JP4775774B2 - Wireless communication device, wireless communication method, and computer program - Google Patents

Description

  The present invention relates to a wireless communication device, a wireless communication method, and a computer program used in the security field and the like.

2. Description of the Related Art Conventionally, mobile phones, personal computers, and the like have been required to automate password lock / unlock or power on / on, and automobiles have been required to automate door lock / unlock. In recent years, various methods have been devised to meet these demands. For example, when a user carries a wireless transmitter to which a unique ID is assigned, the password of a terminal device such as a mobile phone or a personal computer is locked when the user leaves, and unlocked when the user approaches. The technique to be performed is devised. In this type of wireless transmitter, ID data transmitted from the wireless transmitter to the terminal device is encrypted to enhance security. For example, Patent Document 1 discloses a keyless entry system using a password.
JP-A-8-144594

  By the way, in this type of wireless transmitter, power saving is strongly desired. In particular, a wireless communication device that operates by supplying power from a built-in battery requires a power saving function that eliminates the need for battery replacement or charging for a long time and enables continuous operation for a long time. In the conventional wireless transmitter, the battery power consumption is suppressed as much as possible by the intermittent operation that alternately repeats the transmission mode and the sleep mode. In the transmission mode, ID data for authenticating the wireless transmitter is transmitted to the terminal device. Therefore, in the ID data transmission method based on such intermittent operation, the ID data is periodically transmitted from the wireless transmitter to the terminal device. It will be transmitted intermittently. Of the power consumed by the wireless transmitter, the power required for transmitting ID data accounts for the majority, so reducing the power required for transmitting ID data is an issue for long-term operation of the wireless transmitter. ing.

  Therefore, an object of the present invention is to provide a wireless communication device, a wireless communication method, and a computer program that enable a wireless transmitter to operate for a long time.

In order to solve the above-described problems, a wireless communication device according to the present invention includes a wireless transmitter and a wireless receiver. The wireless transmitter includes a first transmission signal including information of all digits of an ID value composed of two or more digits for uniquely identifying the wireless transmitter, and only one digit of the ID value or only the one digit. A transmission module that generates a plurality of second transmission signals including conversion information obtained by converting information based on a predetermined conversion rule for all digits, a first transmission signal and a second transmission signal for all digits Antennas for wireless transmission at different transmission timings are provided. The wireless receiver transmits a predetermined number of pieces of information including only one digit of the ID value or conversion information obtained by converting only the one digit information based on a predetermined conversion rule included in one second transmission signal. The wireless transmitter is authenticated based on whether it matches the information to be transmitted in order . ID value transmission by receiving information of only one digit of ID value or conversion information obtained by converting the ID value based on the conversion rule, and authenticating the wireless transmitter by regarding the reception of the normal ID value The amount of communication data at the time can be reduced. As a result, the power consumption of the wireless transmitter is reduced, and operation for a long time becomes possible.

Here, information of a code different from the code of the ID value may be used as the conversion information. The wireless transmitter may further include a battery that supplies power to the transmission module and a switch that supplies or cuts power from the battery to the transmission module. Each time power is supplied from the battery to the transmission module by operating the switch, the transmission module determines the transmission order of the information of only one digit of the ID value according to the transmission order recognized in advance by the wireless transmitter and the wireless receiver. It may be changed.

In the wireless communication method according to the present invention, the wireless transmitter transmits a first transmission signal including information of all digits of an ID value consisting of two or more digits for uniquely identifying the wireless transmitter to the wireless receiver. And the wireless transmitter transmits to the wireless receiver a plurality of second transmission signals including only one digit information of the ID value or conversion information obtained by converting the one digit information based on a predetermined conversion rule. A step of transmitting the data, and the wireless receiver includes only one digit information of the ID value included in one second transmission signal or conversion information obtained by converting the one digit information based on a predetermined conversion rule. Authenticating the wireless transmitter based on whether it matches information to be transmitted according to a predetermined transmission order . According to this wireless communication method, the amount of communication data at the time of ID value transmission by the wireless transmitter can be reduced, so that the power consumption of the wireless transmitter is reduced and long-time operation is possible.

  A computer program according to the present invention is for causing a wireless communication device including a wireless transmitter and a wireless receiver to execute the above-described wireless communication method. According to this computer program, the power consumption of the wireless transmitter is reduced, and it is possible to operate for a long time.

  According to the present invention, it is possible to provide a wireless communication device, a wireless communication method, and a computer program that enable a wireless transmitter to operate for a long time.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a functional block diagram of the wireless communication device 10. The wireless communication device 10 includes a wireless transmitter 20 and a terminal device 30. The wireless transmitter 20 includes a transmission module 21, an antenna 22, a battery 23, and a switch 24. The transmission module 21 includes a signal processing circuit 25 and a high frequency circuit 26.

  The signal processing circuit 25 includes a CPU and a memory IC, and performs control for reducing power consumption, output processing of ID data, and the like. In the memory IC, ID data and a communication format are stored in advance. The ID data is identification information of two or more digits assigned to uniquely identify the wireless transmitter 20. The communication format conforms to a predetermined communication protocol (for example, a communication protocol for a 400 MHz band specific power-saving radio). Various memories such as a nonvolatile memory and a volatile memory can be applied as the memory IC. The CPU reads the communication format together with the ID data from the memory IC, and intermittently sends a modulation signal of a predetermined interface format (for example, UART serial interface format) modulated at a predetermined transfer rate (for example, 9600 bps) to the high frequency circuit 26. Output periodically. For example, an 8-bit microcomputer can be used as the CPU.

  The signal processing circuit 25 performs an intermittent operation as control for suppressing power consumption. For example, in a transmission period that operates as a transmission mode in a transmission cycle of a predetermined time (for example, every 15 seconds), the signal processing circuit 25 stores and outputs ID data in a predetermined communication format and operates as a sleep mode. During the sleep period, the operations of the signal processing circuit 25 and the high frequency circuit 26 are in a standby state. The signal processing circuit 25 and the high frequency circuit 26 suppress the power consumption of the battery 23 by alternately repeating the transmission mode and the sleep mode.

  The high frequency circuit 26 includes a passive component such as a chip inductor, a chip capacitor, and a chip resistor, a semiconductor element such as a transistor, and the like. The high frequency circuit 26 receives the modulation signal from the signal processing circuit 25 and modulates it into a transmission signal (for example, a binary FSK modulation signal in the 300 MHz band) including the ID data information of the wireless transmitter 20 according to the communication format. The antenna 22 converts the transmission signal generated by the high frequency circuit 26 into an electromagnetic wave and radiates it. The electromagnetic wave radiated from the antenna 22 is designed to comply with the weak wireless standard having a fundamental frequency of 315 MHz.

  The battery 23 supplies power to the signal processing circuit 25 and the high frequency circuit 26. The battery 23 is, for example, a lithium ion battery, and outputs a voltage of DC 3V by rating. The battery 23 consumes power in the range of about 1.8 V to 3.3 V, depending on the minimum operating voltage level in the signal processing circuit 25 and the high frequency circuit 26. The switch 24 is a power switch for supplying or cutting off power from the battery 23 to the signal processing circuit 25 and the high frequency circuit 26. When the transmission signal output from the wireless transmitter 20 is to be temporarily stopped, the power supply from the battery 23 to the signal processing circuit 25 and the high frequency circuit 26 can be cut off by turning off the switch 24. In addition, when it is desired to resume transmission signal output from the wireless transmitter 20, the power supply from the battery 23 to the signal processing circuit 25 and the high frequency circuit 26 can be resumed by turning on the switch 24.

  The terminal device 30 is an electronic device equipped with a wireless communication function such as a mobile phone or a personal computer, and includes a wireless receiver 40 and a CPU 31. The wireless receiver 40 includes an antenna 41, a high frequency circuit 42, and a signal processing circuit 43. ID data included in a transmission signal radiated as a radio wave from the wireless transmitter 20 is received by the antenna 41, demodulated by the high frequency circuit 42, decoded by the signal processing circuit 43, and a predetermined interface format ( For example, it is output to the CPU 31 in a UART serial interface format. The CPU 31 identifies the wireless transmitter 20 based on the ID data received by the wireless receiver 40. For example, when the terminal device 30 is a mobile phone, when the user carrying the wireless transmitter 20 moves and the wireless transmitter 20 and the terminal device 30 are separated from each other by a certain distance, the terminal device 30 is locked, When the wireless transmitter 20 and the terminal device 30 come within a certain distance, the terminal device 30 is unlocked.

  Next, a method for transmitting ID data from the wireless transmitter 20 to the wireless receiver 40 will be described. In this embodiment, a 20-digit decimal number is exemplified as the ID data. For example, the upper 10 digits of the 20 digits are an ID value “01234456789” for uniquely identifying the wireless transmitter 20, and the lower 10 digits are encryptions generated based on the ID value according to a predetermined encryption algorithm. The value is “98765443210”. In order to simplify the description, as an encryption algorithm, an algorithm for generating an encryption value by rearranging each digit of the ID value in reverse is illustrated. Note that it is preferable to add an encryption value to the ID data from the viewpoint of improving security, but it should be noted that the encryption value is not essential in the ID data transmission method according to the present embodiment. When the encryption value is not used, the ID value is the same as the ID data. The ID value may be two or more digits, and the number of digits is not particularly limited. Further, the ID value and the encryption value do not need to be decimal numbers, and may be N-ary numbers (N is an integer of 2 or more).

  The transmission module 21 generates a first transmission signal including information on all digits of ID data including an ID value and an encrypted value, and a plurality of second transmission signals including information on only some digits of the ID value. . The second transmission signal includes information on only a part of the digits of the ID value as far as the ID value is concerned, but information other than information on only a part of the digits of the ID value (for example, a synchronization code or an error required for the communication protocol) A CRC for checking). Each second transmission signal includes information of digits having different ID values. The antenna 22 wirelessly transmits the first transmission signal and the plurality of second transmission signals at different transmission timings. When the wireless receiver 40 receives the first transmission signal, the wireless receiver 40 decrypts all the digits of the ID value from the ID data based on a predetermined encryption algorithm. In the above example, a 10-digit ID value can be obtained by extracting the upper 10 digits of the ID data. Since the transmission order of the information of only some digits of the ID value is recognized in advance between the wireless transmitter 20 and the wireless receiver 40, when the wireless receiver 40 receives the second transmission signal, It is determined whether or not the information of only some digits of the ID value included in the received second transmission signal matches the information to be transmitted in accordance with a predetermined transmission order. When the determination is made, it behaves in the same manner as when regular ID data (all-digit ID data) is received from the transmission module 21, and information on all digits of the ID value is output to the terminal device 30. In this way, the wireless receiver 40 is receiving the second transmission signal that includes only the information of only a part of the digits of the ID value, as if receiving the legitimate ID data. By outputting the information of all digits of the ID value to the terminal device 30 every time the second transmission signal is received, the amount of data required for ID transmission is greatly reduced and consumed by the wireless transmitter 20 Can be suppressed.

  FIG. 2 shows the relationship between the ID data transmitted from the wireless transmitter 20 to the wireless receiver 40 and the ID value output from the wireless receiver 40 to the terminal device 30. At the first transmission timing since the switch 24 is turned on, the first transmission signal including the information “01234578989976543210” of all digits of the ID data is transmitted from the wireless transmitter 20 to the wireless receiver 40. The wireless receiver 40 decodes the information of all digits of the ID value from the received first transmission signal and outputs this to the terminal device 30. At each transmission timing from the second time to the 21st time, a second transmission signal including one-digit information of ID data is sequentially transmitted in accordance with a predetermined transmission order. For example, the second transmission signal including the first digit information “0” of the ID data is transmitted at the second transmission timing, and the second digit information “1” of the ID data is transmitted at the third transmission timing. A second transmission signal including the signal is transmitted. Each time the wireless receiver 40 receives a second transmission signal transmitted at each of the second to 21st transmission timings, the wireless receiver 40 outputs information on all digits of the ID value to the terminal device 30. In the 22nd and subsequent transmissions, the 1st to 21st transmissions may be repeated periodically, or the 2nd to 21st transmissions may be repeated periodically.

  FIG. 3 shows a wireless communication format of a transmission signal for transmitting ID data. This wireless communication format includes a preamble (PR) indicating the beginning of a packet, a synchronization code (SNC) for establishing synchronization, control information (CTL), a data portion (DATA) for storing ID data, and a cyclic redundancy code ( CRC). Here, the number of bits of each of the preamble, the synchronization code, the control information, and the cyclic redundancy code is 32 bits, 32 bits, 8 bits, and 16 bits. In the first transmission signal that transmits 20-digit ID data information all at once, it is necessary to store 48-bit data in the data portion, whereas the second transmission transmits 1-digit ID value information. For this transmission signal, it is sufficient to store 2-bit data in the data portion. As a result, in the transmission mode in which information of all digits of the ID data is stored and transmitted in the first transmission signal, a transmission time of 15 msec is required as shown in FIG. 4, and the current consumption at that time is 1.0 mA. It is. On the other hand, in the transmission mode in which the information of the one-digit ID value is stored in the second transmission signal and transmitted, as shown in FIG. 5, the transmission time of only 9.9 msec is sufficient, and the current consumption at that time is 1.0 mA. In any case, the sleep mode time is 1485 msec, and the current consumption at that time is 1.0 μA. When calculating the average power consumption based on the above analysis, the average value of the current consumed when transmitting all the information of 20-digit ID data at a time is 2.0 μA, whereas it is a single-digit ID. The average value of the current consumed when transmitting value information is 1.66 μA. When the battery capacity of the battery 23 is 60 mAh, the battery life is 3.4 years when the average current consumption is 2.0 μA, whereas the battery life is 4 when the average current consumption is 1.66 μA. It can be extended to 1 year.

  In the above description, the case where the information of each digit of the ID value is transmitted one digit at a time is illustrated, but the present invention is not limited to this, and the information of two or more digits of the ID value is stored in the second transmission signal. May be transmitted. Further, the transmission order of each digit of the ID value does not necessarily have to be transmitted in order from the upper digit to the lower digit, and may be any transmission order that the wireless communication device 20 and the wireless receiver 40 recognize in advance. Further, the transmission order of each digit of the ID value may be determined by the wireless transmitter 20 having the initiative. For example, information on each digit of the ID value is randomly transmitted from the wireless transmitter 20 to the wireless receiver 40. The wireless receiver 40 receives this and stores the transmission order of each digit. Thereafter, the wireless transmitter 20 transmits the information of each digit of the ID value again in the same transmission order. Since the wireless receiver 40 has already stored the transmission order of each digit of the ID value, the information of only some digits of the received ID value is information to be transmitted according to the transmission order stored in advance. It can be determined whether or not they match. In addition, it is not always necessary to transmit the information of only some digits of the ID value, and only the digits of the ID value are based on the conversion rules recognized in advance by the wireless transmitter 20 and the wireless receiver 40. The conversion information obtained by converting the information may be transmitted to the wireless receiver 40. This conversion information is, for example, information of a code system different from the ID value code system. For example, a conversion rule that converts numbers into alphabets can be used as the conversion rule. Since the wireless receiver 40 recognizes the conversion rule in advance, it can reversely convert the received conversion information into information of only some digits of the ID value. Further, the wireless transmitter 20 may change the transmission order of information of only some digits of the ID value every time power is supplied from the battery 23 to the transmission module 21 by operating the switch 24.

  Note that receiving information of only a part of the digits of the ID value or conversion information obtained by converting the information based on the conversion rule and considering it as reception of a regular ID value may lead to a decrease in security. Sex is also conceivable. However, since the wireless transmitter 20 performs an intermittent operation with a duty of 0.1%, as shown in the above example, the transmission timing of ID data from different wireless transmitters 20 competes. Probably close to zero. In this embodiment, since the communicable distance between the wireless transmitter 20 and the wireless receiver 40 is set to about 1.5 m to 3 m, a plurality of different wireless transmitters 20 to the wireless receivers are set. It is rare that ID data is transmitted to 40. For this reason, the transmission mode can be considered by receiving the information of only some digits of the ID value or the conversion information obtained by converting the information based on the conversion rule as the reception of the regular ID value. It is possible to reduce the amount of communication data and reduce power consumption.

It is a functional block diagram of the radio | wireless communication apparatus concerning this embodiment. It is a figure which shows the relationship between ID data transmitted to a wireless receiver from a wireless transmitter, and ID value output to a terminal device from a wireless receiver. It is explanatory drawing of a wireless communication format. It is explanatory drawing of the transmission mode which transmits the information of all the digits of ID data. It is explanatory drawing of the transmission mode which transmits the information of only the one part digit of ID value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wireless communication apparatus 20 ... Wireless communication apparatus 21 ... Transmission module 22 ... Antenna 23 ... Battery 24 ... Switch 25 ... Signal processing circuit 26 ... High frequency circuit 30 ... Radio receiver 31 ... CPU 40 ... Radio receiver 41 ... Antenna 42 ... High frequency circuit 43 ... Signal processing circuit

Claims (7)

A wireless communication device comprising a wireless transmitter and a wireless receiver,
The wireless transmitter is
A first transmission signal including information of all digits of an ID value composed of two or more digits for uniquely identifying the wireless transmitter, and information of only one digit of the ID value or information of only one digit are predetermined. A transmission module that generates a plurality of second transmission signals including the conversion information converted based on the conversion rule for all digits,
An antenna that wirelessly transmits the first transmission signal and the second transmission signal for the total number of digits at different transmission timings,
The wireless receiver has predetermined information of only one digit of the ID value or conversion information obtained by converting the information of only one digit based on a predetermined conversion rule included in one second transmission signal. A wireless communication device that authenticates the wireless transmitter based on whether or not it matches information to be transmitted in accordance with a transmitted order . The wireless communication device according to claim 1,
The conversion information is a wireless communication device that is information having a code different from the code of the ID value. The wireless communication device according to claim 1 or 2,
The wireless transmitter further includes a battery for supplying power to the transmission module, and a switch for supplying or cutting off power from the battery to the transmission module,
Each time power is supplied from the battery to the transmission module by operating the switch, the transmission module changes the transmission order of information of only one digit of the ID value to the wireless transmitter and the wireless receiver. The wireless communication device changes according to the transmission order recognized in advance. The wireless transmitter transmitting to the wireless receiver a first transmission signal including information of all digits of an ID value consisting of two or more digits for uniquely identifying the wireless transmitter;
The wireless transmitter transmits all the digits of the second transmission signal including the information of only one digit of the ID value or the conversion information obtained by converting the information of only one digit based on a predetermined conversion rule to the wireless receiver. Sending a few minutes,
Conversion information obtained by converting only one digit information of the ID value or only one digit information included in one second transmission signal based on a predetermined conversion rule is determined in advance by the wireless receiver. Authenticating the wireless transmitter based on whether it matches information to be transmitted according to the transmitted order of transmission ;
A wireless communication method comprising: The wireless communication method according to claim 4,
The wireless communication method, wherein the conversion information is information having a code different from the code of the ID value. The wireless communication method according to claim 4 or 5, wherein
The wireless transmitter further includes a transmission module that generates the first and second transmission signals, and a switch that supplies or cuts off power from a battery to the transmission module,
A transmission in which the wireless transmitter and the wireless receiver recognize in advance the transmission order of information of only one digit of the ID value each time power is supplied from the battery to the transmission module by operating the switch. The wireless communication method further comprising the step of changing the transmission module according to an order.   A computer program for causing a wireless communication device including a wireless transmitter and a wireless receiver to execute the wireless communication method according to any one of claims 4 to 6.

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