JP2007019892A - Portable terminal device, wireless communication unit, wireless authentication distance measurement method, and wireless authentication distance measurement program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the measurement accuracy of the distance between a portable terminal device and a wireless communication unit.
SOLUTION: Radio waves and sound waves transmitted at the same timing from a mobile terminal device 100 or a key unit 200 are received, and based on a difference in arrival time between reception IDs 2 and 4 received by radio waves and reception IDs 1 and 3 received by sound waves. In addition, the distance between the key unit 200 and the mobile terminal device 100 is calculated. In addition, timing control units 114 and 214 are provided to adjust the timings of the transmission IDs sent to the modulation / sound wave transmission units 111 and 211 and the transmission IDs sent to the transmission / reception units and modulation / demodulation units 113 and 213.
[Selection] Figure 1

Description

  The present invention relates to a mobile terminal device, a wireless communication unit, a wireless authentication distance measurement method, and a wireless authentication distance measurement program that perform wireless authentication by transmitting and receiving wireless signals to and from a wireless communication unit.

  Conventionally, use restriction functions have been added to mobile phones as a measure for preventing unauthorized use by persons other than the owner due to theft or the like. In general, the use restriction function enables a call by releasing the use restriction by an ID by the owner, that is, a personal identification number. The use restriction by the personal identification number and the cancellation thereof require an operation with the keyboard, and the restriction and the release operation are required every time a call is made. If the use restriction is not performed after the call, there is a possibility that the call is made without limitation when the mobile phone is stolen.

Patent Document 1 discloses that when a device such as a mobile phone leaves the owner or the user due to misplacement or theft, the device itself becomes unusable, and the use restriction of the device warns that the device has been separated by a certain distance or more. An apparatus is disclosed.
FIG. 6 is a diagram for explaining a use restriction method for restricting use of a mobile terminal device using wireless authentication communication.

  As shown in FIG. 6, when the mobile terminal device 10 such as a mobile phone is separated from the user's hand and deviates from the authentication distance, the use of the mobile terminal device 10 is restricted, and a wireless communication unit (hereinafter, key unit) possessed by the user 1 is imposed. 20) sounds a misplaced alarm. Specifically, in a system that performs wireless authentication by transmitting and receiving wireless signals between the key unit 20 and the wireless authentication unit in the mobile terminal device 10, the wireless terminal unit 10 (see FIG. 7) in the mobile terminal device 10 when authentication is not established. ) Issues a use restriction signal to restrict functions arbitrarily determined in advance, and in the key unit 20, the wireless authentication unit 21 (see FIG. 7) issues an alarm signal via the user notification means. Thereby, misplacement and theft can be prevented.

  FIG. 7 is a block diagram for realizing the method of restricting the use of the mobile terminal device of FIG.

  In FIG. 7, a mobile terminal device 10 is a mobile terminal device such as a mobile phone / PHS (Personal Handy-Phone System), a PDA (Personal Digital Assistants), a notebook PC, an MP3 player, an HDD player, and the like. Here, a mobile phone is taken as an example.

  The mobile terminal device 10 includes a wireless authentication unit 11 and a wireless communication / data processing unit 12, and the wireless communication / data processing unit 12 is portable by performing wireless communication with the mobile phone base station 1 </ b> B via the wireless communication means 1. Functions as a telephone.

  The key unit 20 includes a wireless authentication unit 21 and user notification means 22 such as a speaker.

  The wireless authentication units 11 and 21 of the mobile terminal device 10 and the key unit 20 perform wireless authentication with each other via the wireless communication unit 2. When the authentication is not established, the mobile terminal device 10 restricts, for example, a call function of a mobile phone. In the key unit 20, an alarm is sounded by the user notification means 22.

Further, the wireless authentication unit 21 of the key unit 20 and the wireless authentication unit 11 of the mobile terminal device 10 have a previously associated ID and are mutually paired by exchanging each other's ID through wireless communication. The authentication is always performed by measuring the attenuation of radio waves for ID exchange in the wireless communication means 2 from the reception level in the wireless authentication units 21 and 11 and determining the communication distance.
Japanese Patent Laid-Open No. 11-88499

  However, in such a portable terminal device that performs conventional wireless authentication, since distance measurement using radio waves is performed, there are cases where an accurate distance cannot be measured due to environmental conditions and obstacles.

  For example, since the distance is assumed from the attenuation amount of the radio communication signal, the attenuation amount changes depending on the obstacle and the radio wave propagation environment condition, and a physically accurate distance cannot be obtained. Usage restrictions are affected by this change in distance measurement. Specifically, since the propagation loss of radio waves in the air is approximately inversely proportional to the square of the distance, a power difference of about 6 dB (1/4) between the propagation loss of 1 m and the propagation loss of 2 m is obtained. However, the power difference of about 6 dB is a value that varies easily depending on the object on which the wireless communication unit is mounted and the reflection / obstruction in the propagation environment.

  If the distance measurement accuracy in wireless authentication is not good, the wearable state (distance between the body and the wireless authentication unit) has changed, so it could not be used suddenly or an obstacle in the communication path. The use is restricted because of the appearance of the user, and the user cannot use it comfortably.

  The present invention has been made in view of the above point, and can improve the measurement accuracy of the distance between the mobile terminal device and the wireless communication unit, and can achieve the effectiveness of wireless authentication, and the wireless communication unit. An object of the present invention is to provide a wireless authentication distance measurement method and a wireless authentication distance measurement program.

  The portable terminal device according to the present invention includes a wireless communication unit that performs radio wave communication with a wireless communication unit, a sound wave communication unit that performs sound wave communication with the wireless communication unit, and the same timing from the wireless communication unit. Based on the calculated distance, a distance calculating means for receiving the radio wave and the sound wave transmitted in step, and calculating a distance between the received radio wave and the arrival time due to the sound wave. And a wireless authentication means for performing wireless authentication.

The wireless communication unit of the present invention includes a wireless communication unit that performs radio wave communication with a mobile terminal device, a sound wave communication unit that performs sound wave communication with the mobile terminal device, and the mobile terminal device at the same timing. A distance calculation means for receiving the radio wave and the sound wave transmitted in the step, and calculating a distance between the mobile terminal device based on the difference between the received radio wave and the arrival time due to the sound wave;
A configuration including a wireless authentication unit that performs wireless authentication based on the calculated distance is adopted.

  The wireless authentication distance measurement method according to the present invention includes: a step of receiving radio waves and sound waves transmitted at the same timing; and a distance between the transmission source device based on a difference between the received radio waves and arrival time due to the sound waves. Distance calculating means for calculating, and performing wireless authentication based on the calculated distance.

  From another point of view, the present invention calculates the distance from the transmission source device based on the step of receiving radio waves and sound waves transmitted at the same timing and the difference between the received radio waves and the arrival time due to the sound waves. A program for causing a computer to execute distance calculation means for performing wireless authentication based on the calculated distance.

  ADVANTAGE OF THE INVENTION According to this invention, the measurement precision of the distance of a portable terminal device and a radio | wireless communication unit can be improved, and the effectiveness of radio | wireless authentication can be aimed at.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 1 is a block diagram showing a configuration of a mobile terminal device using an authentication control method according to an embodiment of the present invention. This embodiment is an example in which a mobile phone is applied to a mobile terminal device.

  In FIG. 1, 100 is a mobile phone (mobile terminal device) that performs wireless authentication, and 200 is a key unit (wireless communication unit) that performs bidirectional wireless communication with the mobile terminal device 100 for authentication.

  The mobile phone (mobile terminal device) 100 includes a wireless authentication unit 110 that performs wireless authentication with the key unit 200 and outputs a use restriction signal when authentication is not established, and a wireless communication / data processing unit 122 having an antenna 121.

  The wireless authentication unit 110 includes a modulation / sound wave transmission unit 111, a sound wave reception / demodulation unit 112, a transmission / reception unit / modem / demodulation unit 113, a timing control unit 114, a timing detection distance measurement unit 115, a mobile phone ID, a key unit ID, and a unique code. A memory 116 to be stored and an authentication determination unit 117 are provided.

  The modulation / sound wave transmission unit 111 modulates the transmission signal (transmission ID1) and transmits it as a sound wave from the output unit 111a.

  The sound wave receiving / demodulating unit 112 receives the sound wave by the receiving unit 112a and demodulates the received signal (reception ID1).

  The transmission / reception unit / modulation / demodulation unit 113 modulates the transmission signal (transmission ID2) and transmits it as a radio wave from the antenna 113a, and receives the radio wave from the antenna 113a and demodulates it to a reception signal (reception ID2).

  The timing control unit 114 adjusts the timing of the transmission ID 1 transmitted to the modulation / sound wave transmission unit 111 and the transmission ID 2 transmitted to the transmission / reception unit / modulation / demodulation unit 113.

  The timing detection distance measuring unit 115 is connected between the mobile terminal device 100 and the key unit 200 based on the time difference between the reception ID 1 received by the sound wave by the sound wave reception / demodulation unit 112 and the reception ID 2 received by the transmission / reception unit / modulation / demodulation unit 113. The distance is calculated.

  The memory 116 stores a mobile phone ID, a key unit ID, and a unique code for authentication, and outputs them to the timing control unit 114 and the authentication determination unit 117. The unique code is for preventing sound interference with other wireless authentication. In order to prevent sound interference with other wireless authentication, a unique code predetermined between the mobile terminal device 100 and the key unit 200 is modulated.

  The authentication determination unit 117 determines whether authentication has been established / not established based on the measurement distance from the timing detection distance measurement unit 115, and sends a use restriction release signal to the wireless communication / data processing unit 122 to release the use restriction of the device when authentication is established. Send it out.

  The wireless communication / data processing unit 122 is a carrier communication unit and a data processing unit of the mobile terminal device 100. Since this embodiment is an example in which the mobile terminal device 100 is applied to a mobile phone, the communication function of the mobile phone body is shown, but the mobile terminal device 100 is a PDA, notebook PC, MP3 player, HDD player. In this case, this part becomes a main body function part of these portable devices. The main body function can be used by receiving the use restriction release signal from the wireless authentication unit 110, and when the use restriction release signal is not received or when the use restriction signal is received, use of a part or all of the main body function is restricted.

  Although not illustrated, the mobile terminal device 100 further includes an LCD display unit, an LED light emitting unit, a speaker, a vibrator, a voice synthesis output unit using a PCM codec, and the like as an external output unit.

  On the other hand, the key unit 200 has the same configuration as the portable terminal device 100 with respect to distance measurement and authentication determination. That is, the key unit 200 performs wireless authentication with the mobile terminal device 100, notifies the wireless authentication unit 210 that outputs an alarm signal when authentication is not established, and the authentication status using an LED or the like, and alerts or emits light when authentication is not established. A user notification unit 220 that alerts the user.

  The wireless authentication unit 210 includes a modulation / sound wave transmission unit 211, a sound wave reception / demodulation unit 212, a transmission / reception unit / modem / demodulation unit 213, a timing control unit 214, a timing detection distance measurement unit 215, a mobile phone ID, a key unit ID, and a unique code. A memory 216 for storing and an authentication determination unit 217 are provided.

  The modulation / sound wave transmission unit 211 modulates the transmission signal (transmission ID 3) and transmits it as a sound wave from the output unit 211a.

  The sound wave receiving / demodulating unit 212 receives the sound wave by the receiving unit 212a and demodulates the received signal (reception ID3).

  The transmission / reception unit / modulation / demodulation unit 213 modulates the transmission signal (transmission ID 4) and transmits it as a radio wave from the antenna 213a, and receives the radio wave from the antenna 213a and demodulates it to a reception signal (reception ID 4).

  The timing control unit 214 adjusts the timing of the transmission ID 1 transmitted to the modulation / sound wave transmission unit 211 and the transmission ID 2 transmitted to the transmission / reception unit / modulation / demodulation unit 213.

  The timing detection distance measurement unit 215 determines whether the key unit 200 and the mobile terminal device 100 are based on the time difference between the reception ID 3 received by the sound wave by the sound wave reception / demodulation unit 212 and the reception ID 4 received by the transmission / reception unit / modulation / demodulation unit 213. Calculate the distance between them.

  The memory 216 stores a mobile phone ID, key unit ID, and unique code for authentication, and outputs them to the timing control unit 214 and the authentication determination unit 217.

  The authentication determination unit 217 determines whether or not the authentication is established based on the measurement distance from the timing detection distance measurement unit 215, and sends a use restriction release signal to the wireless communication / data processing unit 222 to release the use restriction of the device when the authentication is established. Send it out.

  The user notification unit 220 includes an LCD display unit, an LED light emitting unit, a speaker, a vibrator, and the like.

  The wireless authentication unit 210 of the key unit 200 and the wireless authentication unit 110 of the mobile terminal device 100 are configured by a communication module that performs bidirectional wireless communication with low power consumption using, for example, a weak wireless frequency band of 300 MHz band.

  Hereinafter, the wireless authentication distance measurement operation of the mobile terminal device and the wireless communication unit configured as described above will be described.

  FIG. 2 is a diagram for explaining the concept of calculating the distance between the portable terminal device 100 and the key unit 200 used in the present wireless authentication distance measurement method.

  The mobile terminal device 100 and the key unit 200 include transmission / reception units / modulation / demodulation units 113 and 213 that perform radio wave acoustic communication in addition to conventional radio communication using radio waves. As shown in FIG. 2A, although the sound wave depends on the temperature of the medium (air), the propagation speed is approximately 350 m / s, and the radio wave is almost the speed of light even if the medium is air. Therefore, when the sound wave and the radio wave are transmitted at the same time, the arrival time of the radio wave can be ignored.

  As shown in FIG. 2B, between the key unit 200 and the mobile terminal device 100, one transmits a sound wave and a radio wave at the same time, and the other receives a sound wave and a radio wave. Ask for. Then, the distance is obtained from the arrival time difference, the sound speed, and the speed of light (the speed of radio waves). For example, when there is a time difference of about 2.86 ms, a distance of about 1 m is obtained.

  In FIG. 1, the wireless authentication units 110 and 210 of the mobile terminal device 100 and the key unit 200 include modulation / sound wave transmission units 111 and 211 that transmit sound waves and sound wave reception / demodulation units 112 and 212 that receive sound waves, respectively. In addition to the wireless communication using radio waves, the mobile terminal device 100 and the key unit 200 perform acoustic wave communication.

  In addition, the timing control units 114 and 214 adjust the transmission ID timing to make the transmission timings of the sound waves and radio waves transmitted from the modulation / sound wave transmission units 111 and 211 and the transmission / reception units / modulation / demodulation units 112 and 212 the same. To do.

  Further, the timing detection / distance measuring units 115 and 215 are configured to receive the reception IDs 1 and 3 received by the sound waves by the sound wave reception / demodulation units 112 and 212 and the reception IDs 2 and 4 received by the transmission / reception units 113 and 213 by radio waves. Based on the time difference, the distance between the mobile terminal device 100 and the key unit 200 is calculated.

  FIG. 3 is a diagram for explaining a previously associated ID exchange method and a unique ID exchange method for performing wireless authentication. FIG. 3A illustrates a case where wireless authentication is performed using radio waves, and FIG. When wireless authentication is performed using sound waves, FIG. 3C illustrates an example of wireless authentication using only sound waves.

  As shown in FIG. 3A, the mobile terminal device (mobile phone) 100 transmits the mobile phone ID stored in the memory 116 as a radio wave to the key unit 200 as a transmission ID2. In addition, a unique code for measuring the distance is transmitted as a sound wave to the key unit 200 as a transmission ID1. Similarly, the key unit 200 transmits the key unit ID stored in the memory 216 as a radio wave to the mobile terminal device 100 as the transmission ID 4. Further, a unique code for measuring the distance is transmitted as a sound wave to the portable terminal device 100 as the transmission ID 3.

  The mobile terminal device 100 receives the transmission ID 4 transmitted from the key unit 200 and recognizes that the partner key unit is a key unit associated in advance. Further, the mutual distance is calculated from the time difference between the transmission ID 3 and the transmission ID 4 transmitted by the key unit 200. Further, the key unit 200 similarly receives the transmission ID 2 transmitted from the mobile terminal device 100, recognizes that the partner mobile terminal device is a mobile terminal device associated in advance, and transmits the transmission transmitted by the mobile terminal device 100. The mutual distance is calculated from the time difference between ID1 and transmission ID2. The wireless authentication with sound waves shown in FIG. 3B is the same as the wireless authentication with the radio waves in FIG. 3A except that the unique code is replaced with radio waves and the mobile phone ID and key ID are replaced with sound waves. In either case, the distance is measured by the time difference between radio waves and sound waves. In addition, as shown in FIG. 3C, wireless authentication can be performed using only sound waves. These examples will be described later. However, in this case, it is necessary to measure the arrival time of the sound wave itself. Therefore, the portable terminal device 100 and the key unit 200 have absolute time generation sources that are synchronized with each other inside, and measure the distance by the time difference between the absolute time and the arrival time of the sound wave.

  By the way, sound wave transmission may cause interference with transmission sound waves of other portable terminal devices or key units that are not associated with a pair, and may cause reception errors. Therefore, in the present embodiment, for sound wave transmission, a unique code associated with each other in advance is stored as known data in the memories 116 and 216 of the mobile terminal device 100 and the key unit 200, and this unique code is stored in the transmission ID / ID. It uses as reception ID and transmits / receives.

  Also, in radio wave transmission, a pair of pre-associated IDs (mobile phone ID and key ID) are transmitted as a transmission ID and a reception ID, and the authentication determination units 117 and 217 compare the reception ID demodulated by reception. Thus, it is always authenticated whether the other party is associated with each other. On the mobile terminal device 100 side, the authentication determination unit 117 instructs the wireless communication / data processing unit 122 to restrict use from the distance information calculated by the timing detection / distance measurement unit 115 and the authentication result. On the key unit 200 side, the authentication determination unit 217 instructs the user notification unit 220 to perform an alarm or notification from the distance information calculated by the timing detection / distance measurement unit 215 and the authentication result.

  As the unique code, an ID (mobile phone ID or key unit ID) used for authentication may be used as it is. Furthermore, by sending a unique code that is not related to authentication and not an ID used for authentication, there is little damage even if the unique code is analyzed by a third party wireless monitor. Therefore, a unique code that does not coincide with the transmitted sound waves of other portable terminal devices or key units and can be separated at the time of demodulation does not require a complicated encryption technique and can be easily created. As an example of the unique code, a numerical value obtained by combining the numerical value obtained by numbering the manufacturer of the mobile phone and the manufacturing ID number can be used as a nonexistent value.

  Next, with reference to FIGS. 4 and 5, a specific example of the configuration and operation of transmission / reception of sound waves and transmission / reception of radio waves will be described in detail.

  FIG. 4 is a diagram illustrating the configuration of the modulation / sound wave transmission unit 111, the sound wave reception / demodulation unit 112, and the transmission / reception unit / modem / demodulation unit 113.

  In FIG. 4, a modulation / sound wave transmission unit 111 includes an ASK modulation unit 301, a carrier wave generation unit 302 that generates a 40 kHz carrier wave, an amplifier 303, and an ultrasonic transducer 304.

  The sound wave receiving / demodulating unit 112 includes an ultrasonic receiving element 305, an amplifier 306, a filter 307, an ASK demodulating unit 308, and a carrier wave generating unit 302. Here, the carrier wave generation unit 302 shares the same carrier wave generation unit 302 of the modulation / sound wave transmission unit 111.

  On the other hand, the transmission / reception unit / modulation demodulation unit 113 includes an FSK modulation unit 401, a transmission side amplifier 402, an antenna / antenna duplexer 113a, a reception side amplifier 403, a filter 404, an FSK demodulation unit 405, and a carrier generation that generates a 300 MHz carrier wave. Unit 406 and carrier wave generation unit 406.

  First, an operation for transmitting a transmission ID delivered from the timing control unit 114 as a sound wave will be described.

  As shown in FIG. 4A, the transmission ID is modulated by the modulation / sound wave transmission unit 111 and converted into a sound wave.

  The transmission ID is ASK modulated by the ASK modulator 301 and converted to 40 kHz using a carrier wave. Thereafter, amplification is performed by the amplifier 303, and an electric signal is converted into a sound wave by the ultrasonic transducer 304 and emitted into the air. The reason why the ultrasonic frequency band of 40 kHz is used in this embodiment is that it is not audible to the human ear when performing distance measurement communication, and the ultrasonic transducer is small and has a diameter of about 15 mm, and can be realized with a 5 V power supply. This is because there is an element that can be driven and it is suitable for mounting on a mobile phone in terms of small size and low voltage. By using this ultrasonic transducer 304, it is possible to obtain a reach distance of several meters to a maximum of 5 m, which is sufficient for the authentication communication distance between the key unit 200 and the mobile phone.

  Next, the operation of demodulating the received ID and delivering it to the timing control unit 214 will be described.

  As shown in FIG. 4B, the reception ID is demodulated by the sound wave reception / demodulation unit 112 for demodulating the reception ID.

  The received sound wave is converted into an electric signal by the ultrasonic wave receiving element 305. The electric signal is amplified by the amplifier 306, and sent to the ASK demodulator 308 through the filter 307 in order to remove a frequency band component different from the sound wave (transmission sound wave) for demodulation. The ASK demodulator 308 obtains a reception ID by performing ASK demodulation after conversion to a baseband frequency using a carrier wave of 40 kHz. Here, ASK modulation is performed, but a system capable of digital modulation of transmission ID and digital demodulation of reception ID is representatively applied, and another system such as FSK modulation may be performed.

  On the other hand, transmission / reception of radio waves is performed by the transmission / reception unit / modulation demodulation unit 113.

  As shown in FIG. 4C, the transmission ID delivered from the timing controller 114 is FSK modulated by the FSK modulator 401 and converted to a carrier wave of 300 MHz. After that, amplification is performed by the amplifier 402, and an electric signal is converted into a radio wave through the antenna / antenna duplexer 113a and released into the air.

  The reception ID is demodulated by the transmission / reception / modulation demodulation unit 113. The electric signal is amplified by the amplifier 403 and is sent to the FSK demodulator 405 through the filter 404 in order to remove a frequency band component different from the radio wave to be demodulated (transmitted radio wave). The FSK demodulator 405 obtains a reception ID by performing FSK demodulation after conversion to a baseband frequency using a carrier wave of 300 MHz. Although FSK modulation is performed here, ASK modulation may be performed.

  Next, operations of the timing control unit 114 and the timing detection / distance measurement unit 115 will be described.

  FIG. 5 is a diagram illustrating the operation timing of each part of the mobile terminal device 100 and the key unit 200.

  In FIG. 5, transmission ID 1 is transmitted by sound waves from portable terminal device (here, mobile phone) 100, and at the same time transmission ID 2 is transmitted by radio waves, and reception sound waves (= transmission sound waves of mobile phones) are demodulated as reception ID 3 by key unit 200. At the same time, an example is shown in which the received radio wave (= transmitted radio wave of the mobile phone) is demodulated as reception ID4.

  Transmission ID1 and transmission ID2 sent from the timing control unit 114 of the mobile terminal device 100 are a delay time (known as a fixed value of the device) generated in the modulation / sound wave transmission unit 111 of the mobile terminal device 100 in FIG. The transmission sound wave and the transmission radio wave are output at the same timing by time-adjusting the difference from the delay time (known as a fixed value of the device) generated in the signal modulation / demodulation unit 113 by the output timing adjustment amount.

  The transmitted sound wave and the transmitted radio wave are input to the key unit 200 as a received sound wave and a received radio wave with a delay between the sound wave transmission time and the radio wave transmission time in the transmission path. The time difference between the sound wave and the radio wave is a parameter for obtaining the distance of the transmission path, but the time difference cannot be obtained unless the transmission ID 1 and the transmission ID 2 are demodulated. Therefore, in this embodiment, the delay time generated in the sound wave reception / demodulation unit 212 (known as a device fixed value) and the delay time generated in the transmission / reception / modulation demodulation unit 213 circuit (known as a device fixed value) ) Between the two delay amounts. It is obtained as an adjustment amount of the reception timing. By correcting the adjustment amount of the reception timing difference to the timing difference between the obtained reception ID3 (= transmission ID1) and reception ID4 (= transmission ID2), the time difference between the sound wave and the radio wave in the transmission path can be obtained.

  The transmission ID 3 is transmitted from the key unit 200 using sound waves, and at the same time, the transmission ID 4 is transmitted using radio waves. The mobile terminal device 100 demodulates the received sound waves (the transmission sound waves of the key unit) as the reception ID 1 and simultaneously receives the received radio waves (the transmission waves of the key unit). The same operation is performed when the signal is demodulated as reception ID2.

  As described above, according to the present embodiment, radio waves and sound waves transmitted from the mobile terminal device 100 or the key unit 200 at the same timing are received, and reception ID 2 and ID 4 received by the radio waves and reception ID 1 received by the sound waves. , The distance between the key unit 200 and the portable terminal device 100 is calculated based on the difference in arrival time according to ID3, so that the portable terminal device 100 and the portable terminal device 100 are compared with the distance measuring method estimated from the conventional radio wave reception intensity. The measurement accuracy of the distance to the key unit 200 can be increased. In particular, even when the object on which the key unit 200 is worn or the state of wearing is changed, the sound wave is not easily affected by the change, so that accurate distance measurement can be realized regardless of environmental changes. it can. Thereby, it is possible to improve the usability for the user, and it is possible to effectively perform the wireless authentication based on the accurate wireless authentication distance.

  Here, it is also possible to adaptively use the present wireless authentication distance measurement method using sound waves and the conventional distance measurement method using only radio waves. For example, when used in a place where the propagation environment of radio waves is good or in a power saving mode, the distance measurement method using only conventional radio waves may be switched.

  The sound waves used in the modulation / sound wave transmission units 111 and 211 and the sound wave reception / demodulation units 112 and 212 may be ultrasonic waves. When ultrasonic waves are used, since the sound that is being transmitted / received cannot be heard by humans, noise inconvenience can be prevented.

  Furthermore, although the example which uses an electromagnetic wave for ID exchange of authentication was demonstrated so far, it shows that the method of using a sound wave is also possible using FIG.3 (b). For example, in the path of transmission from the mobile terminal device 100 to the key unit 200, the mobile phone ID and the unique code that are the contents of the transmission ID 1 and the transmission ID 2 sent by the timing control unit 114 in the mobile terminal device 100 are exchanged, and the key unit This can be easily done by switching the reception ID 3 and the reception ID 4 received by the timing detection unit 214 on the 200 side. Similarly, the transmission path from the key unit 200 to the mobile phone 100 can be made by switching the transmission ID 3 and transmission ID 4 and the reception ID 1 and reception ID 2.

  For example, wireless authentication can be performed even in an environment where the output of radio waves is restricted, such as in an airplane or a hospital, by performing authentication ID exchange with sound waves and not using radio wave communication means. At this time, since radio wave communication is not performed, distance measurement based on the time difference between radio waves and sound waves cannot be performed. However, the key unit 200 and the timing control units 214 and 114 and the timing detection units 215 and 115 of the portable terminal device 100 are provided with clocks whose absolute times are synchronized. FIG. 3 (c) can determine the absolute time of transmission between each other, and measure the distance using only sound waves from the arrival time difference with respect to this absolute time.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. For example, an example in which the present invention is applied to a mobile phone as a mobile terminal device has been described. However, the present invention is not limited to a mobile phone, and is not limited to a mobile information terminal such as a PDA, a personal computer or a fusion device, MP3 player, HDD player, portable type It can be applied to portable devices such as game machines.

  In this embodiment, the names of the mobile terminal device, the wireless communication unit, and the wireless authentication distance measurement method are used. However, this is for convenience of explanation and includes a mobile phone, a device use restriction device, a distance measurement method, and the like. Of course, it may be.

  Further, the types, numbers, connection methods, and the like of each circuit unit, for example, a wireless authentication unit, which constitute the mobile terminal device and the wireless communication unit are not limited to the above-described embodiments.

  Moreover, the portable terminal device, the wireless communication unit, and the wireless authentication distance measurement method described above are also realized by a program for causing the portable terminal device, the wireless communication unit, and the wireless authentication distance measurement method to function. This program is stored in a computer-readable recording medium.

  A portable terminal device, a wireless communication unit, and a wireless authentication distance measuring method according to the present invention are used for portable terminal devices such as a mobile phone that performs wireless authentication by transmitting and receiving wireless signals to and from the wireless communication unit, and for use in an authentication control system. Useful. It can also be incorporated into a portable device such as a cellular phone as a wireless authentication distance measurement program.

The block diagram which shows the structure of the portable terminal device and radio | wireless communication unit which concern on embodiment of this invention The figure explaining the concept of the distance calculation between the portable terminal device which concerns on the said embodiment, and a key unit The figure explaining the ID exchange method of the portable terminal device which concerns on the said embodiment, and the exchange method of original ID The figure which shows the structure of the modulation | alteration / sound wave transmission part of the portable terminal device which concerns on the said embodiment, a sound wave reception / demodulation part, and a transmission / reception part / modulation / demodulation part The figure which shows the operation | movement timing of each part of the portable terminal device which concerns on the said embodiment, and a key unit. The figure explaining the use restriction method which places a use restriction on a portable terminal device using wireless authentication communication The block diagram which implement | achieves the usage restriction method of the portable terminal device of FIG.

Explanation of symbols

100 Mobile phone (mobile terminal device)
110 Wireless Authentication Unit 111, 211 Modulation / Sound Wave Transmitting Unit 112, 212 Sound Wave Reception / Demodulation Unit 113, 213 Transmission / Reception Unit / Modulation / Demodulation Unit 113a Antenna / Antenna Duplexer 114, 214 Timing Control Unit 115, 215 Timing Detection Distance Measurement Unit 116, 216 Memory 117, 217 Authentication determination unit 121 Antenna 122 Wireless communication / data processing unit 200 Key unit (wireless communication unit)
301 ASK modulator 302,406 Carrier wave generator 303,306,402,403 Amplifier 304 Ultrasonic transducer 305 Ultrasonic receiver 307 Filter 308 ASK demodulator 401 FSK modulator 405 FSK demodulator

Claims (12)

Wireless communication means for performing radio wave communication with the wireless communication unit;
Sound wave communication means for performing sound wave communication with the wireless communication unit;
Distance calculating means for receiving radio waves and sound waves transmitted from the wireless communication unit at the same timing, and calculating a distance between the received radio waves and the arrival time of the sound waves based on the difference in arrival time due to the sound waves; ,
A mobile terminal device comprising: wireless authentication means for performing wireless authentication based on the calculated distance. The wireless authentication means includes
The mobile terminal device according to claim 1, wherein control is performed to determine whether authentication is established / not established based on the calculated distance, and to release restriction on use of the device when authentication is established.   The portable terminal device according to claim 1, further comprising timing control means for performing control to transmit radio waves and sound waves at the same timing to the wireless communication unit.   The portable terminal device according to claim 1, wherein the sound wave communication unit modulates a unique code different from a wireless authentication ID to perform communication using sound waves.   The portable terminal device according to claim 1, wherein the sound wave includes an ultrasonic wave. Wireless communication means for performing radio communication with a mobile terminal device;
Sound wave communication means for performing sound wave communication with the portable terminal device;
Distance calculation means for receiving radio waves and sound waves transmitted from the mobile terminal device at the same timing, and calculating a distance between the received radio waves and the arrival time due to the sound waves; ,
A wireless communication unit comprising: wireless authentication means for performing wireless authentication based on the calculated distance. The wireless authentication means includes
The wireless communication unit according to claim 6, wherein control is performed to determine whether authentication is established / not established based on the calculated distance and to notify the authentication result.   The wireless communication unit according to claim 6, further comprising timing control means for performing control to transmit radio waves and sound waves to the portable terminal device at the same timing.   The wireless communication unit according to claim 6, wherein the sound wave communication unit modulates a unique code different from the wireless authentication ID to perform communication using sound waves.   The wireless communication unit according to claim 6, wherein the sound wave includes an ultrasonic wave. Receiving radio waves and sound waves transmitted at the same timing;
Distance calculating means for calculating a distance between the transmission source device based on the difference between the received time of the radio wave and the sound wave;
A wireless authentication distance measurement method comprising: performing wireless authentication based on the calculated distance. A step of receiving radio waves and sound waves transmitted at the same timing; and a distance calculating means for calculating a distance between the received device and a source device based on a difference in arrival time due to the received radio waves and the sound waves; A program for causing a computer to execute wireless authentication based on distance.

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