless system related to the received radio wave E1 can be referred to by referring to the table. It becomes possible to specify.

  In the radio signal feature extraction method and the radio system identification method according to the present invention, since analysis is performed using the restored baseband signal, signal feature extraction is possible regardless of the radio signal modulation scheme, and radio signal identification is possible. Wireless system can be identified. Further, it is possible to easily identify a radio signal at high speed without changing hardware and algorithm for each radio system, and for example, it is possible to specify a radio system. Furthermore, the present invention can also be used for RFID.

  The present invention is used to specify a wireless system that transmits and receives wireless signals.

It is a block diagram which shows the basic composition of the radio | wireless system specific apparatus which concerns on this invention. It is a block diagram which shows the detailed structure of each element of the radio | wireless system specific apparatus which concerns on this invention. It is a block diagram which shows the actual circuit structure of the radio | wireless system specific apparatus which concerns on this invention. It is a flowchart which shows the radio | wireless system identification process by the radio | wireless system identification apparatus which concerns on this embodiment. It is a spectrum figure which shows the frequency spectrum (A) of the intermediate frequency signal of the electromagnetic wave of a PHS system mobile telephone, and the frequency spectrum (B) of a baseband signal. It is a spectrum figure which shows the frequency spectrum (A) of the intermediate frequency signal of the electromagnetic wave of a PDC system mobile telephone, and the frequency spectrum (B) of a baseband signal. It is a spectrum figure which shows the frequency spectrum (A) of the intermediate frequency signal of the radio wave of a CDMA system mobile telephone, and the frequency spectrum (B) of a baseband signal. It is a spectrum figure which shows the frequency spectrum (A) of the intermediate frequency signal of the electromagnetic wave which comes out of a microwave oven, and the frequency spectrum (B) of a baseband signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Radio system specific apparatus 11 Antenna 12 Receiver 13 Detector 14 Radio system specific part 15 2nd frequency spectrum calculation part 16 Feature extraction part 17 Determination part 18 1st frequency spectrum calculation part 19 Center frequency detection part 20 1st occupied bandwidth Detection unit 21 Detection unit 22 Peak frequency detection unit 23 Second occupied bandwidth detection unit

Claims (4)

From the received radio signal , a first frequency spectrum analysis is performed to obtain a peak frequency of the frequency spectrum related to the radio signal as a center frequency, and the base frequency is obtained by performing quasi-synchronous detection processing using the center frequency as a reference frequency. ,
Obtaining frequency spectrum data related to the baseband signal from the baseband signal by a second frequency spectrum analysis method, obtaining a peak frequency or bandwidth indicating characteristics of the frequency spectrum related to the baseband signal ,
Based on the acquired value of the peak frequency or the value of the bandwidth, the wireless system of the wireless signal is identified with reference to data of the wireless system prepared in advance in a memory.
A method for specifying a wireless system . A wireless system identification device for identifying a wireless system of a wireless signal received by a receiver ,
A peak frequency of a frequency spectrum related to the radio signal is obtained as a center frequency from the received radio signal by first frequency spectrum analysis, and a baseband signal is obtained by performing quasi-synchronous detection processing using the center frequency as a reference frequency. Baseband signal acquisition means ;
Second frequency spectrum calculation means for acquiring frequency spectrum data related to the baseband signal from the baseband signal acquired by the baseband signal acquisition means by a second frequency spectrum analysis method;
Means for detecting a peak frequency or bandwidth indicative of characteristics of the frequency spectrum of the baseband signal ;
Based on the detected value of the peak frequency or the value of the bandwidth, determination means for identifying the wireless system of the wireless signal with reference to data of the wireless system prepared in advance in a memory;
Wireless system identification device, characterized in that it comprises a. The receiver includes a down converter that generates an intermediate frequency signal from the radio signal;
The baseband signal acquisition means includes first frequency spectrum calculation means for calculating the frequency spectrum related to the radio signal from the intermediate frequency signal, and center frequency detection for detecting the center frequency of the frequency spectrum related to the radio signal. And a first occupied bandwidth detection means for detecting an occupied bandwidth at the center frequency of the frequency spectrum related to the radio signal, and acquires the baseband signal based on the center frequency and the occupied bandwidth The wireless system identification device according to claim 2 . The center frequency detection means detects a peak frequency of the frequency spectrum related to the radio signal as the center frequency ,
The first occupied bandwidth detection means said calculating the occupied bandwidth from the peak frequency of the frequency spectrum of the radio signal, calculates based-out between pulling rate to the occupied bandwidth,
4. The radio system specifying apparatus according to claim 3, wherein the baseband signal acquisition unit performs data thinning to reduce the number of data.

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