JP5376809B2 - Wireless terminal device, method and program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct determination of the boundary of a distance between radio terminals in regard to at least two kinds of boundaries, by a simple configuration. <P>SOLUTION: A transmitting part 12 of the radio terminal 10 transmits radio signals of N (N&ge;2) kinds of transmission powers. The radio terminal 20 receives the radio signals by a receiving part 22 and a distance determining part 24 of this terminal determines how many kinds of transmission powers of the radio signals are received by the receiving part 22 of the radio terminal. Thereby the distance between the radio terminals 10 and 20 is determined, and based on the result of determination, a certain function of a body part 25 is locked or the body part 25 is made to output warning information. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a wireless communication technique, and more particularly to a technique for determining a distance between wireless terminal apparatuses.

  As a mechanism for dealing with misplacement or theft of a terminal device such as a mobile phone or a PC, a mechanism for performing authentication processing by inputting a personal identification number or a fingerprint at the time of activation is widely used. However, in such a mechanism, there is a problem that a third party can illegally use a terminal device that has already been activated if it is misplaced or stolen. There is also a method of requesting password authentication and fingerprint authentication at regular intervals from the terminal device other than at the time of startup, but it is necessary to input the password and fingerprint during actual use Inconvenient, not very practical. Even if such a method is executed, there is a risk that data will be stolen or its settings may be changed from when the terminal device is requested for PIN authentication or fingerprint authentication. .

In recent years, a system called “Anshin Key (registered trademark)” has been put into practical use as a technique for solving the above problems (see, for example, Patent Document 1 and Non-Patent Document 1). This system is a technology that can be applied to a wireless terminal device such as a mobile phone or a PC having a wireless communication function, and another wireless terminal device (a use restriction release signal transmission unit “ Use the “Reliable Key”) to solve the above problem. The outline of this system is shown below.
The use restriction release signal transmission unit transmits a use restriction release signal to the wireless terminal device at regular intervals. When the distance between the use restriction release signal sending unit and the wireless terminal device is short, the wireless terminal device can receive this use restriction release signal at a constant interval and maintains a usable state. On the other hand, when the distance between the usage restriction release signal transmission unit and the wireless terminal device is increased and the period during which the wireless terminal device cannot receive the usage control release signal continues for a certain period of time, the wireless terminal device automatically locks itself. In addition, when the distance between the use restriction release signal sending unit and the wireless terminal device becomes close again after the lock and the wireless terminal device can receive the usage control release signal, the wireless terminal device automatically releases its own lock. . Then, the user performs operations such as putting a wireless terminal device such as a mobile phone / PC into a pocket, using the usage restriction cancellation signal transmission unit as a base, so that the usage restriction cancellation signal transmission unit and the wireless terminal device are brought together. As long as it is not lost, security can be secured.
JP-A-9-233542 “Anshin Key”, [online], NTT DoCoMo, [Search January 29, 2008], Internet <http://www.nttdocomo.co.jp/service/anshin/anshinkey/index.html>

However, in the actual operation of the “Anshin Key”, carry and carry wireless terminal devices such as mobile phones and PCs and usage restriction release signal sending units together (in the same pocket or in the same bag, It is often attached to the same key chain, etc.), and there are very many examples of misplacement or theft.
For example, when a company tries to secure the security of mobile communication by using an “an security key” for an employee, a wireless terminal device such as a mobile phone / PC and a usage restriction release signal transmission unit such as an “an security key” When carrying around, how to prevent them from being carried together has become an important issue.

As a method for solving this problem, when a wireless terminal device such as a mobile phone or a PC and a use restriction release signal transmission unit such as an security key approach a certain distance or less, the wireless terminal device or the use restriction release signal transmission unit However, it is conceivable to tell the user that these are approaching by some means. This allows the user to own and carry them separately, reducing the risk of losing them together.
In order to realize such a method, it is necessary to detect both the case where the wireless terminal device and the use restriction release signal transmission unit are too far apart and the case where they are too close. Distance boundary judgment must be performed. When this is realized by a general technique, the electric field strength of the use restriction cancellation signal received by the wireless terminal device is measured, the inter-device distance is estimated based on the measured value, and the inter-device distance boundary determination is performed. become. However, in this case, the wireless terminal device must be provided with a function for measuring the electric field strength of the use restriction release signal, which complicates the configuration of the wireless terminal device. Such a problem is not limited to the system using the “reliable key”, but is common to systems that need to determine the boundary between the distances between two wireless terminal devices at least at two types of boundaries.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a technique capable of determining a boundary of a distance between wireless terminal devices at least two types of boundaries with a simple configuration. To do.

  In the present invention, in order to solve the above-described problem, a first wireless terminal device having a transmission unit that transmits wireless signals of N (N ≧ 2) types of transmission power and a second wireless device having a reception unit that receives wireless signals. A terminal device, and at least one of the first wireless terminal device and the second wireless terminal device determines how many types of transmission power wireless signals are received by the receiving unit of the second wireless terminal device An inter-device distance determination system further including a distance determination unit that determines a distance between the first wireless terminal device and the second wireless terminal device is provided. The “transmission power” in the present invention means the power of the radio signal (the strength of the radio signal) at the time when the radio signal is output from the transmission unit.

  Here, the first wireless terminal device transmits wireless signals of N (N ≧ 2) types of transmission power. The transmitted radio signal is attenuated in the air propagation process and reaches the second radio terminal apparatus. Even if the distance from the first wireless terminal device to the second wireless terminal device is the same, if the transmission power at the first wireless terminal device is large, the transmission at the second wireless terminal device is smaller than when the transmission power is small. The strength of the received radio signal (generally expressed by concepts such as electric field strength and power density) is increased, and the probability of being able to be received accurately by the receiving circuit is increased. The present invention utilizes this, and among the radio signals of N (N ≧ 2) types of transmission power transmitted from the first radio terminal device, the radio signal of what type of transmission power is received by the second radio terminal device. The boundary determination of the inter-device distance is performed on at least two types of boundaries using the determination as to whether or not it is received by the unit.

  Further, in the present invention, without adding a complicated function for measuring the electric field strength of received power, the function normally provided in the communication device is used by the method unique to the present invention to determine the distance between the wireless terminal devices. Is going.

  As described above, according to the present invention, it is possible to perform the boundary determination of the distance between the wireless terminal devices with at least two types of boundaries with a simple configuration.

The best mode for carrying out the present invention will be described below with reference to the drawings.
[First Embodiment]
First, a first embodiment of the present invention will be described.
The first embodiment includes a first wireless terminal device having a transmitter that transmits wireless signals of N (N ≧ 2) types of transmission power, and a second wireless terminal device having a receiver that receives wireless signals. Then, the second wireless terminal device determines how many types of transmission power wireless signals are received by the receiving unit of the second wireless terminal device, so that the first wireless terminal device and the second wireless terminal device It is a form which has the distance determination part which determines the distance between.

<Principle>
First, the principle of the first embodiment will be described taking N = 2 as an example.
FIG. 1 is a conceptual diagram for explaining the principle of the first embodiment when N = 2.
FIG. 1A shows a state in which the distance between the first wireless terminal device and the second wireless terminal device is a certain first distance or less, and FIG. 1B shows that this distance is less than the first distance. Is larger than a certain second distance, and FIG. 1C shows a state where this distance is larger than the second distance.
In the state shown in FIG. 1A, both of two types of radio signals (strong signal and weak signal) of transmission power transmitted from the transmission unit of the first radio terminal apparatus have reached the second radio terminal apparatus. Since it has sufficient strength at the time, it is determined that any of these radio signals has been received by the receiving unit of the second radio terminal apparatus. The second wireless terminal device determines the distance between the first wireless terminal device and the second wireless terminal device based on the determination result that the wireless signals having the two types of transmission power are received by the receiving unit of the second wireless terminal device. Is less than or equal to a certain first distance. In the present embodiment, “the radio signal is received by the receiving unit of the second radio terminal device” means that the second radio terminal device receives the information in a state where the information included in the radio signal can be reproduced by the second radio terminal device. Means that it was received by Here, reproducible includes both a concept that can be reproduced without error correction and a concept that can be reproduced by performing error correction.

  In the state shown in FIG. 1B, a radio signal having a strong transmission power (strong signal) is transmitted to the second radio terminal apparatus among the two types of radio signals having a transmission power transmitted from the transmission unit of the first radio terminal apparatus. Although it has sufficient strength at the time of arrival, a radio signal with weak transmission power (weak signal) does not have sufficient strength at the time of arrival at the second radio terminal apparatus. In this case, it is determined that the strong signal is received by the receiving unit of the second wireless terminal device, but the weak signal is not determined to be received by the receiving unit of the second wireless terminal device. The second wireless terminal device determines the distance between the first wireless terminal device and the second wireless terminal device based on the determination result that the wireless signal having the one type of transmission power is received by the receiving unit of the second wireless terminal device. Is greater than the first distance and less than or equal to the second distance.

In the state shown in FIG. 1 (c), the radio signals having the two types of transmission power transmitted from the transmission unit of the first radio terminal apparatus do not have sufficient strength when they reach the second radio terminal apparatus. None of these radio signals are received by the receiving unit of the second radio terminal apparatus. The second wireless terminal device has a determination result that a wireless signal is not received by the receiving unit of the second wireless terminal device (a wireless signal of zero type of transmission power has been received by the receiving unit of the second wireless terminal device). It is determined that the distance between the first wireless terminal device and the second wireless terminal device is greater than the second distance.
In FIG. 1, N = 2 is set, and the principle of performing the boundary determination of the inter-device distance at the two boundaries of the first distance and the second distance is shown, but the present invention is not limited to this. In general, the first wireless terminal device transmits wireless signals of N (N ≧ 2) types of transmission power, and the second wireless terminal device receives wireless signals of various types of transmission power by the second wireless terminal device. In the case where the inter-device distance is determined by determining whether the signal has been received by the unit, the second wireless terminal device can perform the boundary determination of the inter-device distance at N boundaries. Further, the radio signal transmitted from the first radio terminal apparatus may function as a use restriction release signal or may function as a use permission signal.

Next, Example 1 which is one example of the first embodiment will be described.
In the first embodiment, the transmission unit of the first wireless terminal device transmits wireless signals in which the number of transmissions within a certain time is fixed for each transmission power at different times. Then, the distance determining unit of the second wireless terminal apparatus determines how many types of wireless signals with different transmission powers are based on the number of wireless signals determined to be received by the receiving unit of the second wireless terminal apparatus within a certain time. 2 It is determined whether or not the signal is received by the receiving unit of the wireless terminal device. Hereinafter, Example 1 will be described in detail.
<Configuration>
FIG. 2 is a block diagram illustrating the configuration of the inter-device distance estimation system 1 of Example 1 which is an example of the first embodiment. 3 is a block diagram illustrating the configuration of the wireless terminal device 10 of FIG. 2, and FIG. 4 is a block diagram illustrating the configuration of the wireless terminal device 20 of FIG.

As shown in FIG. 2, the inter-device distance estimation system 1 of the present embodiment includes a wireless terminal device 10 (corresponding to “first wireless terminal device”) and a wireless terminal device 20 (corresponding to “second wireless terminal device”). And have.
As shown in FIG. 2, the wireless terminal device 10 of the present embodiment includes a signal generator 11 that outputs a digital signal of an identification code, and N (N ≧ 2) types of wireless signals generated based on the identification code. It has the transmission part 12 which transmits with transmission power, and the antenna 13 which discharge | releases the transmitted radio signal in the air. As shown in FIG. 3, the signal creation unit 11 includes an identification code register 11a that stores an identification code, and an identification code generation circuit 11b that generates a digital signal of the identification code. The transmission unit 12 includes a modulation circuit 12a and a modulation circuit 12a. , A frequency synthesizer circuit 12b including a voltage controlled oscillator (VCO), a phase-locked loop (PLL) circuit, and the like, a power amplifier 12c, and an output control circuit 12d for controlling the output of the power amplifier 12c.

  As shown in FIG. 2, the wireless terminal device 20 of this embodiment includes antennas 21 and 26, a receiving unit 22 that receives a wireless signal, and a wireless signal of various types of transmission power is received by the receiving unit 22. A distance determination unit 23 that determines the distance between the wireless terminal device 10 and the wireless terminal device 20, and an instruction signal generation unit 24 that generates an instruction signal based on the determination result of the distance determination unit 23. And a main body 25 which is a mobile communication terminal device such as a mobile phone or a PDA (Personal Digital Assistant). As shown in FIG. 4, the receiving unit 22 includes a low noise amplifier 22a, a mixer 22b, a frequency synthesizer circuit 22c, and a demodulation circuit 22d. The distance determination unit 23 includes an identification code register 23a that stores an identification code, comparison units 23c and 23g, a counter 23e, and a threshold value register 23f that stores a predetermined threshold value. The main body 25 includes an antenna duplexer 25a, a low noise amplifier 25b, a mixer 25c, a demodulation circuit 25d, a power amplifier 25e, a modulation circuit 25f, a frequency synthesizer 25g, a baseband processing circuit 25j, ROM (Read Only Memory) 25k, RAM (Random Access Memory) 25m, a processing unit 25n for performing general-purpose processing, a lock control unit 25p for locking at least a part of functions of the main body unit 25, and input / output control An input / output control unit 25q for performing the input, an input unit 25r composed of an input device such as a number key and a camera and their drive circuit, a speaker unit 25s composed of a speaker and its drive circuit, a display panel and a light emitting diode And a display unit 25t including a drive circuit thereof, and a vibrator unit 25u including a motor and a drive circuit thereof. That. The speaker unit 25s, the display unit 25t, and the vibrator unit 25u correspond to an output unit.

  The processing unit 25n, the lock control unit 25p, the input / output control unit 25q, and the instruction signal generation unit 24 may be a processing unit configured by reading a predetermined program into the CPU, or may be a hardware such as an integrated circuit. It may be configured by wear. For communication between the wireless terminal device 10 and the wireless terminal device 20, for example, a short-range wireless communication technique represented by Bluetooth or wireless LAN can be used. The specifications have been widely standardized by IEEE (The Institute of Electrical and Electronics Engineers, Inc.), an academic society of electrical and electronic technology mainly based in the United States. For example, see http://www.ieee.org/portal/site).

<Processing>
Next, the inter-apparatus distance determination process of the present embodiment will be described. As the following premise, it is assumed that the identification code which is the same digital bit string is stored in the identification code register 11a of the wireless terminal device 10 and the identification code register 23a of the wireless terminal device 20. This identification code may or may not be unique to each pair of the wireless terminal device 10 and the wireless terminal device 20.
[Processing of Wireless Terminal Device 10]
When the inter-device distance determination system 1 is activated, a control circuit (not shown) inputs a read signal to the identification code register 11a according to a certain rule (this rule is called rule A). The identification code register 11a outputs an identification code to the identification code generation circuit 11b each time a read signal is input. The identification code generation circuit 11b generates a digital signal in which information for specifying the start position is added to the input identification code and outputs it to the modulation circuit 12a. The modulation circuit 12a further receives a transmission signal from the frequency synthesizer circuit 12b, and the modulation circuit 12a generates and outputs, for example, a 2.4 GHz band modulation signal corresponding to the identification code. The modulation signal output from the modulation circuit 12a is input to the power amplifier 12c. The output power of the power amplifier 12c is controlled to N (N ≧ 2) types by the output control circuit 12d (this control rule is referred to as rule B). As a result, each modulated signal is amplified with one of N (N ≧ 2) types of transmission power, output to the antenna 13, and radiated therefrom. As a result, N (N ≧ 2) types of transmission power radio signals are transmitted. In addition, the transmission unit 21 according to the present embodiment fixes the number of transmissions of radio signals within a predetermined time for each transmission power, and transmits the signals at different times. Hereinafter, rules A and B for transmitting such a radio signal will be exemplified.

≪Rule 1≫
Rule A: Read signals are input to the identification code register 11a at regular intervals τ. As a result, the identification code register 11a outputs the identification code at a constant interval τ.
Rule B: The output control circuit 12d switches the output power of the power amplifier 12c alternately between two types so that the modulation signal input at a constant interval τ is alternately amplified with two types of output power. Thereby, the transmission part 12 transmits the radio signal of two types of transmission power alternately by the fixed space | interval (tau).

≪Rule 2≫
Rule A: Read signals are input to the identification code register 11a at regular intervals τ. As a result, the identification code register 11a outputs the identification code at a constant interval τ.
Rule B: In the output control circuit 12d, α (α ≧ 2) modulation signals that are continuously input at a constant interval τ are amplified by the output power β, and the next input modulation signal is The output power of the power amplifier 12c is switched between two types in a certain order so that the process of amplification with the output power γ (β ≦ γ) is repeated. Thereby, the transmission unit 12 repeats the process of transmitting one radio signal with the second transmission power (> first transmission power) after transmitting α (α ≧ 2) radio signals with the first transmission power. Thus, the power consumption can be reduced by increasing the transmission frequency of the wireless signal with the smaller transmission power than the wireless signal with the larger transmission power.

≪Rule 3≫
Rule A: Read signals are input to the identification code register 11a at regular intervals τ. As a result, the identification code register 11a outputs the identification code at a constant interval τ.
Rule B: The output control circuit 12d switches the output power of the power amplifier 12c to three types in a fixed order so that modulated signals input at a constant interval τ are sequentially amplified with three types of output power. The transmission unit 12 transmits radio signals of three types of transmission power at a constant order and at a constant interval τ.

≪Rule 4≫
Rule A: α (α is a fixed value of 2 or more) read signals are input to the identification code register 11a within a fixed period at random intervals. As a result, the identification code register 11a outputs α identification codes at random intervals within a certain period.
Rule B: The output control circuit 12d switches the output power of the power amplifier 12c to three types in a fixed order so that α modulation signals input within a predetermined period are sequentially amplified with three types of output power, respectively. . The transmission unit 12 transmits wireless signals of three types of transmission power in a certain order).

[Processing of Wireless Terminal Device 20]
The radio terminal device 20 receives a radio signal with the antenna 21 and sends it to the low noise amplifier 22a. The low noise amplifier 22a amplifies the radio signal and sends it to the mixer 22b. The mixer 22b uses the transmission signal output from the frequency synthesizer circuit 22c, converts the radio signal into an intermediate frequency signal of about several MHz, and outputs it to the demodulation circuit 22d. The demodulation circuit 22d demodulates the signal and sends the demodulated signal to the comparison unit 23c. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code register 23a, and the identification code register 23a outputs the identification code to the comparison unit 23c. The comparison unit 23c extracts the identification code from the input demodulated signal, compares the extracted identification code with the identification code input from the identification code register 23a, and determines whether or not they match. Then, the comparison unit 23c outputs a value 1 to the counter 23e if they match, and outputs a value 0 to the counter 23e if they do not match. Here, if the radio signal transmitted from the radio terminal apparatus 10 is received by the radio terminal apparatus 20 with sufficient reception power, the identification code is accurately extracted from the demodulated signal, and therefore the output of the comparison unit 23c is a value. 1 On the other hand, if the wireless signal transmitted from the wireless terminal device 10 is not received by the wireless terminal device 20 with sufficient reception power, the identification code cannot be accurately extracted from the demodulated signal. 0.

The counter 23e counts up only when the value 1 is input, and stores the count value. Further, the counter 23e transmits the count value to the comparison unit 23g every time a certain time elapses. The count value at this point corresponds to “the number of radio signals determined to be received by the receiving unit 22 of the radio terminal device 20 within a certain time”. The counter 23e resets the count value to 0 after outputting the count value to the comparison unit 23g.
Further, using the output of the count value as a trigger, a control circuit (not shown) inputs a read signal to the threshold value register 23f, and the threshold value register 23f outputs the threshold value to the comparison unit 23g. The comparison unit 23g compares the input count value with a threshold value, and determines how many types of transmission power wireless signals transmitted from the wireless terminal device 10 are received by the reception unit 22 of the wireless terminal device 20. As described above, the wireless terminal device 10 transmits wireless signals in which the number of transmissions within a certain time is fixed for each transmission power at different times. Therefore, by comparing the number of radio signals determined to be received by the receiving unit 22 of the radio terminal device 20 within a certain time, that is, the count value and the threshold value, how many types are transmitted from the radio terminal device 10. It is possible to determine whether or not a radio signal having a transmission power of 2 is received by the receiving unit 22 of the wireless terminal device 20. The determination result also corresponds to the determination result of the inter-device distance between the wireless terminal device 10 and the wireless terminal device 20 (see FIG. 1).

Hereinafter, this determination content is illustrated for the above-described rule examples 1 to 4.
<< In the case of rule example 1 >>
For example, it is assumed that the wireless terminal device 10 alternately transmits five wireless signals of two types of transmission power within a certain time (for example, one minute) until the counter 23e is reset. If the receiving unit 22 of the wireless terminal device 20 has received these correctly (see FIG. 1A), the count value output from the counter 23e is 10 ideally. Also, if the receiving unit 22 of the wireless terminal device 20 has correctly received only a wireless signal having a large transmission power (see FIG. 1B), the count value output from the counter 23e is 5 and ideally. Become. If the receiving unit 22 of the wireless terminal device 20 has not received any wireless signal correctly (see FIG. 1C), the count value output from the counter 23e is ideally 0. Actually, an error occurs in the count value due to the influence of the environment or the like, but the inter-device distance can be determined by using a value obtained by setting a predetermined margin as an ideal count value corresponding to each inter-device distance as a threshold value. In the above example, for example, two values 8 and 2 are set as threshold values, and the comparison unit 23g outputs a comparison result between the two threshold values and the count value. In this case, for example, a count value of 8 or more corresponds to a determination result that radio signals having two types of transmission power are received by the receiving unit 22 of the wireless terminal device 20, and the count value is 2 or more and 8 Is less than 2, which corresponds to the determination result that the reception unit 22 of the wireless terminal device 20 has received one type of transmission power, and that the count value is less than 2 This corresponds to the determination result that the wireless signal is received by the receiving unit 22 of the wireless terminal device 20 (no wireless signal is received).

≪In the case of rule example 2≫
For example, the wireless terminal device 10 transmits a wireless signal with a strong transmission power twice and a wireless signal with a weak transmission power 10 times within a certain time (for example, 1 minute) until the counter 23e is reset. Suppose.
In this case, for example, two values of 5 and 1 are set as threshold values, and the comparison unit 23g outputs a comparison result between the two threshold values and the count value. For example, a count value of 5 or more corresponds to a determination result that two types of transmission power radio signals have been received by the reception unit 22 of the radio terminal device 20, and the count value is 1 or more and less than 5 Is equivalent to the determination result that the radio signal of one type of transmission power has been received by the receiving unit 22 of the radio terminal apparatus 20, and that the count value is less than 1, This corresponds to the determination result that the radio signal is received by the receiving unit 22 of the radio terminal device 20 (no radio signal is received).

<< In the case of rule examples 3 and 4 >>
For example, the wireless terminal device 10 transmits the wireless signal with the strongest transmission power twice within a certain time (for example, 1 minute) until the counter 23e is reset, and transmits the wireless signal with the intermediate transmission power five times. Assume that the radio signal having the weakest transmission power is transmitted 10 times.
In this case, for example, three values of 10, 5, and 1 are set as threshold values, and the comparison unit 23g outputs a comparison result between the three threshold values and the count value. For example, a count value of 10 or more corresponds to a determination result that radio signals having three types of transmission power have been received by the receiving unit 22 of the wireless terminal device 20, and the count value is 5 or more and less than 10 Is equivalent to the determination result that the radio signal of two types of transmission power has been received by the reception unit 22 of the radio terminal device 20, and that the count value is less than 1, This corresponds to the determination result that the wireless signal has been received by the receiving unit 22 of the wireless terminal device 20 (end of the description of the determination content).
The comparison result output from the comparison unit 23g is input to the instruction signal generation unit 24. The instruction signal generation unit 24 generates and outputs an instruction signal using the input comparison result. The instruction signal is a signal indicating instruction contents for the main body 25. Hereinafter, a specific example of the instruction signal will be described.

<< Specific example 1 of instruction signal >>
In this example, the instruction signal generation unit 24 receives a radio signal having a transmission power of a comparison result output from the comparison unit 23g of “M (N ≧ M ≧ 2, M is a fixed value)” or more. In the case of “determination result that is received at 22”, an instruction signal for locking a certain function of the main body unit 25 included in the wireless terminal device 20 is generated and output. For example, when N = 2 and M = 2, the instruction signal generation unit 24 indicates that the comparison result output from the comparison unit 23g is “a wireless signal having two types of transmission power is received by the reception unit 22 of the wireless terminal device 20. If it is equivalent to “determination result (decision result that count value is 8 or more in the example of rule example 1)”, an instruction signal for locking a certain function of the main body 25 is generated and output. To do.

In this case, the instruction signal for locking a certain function of the main body unit 25 may include an instruction to execute a lock that cannot be released without inputting secret information such as a password.
In addition, the instruction signal generation unit 24 may generate and output an instruction signal for locking a certain function of the main body unit 25 a plurality of times. For example, when the above condition is satisfied for the first time, a first instruction signal for locking the first function of the main body unit 25 is generated and output, and the above-described condition is maintained even after a predetermined time has elapsed since the generation and output of the first instruction signal. If the condition is satisfied, a second instruction signal for locking the second function of the main body 25 may be generated and output. Alternatively, when the above condition is satisfied for the first time, a first instruction signal for executing a lock that can be released without inputting confidential information is generated and output for a certain function of the main body 25, and the first instruction is generated. If the above condition is satisfied even after a lapse of a certain time from the generation / output of the signal, a second instruction signal for executing a lock that cannot be released without inputting confidential information may be generated / output. . Further, for example, when N = 3 and the comparison result output from the comparison unit 23g corresponds to “a determination result that two types of transmission power wireless signals are received by the reception unit 22 of the wireless terminal device 20”. A first instruction signal for locking the first function of the main body 25 is generated and output, and the comparison result output from the comparison unit 23g is “a wireless signal of three types of transmission power is received by the reception unit 22 of the wireless terminal device 20”. In the case of “determination result that has been performed”, a second instruction signal for locking the second function of the main body 25 may be generated and output.

Further, when the comparison result output from the comparison unit 23g corresponds to the determination result that the wireless signal of M types or more of transmission power is received by the reception unit 22 of the wireless terminal device 20, and further satisfies another condition In addition, an instruction signal for locking a certain function of the main body 25 may be generated and output. As a specific example of “another condition”, there is, for example, “a certain time or more has passed since the last instruction signal was generated / output”.
≪Specific example 2 of instruction signal≫
In this example, the instruction signal generation unit 24 receives a comparison result output from the comparison unit 23g as “P (N ≧ P ≧ 2) types or more of radio signals with transmission power received by the reception unit 22 of the wireless terminal device 20. In the case of the “determination result”, an instruction signal for causing the main body unit 25 of the wireless terminal device 20 to output warning information is generated. Examples of warning information include warning sound output, vibrator drive, warning screen display, light emission of light emitting diodes and change of the emission color thereof.

The instruction signal generation unit 24 may generate and output an instruction signal for causing the main body unit 25 to output warning information a plurality of times. For example, when the above condition is satisfied for the first time, a first instruction signal for driving the vibrator is generated and output, and the above condition is satisfied even after a lapse of a certain time from the generation and output of the first instruction signal. If so, a second instruction signal for outputting a warning sound may be generated and output.
Also, << specific examples 1 and 2 of instruction signals >> may be combined. For example, when N = 3 and the comparison result output from the comparison unit 23g corresponds to the “determination result that two types of transmission power wireless signals are received by the reception unit 22 of the wireless terminal device 20”, the main body unit The first instruction signal for causing the alarm information to be output to 25 is generated and output, and the comparison result output from the comparison unit 23g is “a wireless signal of three types of transmission power is received by the reception unit 22 of the wireless terminal device 20”. In the case of “determination result”, a second instruction signal for locking a certain function of the main body 25 may be generated and output.
Further, the comparison result output from the comparison unit 23g corresponds to the “determination result that radio signals having M or more types of transmission power are received by the reception unit 22 of the wireless terminal device 20”, and further satisfies another condition. Sometimes, an instruction signal for causing the main body unit 25 to output warning information may be generated and output.

<< Specific example 3 of instruction signal >>
Further, in addition to the instruction signal exemplified in << Specific Examples of Instruction Signals 1 and 2 >>, the comparison result output from the comparison unit 23g is “Q (1 ≦ Q <N) or more radio signals with transmission power of the second or higher type. In the case of “determination result that is not received by the receiving unit of the wireless terminal device”, an instruction signal for locking a certain function of the main body unit 25 may be generated. For example, N = 2, Q = 1, and the comparison result output from the comparison unit 23g is “a determination result that no radio signal of any transmission power is received by the reception unit 22 of the wireless terminal device 20”. In a corresponding case, an instruction signal for locking a certain function of the main body unit 25 may be generated (end of description of a specific example of the instruction signal).

The instruction signal generated from the instruction signal generation unit 24 is input to the lock control unit 25p or the input / output control unit 25q, and the lock control unit 25p and the input / output control unit 25q each perform processing indicated by the input instruction signal. Execute.
For example, when an instruction signal for locking a certain function of the main body unit 25 is input to the lock control unit 25p, the lock control unit 25p locks a certain function of the main body unit 25 indicated by the instruction signal. Accordingly, the lock control unit 25p determines that the distance determination unit 23 determines that the wireless signal of M (N ≧ M ≧ 2) types or more of transmission power is received by the reception unit 22 of the wireless terminal device 20, or On the condition that the distance determination unit 23 determines that a radio signal having transmission power of Q (1 ≦ Q <N) or more is not received by the reception unit 22 of the wireless terminal device 20, the wireless terminal device 10 A certain function is locked.

When this instruction signal includes an instruction to execute a lock that cannot be released without input of secret information, the lock control unit 25p determines that a certain function of the main body unit 25 indicated by the instruction signal Lock it so that it cannot be released without input. Such a lock is not locked unless confidential information necessary for releasing the lock is input to the input unit 25r. That is, the lock control unit 25p in this case releases the lock on the condition that the secret information necessary for releasing the lock is input to the input unit 25r.
Also, for example, when an instruction signal for causing the input / output control unit 25q to output warning information is input, the input / output control unit 25q displays the warning information indicated by the instruction signal as the speaker unit 25s, the display unit 25t, or Output to the output unit of the vibrator unit 25u. Thereby, the output unit warns as a necessary condition that the distance determination unit 23 has determined that radio signals having transmission power of P (N ≧ P ≧ 2) types or more have been received by the reception unit 22 of the wireless terminal device 20. Output information.

<Characteristics of Example 1>
As described above, the inter-device distance determination system according to the first embodiment includes the wireless terminal device 10 including the transmission unit 12 that transmits wireless signals with N (N ≧ 2) types of transmission power, and the reception unit that receives the wireless signals. 22. A distance determination unit 23 that determines the distance between the wireless terminal device 10 and the wireless terminal device 20 by determining how many types of transmission power wireless signals are received by the receiving unit 22 of the wireless terminal device 20 And a wireless terminal device 20 having Thereby, it becomes possible to determine the distance between the radio | wireless terminal apparatus 10 and the radio | wireless terminal apparatus 20, without taking the complicated structure for measuring an electric field strength.

  In the first embodiment, the 12 transmitters of the wireless terminal device 10 transmit radio signals in which the number of transmissions within a certain time is fixed for each transmission power at different times, and the distance determination unit 23 is constant. Based on the number of radio signals determined to have been received by the receiving unit 22 of the wireless terminal device 20 within a predetermined time period, it is determined how many types of transmission power wireless signals have been received by the receiving unit 22 of the wireless terminal device 20 It was decided. Thereby, even if there is no difference other than the transmission power in the radio signals of N (N ≧ 2) types of transmission power transmitted from the wireless terminal device 10, the distance determination unit 23 can determine how many types of transmission power. It can be determined whether the wireless signal is received by the receiving unit 22 of the wireless terminal device 20. Further, the distance determination unit 23 of this embodiment can be easily configured using a register, a comparator, a counter, and the like, and its cost is generally low.

  In addition, the lock control unit 25p of the wireless terminal device 20 determines that the wireless signal having M (N ≧ M ≧ 2) types or more of transmission power is received by the receiving unit 22 of the wireless terminal device 20 by the distance determining unit 23. If it is necessary to lock a certain function of the main body 25 of the wireless terminal device 20 as a necessary condition, the main body 25 is used unless the wireless terminal device 10 and the wireless terminal device 20 are separated from each other by a certain distance or more. Can not. Thereby, when a user carries the radio | wireless terminal apparatus 10 and the radio | wireless terminal apparatus 20, the probability of putting these in the same bag or connecting with a key ring can be reduced. Thereby, the probability that the wireless terminal device 10 and the wireless terminal device 20 are lost or stolen at the same time can be reduced.

In addition, when it is necessary to input secret information such as a personal identification number to unlock a function once locked, safety can be further improved. That is, when the wireless terminal device 10 and the wireless terminal device 20 are lost or stolen at the same time, it is assumed that the distance between these devices is short, and a certain function of the main body 25 is locked when the device is lost or stolen. It is assumed that Thereby, it is possible to prevent an unauthorized use of a certain function of the main body 25 of the wireless terminal device 20 that has been lost or stolen.
Further, in the first embodiment, it is necessary that it is determined by the distance determination unit 23 that the wireless signal having the transmission power of Q (1 ≦ Q <N) or more is not received by the reception unit 22 of the wireless terminal device 20. As a condition, when a certain function of the main body 25 of the wireless terminal device 20 is locked, it is possible to improve safety in a system similar to the above-described “reliable key”.

Further, in the first embodiment, it is necessary that the distance determination unit 23 determines that a radio signal having transmission power of P (N ≧ P ≧ 2) types or more has been received by the reception unit 22 of the second wireless terminal device 20. When the warning information is output as described above, when the user carries the wireless terminal device 10 and the wireless terminal device 20, the probability of putting them in the same bag or connecting them with a key holder can be reduced. Thereby, the probability that the wireless terminal device 10 and the wireless terminal device 20 are lost or stolen at the same time can be reduced.
The present invention is not limited to the first embodiment. For example, in the first embodiment, the instruction signal generated by the instruction signal generation unit 24 of the wireless terminal device 20 is sent to the main body unit 25 of the wireless terminal device 20, and a certain function of the main body unit 25 is locked or warning information is transmitted. Was output. However, the lock control unit, the input / output control unit, the input unit, and the output unit are provided in the wireless terminal device 10, and the instruction signal generated by the instruction signal generation unit 24 of the wireless terminal device 20 is transmitted to the wireless terminal device 10. The lock control unit of the terminal device 10 locks a certain function of the wireless terminal device 10 or a device connected thereto as described above, or the input / output control unit outputs warning information to the output unit. May be. Furthermore, in order to release the lock, the secret information input from the input unit of the wireless terminal device 10 or the wireless terminal device 20 may be required. Specifically, for example, the instruction signal generated by the instruction signal generation unit 24 of the wireless terminal device 20 is transmitted to the wireless terminal device 10, and the lock control unit of the wireless terminal device 10 that has received this transmits the instruction signal of the wireless terminal device 10. The function of the signal creation unit 11 or the transmission unit 12 may be locked, and the transmission of the wireless signal by the wireless terminal device 10 may be stopped until secret information is input to the input unit of the wireless terminal device 10. Thereby, since the wireless signal from the wireless terminal device 10 is not received by the wireless terminal device 20, the function of the main body 25 of the wireless terminal device 20 is locked until the secret information is input.

  Further, for example, the wireless terminal device 10 further includes the function of the wireless terminal device 20, the wireless terminal device 20 further includes the function of the wireless terminal device 10, and a plurality of wireless terminal devices 10 and 20 are provided. Transmits and receives wireless signals of various types of transmission power, performs distance determination between devices according to the logic described above, and locks one or both functions and restricts use when communication is not possible due to distance between each other It is good as well. Furthermore, in this case, both or one or both of the wireless terminal device 10 and the wireless terminal device 20 perform transmission / reception of wireless signals having a plurality of types of transmission power, perform inter-device distance determination according to the above-described logic, and increase the distance between each other. One or both of the functions may be locked to restrict the use not only when communication is not possible, but also when the distance between each other is too close.

The distance determination unit 23 illustrated in FIG. 4 can be configured by causing a computer including a CPU, a memory, and the like to read a predetermined program. FIG. 5 is a diagram illustrating a configuration of a distance determination unit configured by causing a computer to read a predetermined program, and FIG. 6 is a flowchart for explaining the processing. Hereinafter, the configuration and processing in this case will be described.
In this case, the distance determination unit 23 includes a reception signal storage area 23h, an identification code storage area 23i, a count storage area 23j, and a threshold storage area 23k including a memory, and a comparison section 23m configured by reading a predetermined program into the CPU. , 23p, a counter 23n, and a control unit 23q. The identification code storage area 23i stores the aforementioned identification code, and the threshold storage area 23k stores the aforementioned threshold.

  The demodulated signal output from the demodulation circuit 22d (FIG. 4) after resetting the count value in the count storage area 23j (step S1) is first stored in the reception signal storage area 23h (step S2). Using this as a trigger, the comparator 23m reads the demodulated signal from the received signal storage area 23h and reads the identification code from the identification code storage area 23i. Further, the comparison unit 23m extracts the identification code from the input demodulated signal, compares the extracted identification code with the identification code read from the identification code storage area 23i, and determines whether or not they match (step S23). S3). The comparison unit 23m outputs a value 1 to the counter 23n if they match, and outputs a value 0 to the counter 23n if they do not match. The counter 23e counts up the count value in the count storage area 23j only when the value 1 is input, and stores the count value in the count storage area 23j (steps S4 and S5). Next, the controller 23q determines whether or not a certain time has elapsed since the counter reset (step S6). Here, if it is determined that a certain time has not elapsed since the counter reset, the process returns to step S2. On the other hand, when it is determined that a certain time has elapsed since the counter reset, the comparison unit 23p reads the count value from the count storage area 23j, reads the threshold value from the threshold storage area 23k, and compares them (step S7). The comparison result is sent to the instruction signal generator 24.

Next, Example 2 which is one example of the first embodiment will be described.
In the second embodiment, the transmission unit of the first wireless terminal device transmits wireless signals having different transmission intervals for each transmission power at different times. Then, the distance determination unit of the second wireless terminal device receives the radio signal of what kind of transmission power based on the reception interval of the wireless signal determined to be received by the reception unit of the second wireless terminal device. It is determined whether it was received by the receiving unit. Hereinafter, the second embodiment will be described focusing on the differences from the first embodiment.
The differences between the first embodiment and the second embodiment are only the features required for the radio signal transmitted by the transmission unit of the first wireless terminal device and the distance determination unit. Hereinafter, only these differences will be described, and the other points are the same as those in the first embodiment, and thus description thereof will be omitted.

FIG. 7A is a block diagram illustrating a configuration of the distance determination unit 123 included in the wireless terminal device 120 (corresponding to “second wireless terminal device”) according to the second embodiment. In FIG. 7A, the same reference numerals as those in FIG.
As shown in FIG. 7A, the distance determination unit 123 of the second embodiment is configured by replacing the counter 23e of the distance determination unit 23 of the first embodiment with a pulse interval detection circuit 123e that outputs the time interval of the input pulse. It is. Hereinafter, the process of the distance determination part 123 of Example 2 is demonstrated.
The radio signal received by the reception unit 22 of the wireless terminal device 120 is converted into a demodulated signal as described above and input to the comparison unit 23c. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code register 23a, and the identification code register 23a outputs the identification code to the comparison unit 23c. The comparison unit 23c extracts the identification code from the input demodulated signal, compares the extracted identification code with the identification code input from the identification code register 23a, and determines whether or not they match. Then, the comparison unit 23c outputs a value 1 to the pulse interval detection circuit 123e if they match, and outputs a value 0 to the pulse interval detection circuit 123e if they do not match.

  The pulse interval detection circuit 123e compares the pulse interval value of the value 1 signal sequentially input from the comparison unit 23c (corresponding to the reception interval value of the radio signal determined to be received by the reception unit 22 of the wireless terminal device 120). To the unit 23g. With this as a trigger, a control circuit (not shown) inputs a read signal to the threshold register 23f, and the threshold register 23f outputs the threshold to the comparator 23g. The comparison unit 23g compares the input pulse interval value with the threshold value, and determines how many types of transmission power wireless signals transmitted from the wireless terminal device 10 are received by the reception unit 22 of the wireless terminal device 120. . As described above, the wireless terminal device 10 according to the second embodiment transmits wireless signals having different transmission intervals for each transmission power at different times. Therefore, the reception interval of the radio signal determined to be received by the reception unit 22 of the radio terminal device 120, that is, the pulse interval value of the signal of value 1 is compared with the threshold value, and transmitted from the radio terminal device 10. It is possible to determine how many types of transmission power wireless signals are received by the receiving unit 22 of the wireless terminal device 120. The determination result also corresponds to the determination result of the inter-device distance between the wireless terminal device 10 and the wireless terminal device 120. Hereinafter, this determination content will be exemplified for the above-described rule examples 1 and 3.

<< In the case of rule example 1 >>
For example, it is assumed that the wireless terminal device 10 alternately transmits five wireless signals of two types of transmission power within a certain time (for example, one minute). If the receiving unit 22 of the wireless terminal device 120 has received these correctly, the above-described pulse interval value is ideally 6 seconds. Also, if the receiving unit 22 of the wireless terminal device 120 correctly receives only a wireless signal having a large transmission power, the above-described pulse interval value is ideally 12 seconds. If the receiving unit 22 of the wireless terminal device 120 has not received any wireless signal correctly, the above-described pulse interval value is ideally infinite.

  Actually, an error occurs in the pulse interval value due to the influence of the environment, etc., but a value obtained by setting a predetermined margin to the ideal pulse interval value corresponding to the distance between devices is set as a threshold value, and judgment is made based on a plurality of comparison results. By doing so, the distance between devices can be determined. In the above example, for example, two values of 8 seconds and 14 seconds are used as threshold values, and the comparison unit 23g compares the two threshold values with the pulse interval value output from the pulse interval detection circuit 123e. In this case, for example, the comparison result that the pulse interval value is 8 seconds or less continues for δ (δ is a constant equal to or greater than 1) times. The comparison result that the comparison result that the pulse interval value exceeds 8 seconds and is 14 seconds or less continues for δ times is a wireless signal of one type of transmission power. This corresponds to the determination result of reception by the receiving unit 22. Further, for example, the determination result that the time during which the pulse interval value is not input to the comparison unit 23g has continued for 60 seconds or more is determined as the determination that no type of wireless signal is received by the reception unit 22 of the wireless terminal device 120. As a result.

<< In the case of rule example 3 >>
For example, it is assumed that the wireless terminal device 10 transmits wireless signals of three types of transmission power at a fixed order and at a fixed interval of 5 seconds. If the receiving unit 22 of the wireless terminal device 120 has received all of these correctly, the above-described pulse interval value is ideally 5 seconds. In addition, if the receiving unit 22 of the wireless terminal device 120 correctly receives only the wireless signals having the maximum and second transmission powers, the above-described pulse interval value is ideally 5 seconds or 10 seconds. Also, if the receiving unit 22 of the wireless terminal device 120 correctly receives only the wireless signal having the maximum transmission power, the above-described pulse interval value is ideally 15 seconds. If the receiving unit 22 of the wireless terminal device 120 has not received any wireless signal correctly, the above-described pulse interval value is ideally infinite.

  In this example, for example, three values of 7 seconds, 12 seconds, and 17 seconds are used as threshold values, and the comparison unit 23g compares the three threshold values with the pulse interval values output from the pulse interval detection circuit 123e. In this case, for example, the comparison result that the comparison result that the pulse interval value is 7 seconds or less continues for δ (δ is a constant of 2 or more) times is a wireless signal with three types of transmission power. The comparison result that the pulse interval value is 7 seconds or less and the comparison result that exceeds 7 seconds and 12 seconds or less are alternately repeated δ times. The comparison result corresponds to the determination result that the radio signal of the transmission power is received by the reception unit 22 of the radio terminal device 120, and the comparison result that the pulse interval value exceeds 12 seconds and is equal to or less than 17 seconds is δ times. This corresponds to a determination result that the reception unit 22 of the wireless terminal device 120 has received one type of transmission power wireless signal. Further, for example, the determination result that the time during which the pulse interval value is not input to the comparison unit 23g has continued for 60 seconds or more is determined as the determination that no type of wireless signal is received by the reception unit 22 of the wireless terminal device 120. The result may be a result (end of the explanation of the example of determination content).

As in the first embodiment, the comparison result output from the comparison unit 23p is input to the instruction signal generation unit 24, and is used to generate an instruction signal similar to that in the first embodiment.
<Features of Example 2>
In the second embodiment, 12 transmission units of the wireless terminal device 10 transmit wireless signals having different transmission intervals for each transmission power at different times, and the distance determination unit 123 is received by the reception unit 22 of the wireless terminal device 120. Based on the reception interval of the wireless signal determined to be received, it is determined how many types of transmission power wireless signals are received by the receiving unit 22 of the wireless terminal device 120. Thereby, even if there is no difference other than the transmission power in the radio signals of N (N ≧ 2) types of transmission power transmitted from the wireless terminal device 10, the distance determination unit 23 can determine how many types of transmission power. It can be determined whether the wireless signal is received by the receiving unit 22 of the wireless terminal device 20.

The distance determination unit 123 illustrated in FIG. 7A can be configured by causing a computer including a CPU, a memory, and the like to read a predetermined program. FIG. 7B is a diagram illustrating a configuration of a distance determination unit configured by causing a computer to read a predetermined program, and FIG. 8 is a flowchart for explaining the processing. Hereinafter, the configuration and processing in this case will be described.
In this case, the distance determination unit 123 includes a reception signal storage area 23h, an identification code storage area 23i, a reception time storage area 123j, and a threshold storage area 23k made of memory, and a comparison unit configured by reading a predetermined program into the CPU. 23m, 23p, reception interval detector 123n, and controller 23q. The identification code storage area 23i stores the aforementioned identification code, and the threshold storage area 23k stores the aforementioned threshold.

  The demodulated signal output from the demodulating circuit 22d (FIG. 4) is first stored in the received signal storage area 123h (step S21). Using this as a trigger, the comparator 23m reads the demodulated signal from the received signal storage area 23h and reads the identification code from the identification code storage area 23i. Furthermore, the comparison unit 23m extracts the identification code from the read demodulated signal, compares the extracted identification code with the identification code read from the identification code storage area 23i, and determines whether or not they match ( Step S22). The comparison unit 23m outputs a value 1 to the reception interval detection unit 123n if they match, and outputs a value 0 to the reception interval detection unit 123n if they do not match (step S23). The reception interval detection unit 123n stores the current time in the reception time storage area 123j as the reception time t only when the value 1 is input (step S24). Next, the reception interval detection unit 123n reads the reception time t stored in step S24 from the reception time storage area 123j and the latest reception time t-1 before that, and calculates the time difference between them as a reception interval value. And stored in the reception time storage area 123j (step S25). Next, the comparison unit 23p reads the reception interval value from the reception time storage area 123j, reads the threshold value from the threshold value storage area 23k, and compares them (step S26). The comparison result is sent to the instruction signal generator 24.

Next, Example 3 which is one example of the first embodiment will be described.
In the third embodiment, the transmission unit of the first wireless terminal device transmits N types of radio signals having differences other than the transmission power with different transmission powers for the respective types. Based on this difference, the distance determination unit of the second wireless terminal device determines how many types of transmission power wireless signals are received by the receiving unit of the second wireless terminal device. Hereinafter, the third embodiment will be described focusing on the differences from the first embodiment.
The difference between the first embodiment and the third embodiment is only the signal creation unit of the first wireless terminal device and the distance determination unit of the second wireless terminal device. Hereinafter, only these differences will be described, and the other points are the same as those in the first embodiment, and thus description thereof will be omitted.

FIG. 9A is a block diagram illustrating a configuration of the distance determination unit 223 included in the wireless terminal device 210 (corresponding to “first wireless terminal device”) according to the third embodiment. FIG. 9B is a block diagram illustrating the configuration of the distance determination unit 223 included in the wireless terminal device 220 (corresponding to “second wireless terminal device”) according to the third embodiment. In FIG. 9, the same reference numerals as those in FIG.
As illustrated in FIG. 9A, the signal creation unit 211 of the wireless terminal device 210 according to the third embodiment includes identification code registers 211 a-1 to N that store identification codes of N types of formats, and an identification code generation circuit. 211b-1 to N. As shown in FIG. 9B, the distance determination unit 223 according to the third embodiment includes identification code registers 223a- that store identification codes of N types of formats stored in the identification code registers 211a-1 to 211a-1, respectively. 1 to N, comparison units 223c-1 to N, counters 223e-1 to N, comparison units 223g-1 to N, and a threshold register 223f.
Hereinafter, the processing of the third embodiment will be described focusing on the differences from the first embodiment.

[Processing of Wireless Terminal Device 210]
When the inter-device distance determination system is activated, a control circuit (not shown) inputs a read signal to one of the identification code registers 211a-1 to 211a-1 according to a certain rule, and each identification code register 211a-1 To N output identification codes to the identification code generation circuits 211b-1 to 211b-N each time a read signal is input. Each of the identification code generation circuits 211b-1 to 211b-1N generates a digital signal to which information for specifying the input identification code and its start position is added, and outputs it to the modulation circuit 12a. The modulation circuit 12a generates a modulation signal corresponding to the identification code and outputs the modulation signal to the power amplifier 12c. The power amplifier 12c has the output power corresponding to the type of the identification code format corresponding to the modulation signal on a one-to-one basis. The modulated signal is amplified and transmitted through the antenna 13. As a result, the transmission unit 12 transmits N types of radio signals having differences other than the transmission power with different transmission powers for the respective types.

[Processing of Wireless Terminal Device 220]
In the following, only the process of the distance determination unit 223, which is the difference from the first embodiment, will be described, and the description of the process of the other wireless terminal device 220 will be omitted.
The demodulated signal output from the reception unit 22 is input to each comparison unit 223c-1 to N. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code registers 223a-1 to 223-N, and the identification code registers 223a-1 to 223-n respectively store the identification codes held in the comparison units 223c- 1 to N. Each comparison unit 223c-1 to N extracts the identification code from the input demodulated signal, compares the extracted identification code with the identification code input from each of the identification code registers 223a-1 to N, and It is determined whether or not they match. Then, each comparison unit 223c-1 to N outputs a value 1 to the counters 223e-1 to N if they match, and outputs a value 0 to the counters 223e-1 to N if they do not match. Each counter 223e-1 to N counts up only when the value 1 is input, and stores the count value. Each counter 223e-1 to N outputs a count value to each of the comparison units 223g-1 to N every time a certain time elapses. Note that the count values output from the counters 223e-1 to N at this point in time are “the radio signal determined to be received by the receiving unit 22 of the radio terminal device 220 within a certain period of time, the transmission power It corresponds to “the number counted for each”. Based on these count values, it is possible to determine how many types of transmission power radio signals are received by the reception unit 22. Each of the counters 223e-1 to 223e-N resets the count value to 0 after outputting the count value.

  Further, with the output of each count value as a trigger, a control circuit (not shown) inputs a read signal to the threshold value register 223f, and the threshold value register 223f outputs the threshold value to each of the comparison units 223g-1 to N. Each of the comparison units 223g-1 to 223N compares the input count value with the threshold value, and the radio signal of the various types of transmission power transmitted from the radio terminal device 210 is received by the reception unit 22 of the radio terminal device 220. It is determined. For example, each comparison unit 223g-1 to N compares the input count value with a threshold value, and outputs a value 1 when the count value exceeds the threshold value, and sets a value 0 when the count value is equal to or less than the threshold value. Output. In this case, the total number of values 1 output from the comparison units 223g-1 to N is the type of transmission power of the radio signal that is determined to be received by the reception unit 22 of the radio terminal device 220. The values output from the comparison units 223g-1 to N are input to the instruction signal generation unit 224, and are used to generate instruction signals similar to those in the first embodiment.

<Features of Example 3>
In the third embodiment, the transmission unit 12 of the wireless terminal device 210 transmits N types of wireless signals having differences other than the transmission power with different transmission powers for the respective types. Thereby, the accuracy of determination of which transmission power of the radio signal is received by the reception unit 22 of the radio terminal device 220 is improved. As a result, it is possible to perform detailed device-to-device distance determination using many types of radio signals having transmission power.
The distance determination unit 223 illustrated in FIG. 9B can be configured by causing a computer including a CPU, a memory, and the like to read a predetermined program. FIG. 10 is a diagram illustrating a configuration of a distance determination unit configured by causing a computer to read a predetermined program, and FIG. 11 is a flowchart for explaining the processing. Hereinafter, the configuration and processing in this case will be described.

In this case, the distance determination unit 223 includes a reception signal storage area 223h, an identification code storage area 223i, a count storage area 223j, and a threshold storage area 223k made of a memory, and a comparison section 223m configured by reading a predetermined program into the CPU. , 223p, a counter 223n, and a control unit 23q. The identification code storage area 223i stores the above-described N types of identification codes, and the threshold storage area 223k stores the above-described threshold.
After resetting the count value of the count storage area 223j (step S31), the demodulated signal output from the reception unit 22 is first stored in the reception signal storage area 223h (step S32). Using this as a trigger, the comparison unit 223m reads the demodulated signal from the received signal storage area 223h and reads the identification code from the identification code storage area 223i. Further, the comparison unit 223m extracts the identification code from the read demodulated signal, compares the extracted identification signal with the identification code read from the identification code storage area 223i, and the identified signal is an identification code of any format. Is determined (step S33).

When the comparison unit 223m detects such a match, the comparison unit 223m sends information specifying the matched format to the counter 223n. Only when this information is received, the counter 223n counts up the count value corresponding to the format specified thereby, and stores it in the count storage area 223j (step S35).
Next, the control unit 23q determines whether or not a certain time has elapsed since the counter was reset (step S36). Here, if it is determined that a certain time has not elapsed since the counter was reset, the process returns to step S32. On the other hand, when it is determined that a certain time has elapsed since the counter was reset, the comparison unit 223p reads the threshold value from the threshold value storage area 223k, obtains the number of formats whose count value exceeds the threshold value, and outputs the number.

  In addition, a present Example does not limit this invention. For example, in this embodiment, identification signals of N types of formats are used, and the difference in the format is set as a difference other than the transmission power of the N types of radio signals. However, for example, the wireless terminal device 210 may transmit a wireless signal at a different frequency for each type of transmission power, and may determine the transmission power of the wireless signal received by the wireless terminal device 220 based on the difference in frequency. Further, for example, the wireless terminal device 210 transmits a wireless signal corresponding to an identification code different for each type of transmission power, and the wireless terminal device 220 determines the transmission power of the wireless signal received by the difference in the identification code. May be. In addition, for example, the wireless terminal device 210 transmits a wireless signal including an additional signal that is different for each type of transmission power, and the transmission power of the wireless signal received by the wireless terminal device 220 is determined based on the difference of the additional signal. Also good.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment, the second wireless terminal device returns a response signal to the transmission of the wireless signal from the first wireless terminal device.
That is, in the second embodiment, when the transmission unit of the first radio terminal apparatus transmits radio signals of N (N ≧ 2) types of transmission power and these are received by the reception unit of the second radio terminal apparatus. The transmission unit of the second wireless terminal device transmits a response signal. Then, the reception unit of the first radio terminal apparatus receives the response information, and the distance determination unit uses the response information to determine how many types of transmission power radio signals are received by the reception unit of the second radio terminal apparatus. By determining the distance between the first wireless terminal device and the second wireless terminal device.

<Principle>
Taking the case of N = 2 as an example, the principle of the second embodiment will be described.
12 and 13 are conceptual diagrams for explaining the principle of the second embodiment when N = 2.
FIG. 12A shows a state where the distance between the first wireless terminal device and the second wireless terminal device is a certain first distance or less, and FIG. 12B shows that this distance is less than the first distance. Is larger than a certain second distance, and FIG. 13 shows a state where this distance is larger than the second distance.

  In the state shown in FIG. 12A, both of the two types of radio signals (strong signal and weak signal) transmitted from the transmission unit of the first radio terminal apparatus have reached the second radio terminal apparatus. Since it has sufficient strength at the time, it is determined that any of these radio signals has been received by the receiving unit of the second radio terminal apparatus. Each time the second wireless terminal device determines that a wireless signal has been received by the receiving unit of the second wireless terminal device, the second wireless terminal device transmits a response signal to the first wireless terminal device. The first wireless terminal device has received a response signal corresponding to the two types of wireless signals having the transmission power, so that the distance between the first wireless terminal device and the second wireless terminal device is a certain first distance. It is determined that: In the present embodiment, “the radio signal is received by the receiving unit of the second radio terminal device” means that the second radio terminal device receives the information in a state where the information included in the radio signal can be reproduced by the second radio terminal device. Means that it was received by In addition, “the first wireless terminal device has received the response signal” in this embodiment means that the information included in the response signal is received by the receiving unit of the first wireless terminal device in a state that can be reproduced by the first wireless terminal device. Means that. Here, reproducible includes both a concept that can be reproduced without error correction and a concept that can be reproduced by performing error correction.

  In the state shown in FIG. 12B, a radio signal having a strong transmission power (strong signal) is transmitted to the second radio terminal apparatus among the two types of radio signals having a transmission power transmitted from the transmission unit of the first radio terminal apparatus. Although it has sufficient strength at the time of arrival, a radio signal with weak transmission power (weak signal) does not have sufficient strength at the time of arrival at the second radio terminal apparatus. In this case, it is determined that the strong signal is received by the receiving unit of the second wireless terminal device, but the weak signal is not determined to be received by the receiving unit of the second wireless terminal device. Each time the second wireless terminal device determines that a wireless signal has been received by the receiving unit of the second wireless terminal device, the second wireless terminal device transmits a response signal to the first wireless terminal device. The first wireless terminal device has received a response signal corresponding to a wireless signal of one type of transmission power, so that the distance between the first wireless terminal device and the second wireless terminal device is greater than the first distance. It determines with it being below 2nd distance.

  In the state shown in FIG. 13, the radio signals having two types of transmission power transmitted from the transmission unit of the first radio terminal device do not have sufficient strength when they reach the second radio terminal device. It is not determined that any wireless signal has been received by the receiving unit of the second wireless terminal device. Therefore, the second wireless terminal device does not transmit a response signal to the first wireless terminal device. The first wireless terminal device determines that the distance between the first wireless terminal device and the second wireless terminal device is greater than the second distance because it does not receive the response signal. In FIG. 13, the principle of performing the boundary determination of the inter-device distance at the two boundaries of the first distance and the second distance is shown with N = 2, but the present invention is not limited to this.

Next, Example 4 which is one example of the second embodiment will be described.
In the fourth embodiment, the transmission unit of the first wireless terminal device transmits wireless signals in which the number of transmissions within a certain time is fixed for each transmission power at different times. The transmission unit of the second wireless terminal device transmits a response signal every time it is determined that the reception unit has received a wireless signal. The first wireless terminal device receives the response signal, and the distance determination unit included in the first wireless terminal device indicates the number of response signals determined to be received by the receiving unit of the first wireless terminal device within a certain period of time. Determining how many types of radio signals of transmission power are received by the receiver of the second radio terminal apparatus as the number of radio signals determined to have been received by the receiver of the second radio terminal apparatus within the certain time To do. Hereinafter, Example 4 will be described in detail.

<Configuration>
FIG. 14 is a block diagram illustrating the configuration of the inter-device distance estimation system 301 of Example 4 which is an example of the second embodiment. FIG. 15A is a block diagram illustrating the configuration of the wireless terminal device 310 in FIG. 14, and FIG. 15B is a block diagram illustrating the configuration of the wireless terminal device 320 in FIG. 14. In addition, about the structure demonstrated in Example 1, the same code | symbol as FIG.3, 4 is used, and those description is abbreviate | omitted.
As shown in FIG. 14, the inter-device distance estimation system 301 of the present embodiment includes a wireless terminal device 310 (corresponding to “first wireless terminal device”) and a wireless terminal device 320 (corresponding to “second wireless terminal device”). And have.

As shown in FIG. 14A, the wireless terminal device 310 of the present embodiment includes a signal creation unit 11, a transmission unit 12, antennas 13 and 311, a reception unit 312, a distance determination unit 313, and an instruction signal generation unit. 314, a main body portion 25, and an antenna 26. As shown in FIG. 15A, the distance determination unit 313 includes an identification code register 313a, a comparison unit 313c, a counter 313e, a comparison unit 313g, and a threshold value register 313f.
As shown in FIG. 14 (b), the wireless terminal device 320 of the present embodiment includes antennas 312, 325, a receiving unit 22, a reception determining unit 322, a response signal generating unit 323, A transmission unit 324. 15B, the reception determination unit 322 includes an identification code register 322a and a comparison unit 322c, and the response signal creation unit 323 includes an identification code generation circuit 323b and an identification code register 323a. And have.

<Processing>
Next, the inter-apparatus distance determination process of the present embodiment will be described. As the following premise, the identification code register 313a of the wireless terminal device 310 and the identification code registers 313a and 323a of the wireless terminal device 320 include the identification code register 11a (see FIG. 3) of the signal creation unit 11 described in the first embodiment. ) Is stored in the same identification code.
[Wireless signal transmission processing of wireless terminal device 310]
When the inter-device distance determination system 301 is activated, as in the first embodiment, the transmission unit 12 of the wireless terminal device 310 transmits wireless signals with N (N ≧ 2) types of transmission power to the number of transmissions within a certain time. Each transmission power is fixed and transmitted at different times.

[Processing of Wireless Terminal Device 320]
The wireless terminal device 320 receives a wireless signal by the antenna 21 and receives it by the receiving unit 22 as in the first embodiment. The demodulated signal output from the receiver 22 is sent to the comparator 322c. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code register 322a, and the identification code register 322a outputs the identification code to the comparison unit 322c. The comparison unit 322c extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from the identification code register 322a, and determines whether or not they match. Then, if they match, the comparison unit 322c outputs a read signal to the identification code register 323a. As a result, the identification code register 323a outputs the identification code to the identification code generation circuit 323b, and the identification code generation circuit 323b generates a response signal in which information for specifying the start position is added to the input identification code. And output to the transmission unit 324. The transmission unit 324 modulates and amplifies this response signal, and transmits it via the antenna 325. In order to avoid interference, different frequencies are used for transmission of a radio signal from the wireless terminal device 310 and transmission of a response signal from the wireless terminal device 320.

[Response signal reception processing of wireless terminal device 310]
The response signal is received by the antenna 311 of the wireless terminal device 310, received by the receiving unit 312, and the demodulated signal is sent to the comparing unit 313c. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code register 313a, and the identification code register 313a outputs the identification code to the comparison unit 313c. The comparison unit 313c extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from the identification code register 313a, and determines whether or not they match. The comparison unit 313c outputs a value 1 to the counter 313e if they match, and outputs a value 0 to the counter 313e if they do not match.

The counter 313e counts up only when the value 1 is input, and stores the count value. Further, the counter 313e transmits the count value to the comparison unit 313g every time a certain time elapses. Note that the count value at this time corresponds to “the number of response signals determined to be received by the receiving unit 312 of the first wireless terminal device 310 within a certain time”. The counter 313e resets the count value to 0 after outputting the count value to the comparison unit 313g.
Further, using the output of the count value as a trigger, a control circuit (not shown) inputs a read signal to the threshold value register 313f, and the threshold value register 313f outputs the threshold value to the comparison unit 23g. The comparison unit 313g compares the input count value with a threshold value, and determines the number of response signals determined to be received by the reception unit 312 of the wireless terminal device 310 within a certain time as a wireless signal within the certain time. As the number of radio signals determined to be received by the receiving unit 22 of the terminal device 320, it is determined how many types of radio signals of the transmission power are received by the receiving unit 22 of the radio terminal device 320. Note that the threshold setting and the processing of the comparison unit 313g are the same as the threshold value of the first embodiment and the processing of the comparison unit 23g. The comparison result output from the comparison unit 313g is input to the instruction signal generation unit 314. The instruction signal generation unit 314 performs the same processing as the instruction signal generation unit 24 of the first embodiment to generate the instruction signal. , Output to the main body 25. The subsequent steps are the same as those in the first embodiment.

<Features of Example 4>
In the present embodiment, the main body 25 such as a mobile phone can be provided on the side of the wireless terminal device 310 that transmits a wireless signal of transmission power, and the power consumption on the side of the wireless terminal device 320 can be kept low. Therefore, like RFID, the present invention can be applied to a system in which a current is generated by a coil based on a received radio wave signal and a response signal is returned using the current. In this case, for example, the wireless terminal device 310 functions as an RFID reader / writer device, and the wireless terminal device 320 functions as an RF tag.

  The fifth embodiment is a modification of the first, third, and fourth embodiments, and the first wireless terminal device transmits N types of wireless signals having differences other than the transmission power with different transmission powers for the respective types. The second wireless terminal device returns the same response signal regardless of the difference. Below, it demonstrates centering on difference with Example 1,3,4.

<Configuration>
FIG. 16A is a block diagram illustrating a configuration of the wireless terminal device 410 (corresponding to “first wireless terminal device”) of the fifth embodiment, and FIG. 16B is a wireless terminal device 420 (“second wireless terminal”). 2 is a block diagram illustrating a configuration of “terminal device”. In addition, about the structure demonstrated in Example 1, 3, 4, the code | symbol same as FIG. 3, 4, 9, 15 is used, and those description is abbreviate | omitted.
As shown in FIG. 16A, the difference between the wireless terminal device 410 of the fifth embodiment and the wireless terminal device 310 of the fourth embodiment is that the signal creating unit 11 is replaced with the signal creating unit 211 of the third embodiment. Is a point. Also, as shown in FIG. 16B, the difference between the wireless terminal device 420 of the fifth embodiment and the wireless terminal device 320 of the fourth embodiment is that the reception determination unit 322 has N identification code registers 423a-1 To N and comparison units 423c-1 to N are replaced with reception determination units 423.

<Processing>
Hereinafter, the processing of the fifth embodiment will be described focusing on the differences from the first, third, and fourth embodiments. As the following premise, the identification code registers 423a-1 to 423-N store identification codes of N types of formats stored in the identification code registers 211a-1 to 211a-N of the third embodiment. Shall.

[Processing of Wireless Terminal Device 410]
When the inter-apparatus distance determination system is activated, as in the third embodiment, the transmission unit 12 transmits N types of radio signals having different formats of corresponding identification codes with different transmission powers for the respective types.
[Processing of Wireless Terminal Device 420]
In the following, the processing of the reception determination unit 423, which is a difference from the fourth embodiment, will be mainly described, and the description of the common points with the fourth embodiment will be omitted.

  The demodulated signal output from the receiving unit 22 is input to each of the comparing units 423c-1 to N. With this as a trigger, a control circuit (not shown) inputs read signals to the identification code registers 423a-1 to 423-N, and the identification code registers 423a-1 to 423-n respectively store the identification codes held in the comparison units 423c- 1 to N. Each comparison unit 423c-1 to N extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from each of the identification code registers 423a-1 to 423, and It is determined whether or not they match. Then, each of the comparison units 423c-1 to 423-N outputs a read signal to the identification code register 323a if they match. Since the subsequent processing is the same as that of the fourth embodiment, description thereof is omitted.

  In addition, a present Example does not limit this invention. For example, in this embodiment, identification signals of N types of formats are used, and the difference in the format is set as a difference other than the transmission power of the N types of radio signals. However, for example, the wireless terminal device 410 may transmit a wireless signal at a different frequency for each type of transmission power, and the wireless terminal device 420 may determine the transmission power of the wireless signal based on the difference in frequency. Further, for example, the wireless terminal device 410 transmits a wireless signal corresponding to an identification code that differs for each type of transmission power, and the wireless terminal device 420 determines the transmission power of the wireless signal received by the difference in the identification code. May be. Also, for example, the wireless terminal device 410 transmits a wireless signal including an additional signal that differs for each type of transmission power, and the wireless terminal device 420 determines the transmission power of the wireless signal received by the wireless terminal device 420 based on the difference of the additional signal. Also good.

  The sixth embodiment is a modification of the first, second, and fourth embodiments. In a present Example, the transmission part of a 1st radio | wireless terminal apparatus transmits the radio signal of N types of transmission power from which a transmission interval differs for every transmission power at different time, respectively. The transmission unit of the second wireless terminal device transmits a response signal each time it is determined that the reception unit has received a wireless signal. Then, the first wireless terminal device receives the response signal, and the distance determination unit included in the first wireless terminal device sets the reception interval of the response signal determined to be received by the receiving unit of the first wireless terminal device to the second As a radio signal reception interval determined to be received by the reception unit of the wireless terminal device, it is determined how many types of transmission power radio signals are received by the reception unit of the second wireless terminal device. Hereinafter, the difference from the first, second, and fourth embodiments will be mainly described.

FIG. 17 is a block diagram illustrating the configuration of a wireless terminal device 510 (corresponding to “first wireless terminal device”) according to the sixth embodiment. In addition, about the structure demonstrated in Example 1, 4, the code | symbol same as FIG.3, 4,14,15 is used, and those description is abbreviate | omitted.
The inter-device distance determination system of the present embodiment is obtained by replacing the wireless terminal device 310 constituting the inter-device distance determination system 301 (FIG. 14) of the fourth embodiment with a wireless terminal device 510.
As illustrated in FIG. 17A, the wireless terminal device 510 of the present embodiment has a configuration in which the distance determination unit 313 (FIG. 15A) of the wireless terminal device 310 of Embodiment 4 is replaced with a distance determination unit 513. Become. The distance determination unit 513 has a configuration in which the counter 313e of the distance determination unit 313 is replaced with a pulse interval detection circuit 513e that outputs a time interval of input pulses. Hereinafter, the processing of the sixth embodiment will be described focusing on differences from the first and fourth embodiments.

  First, the transmission unit 12 of the wireless terminal device 510 transmits N types of transmission power radio signals having different transmission intervals for each transmission power through the antenna 13 at different times. Similarly to the fourth embodiment, when it is determined that these wireless signals are received by the wireless terminal device 320 (FIG. 15), the wireless terminal device 320 transmits a response signal. The transmitted response signal is received by the antenna 311 of the wireless terminal device 510, received by the receiving unit 312, and the demodulated signal is sent to the comparing unit 313c. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code register 313a, and the identification code register 313a outputs the identification code to the comparison unit 313c. The comparison unit 313c extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from the identification code register 313a, and determines whether or not they match. The comparison unit 313c outputs a value 1 to the counter 313e if they match, and outputs a value 0 to the pulse interval detection circuit 513e if they do not match.

  The pulse interval detection circuit 513e compares the pulse interval value of the value 1 signal sequentially input from the comparison unit 313c (corresponding to the reception interval value of the radio signal determined to be received by the reception unit 22 of the wireless terminal device 320). To the unit 23g. With this as a trigger, a control circuit (not shown) inputs a read signal to the threshold value register 313f, and the threshold value register 313f outputs the threshold value to the comparison unit 313g. The comparison unit 313g compares the input pulse interval value with a threshold value, and determines how many types of transmission power wireless signals transmitted from the wireless terminal device 510 are received by the reception unit 22 of the wireless terminal device 320. . As described above, the wireless terminal device 510 according to the sixth embodiment transmits wireless signals having different transmission intervals for each transmission power at different times. Therefore, the reception interval of the radio signal determined to be received by the reception unit 22 of the radio terminal device 320, that is, the pulse interval value of the signal of value 1 is compared with the threshold value, and transmitted from the radio terminal device 510. It is possible to determine how many types of transmission power wireless signals are received by the receiving unit 22 of the wireless terminal device 320. The determination result also corresponds to the determination result of the inter-device distance between the wireless terminal device 510 and the wireless terminal device 320. A specific example of this determination content is the same as that described in the second embodiment.

  The seventh embodiment is a modification of the first and fourth embodiments, and how many types of transmission are performed based on the time until a response signal to the wireless signal transmitted from the first wireless terminal apparatus is returned to the first wireless terminal apparatus. It is determined whether a wireless signal of power is received by the receiving unit of the second wireless terminal device. That is, the transmission unit of the first wireless terminal device of the present embodiment transmits wireless signals of N types of transmission power at intervals exceeding the fixed time length T. The second radio terminal device transmits a response signal every time it is determined that the radio signal is received by the receiving unit. The first wireless terminal device receives the response signal, and the distance determination unit receives the reception unit of the first wireless terminal device within a fixed time length R (0 <R ≦ T) after the transmission unit transmits the wireless signal. When it is determined that the response signal is received, it is determined that the radio signal transmitted by the transmission unit is received by the reception unit of the second radio terminal apparatus, and radio signals of various types of transmission power are received by the second radio terminal. It is determined whether the signal is received by the receiving unit of the apparatus. Hereinafter, the difference from the first and fourth embodiments will be mainly described.

<Configuration>
FIG. 18 is a block diagram illustrating a configuration of a wireless terminal device 610 (corresponding to “first wireless terminal device”) according to the seventh embodiment. In FIG. 18, the same reference numerals as those in FIGS.
The inter-device distance determination system of the present embodiment is obtained by replacing the wireless terminal device 310 constituting the inter-device distance determination system 301 (FIG. 14) of the fourth embodiment with a wireless terminal device 610. As illustrated in FIG. 18, the wireless terminal device 610 has a configuration in which the distance determination unit 313 constituting the wireless terminal device 310 is replaced with a distance determination unit 613. The distance determination unit 613 replaces the counter 313e constituting the distance determination unit 313 with a clock counter 613e that counts the number of clock signals, and generates a clock signal 613d that generates the clock signal, a switch 613h, and N types of transmissions. In this configuration, N counters 613e-1 to 613-N corresponding to the respective electric powers are added.

<Processing>
Hereinafter, the processing of the seventh embodiment will be described focusing on the differences from the first and fourth embodiments.
[Processing of Wireless Terminal Device 610]
When the inter-device distance determination system is activated, the transmission unit 12 of the wireless terminal device 610 transmits wireless signals of N types of transmission power at intervals exceeding the fixed time length T. Further, the signal creation unit 11 outputs a count start signal to the clock counter 613e every time a digital signal of an identification code is output to the transmission unit 12. The clock counter 613e to which the count start signal is input resets the count value to 0 and then starts counting the clock signal. Further, each time a radio signal is transmitted, the transmission unit 12 inputs a transmission power signal for specifying the type of transmission power as a control signal to the switch 613h. Thereby, the switch 613h connects the comparison unit 313g and any one of the counters 613e-1 to 613e-1 to 613N corresponding to the transmission power indicated by the transmission power signal. This state is maintained until a new transmission power signal is input to the switch 613h.

  Similarly to the fourth embodiment, when it is determined that a wireless signal is received by the wireless terminal device 320 (FIG. 15), the wireless terminal device 320 transmits a response signal. The transmitted response signal is received by the antenna 311 of the wireless terminal device 510, received by the receiving unit 312, and the demodulated signal is sent to the comparing unit 313c. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code register 313a, and the identification code register 313a outputs the identification code to the comparison unit 313c. The comparison unit 313c extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from the identification code register 313a, and determines whether or not they match. Then, the comparison unit 313c outputs a count end signal to the clock counter 613e if they match. The clock counter 613e to which the count end signal is input outputs the count value to the comparison unit 313g. Here, the count value output to the comparison unit 313g corresponds to the response time from when the wireless terminal device 610 transmits a wireless signal until the response signal is received.

  Using this count value output as a trigger, a control circuit (not shown) inputs a read signal to the threshold value register 313f, and the threshold value register 313f is a threshold value (a count value corresponding to a fixed time length R (0 <R ≦ T)). Is output to the comparison unit 313g. The comparison unit 313g compares the count value with the threshold value, and if the count value ≦ the threshold value, outputs a value 1 to the switch 613h, otherwise outputs a value 0 to the switch 613h. This comparison result indicates whether or not it is determined that the response signal is received by the receiving unit 312 of the wireless terminal device 610 within the fixed time length R after the transmitting unit 12 of the wireless terminal device 610 transmits the wireless signal. Will be shown.

  The value output to the switch 613h is input to any of the counters 613e-1 to 613e-1 to 613e connected at that time, and the counter is counted up only when the value is 1. After a predetermined time has elapsed, the count values of the counters 613e-1 to N are output to the instruction signal generation unit 614, and the count values of the counters 613e-1 to N are reset to zero. Note that the count values of the counters 613e-1 to 613-N output to the instruction signal generation unit 614 determine how many types of transmission power radio signals have been received by the reception unit 22 of the wireless terminal device 320 within a certain period of time. Result.

<Features of Example 7>
In the seventh embodiment, the transmission unit 12 of the wireless terminal device 610 transmits N types of transmission power wireless signals at intervals exceeding the fixed time length T, and the second wireless terminal device 320 receives the reception unit. A response signal is transmitted every time it is determined at 22 that a radio signal has been received. Then, when the wireless terminal device 610 receives the response signal and determines that the response signal is received within the fixed time length R (0 <R ≦ T) after the transmission unit transmits the wireless signal, It is determined that the radio signal transmitted by the transmission unit has been received by the reception unit 22 of the wireless terminal device 320, and it is determined how many types of transmission power wireless signals have been received by the reception unit 22 of the wireless terminal device 320. In this case, even if there is no difference other than the transmission power in the N (N ≧ 2) types of transmission power radio signals transmitted from the line terminal device 610, the radio terminal device can transmit any number of types of transmission power radio signals. It can be determined whether or not the signal has been received by the receiving unit 22.

  In addition, this invention is not limited to this Example. The signal creation unit 11 outputs the count start signal to the clock counter 613e every time the digital signal of the identification code is output to the transmission unit 12, but only when transmitting a “radio signal having a specific transmission power”. The count start signal may be output to the clock counter 613e. In this case, the switch 613h and the counters 613e-1 to 613e do not have to be provided, and the distance between the wireless terminal device 610 and the wireless terminal device 320 is a predetermined distance only by the comparison result output from the comparison unit 313g. It is possible to determine whether or not the distance is “a distance that can be received by the wireless terminal device 320”.

  The eighth embodiment is a modification of the first, third, fourth, and fifth embodiments. In the case of a present Example, a 1st radio | wireless terminal apparatus transmits N types of radio signals which also have differences other than transmission power with the transmission power which changes with the said types. Each time the second radio terminal apparatus determines that the radio signal has been received by the receiving unit, the second radio terminal apparatus transmits a response signal that differs for each type of radio signal. The first wireless terminal apparatus receives the response signal, determines which response signal is received by the receiving unit of the first wireless terminal apparatus based on the difference for each response signal, and how many types of transmission power It is determined whether the wireless signal is received by the receiving unit of the second wireless terminal device. Below, it demonstrates centering on difference with Example 1,3,4,5.

<Configuration>
FIG. 19 is a block diagram illustrating a configuration of a wireless terminal device 710 (corresponding to “first wireless terminal device”) according to the eighth embodiment, and FIG. 20 is a wireless terminal device 720 (corresponding to “second wireless terminal device”). It is the block diagram which illustrated the composition of. In addition, about the structure demonstrated in Example 1,3,4,5, the code | symbol same as FIG.3, 4,9,15,16 is used, and those description is abbreviate | omitted.
As illustrated in FIG. 19, the wireless terminal device 710 according to the eighth embodiment replaces the signal creation unit 11 of the wireless terminal device 310 (FIG. 15) according to the fourth embodiment with the signal creation unit 211 according to the third embodiment, thereby replacing the distance determination unit. In this configuration, 313 is replaced with a distance determination unit 713. The distance determination unit 713 includes N identification code registers 713a-1 to 713a-1 to N, comparison units 713c-1 to N, counters 713e-1 to N, comparison units 713g-1 to N, and a threshold value register 713f. And have.

  As illustrated in FIG. 20, the wireless terminal device 720 according to the eighth embodiment replaces the reception determination unit 322 of the wireless terminal device 320 (FIG. 15) according to the fourth embodiment with a reception determination unit 723, thereby generating a response signal generation unit 323. Is replaced with a response signal creation unit 723. The reception determination unit 723 includes identification code registers 423a-1 to N and comparison units 423c-1 to N. The response signal lyric unit 723 includes identification code registers 723a-1 to 723-N and identification code generation circuits 723b-1 to N.

<Processing>
Hereinafter, the processing of the eighth embodiment will be described focusing on the differences from the first, third, fourth, and fifth embodiments. As the following premise, the identification code registers 423a-1 to 423-N store the identification codes of N types of formats stored in the identification code registers 211a-1 to 211-N of the third embodiment, respectively. The identification code registers 713a-1 to 713-N store the identification codes of N types of formats stored in the identification code registers 211a-1 to N of the third embodiment, respectively, and are stored in the identification code registers 723a-1 to N, respectively. Are stored in the identification code registers 211a-1 to 211-N according to the third embodiment, respectively.

[Transmission processing of wireless terminal device 710]
When the inter-apparatus distance determination system is activated, as in the third embodiment, the transmission unit 12 transmits N types of radio signals having different formats of corresponding identification codes with different transmission powers for the respective types.

[Processing of Wireless Terminal Device 720]
In the following, the processes of the reception determination unit 423 and the response signal creation unit 723 that are different from the fourth embodiment will be mainly described, and the description of the common points with the fourth embodiment will be omitted.
The demodulated signal output from the receiving unit 22 is input to each of the comparing units 423c-1 to N. With this as a trigger, a control circuit (not shown) inputs read signals to the identification code registers 423a-1 to 423-N, and the identification code registers 423a-1 to 423-n respectively store the identification codes held in the comparison units 423c- 1 to N. Each comparison unit 423c-1 to N extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from each of the identification code registers 423a-1 to 423, and It is determined whether or not they match. Each comparison unit 423c-1 to N outputs a read signal to the corresponding identification code register 723a-1 to N only when they match. Each of the identification code registers 723a-1 to 723a-1 to 723N to which the read signal is input outputs the identification code held by each. The digital signal of the identification code output from each identification code register 723a-1 to N is input to the transmission unit 324, modulated and amplified by the transmission unit 324, transmitted as a response signal, and emitted from the antenna 325.

[Reception processing of wireless terminal device 710]
When the response signal is received by the antenna of the wireless terminal device 710 and received by the receiving unit 312, the demodulated signal is input to each of the comparing units 713 c-1 to 713 c -N. With this as a trigger, a control circuit (not shown) inputs a read signal to the identification code registers 713a-1 to 713a-N, and the identification code registers 713a-1 to 713-n respectively store the identification codes held in the comparison units 713c- 1 to N. Each comparison unit 713c-1 to N extracts an identification code from the input demodulated signal, compares the extracted identification code with the identification code input from each of the identification code registers 713a-1 to 713N, and It is determined whether or not they match. Then, the comparison units 713c-1 to 713-N output a value 1 to the counters 713e-1 to N if they match, and output a value 0 to the counters 713e-1 to N if they do not match. Each of the counters 713e-1 to 713e counts up only when the value 1 is input, and stores the count value. Each of the counters 713e-1 to N outputs a count value to each of the comparison units 713g-1 to N every time a predetermined time elapses. Note that the count values output from the counters 713e-1 to N at this point in time are “the response signal determined to have been received by the receiving unit 312 of the wireless terminal device 710 within a certain period of time. It corresponds to “the number counted for each transmission power”, and further corresponds to “the number counted for each transmission power of radio signals determined to be received by the receiving unit 22 of the wireless terminal device 720 within a certain time”. Based on these count values, it is possible to determine how many types of transmission power radio signals are received by the reception unit 22. Each of the counters 713e-1 to 713e-N resets the count value to 0 after outputting the count value.

  Further, with the output of each count value as a trigger, a control circuit (not shown) inputs a read signal to the threshold value register 713f, and the threshold value register 713f outputs the threshold value to each of the comparison units 713g-1 to N. Each comparison unit 713g-1 to N compares the input count value with a threshold value, and determines which response signal is received by the reception unit 312 of the wireless terminal device 710. It is determined how many types of transmitted wireless signals are received by the receiving unit 22 of the wireless terminal device 720. For example, each of the comparison units 713g-1 to 713g-N compares the input count value with a threshold value, outputs a value 1 when the count value exceeds the threshold value, and sets a value 0 when the count value is equal to or less than the threshold value. Output. In this case, the total number of values 1 output from the comparison units 713g-1 to N is the type of transmission power of the radio signal determined to be received by the reception unit 22 of the radio terminal device 720. The values output from the comparison units 713g-1 to 713-N are input to the instruction signal generation unit 714, and are used to generate instruction signals similar to those in the first embodiment.

<Features of Example 8>
In the eighth embodiment, the transmission unit 312 of the wireless terminal device 710 transmits N types of wireless signals having differences other than the transmission power with different transmission power for each type, and the wireless terminal device 720 receives the reception unit. Each time it is determined that a radio signal has been received, a different response signal is transmitted for each type of the radio signal. As a result, the distance determination unit 713 included in the wireless terminal device 710 determines which response signal is received by the reception unit 312 of the wireless terminal device 710, so that a wireless signal of what type of transmission power is transmitted to the wireless terminal device 720. It is possible to determine whether or not the signal has been received by the receiver 22. Thereby, the accuracy of the determination of which transmission power of the radio signal is received by the reception unit 22 of the radio terminal device 720 is improved. As a result, it is possible to perform detailed device-to-device distance determination using many types of radio signals having transmission power.

  In addition, a present Example does not limit this invention. For example, in this embodiment, identification signals of N types of formats are used, and the difference in the format is set as a difference other than the transmission power of the N types of radio signals. However, for example, the wireless terminal device 710 may transmit a wireless signal at a different frequency for each type of transmission power, and the wireless terminal device 720 may determine the transmission power of the wireless signal based on the difference in frequency. Further, for example, the wireless terminal device 710 transmits wireless signals corresponding to different identification codes for each type of transmission power, and the wireless terminal device 720 determines the transmission power of the wireless signal received by the difference in the identification codes. May be. Further, for example, the wireless terminal device 710 transmits a wireless signal including an additional signal that differs for each type of transmission power, and the transmission power of the wireless signal received by the wireless terminal device 720 is determined based on the difference of the additional signal. Also good. Similarly, in this embodiment, a response signal having a different format is transmitted for each type of radio signal. However, the frequency of the response signal differs for each type of received radio signal, or the type of received radio signal. Response signals corresponding to different additional signals may be generated for each.

[Other variations]
In each of the above-described embodiments, the transmission unit of the first wireless terminal apparatus controls the output of the power amplifier to generate N types of transmission power wireless signals. However, the configuration may be such that radio signals of N types of transmission power are generated by other methods. For example, a configuration may be adopted in which N signal paths of the wireless signal output from the power amplifier 12c are provided and N types of transmission power wireless signals are generated by making the attenuation amount and impedance matching of each signal path different. .

  FIG. 21 is a block diagram illustrating a configuration of a wireless terminal device 810 that generates wireless signals of two types of transmission power by varying the signal path attenuation amount. In the example of FIG. 21, the signal path of the radio signal output from the power amplifier 12c is switched in two ways by the switch 812e, and an attenuator 812d is interposed in one of these two paths. As a result, the transmission power of the radio signal to be transmitted is greater when the switch 812e is switched to the other path side than when the switch 812e is switched to the signal path side on the attenuator 812d side. As a result, two types of radio signals with transmission power can be generated. Also, instead of using a switch, an N channel sequence is provided in the first wireless terminal device, and a radio signal with N types of transmission power is generated with different attenuation amounts and impedance matching for each sequence. Also good.

In each of the above embodiments and examples, the first wireless terminal device transmits wireless signals of N (N ≧ 2) types of transmission power, the second wireless terminal device receives the wireless signal, and the first wireless terminal device receives the wireless signal. At least one of the terminal device and the second wireless terminal device determines how many types of transmission power wireless signals are received by the receiving unit of the second wireless terminal device, whereby the first wireless terminal device and the second wireless terminal It was decided to determine the distance to the device.
However, a first wireless terminal device having at least a transmitter that transmits the first radio signal and a receiver that receives the radio signal, a transmitter that transmits at least the second radio signal, and a receiver that receives the radio signal The first wireless signal and the second wireless signal have different transmission power, and at least one of the first wireless terminal device and the second wireless terminal device has the first wireless signal Is received by the receiving unit of the second wireless terminal device and whether the second wireless signal is received by the receiving unit of the first wireless terminal device, thereby determining the first wireless terminal device and the second wireless terminal device The problem can be solved even by the inter-device distance determination system characterized by further including a distance determination unit that determines the distance between the two.

FIG. 22 is a block diagram showing an example of the configuration of such an inter-device distance determination system 901.
As illustrated in FIG. 22, the inter-device distance determination system 901 includes a wireless terminal device 910 (corresponding to “wireless terminal device”) and a wireless terminal device (corresponding to “second wireless terminal device”). Here, each of the transmission units 912 and 922 transmits a radio signal having at least one type of transmission power. Further, the transmission power of the radio signal transmitted from the transmission unit 912 is smaller than the transmission power of the radio signal transmitted from the transmission unit 922. The other components are as described above.

In this system, the first wireless signal is transmitted from the transmission unit 912 of the wireless terminal device 910 through the antenna 13, and the second wireless signal is also transmitted from the transmission unit 922 of the wireless terminal device 920 through the antenna 321. Here, the transmission power and transmission frequency of these radio signals are different. The wireless terminal device 920 transmits a response signal from the transmitting unit 324 through the antenna 325 every time the receiving unit 22 receives the first wireless signal transmitted from the wireless terminal device 910.
The second wireless signal and the response signal transmitted from the wireless terminal device 920 are received by the antenna 311 and received by the receiving unit 312, and their demodulated signals are sent to the distance determining unit 313. The distance determination unit 313 uses the demodulated signal transmitted, whether the first wireless signal is received by the receiving unit 22 of the wireless terminal device 920 and the second wireless signal is received by the receiving unit 312 of the wireless terminal device 910. By determining whether or not, the distance between the wireless terminal device 910 and the wireless terminal device 920 is determined.

That is, since the transmission powers of the first radio signal and the second radio signal are different from each other, the following three states can be considered according to the distance between the radio terminal device 910 and the radio terminal device 920.
State 1: State where the first wireless signal is received by the receiving unit 22 of the wireless terminal device 920 and the second wireless signal is received by the receiving unit 312 of the wireless terminal device 910 State 2: The first wireless signal is wireless terminal A state in which the reception unit 22 of the device 920 receives the second radio signal or a reception unit 312 of the wireless terminal device 910 State 3: a first wireless signal is received by the reception unit 22 of the wireless terminal device 920 And the second wireless signal is not received by the receiving unit 312 of the wireless terminal device 910. Here, the distance between the first wireless signal and the second wireless signal is closest in the state 1, and in the state 2 Is the next closest, state 3 is the farthest. Therefore, by determining whether the first wireless signal is received by the receiving unit 22 of the wireless terminal device 920 and whether the second wireless signal is received by the receiving unit 312 of the wireless terminal device 910, the wireless terminal device 910 and The distance to the wireless terminal device 920 can be determined. Further, when the transmission power of the first radio signal <the transmission power of the second radio signal, the power consumption of the wireless terminal device 910 related to the present system can be suppressed from the power consumption of the wireless terminal device 920. Therefore, for example, it is possible to apply the wireless terminal device 910 to a device side such as a mobile phone where power saving is particularly desired, and the wireless terminal device 910 to a device side such as a desktop computer that does not require much power saving. Become. Conversely, if the transmission power of the first radio signal is greater than the transmission power of the second radio signal, the reverse application is possible.

  In each of the above embodiments, whether or not a radio signal or a response signal is received by the receiving unit of the radio terminal device depends on whether or not the radio terminal device that has received the radio signal or the response signal can reproduce the identification code included therein. I was judging. However, it is determined whether or not information (digital information, etc.) included in the radio signal or response signal is received in a reproducible state by other methods, and the radio signal or response is received by the reception unit of the radio terminal device based on the determination result. It may be determined whether a signal has been received. For example, it is determined whether or not the radio signal or the information included in the response signal is received in a reproducible state using a challenge and response technique, and the radio signal is received by the receiving unit of the radio terminal device based on the determination result. Alternatively, it may be determined whether or not a response signal has been received (for example, refer to “http://www.spc-c.com/about/sasakura/CCR_sasakura_WEBdoc.pdf”). In addition, the second wireless terminal device needs to have a configuration for measuring the electric field strength. The receiving circuit of the second wireless terminal device such as a mobile phone or a PC is provided with a plurality of electric field strength threshold determination means, and the second wireless terminal device If the radio wave is received exceeding the higher threshold, it is determined that the distance from the first wireless terminal device such as the security key is too close, and the device locks itself or issues an alarm. Is also possible.

Further, a method for locking a certain function of the wireless terminal device is not limited to the above-described embodiment. For example, the function of the wireless terminal device is locked every time the wireless terminal device is activated, and a certain function of the wireless terminal device is locked when the lock control unit restarts the wireless terminal device. May be.
In addition to the above-described configurations, the security function that already exists (a password is required when the wireless terminal device is requested to enter a personal identification number when the wireless terminal device is activated, or when the key operation of the wireless terminal device is not performed even during activation. It is needless to say that the security function can be further enhanced by using a combination of such functions as requesting the input of the password or encrypting a storage area such as a hard disk in the wireless terminal device. Moreover, the structure which compounded the structure of at least one part of each Example may be sufficient. Furthermore, the present invention may be applied to a communication system including three or more wireless terminal devices. Further, the output signal of the distance determination unit of each embodiment is not a signal that directly indicates the inter-device distance, but is a signal that can uniquely identify the range. As a modification of each embodiment, the distance determination unit of each embodiment directly uses the determination results described above to directly determine the range of the distance between devices (for example, first distance range <second distance range <third distance range). A processing unit that generates the signal shown in FIG. Similarly, some of the output signals of the distance determination unit of the above embodiment do not directly indicate how many types of transmission power radio signals are received by the reception unit of the second radio terminal apparatus. Even in this case, these signals are signals that can uniquely specify how many types of transmission power of radio signals are received by the receiving unit of the second radio terminal apparatus. As a modification of the above embodiment, the distance determination unit of the above embodiment directly indicates how many types of transmission power radio signals are received by the reception unit of the second wireless terminal device using each determination result described above. You may provide the process part which produces | generates a signal. Such a processing unit may be configured by an integrated circuit, or may be configured by executing on the CPU a program describing the processing content of the processing unit.

In each embodiment, the mobile phone and the PDA are used as the main unit, but other application devices such as a PC, an IC card, and an RF tag may be used as the main unit.
In addition, as described above, the signal creation unit, the distance determination unit, the reception determination unit, the instruction signal generation unit, the lock control unit, the input / output control unit, the processing unit, and other configurations include a CPU (central processing unit), a memory, and the like. It can be realized by a computer provided. In this case, the processing contents that each of these parts should have are described in a program, and the processing functions of the above parts are realized by the CPU executing it. In accordance with the program, the CPU that has read the program reads the data necessary for each processing step from the memory, performs arithmetic processing, and stores the processing result in the memory, thereby repeating the above-described parts. The processing function is realized.

  The program describing the processing contents can be recorded on a computer-readable recording medium. The computer-readable recording medium may be any medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, or a semiconductor memory. Specifically, for example, the magnetic recording device may be a hard disk device or a flexible Discs, magnetic tapes, etc. as optical disks, DVD (Digital Versatile Disc), DVD-RAM (Random Access Memory), CD-ROM (Compact Disc Read Only Memory), CD-R (Recordable) / RW (ReWritable), etc. As the magneto-optical recording medium, MO (Magneto-Optical disc) or the like can be used, and as the semiconductor memory, EEP-ROM (Electronically Erasable and Programmable-Read Only Memory) or the like can be used.

The program is distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM in which the program is recorded. Furthermore, the program may be distributed by storing the program in a storage device of the server computer and transferring the program from the server computer to another computer via a network.
A computer that executes such a program temporarily stores the program in its own storage device, for example. When executing the process, this computer reads the program stored in its own storage device and executes the process according to the read program. Alternatively, the computer may directly read the program from the portable recording medium and execute processing according to the program, and each time the program is transferred from the server computer to the computer, It is good also as performing the process according to. Note that the program in this embodiment includes information that is used for processing by an electronic computer and that conforms to the program (data that is not a direct command to the computer but has a property that defines the processing of the computer).

  As an example of the application field of the present invention, a mobile phone, a PDA terminal, and the like can be exemplified. By applying the present invention to these, security at the time of loss or theft is improved.

FIG. 1 is a conceptual diagram for explaining the principle of the first embodiment when N = 2. FIG. 1A shows a state in which the distance between the first wireless terminal device and the second wireless terminal device is a certain first distance or less, and FIG. 1B shows that this distance is less than the first distance. Is larger than a certain second distance, and FIG. 1C shows a state where this distance is larger than the second distance. FIG. 2 is a block diagram illustrating the configuration of the inter-device distance estimation system of Example 1 which is an example of the first embodiment. FIG. 3 is a block diagram illustrating the configuration of the wireless terminal device (first wireless terminal device) in FIG. 2 (first embodiment). FIG. 4 is a block diagram illustrating the configuration of the wireless terminal device (second wireless terminal device) in FIG. 2 (Example 1). FIG. 5 is a diagram illustrating the configuration of a distance determination unit configured by causing a computer to read a predetermined program (Example 1). FIG. 6 is a flowchart for explaining processing of a distance determination unit configured by causing a computer to read a predetermined program (Example 1). FIG. 7A is a block diagram illustrating a configuration of a distance determination unit included in the wireless terminal device according to the second embodiment. FIG. 7B is a diagram illustrating a configuration of a distance determination unit configured by causing a computer to read a predetermined program. FIG. 8 is a flowchart for explaining processing of a distance determination unit configured by causing a computer to read a predetermined program (second embodiment). FIG. 9A is a block diagram illustrating a configuration of a distance determination unit included in the wireless terminal device according to the third embodiment. FIG. 9B is a block diagram illustrating a configuration of a distance determination unit included in the wireless terminal device according to the third embodiment. FIG. 10 is a diagram illustrating the configuration of a distance determination unit configured by causing a computer to read a predetermined program (third embodiment). FIG. 11 is a flowchart for explaining processing of a distance determination unit configured by causing a computer to read a predetermined program (third embodiment). FIG. 12 is a conceptual diagram for explaining the principle of the second embodiment when N = 2. FIG. 13 is a conceptual diagram for explaining the principle of the second embodiment when N = 2. FIG. 14 is a block diagram illustrating the configuration of the inter-device distance estimation system 301 of Example 4 which is an example of the second embodiment. 15A is a block diagram illustrating the configuration of the wireless terminal device (first wireless terminal device) in FIG. 14, and FIG. 15B is a wireless terminal device (second wireless terminal) in FIG. (Embodiment 4) FIG. FIG. 16A is a block diagram illustrating a configuration of a wireless terminal device (first wireless terminal device) according to the fifth embodiment, and FIG. 16B illustrates a wireless terminal device (second wireless terminal) according to the fifth embodiment. It is the block diagram which illustrated the composition of (apparatus). FIG. 17 is a block diagram illustrating a configuration of a wireless terminal device (first wireless terminal device) according to the sixth embodiment. FIG. 18 is a block diagram illustrating the configuration of the wireless terminal device (first wireless terminal device) according to the seventh embodiment. FIG. 19 is a block diagram illustrating the configuration of the wireless terminal device (first wireless terminal device) according to the eighth embodiment. FIG. 20 is a block diagram illustrating the configuration of the wireless terminal device (second wireless terminal device) according to the eighth embodiment. FIG. 21 is a block diagram illustrating a configuration of a wireless terminal device that generates wireless signals with two types of transmission power by varying the attenuation amount of the signal path. FIG. 22 is a block diagram showing a modification of the configuration of the inter-device distance determination system.

Explanation of symbols

10,310,410,510,610,710,810,910 Wireless terminal device (first wireless terminal device)
20,120,220,320,420,720,920 Wireless terminal device (second wireless terminal device)

Claims (8)

A wireless terminal device,
A receiver for receiving a radio signal;
A determination unit that determines how many types of transmission power radio signals are received by the reception unit among N (N ≧ 2) types of transmission power radio signals transmitted from other radio terminal devices ;
An instruction signal generation unit that generates an instruction signal that instructs to lock the processing function of the wireless terminal device or output warning information from the wireless terminal device, based on the determination by the determination unit;
The instruction signal generator is
The instruction signal is generated on the condition that the determination unit determines that a radio signal having a transmission power of P (N ≧ P ≧ 2) or more is received by the reception unit, and
Generating the instruction signal on the condition that the determination unit determines that a radio signal having transmission power of Q (1 ≦ Q <P) or more is not received by the reception unit;
A wireless terminal device.   A wireless terminal device,
  N (N ≧ 2) types of transmission power transmitting units that transmit wireless signals to other wireless terminal devices;
  A receiving unit that receives a response signal to the wireless signal from the other wireless terminal device;
  A determination unit that determines how many types of radio signals of the transmission power among the N types of radio signals of the transmission power are received by the other radio terminal device by the response signal;
  An instruction signal generation unit that generates an instruction signal that instructs to lock the processing function of the wireless terminal device or output warning information from the wireless terminal device, based on the determination by the determination unit;
  The instruction signal generator is
  The instruction signal is generated on the condition that the determination unit determines that a radio signal having a transmission power of P (N ≧ P ≧ 2) or more is received by the reception unit, and
  Generating the instruction signal on the condition that the determination unit determines that a radio signal having transmission power of Q (1 ≦ Q <P) or more is not received by the reception unit;
  A wireless terminal device.   The wireless terminal device according to claim 1,
  The wireless terminal apparatus characterized in that the wireless signals of N types of transmission power transmitted from the other wireless terminal apparatuses include different identification codes for the respective types.   The wireless terminal device according to claim 2,
  The transmission unit transmits N types of transmission power radio signals including different identification codes with different transmission power for each type.   The wireless terminal device according to any one of claims 1 to 4,
  The wireless terminal device further comprising an input unit that receives an input of secret information necessary for releasing the lock made by the instruction signal.   An instruction signal generation method for generating an instruction signal for instructing locking of a processing function of a wireless terminal device or output of warning information from the wireless terminal device,
  Receiving a radio signal in the receiving unit;
  A step of determining, by the determination unit, how many types of transmission power wireless signals are received by the reception unit among N (N ≧ 2) types of transmission power wireless signals transmitted from other wireless terminal devices; ,
  Generating the instruction signal in the instruction signal generation unit on the condition that it has been determined that a radio signal of transmission power of P (N ≧ P ≧ 2) types or more has been received by the reception unit;
  The instruction signal generation unit generates the instruction signal on the condition that it is determined that a radio signal having a transmission power of Q (1 ≦ Q <P) or more is not received by the reception unit;
  An instruction signal generation method characterized by comprising:   An instruction signal generation method for generating an instruction signal for instructing locking of a processing function of a wireless terminal device or output of warning information from the wireless terminal device,
  A step of transmitting a wireless signal of N (N ≧ 2) types of transmission power to another wireless terminal device in a transmission unit;
  Receiving a response signal to the wireless signal from the other wireless terminal device at a receiving unit;
  A determination unit that determines, by the determination unit, how many types of radio signals with the transmission power among the N types of radio signals with the response signal are received by the other radio terminal device;
  Generating the instruction signal in the instruction signal generation unit on the condition that it has been determined that a radio signal of transmission power of P (N ≧ P ≧ 2) types or more has been received by the reception unit;
  The instruction signal generation unit generates the instruction signal on the condition that it is determined that a radio signal having a transmission power of Q (1 ≦ Q <P) or more is not received by the reception unit;
  An instruction signal generation method characterized by comprising: A program for causing a computer to function as the wireless terminal device according to claim 1 .

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