JPH0865193A - Specifying device for radio equipment - Google Patents

Abstract

PURPOSE: To allow the device to specify a model of a radio equipment by observing simultaneously all frequency components of a band width of a radio wave emitted from the radio equipment in real time and obtaining a characteristic of the radio equipment based on a parameter obtained through spectrum analysis of the radio wave. CONSTITUTION: An antenna 10 receives a radio wave from a radio equipment and a signal from the antenna is given to plural band pass filters 18 whose center frequencies differ from each other. A memory 20 stores output signals of the plural band pass filters and an external storage device 36 stores each parameter with respect to spectrums of the plural different radio equipments. A microprocessor 24 obtains the parameter of the spectrum based on the storage content of the memory 20 and compares the storage contents of the external storage device 36 to specify the radio equipment whose radio wave is received by the antenna based on the comparison result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for receiving a radio wave emitted by a wireless device and analyzing the received signal by frequency (spectrum) to identify the wireless device.

[0002]

2. Description of the Related Art In order to use radio waves effectively and systematically, it is necessary to use each wireless device under a predetermined condition. However, a failure of a wireless device or an illegal operation of the wireless device may cause a failure in the operation of another wireless device.
Therefore, when an abnormal radio wave or a radio wave outside the specified frequency band is found, it is necessary to identify the wireless device generating the radio wave.

The radio waves generated by the radio equipment have characteristics according to the type of each radio equipment, and these characteristics can be obtained from a certain tendency in various parameters of the radio waves. The radio wave parameters that characterize wireless devices are:
There are frequency (maximum) fluctuation, phase (maximum) fluctuation, time until the transmission frequency stabilizes, center frequency, carrier-to-noise ratio (c / n), and the like. These parameters are measured in advance for each type of wireless device and stored in a database, the parameters of the target radio waves are measured, and if the measurement results are compared with the database, in principle, the radio waves are generated. You can specify the type of wireless device in use.

One of the conventional measuring instruments for measuring radio waves is
There is a spectrum analyzer. However, in the spectrum analyzer, the input signal (the output signal of the antenna)
In order to analyze each frequency component of, the input signal and the frequency sweep signal (the signal whose frequency changes sequentially with time) are mixed, and the mixed output is supplied to the filter of the predetermined frequency. The level of each frequency component is sequentially extracted as time passes.

[0005]

[Problems to be Solved by the Invention]
In the case of the analyzer, since the frequency sweep signal is used,
It takes a certain amount of time to monitor a given frequency range.
That is, at a certain point of time, only a specific frequency component can be monitored. Therefore, if the time when the wireless device generates a characteristic radio wave does not correspond to the monitoring frequency of the spectrum analyzer, the characteristic point is missed. In particular, when the cycle in which the wireless device generates a characteristic radio wave and the frequency sweep cycle of the spectrum analyzer are accidentally synchronized, this characteristic point cannot be captured.

Therefore, an object of the present invention is to monitor all frequency components of a radio wave in a predetermined frequency range simultaneously in real time,
It is to provide a wireless device identification device that can capture the characteristics of a wireless device.

[0007]

According to the radio equipment identifying apparatus of the present invention, the receiving means receives the radio wave from the radio equipment, and the plurality of band pass filters each having a different center frequency are provided from the receiving means. Receive a signal. The first storage unit stores the output signals of the plurality of band pass filters, and the second storage unit stores the parameters of the different wireless devices. The detection means obtains the parameter value of the spectrum from the stored contents of the first storage means. The comparison means compares the stored contents of the first storage means and the stored contents of the second storage means, and the specifying means specifies the wireless device received by the receiving means according to the comparison result of the comparing means.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of the preferred embodiment of the present invention. The antenna 10 serving as a receiving unit captures radio waves from various wireless devices (for example, car radio, portable transceiver, base radio station, etc.), converts the radio waves into electric signals, and supplies the electric signals to the frequency converter 12. The antenna 10
The frequency characteristic of covers the frequency range to be monitored. The frequency converter 12 lowers the output frequency of the antenna 10 by a fixed frequency as a whole, and relaxes the signal processing condition of the circuit in the subsequent stage. The amplifier 14 amplifies the output signal of the frequency converter 12 and supplies it to the analog / digital (A / D) converter 16 and the controller (control means) 38. The A / D converter 16 samples the analog signal from the amplifier 14 according to the sampling signal from the controller 38 and converts it into a digital signal.

The A / D converter 16 has N (N is a positive integer) digital bandpass filters 18 for digital output signals.
Supply to. Each of these digital filters 18
It is composed of a digital delay circuit, a weighting circuit, an adder, etc., and its center frequency and bandwidth can be set individually and digitally by controlling the delay amount, the weighting coefficient, etc. by the controller 38. The digital output signal of the bandpass filter 18 is stored in a memory 20 (first storage means) such as a random access memory (RAM). Also,
The controller 38 controls the write mode and read mode of the memory 20 and also supplies an address signal.

The controller 38 performs the above control by
It includes a variable clock generator, digital latch circuits, address counters, logic gates and comparators. The oscillation frequency of the variable clock generator is controlled by the control signal from the bus 22, and this clock signal is supplied to the A / D converter 16. Also, a digital control signal from the bus 22 is stored in the digital latch circuit to select each of the filters 18.

In addition, the controller 38 also includes a trigger circuit. By the operation of this trigger circuit, the trigger data from the bus 22 is latched in the latch circuit and converted into an analog signal by the digital / analog (D / A) converter,
The output signal of the amplifier 14 is compared by the comparator. When this comparison output signal is generated, the programmable counter measures a predetermined period (time) to stop the write mode of the memory 20 and set it to the read mode. Therefore, the memory 20 stores the states of the radio waves before and after the trigger is generated. The preset value of the programmable counter is supplied from the bus 22. The address counter counts the clock signals from the clock generator and generates an address signal for the memory 20.

The digital data read from the memory 20 is supplied to the bus 22. A microprocessor (μP) 24 that performs various processes such as operating as comparing means and specifying means is connected to this bus. Further, the bus 22 is also connected to a read only memory (ROM) 26 that stores the processing program of the μP 24, a RAM 28 that is a temporary storage element, and a display unit 30 that displays a set value, a specific processing result, and the like. ing. Further, the printer 32 connected to the bus 22 prints a specific processing result and the like, and the input device 34 such as a keyboard supplies the input of the operator to the bus 22. The external storage device 36 such as a hard disk is a second storage unit that stores parameters of different wireless devices. Further, the control data for the controller 38 described above is transferred to the controller 38 by the μP 24 according to an instruction from the input device 34.

FIG. 2 is a diagram showing a frequency variation over time by capturing a radio wave generated by a certain radio device.
As can be seen from this figure, the parameters for identifying the wireless device from the radio wave include frequency (maximum) fluctuation, time until the transmission frequency stabilizes, and center frequency. Also,
Parameters that can be used to identify the wireless device include phase (maximum) fluctuation and carrier / noise ratio. For the frequency (maximum) fluctuation, the phase (maximum) fluctuation, the center frequency, and the carrier / noise ratio, the values at the start of transmission of the wireless device, during the call, and when the transmission is completed are used. The values of these parameters are within a certain range determined by the model of the wireless device (model name of the manufacturer, certified number of the certified wireless device, etc.). The values of these parameters are measured in advance for as many types of wireless devices as possible. For this measurement, the device of FIG. 1 may be used as described later. The measured values are stored in the external storage device 36 in advance as a database for each model of the wireless device.

The operation of the present invention will now be described with reference to the flow chart of FIG. The following operations are controlled by the μP 24 by the software stored in the ROM 26. First, the operator uses the input device 34 to set the center frequency and bandwidth of each of the bandpass filters 18 according to the radio frequency to be observed. At this time, the bandpass filter 1
Each frequency band of 8 is set so as to be sequentially continuous. Further, the frequency reduction coefficient of the frequency converter 12 is set as necessary. Next, in step 50, the antenna 10 receives a radio wave from the wireless device. The frequency of the signal from the antenna 10 is reduced by the frequency converter 12, amplified by the amplifier 14, and then converted into a digital signal by the A / D converter 16. The digital signal is separated by the digital band pass filter 18 into each frequency band. It should be noted that here, since a frequency sweep type frequency mixer is not used and a plurality of band pass filters are used, all frequency components in a predetermined frequency range can be simultaneously analyzed in real time.

The output signal of the frequency band filter 18 is sequentially accumulated in the memory 20 under the control of the controller 38. When the trigger circuit in the controller 38 detects the start of transmission or the completion of transmission of the wireless device that is generating the signal due to the change in the radio frequency signal captured in the band in the frequency band being observed, After a predetermined time has passed, the memory 20
Stop the write mode of. By setting the predetermined time, it is possible to capture the signal during the call of the wireless device in the memory 20.

Next, the contents stored in the memory 20 are RAM
28, and the μP 24 operates as detection means,
Spectrum analysis is performed (step 52) to obtain the value of each parameter. Here, the μP 24 is
Frequency fluctuations, phase fluctuations, time until stabilization of the transmission frequency, center frequency, and carrier-to-noise ratio are obtained as parameter values during a call and at the time of completion of transmission. Next, at step 54, the μP 24 operates as a comparison means,
The obtained parameter values are sequentially compared with the parameter values of the plurality of wireless devices in the registered database stored in the external storage device 36. In step 56, if the comparison results match, the process proceeds to step 58, and if they do not match, the process proceeds to step 60. In this comparison, μP24 is
Provide a certain tolerance. This tolerance can be set by the operator from the input device 34.

In steps 58 and 60, the μP 24 operates as a specifying means. Then, if they match within a certain range of the comparison result (step 58), the model of the wireless device having the matched parameter value is displayed on the display unit 30.
If the comparison result does not match (step 60), the observed radio wave is not generated by the registered wireless device, so it may be an illegal radio wave and the wireless device may be out of order. There is a nature. Of course, although not registered in the external storage device 36, there is a possibility that the wireless device is normal (regular) and normal. In any case, the μP 24 displays on the display 30 that the model of the registered wireless device does not match. The display 30 may display the measured parameter value in addition to these displays. These display results can be printed by the printer 32.

Although the preferred embodiment of the present invention has been described above, various modifications and changes can be made without departing from the spirit of the present invention. For example, a plurality of A / D converters may be provided in each stage after each stage of the bandpass filter.
In this case, the A / D converter 16 is unnecessary and each of the bandpass filters 18 is an analog filter. Further, each of the filters 18 may be provided with a determination circuit in the subsequent stage, and the output level of each filter 18 may be compared with a predetermined level, and the output level below this predetermined level may be ignored. With this configuration, it is possible to automatically remove less than the noise level and simplify the μP processing.

[0019]

As described above, according to the present invention, all frequency components of the bandwidth of the radio wave emitted by the radio equipment are simultaneously observed in real time, and the radio wave is analyzed from the parameter values obtained by spectrum analysis to obtain the The model of a wireless device can be specified by finding its characteristics. Therefore, the characteristic of the radio wave of the wireless device is not missed in time.

[Brief description of drawings]

FIG. 1 is a block diagram of a preferred embodiment of the present invention.

FIG. 2 is a frequency vs. time relationship diagram illustrating the operation of the present invention.

FIG. 3 is a flowchart illustrating the operation of the present invention.

[Explanation of symbols]

10 Antenna (Reception Means) 12 Frequency Converter 14 Amplifier 16 A / D Converter 18 Band Pass Filter 20 Memory (First Storage Means) 24 Microprocessor (Detection Means, Comparison Means, Identification Means) 26 ROM 28 RAM 30 Indicator 32 printer 34 input device 36 external storage device (second storage means) 38 controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Sega 5-9-31 Kitashinagawa, Shinagawa-ku, Tokyo Inside Sony Tektronix Co., Ltd.

Claims (5)

[Claims] 1. Receiving means for receiving radio waves from a wireless device, a plurality of band pass filters for receiving signals from the receiving means, each having a different center frequency, and storing output signals of the plurality of band pass filters. A first storage means; a parameter detection means for obtaining a spectrum parameter value from the stored contents of the first storage means; a second storage means for storing the spectrum parameter value of each of a plurality of different wireless devices; Comparing means for comparing the parameter value stored in the storage means and the parameter value detected by the detecting means, and specifying means for specifying the wireless device received by the receiving means according to the comparison result of the comparing means. A wireless device identification device. 2. The first storage means is an internal storage device, the second storage means is an external storage device, and the comparing means and the specifying means are microprocessors. Radio equipment identification device. 3. The wireless device specification according to claim 1, wherein the parameter is at least one of frequency fluctuation, phase fluctuation, time until stabilization of transmission frequency, center frequency, and carrier-to-noise ratio. apparatus. 4. An analog-to-digital converter for converting the signal from the receiving means into a digital signal and supplying the digital signal to the plurality of band pass filters, each of the plurality of band pass filters comprising: The wireless device identification device according to claim 1, wherein the wireless device identification device is a digital filter. 5. The wireless device identifying apparatus according to claim 4, wherein the center frequency and the bandwidth of the digital filter are variable.