JP2017028427A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system capable of reinforcing the security of radio communication performed between a transmission device and a reception device.SOLUTION: A communication system 100 comprises a transmission device 1 and a reception device 2. The transmission device 1 generates a first radio signal by FM modulation based on a modulated signal generated by MSK modulation based on first data, and a second radio signal by FSK modulation based on second data, and then transmits the generated first radio signal and second radio signal by radio. The reception device 2 receives the first radio signal and second radio signal from the transmission device 1 by radio, and performs control on the basis of the first radio signal and second radio signal received by radio.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication system.

  Conventionally, a wireless disaster prevention system for monitoring the occurrence of a fire in a monitoring area and notifying the occurrence of the fire is known. This wireless disaster prevention system includes a wireless sensor, a wireless reception repeater, and a receiver, and the wireless reception repeater has only one type of communication method (for example, with a wireless sensor). , A communication method using the FSK modulation method), and when a fire is detected, a fire telegram transmitted wirelessly from the wireless sensor is relayed to the receiver to notify the fire occurrence. (For example, refer to Patent Document 1).

Japanese Patent Laying-Open No. 2015-38681

  However, in the wireless disaster prevention system, after a fire telegram from a wireless sensor is illegally received and stored using a predetermined spoofing communication device, a predetermined spoofing communication device is used instead of the wireless sensor. There is a possibility that spoofed wireless communication may be performed such that the stored fire telegram is illegally wirelessly transmitted to the wireless reception repeater.

  The present invention has been made in view of the above, and can enhance the security of wireless communication performed between a transmission device such as a wireless sensor and a reception device such as a wireless reception repeater. An object of the present invention is to provide a communication system.

  In order to solve the above-described problem and achieve the object, the communication system according to claim 1 is a communication system including a transmission device and a reception device, and the transmission device is based on first data. First radio signal generation means for generating a first radio signal by FM modulation based on a modulated signal generated by MSK modulation, and second radio signal generation means for generating a second radio signal by FSK modulation based on second data Transmitting means for wirelessly transmitting the first wireless signal generated by the first wireless signal generating means of the transmitting apparatus and the second wireless signal generated by the second wireless signal generating means of the transmitting apparatus; The receiving device includes: a receiving unit that wirelessly receives the first wireless signal and the second wireless signal wirelessly transmitted by the transmitting unit of the transmitting device; and the receiver of the receiving device. There based on the radio received first radio signal and the second radio signal, and a control means for controlling.

  The communication system according to claim 2 is the communication system according to claim 1, wherein the control unit of the receiving device receives the first radio signal and the second radio signal wirelessly received by the receiving unit of the receiving device. An acquisition unit that acquires the first data and the second data based on a signal, a verification unit that collates the first data and the second data acquired by the acquisition unit of the reception device, and the reception device And a processing means for performing processing according to the first data and the second data based on the collation result of the collation means.

  The communication system according to claim 3 is the communication system according to claim 1, wherein one of the first data and the second data is encrypted data, and the first data or The other data of the second data is data for decoding the one data, and the control means of the receiving device is configured to receive the first wireless data received wirelessly by the receiving means of the receiving device. An acquisition unit that acquires the one data and the other data based on a signal and the second wireless signal; and the other data acquired by the acquisition unit of the reception device Based on the result of decoding by the decoding means of the receiving device and the decoding means for decoding the one data acquired by the acquisition means, the processing corresponding to the one data is performed And a physical means.

  The communication system according to claim 4 is the communication system according to claim 1, wherein the transmission means of the transmission device wirelessly transmits one of the first radio signal and the second radio signal. Then, the wireless signal is configured to wirelessly transmit the other wireless signal of the first wireless signal or the second wireless signal, and the one wireless signal of the first data or the second data is transmitted to the wireless signal. The corresponding one of the data includes frequency band specifying information for specifying the frequency band of the other radio signal, and the control unit of the receiving device transmits the radio transmitted by the receiving unit of the receiving device. When one wireless signal is wirelessly received, an acquisition unit that acquires the one data based on the one wireless signal received wirelessly and the one of the data acquired by the acquisition unit of the reception device Based on the frequency band specific information contained in the data, and a switching means for switching a frequency band for receiving a radio signal in the receiving means of the receiving device.

  According to the communication system of claim 1, both of the first radio signal generated by the MSK modulation and the FM modulation based on the first data and the second radio signal generated by the FSK modulation based on the second data. Since wireless communication is performed between the transmission device and the reception device using the signal, for example, the first data and the second data are transmitted using a predetermined spoofing communication device that performs wireless communication using only one type of communication method. Since it is difficult to store both data, it is possible to prevent the predetermined spoofing communication device from impersonating the transmission device, and to enhance the security of wireless communication performed between the transmission device and the reception device. become.

  According to the communication system of the second aspect, the first data and the second data acquired from the first radio signal and the second radio signal are collated, and the process is performed based on the collation result. Processing is performed only when complete data (that is, one data and the other data) is prepared, so that unauthorized processing is prevented from being performed based only on unauthorized data from a predetermined spoofing communication device. It becomes possible to improve the reliability of the communication system.

  According to the communication system according to claim 3, one of the first data and the second data acquired from the first radio signal and the second radio signal is decoded based on the other data, and is decoded. Therefore, for example, the processing is performed only when two legitimate data (that is, one data and the other data) are prepared, and an illegal communication from a predetermined spoofing communication device is performed. It is possible to prevent unauthorized processing from being performed based only on data, and to improve the reliability of the communication system.

  According to the communication system according to claim 4, the transmitting device wirelessly transmits one of the first radio signal and the second radio signal corresponding to one data including the frequency band specifying information. After transmitting, the other wireless signal is wirelessly transmitted, and the receiving device switches the frequency band based on the frequency band specifying information included in one data. For example, while switching the frequency band of the received wireless signal By performing wireless communication, it is possible to prevent the reception device from performing wireless communication with a predetermined spoofing communication device, and to further enhance the security of wireless communication performed between the transmission device and the reception device. It becomes possible.

It is the schematic which shows the structure of the communication system which concerns on Embodiment 1 of this invention. It is a figure which shows an example of collation data. It is a wave form diagram of various signals, (a) is a figure which illustrated the modulated analog signal generated in the MSK modulation part of a transmitting device, and (b) is the waveform demodulating part of a receiving device with respect to the 1st demodulated signal. It is the figure which illustrated the binary signal which binarized the to-be-modulated analog signal of (a) using the waveform shaping threshold value used by (c), (c) is a signal which shows the 2nd digital data which the transmission terminal produced | generated. FIG. It is a flowchart of the transmission process and acquisition process of a communication system. It is a flowchart of the output process of a communication system. It is a wave form diagram of various signals about the 1st radio signal, (a) is a figure which illustrated the 1st demodulated signal generated in a demodulator, and (b) is a waveform based on the 1st demodulated signal of (a). It is the figure which illustrated the binary signal produced | generated in the shaping part. It is a wave form diagram of various signals about the 2nd radio signal, (a) is a figure which illustrated the 2nd demodulated signal generated in a demodulator, and (b) is a waveform based on the 2nd demodulated signal of (a). It is the figure which illustrated the binary signal produced | generated in the shaping part. 6 is a schematic diagram illustrating a configuration of a communication system according to Embodiment 2. FIG. It is a flowchart of the transmission process and acquisition process of a communication system. It is a flowchart of the output process of a communication system. 6 is a schematic diagram illustrating a configuration of a communication system according to Embodiment 3. FIG. It is a flowchart of the transmission process and acquisition output process of a communication system.

  Hereinafter, embodiments of a communication system according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments.

[Basic concept of the embodiment]
First, the basic concept of the embodiment will be described. The embodiment schematically illustrates a communication system that wirelessly receives a first wireless signal and a second wireless signal wirelessly transmitted by a transmission device and performs control based on the wirelessly received first wireless signal and second wireless signal. It is about.

  Here, the “communication system” is a system that performs communication, and includes at least a transmission device and a reception device.

  The “transmitting device” is a wireless signal transmitting unit that wirelessly transmits the first wireless signal and the second wireless signal, and includes, for example, a human sensor, a door opening / closing sensor, a sensor, and a wireless transmitter. The “first wireless signal” and the “second wireless signal” are signals for wireless communication, and are signals generated by a predetermined modulation method based on predetermined data. The “human sensor” is a device that senses the human body in the monitoring area, the “door open / close sensor” is a device that senses the open / closed state of the door in the monitoring area, and the “sensor” is an abnormality in the monitoring area. This means is a sensing means for sensing the presence or absence, for example, a fire detector for detecting fire by detecting smoke or heat, a gas leak detector for detecting gas, and the like. A “wireless transmitter” is a device that transmits a wireless signal. For example, a device that receives data from a human sensor, a door opening / closing sensor, or a sensor and wirelessly transmits a wireless signal based on the received data. Etc. The “monitoring area” is an area to be monitored, and is a concept including, for example, a building room, a hallway, a staircase, and the like.

  The “reception device” is a wireless signal receiving unit that wirelessly receives and controls a wireless signal, and corresponds to, for example, a disaster prevention receiver, an output device, a relay device, and the like. “Disaster prevention receiver” is a disaster prevention receiving means that receives a signal and performs disaster prevention processing based on the received signal, and has, for example, a function to notify the occurrence of an abnormality to the outside (that is, a transfer function). Or a device that does not have a transfer function and does not notify the outside of the occurrence of an abnormality. “Abnormal” is different from normal, and includes, for example, the occurrence of a fire or the occurrence of a gas leak in the monitoring area. The “output device” is an output unit that receives a signal and outputs information, and includes, for example, a display device that displays and outputs information. The “relay device” is a relay unit that relays a signal, and corresponds to, for example, a device that analyzes a received signal and relays the signal based on the analysis result.

  “Control” performed by the “receiving device” is control related to the communication system, for example, control performed by collating data based on the collation result, control performed by decoding data based on the decryption result, and The control etc. which switch the frequency band which receives the radio signal in a receiver are mentioned.

  In each embodiment described below, the “transmitting device” is a “door open / close sensor”, the “receiving device” is an “output device”, and the “first wireless signal” is based on “first data”. This is a radio signal generated by FM (Frequency Modulation) based on a modulated signal generated by MSK (Minimum Shift Keying), and the “second radio signal” is obtained by “FSK (Frequency Shift Keying) based on second data. A case of “generated radio signal” will be described. Specifically, the “control” performed by the “receiving device” is described in the first embodiment as “control performed by collating data based on the collation result”, and in the second embodiment, “encryption”. In the third embodiment, “control for switching a frequency band for receiving a radio signal” in the receiving apparatus will be described.

[Specific contents of the embodiment]
Next, specific contents of each embodiment will be described.

(Embodiment 1)
First, the first embodiment will be described. In this embodiment, the “first data” and the “second data” are data having the same content (specifically, the same data string), and the “receiving device” collates the data into the collation result. The case where control is performed based on this will be described.

(Constitution)
First, the configuration of the communication system according to the present embodiment will be described. FIG. 1 is a schematic diagram showing a configuration of a communication system according to the present embodiment. As shown in FIG. 1, a communication system 100 is a system that performs communication, and includes a transmission device 1 and a reception device 2. These devices can communicate wirelessly. In the communication system 100, an arbitrary number (that is, only one or a plurality) of the transmission device 1 and the reception device 2 may be provided based on the content and amount of data to be communicated. In the following, a case where only one transmitting device 1 and one receiving device 2 are provided will be described (the communication system 300 according to the second embodiment and the communication system 500 according to the third embodiment to be described later). The same shall apply).

(Configuration-Transmitter)
First, the configuration of the transmission device 1 will be described. The transmission device 1 is a wireless signal transmission unit that wirelessly transmits a wireless signal, and is a door open / close sensor that detects an open / closed state of a door (not shown) and outputs a detection result. As illustrated in FIG. 11, a wireless communication unit 12, a storage unit 13, and a control unit 14.

(Configuration-Transmitter-Detector)
The detection unit 11 is a detection unit that detects an open / closed state of a door (not shown), and outputs a signal indicating the open / closed state of the door, and includes, for example, a hall element.

(Configuration-Transmitter-Wireless communication unit)
The wireless communication unit 12 is a communication unit that performs wireless communication with the receiving device 2, in particular, a transmission unit that wirelessly transmits a first wireless signal and a second wireless signal described later. For example, a communication circuit for wireless communication Etc. are provided.

(Configuration-Transmitter-Storage unit)
The storage unit 13 is a storage unit that stores a program and various data necessary for the operation of the transmission device 1. The storage unit 13 is configured using, for example, a hard disk (not shown) as an external storage device, but instead of or together with the hard disk, a magnetic storage medium such as a magnetic disk, or a DVD or Blu-ray disk is used. Any other storage medium including such an optical storage medium can be used (this also applies to the storage units of other apparatuses and devices).

(Configuration-Transmitter-Control unit)
The control unit 14 is a control unit that controls the transmission device 1. Specifically, the control unit 14 includes a CPU, various programs that are interpreted and executed on the CPU (including a basic control program such as an OS and an application program that is activated on the OS and realizes a specific function), and The computer includes an internal memory such as a RAM for storing programs and various data. In particular, the program according to the present embodiment is substantially installed in the transmission device 1 via an arbitrary storage medium or network, thereby substantially configuring each unit of the control unit 14 (for these points, The same applies to the control unit of the device and equipment).

  The control unit 14 includes a first data generation unit 141, a first signal generation unit 142, a second data generation unit 143, and a second signal generation unit 144 in terms of functional concept.

(Configuration-Transmitting device-Control unit-First data generation unit)
The first data generation unit 141 is data generation means for generating first digital data (first data). Specifically, the first data generation unit 141 generates first digital data indicating the detection result of the detection unit 11. Here, the “first digital data” is a set of data discretized into two values (for example, “0” and “1”), and the data rate of the first digital data is arbitrarily set. However, here, it is assumed that it is set to “1200” (bps) (the same applies to “first digital data” in the second and third embodiments described later). .

(Configuration-Transmitter-Control unit-First signal generation unit)
The first signal generation unit 142 is a first radio signal generation unit that generates a first radio signal to be described later, and includes an MSK modulation unit 142A and an FM modulation unit 142B as shown in FIG.

  The MSK modulation unit 142A is a signal generation unit that performs MSK modulation based on the first digital data generated by the first data generation unit 141 to generate a modulated analog signal. The “modulated analog signal” is a signal generated by modulation, specifically, a signal generated by the MSK modulation unit 142A, which is a first frequency analog signal and the first frequency. Is a signal including an analog signal of a second frequency which is a different frequency. The “first frequency” is the frequency of one of the two types of signals included in the modulated signal, and the “second frequency” is the frequency of the two types of signals. Is the frequency of the other signal. The first frequency and the second frequency can be set to any frequency according to a predetermined rule (for example, the modulation index is “0.5”). The following description will be given on the assumption that “frequency value” = “1800 (Hz)” and “second frequency value” = “1200 (Hz)”.

  The FM modulation unit 142B is a first radio signal generation unit that performs FM modulation based on the modulated analog signal generated by the MSK modulation unit 142A and generates a first radio signal. The “first radio signal” is a signal generated by modulation, and specifically, a radio signal generated by the FM modulation unit 142B. The frequency band of the first radio signal can be arbitrarily set based on the communication distance or predetermined regulations, but here, the FM modulation unit 142B is the first of the “426 (MHz) band”. The following description will be made on the assumption that a radio signal is generated.

(Configuration-Transmitting device-Control unit-Second data generation unit)
The second data generation unit 143 is data generation means for generating second digital data (second data). Specifically, the second data generation unit 143 is a digital that shows the same content as the first digital data generated by the first data generation unit 141. Second digital data that is data (that is, digital data having the same data string as the data string of the first digital data) is generated. Here, the “second digital data” is a set of data discretized into two values (for example, “0” and “1”), and the data rate of the second digital data is arbitrarily set. Here, the following description will be given assuming that the data rate is set to “4800” (bps) higher than “1200” (bps) in the first digital data ( The same applies to the “second digital data” in the second and third embodiments).

(Configuration-Transmitter-Control unit-Second signal generation unit)
The second signal generation unit 144 is a second radio signal generation unit that generates a second radio signal to be described later, and includes an FSK modulation unit 144A as shown in FIG.

  The FSK modulation unit 144A is a second radio signal generation unit that performs FSK modulation based on the second digital data generated by the second data generation unit 143 and generates a second radio signal. The “second radio signal” is a signal generated by modulation, specifically, a radio signal generated by the FSK modulation unit 144A, which is a signal of the first FSK frequency and the first FSK frequency. Is a signal including a second FSK frequency signal which is a different frequency. The “first FSK frequency” is the frequency of one of the two types of signals included in the second radio signal, and the “second FSK frequency” is the frequency of the two types of signals. This is the frequency of the other signal. The first FSK frequency and the second FSK frequency can be arbitrarily set based on a communication distance or predetermined regulations, but here, the first radio signal and the second radio signal are mutually connected. The FSK modulation unit 144A sets the “first FSK frequency value” = “426.247 (MHz)” and the “second FSK frequency value” = “426.253 (MHz)” so that radio signals of the same channel are obtained. The following description will be given assuming that two radio signals are generated. The specific processing contents by each unit of the control unit 14 will be described later.

(Configuration-Receiver)
Next, the configuration of the receiving device 2 will be described. The receiving device 2 is a radio signal receiving unit that receives and controls the first radio signal and the second radio signal from the transmitting device 1, and is an output device that displays and outputs information, and is shown in FIG. As shown, the wireless communication unit 21, the storage unit 22, the output unit 23, and the control unit 24 are provided.

(Configuration-Receiver-Wireless communication unit)
The wireless communication unit 21 is a communication unit that performs wireless communication with the transmission device 1, in particular, a reception unit that wirelessly receives the first wireless signal or the second wireless signal. For example, the wireless communication unit 21 includes a communication circuit for wireless communication. It is prepared for.

(Configuration-receiving device-storage unit)
The storage unit 22 is a storage unit that stores programs and various data necessary for the operation of the receiving device 2. The storage unit 22 stores collation data.

  “Verification data” is data for verifying a signal wirelessly received by the wireless communication unit 21, and specifically, data for verifying sampling data described later. FIG. 2 is a diagram illustrating an example of collation data. As shown in FIG. 2, the collation data includes items “wireless signal”, item “data”, item “modulated analog signal”, item “reference data string”, and information corresponding to each item. Configured in association.

  Here, the information corresponding to the item “wireless signal” is information for specifying the wireless signal received by the receiving device 2 (“first wireless signal” and “second wireless signal” in FIG. 2).

  The information corresponding to the item “data” is information transmitted by a radio signal received by the receiving device 2 (in FIG. 2, “0” of “first digital data”, “1” of “first digital data”). , “0” for the second digital data, and “1” for the second digital data). Note that “0” in the first digital data in FIG. 2 indicates “0” in the first digital data of 1200 (bps) generated by the first data generation unit 141 of the transmission device 1 in FIG. In FIG. 2, “1” in the first digital data is assumed to indicate “1” in the first digital data. Further, “0” of the second digital data in FIG. 2 indicates “0” in the second digital data of 4800 (bps) generated by the second data generation unit 143 of the transmission device 1 of FIG. In FIG. 2, “1” in the second digital data is assumed to indicate “1” in the second digital data.

  The information corresponding to the item “modulated analog signal” is a modulated analog signal that is a basis of a radio signal received by the receiving device 2 (in FIG. 2, “1800 (Hz) signal”, “1200 ( Hz) signal "and" none "). Note that “a signal of 1800 (Hz)” in FIG. 2 indicates a signal of the first frequency (that is, 1800 (Hz)) among the modulated analog signals generated by the MSK modulation unit 142A described above. , “1200 (Hz) signal” in FIG. 2 indicates a signal of the second frequency (that is, 1200 (Hz)) of the modulated analog signal, and “none” in FIG. There is no modulated analog signal that is the basis of the signal (that is, without generating the modulated analog signal, a digital signal (here, the second digital data) is converted into a radio signal (here, the second radio signal). ) Is generated directly).

  Information corresponding to the item “reference data string” (hereinafter referred to as reference data string information) is a data string serving as a reference for collating sampling data described later (in FIG. 2, binary (for example, “0”, “1”). ) A set of data, “111100001111”, “00000011111”, “000”, and “111”). The reference data string information is set based on a waveform shaping threshold and a sampling rate set in an analysis unit 242 described later. A specific setting method will be described later. The collation data shown in FIG. 2 is stored when the user inputs it through an input unit (not shown).

(Configuration-Receiver-Output unit)
Returning to FIG. 1, the output unit 23 is an output unit that outputs information, and includes, for example, a display.

(Configuration-Receiver-Controller)
The control unit 24 is a control unit that controls the receiving device 2. The control unit 24 includes a demodulation unit 241, an analysis unit 242, an acquisition unit 243, a collation unit 244, and a processing unit 245 in terms of functional concept.

(Configuration-Receiver-Controller-Demodulator)
The demodulator 241 is a demodulated signal generating unit that generates a demodulated signal described later by demodulating the radio signal wirelessly received by the radio communication unit 21. Here, the “demodulated signal” is a signal generated by demodulating a radio signal, and specifically, a first demodulated signal generated by demodulating the first radio signal (that is, a transmitting device). Signal corresponding to the modulated analog signal used in one FM modulation unit 142B) or a second demodulated signal generated by demodulating the second radio signal (that is, used in the FSK modulation unit 144A of the transmission apparatus 1). Signal corresponding to the second digital data).

(Configuration-Receiver-Controller-Analyzer)
The analysis unit 242 is an analysis unit that analyzes the demodulated signal generated by the demodulation unit 241 at a sampling rate described later, and includes a waveform shaping unit 242A, a sampling unit 242B, and a determination unit 242C as illustrated in FIG. Yes.

  The waveform shaping unit 242A compares the value of the demodulated signal generated by the demodulation unit 241 with a waveform shaping threshold described later, and based on the comparison result, the binary signal (that is, “0” or “1”). Binary signal generating means for generating at least one signal), for example, comprising a comparator circuit. Here, the “waveform shaping threshold value” is a threshold value for generating a binary signal, and specific values are arbitrary for each demodulated signal (that is, the first demodulated signal and the second demodulated signal). In the following description, it is assumed that the central value between the maximum value and the minimum value of the amplitude of each demodulated signal is set as the waveform shaping threshold for each demodulated signal. .

  The sampling unit 242B is an acquisition unit that acquires later-described sampling data by sampling the binary signal generated by the waveform shaping unit 242A at a later-described sampling rate. Here, the “sampling rate” is a sampling frequency for acquiring data corresponding to a binary signal, and a specific value is information transmitted by a radio signal received by the receiving device 2 (that is, 1200 ( “0” and “1” in the first digital data of bps) and “0” and “1” in the second digital data of 4800 (bps)) are arbitrarily set as long as the frequencies can be collated. be able to. That is, as the value of “sampling rate”, “1200”, “1800”, which is the value of the frequency of the signal included in the modulated analog signal based on the first digital data of 1200 (bps), and the second digital data The common multiple of “4800”, which is the value of the data rate, can be used. Specifically, from the viewpoint of reducing the amount of data to be processed, “14400”, which is the least common multiple of the aforementioned “1200”, “1800”, and “4800”, is set as the sampling rate value. Will be described below. The “sampling data” is data acquired by sampling the binary signal at the sampling rate by the sampling unit 242B.

  Based on the sampling data acquired by the sampling unit 242B and the collation data stored in the storage unit 22, the determination unit 242C allows the wireless communication unit 21 to select either the first wireless signal or the second wireless signal. It is a determination means which determines whether or not has been received.

(Configuration-Receiving device-Control unit-Acquisition unit)
The acquisition unit 243 is an acquisition unit that acquires data transmitted by the first wireless signal and the second wireless signal wirelessly received by the wireless communication unit 21 based on the analysis result of the analysis unit 242.

(Configuration-Receiving device-Control unit-Verification unit)
The collation unit 244 is a collation unit that collates the data acquired by the acquisition unit 243.

(Configuration-Receiving device-Control unit-Processing unit)
The processing unit 245 is a processing unit that performs processing based on the collation result of the collation unit 244. The specific processing contents by each unit of the control unit 24 will be described later.

(Configuration-setting method of reference data string information in FIG. 2)
Next, a specific method for setting the reference data string information shown in FIG. 2 will be described. The reference data string information in FIG. 2 is information (ie, information transmitted by a radio signal received by the receiving device 2) based on the waveform shaping threshold used in the waveform shaping unit 242A and the sampling rate used in the sampling unit 242B (that is, It is set so as to correspond to a 1200 (Hz) signal, a 1800 (Hz) signal, and 4800 (bps) second digital data among modulated analog signals. 3A and 3B are waveform diagrams of various signals, FIG. 3A is a diagram illustrating a modulated analog signal generated in the MSK modulation unit 142A of the transmission apparatus 1, and FIG. 3B is a waveform shaping unit of the reception apparatus 2. FIG. 24B is a diagram illustrating a binary signal obtained by binarizing the modulated analog signal of (a) using the waveform shaping threshold used for the first demodulated signal in 242A, and (c) is generated by the transmission apparatus 1 It is the figure which illustrated the signal which shows the 2nd digital data of 4800 (bps) which did. Note that the modulated analog signal generated by the MSK modulation unit 142A is actually distorted due to a predetermined delay or the like, but in FIG. 3A, the distortion is displayed for convenience of explanation. Is omitted (the same applies to FIGS. 6A and 7A described later). The times t1 to t24 on the horizontal axis in FIGS. 3A to 3C correspond to each other, and indicate the sampling time based on the sampling rate (that is, the time to acquire data). explain. Specifically, FIG. 3A illustrates two bits of 1200 (bps) first digital data generated by the first data generation unit 141 of the transmission device 1 (specifically, from the left side to the right side of the page) 0 ”and“ 1 ”), and the portion corresponding to“ the signal of the first frequency (1800 (Hz)) ”in FIG. 3A is“ first digital data ”. ”=“ 0 ”, and the portion corresponding to“ the signal of the second frequency (1200 (Hz)) ”corresponds to“ first digital data ”=“ 1 ”. 3C specifically shows 8 bits of the second digital data of 4800 (bps) generated by the second data generation unit 143 of the transmission device 1 (specifically, from the left side to the right side of the page). And “1”, “0”, “1”, “0”, “1”, “0”, “1”, “0”).

  Specifically, for the setting of the reference data string information in FIG. 2, the data corresponding to t1 to t12 in FIG. 3B corresponds to the item “data” = “0” of the first digital data in FIG. Registered as reference data string information, and data corresponding to t13 to t24 in FIG. 3B is set as reference data string information corresponding to the item “data” = “1” of the first digital data in FIG. The data corresponding to t1 to t3 in FIG. 3C is registered as reference data string information corresponding to the item “data” = “second digital data“ 1 ”” in FIG. 2) is registered as reference data string information corresponding to the item “data” = “second digital data“ 0 ”” in FIG.

(processing)
Next, control processing executed by the communication system 100 configured as described above will be described. The “control process” is a process for performing control related to the communication system 100, is a process performed based on the first radio signal and the second radio signal from the transmission device 1, and the specific process content is arbitrary. However, here, the process of displaying the door open / closed state (not shown) on the output unit 23 of the receiving device 2 and outputting it will be described as a control process. The “control process” described here is assumed to include the following “transmission process”, “acquisition process”, and “output process”. The “transmission process” is a process of transmitting a radio signal, and is a process executed by the transmission apparatus 1 and starts when the communication system 100 starts operating when the communication system 100 is turned on. It is processing to do. The “acquisition process” is a process for acquiring data and is executed by the receiving device 2 and is repeatedly executed after starting activation at the same timing as the “transmission process” described above. It is processing. The “output process” is a process for displaying and outputting data, and is a process executed by the receiving device 2 and is activated when demodulated digital data (to be described later) is acquired by the “acquisition process” described above. It is a process to start.

  FIG. 4 is a flowchart of transmission processing and acquisition processing of the communication system 100. FIG. 5 is a flowchart of output processing of the communication system 100. In the following, “step” is abbreviated as “S”. FIG. 6 is a waveform diagram of various signals related to the first radio signal, (a) is a diagram illustrating the first demodulated signal generated in the demodulator 241, and (b) is the first demodulation of (a). It is the figure which illustrated the binary signal produced | generated in 242 A of waveform shaping parts based on the signal. FIG. 7 is a waveform diagram of various signals related to the second radio signal, (a) is a diagram illustrating the second demodulated signal generated in the demodulator 241, and (b) is the second demodulated signal of (a). It is the figure which illustrated the binary signal produced | generated in 242 A of waveform shaping parts based on the signal. These time scales in FIGS. 6 and 7 (specifically, the time between the dot-and-dash lines adjacent to each other shown in FIGS. 6 and 7) are the same as those in FIG. The following description will be given on the assumption that the same scale as the time between adjacent one-dot chain lines shown in FIG.

(Processing-Transmission processing)
First, transmission processing of the transmission device 1 will be described. First, in SA1 of FIG. 4, the first data generation unit 141 generates first digital data. Specifically, the detection result of the detection unit 11 is shown, and first digital data of “1200” (bps) is generated. Here, for example, it is assumed that first digital data including preamble data and detection result data is generated. The “preamble data” is data of a predetermined number of bits (for example, 8 bits) used for the determination performed by the receiving device 2 and is data in which “0” and “1” are alternately repeated. is there. The “detection result data” is data for specifying the detection result of the detection unit 11, and data indicating the door itself (not shown) and the open / closed state of the door by a predetermined data string of “0” and “1”. It is.

  Next, in SA2, the MSK modulation unit 142A of the first signal generation unit 142 generates a modulated analog signal. Specifically, “0” in the first digital data is converted to “analog signal of 1800 (Hz)” by MSK modulation based on the first digital data generated in SA1, and “1” in the first digital data. Is converted into “1200 (Hz) analog signal” to generate a modulated analog signal including these “1800 (Hz) analog signal” and “1200 (Hz) analog signal”. More specifically, a modulated analog signal including “1800 (Hz) analog signal” and “1200 (Hz) analog signal” for each period corresponding to the reference time is generated. Here, the “reference time” is a fixed time that determines the time length of the modulated analog signal corresponding to one bit of the first digital data, and represents the period of each analog signal included in the modulated analog signal. It is a fixed time that is a standard to be determined. As the reference time, any time can be used. Here, an analog signal having a lower frequency between the analog signal having the first frequency and the analog signal having the second frequency (that is, 1200 ( The case where the time for one cycle of the analog signal (Hz) is used as the reference time will be described below.

  Here, for example, for the first digital data of 2 bits “1” and “0” generated in SA1, as shown in FIG. 3A, an analog signal of 1200 (Hz) for one cycle is used. A modulated analog signal including 1800 (Hz) analog signals for 1.5 periods is generated.

  Returning to FIG. 4, in SA3, the FM modulation unit 142B of the first signal generation unit 142 generates a first radio signal. Specifically, a first wireless signal in the 426 (MHz) band is generated by FM modulation based on the modulated analog signal generated in SA2.

  Next, in SA4, the control unit 14 wirelessly transmits the first wireless signal. Specifically, the first radio signal generated in SA3 is transmitted via the radio communication unit 12.

  Next, in SA5, the second data generation unit 143 generates second digital data. Specifically, the detection result of the detection unit 11 is shown, and second digital data “4800” (bps) is generated. Here, for example, the second digital data that is the same digital data as the first digital data except for the data rate (that is, digital data having the same data string as the data string of the first digital data) is generated. That is, for example, second digital data including preamble data and detection result data is generated.

  Next, in SA6, the FSK modulation unit 144A of the second signal generation unit 144 generates a second radio signal. Specifically, “0” in the second digital signal is converted into a signal of the first FSK frequency (that is, 426.247 (MHz)) by FSK modulation based on the second digital signal generated in SA5, and The second wireless signal is generated by converting “1” in the second digital signal into a signal having the second FSK frequency (that is, 426.253 (MHz)). As described above, the first FSK frequency and the second FSK frequency are set to frequencies in the frequency band of the first radio signal (that is, the first radio signal and the second radio signal are the same channel radio signal and Therefore, both the first wireless signal and the second wireless signal can be wirelessly received by the receiving device 2 in FIG.

  Returning to FIG. 4, in SA7, the control unit 14 wirelessly transmits the second wireless signal, and then ends the transmission process. Specifically, the second radio signal generated in SA6 is transmitted via the radio communication unit 12.

(Processing-Acquisition processing)
Next, the acquisition process of the receiving device 2 will be described. Here, as described above, the preamble data is included in both the first digital data of the first radio signal and the second digital data of the second radio signal from the transmission apparatus 1 in FIG. A case where processing is performed while paying attention to will be described below.

  First, in SB <b> 1 of FIG. 4, the control unit 24 determines whether a wireless signal is received wirelessly. Specifically, it is determined whether the first radio signal or the second radio signal from the transmission device 1 is received via the radio communication unit 21. And, when it is determined that the first radio signal or the second radio signal is not received (that is, when it is determined that neither the first radio signal nor the second radio signal is received) (NO of SB1), SB1 is repeatedly executed. Moreover, when it determines with having received the 1st radio signal or the 2nd radio signal (YES of SB1), it transfers to SB2.

  Next, in SB2, the demodulator 241 generates a demodulated signal. Specifically, a demodulated signal is generated by demodulating the radio signal received in SB1 by a predetermined method. Here, the “predetermined scheme” is a modulation scheme in the FM modulation section 142B of the transmission apparatus 1 in FIG. 1 and a demodulation scheme corresponding to the modulation scheme in the FSK modulation section 144A of the transmission apparatus 1. This is a demodulation method realized by a demodulation circuit (that is, a detection circuit).

  Here, for example, when the first radio signal generated by the FM modulation based on the modulated analog signal shown in FIG. 3A is received in SB1 in FIG. 4, in SB2, FIG. ) Is generated. Further, for example, when the second radio signal generated by the FSK modulation based on the second digital data corresponding to the signal shown in FIG. 3C is received at SB1 in FIG. A second demodulated signal shown in 7 (a) is generated.

  Returning to FIG. 4, in SB3, the waveform shaping unit 242A generates a binary signal. Specifically, the value of the demodulated signal generated in SB2 is compared with the waveform shaping threshold value, and a binary signal is generated based on the comparison result. For the binary signal to be generated, if the demodulated signal value is equal to or greater than the waveform shaping threshold, a signal corresponding to one of the logical values (eg, “1”) is generated, and the demodulated signal value is used for waveform shaping. A binary signal is generated by generating a signal corresponding to the other logical value (for example, “0”) when it is less than the threshold. As a specific method for generating the binary signal, an arbitrary method can be used, but it may be generated using a comparator circuit as described below. Specifically, for this technique, the demodulated signal generated in SB2 is input to one input of the comparator circuit, and the signal corresponding to the waveform shaping threshold (for example, 0) is input to the other input of the comparator circuit. (V) is input, and the signal output from the comparator circuit is used as a binary signal.

  Here, for example, when the first demodulated signal shown in FIG. 6A is generated in SB2, the binary signal shown in FIG. 6B is generated in SB3. For example, when the second demodulated signal shown in FIG. 7A is generated in SB2, the binary signal shown in FIG. 7B is generated in SB3.

  Returning to FIG. 4, in SB <b> 4, the sampling unit 242 </ b> B acquires the sampling data, and stores the acquired sampling data in the storage unit 22. Specifically, the binary signal generated in SB3 is set to the sampling rate set as described above (that is, the value of the first frequency in the modulated analog signal generated in the MSK modulation unit 142A of the transmission device 1). By sampling at the sampling frequency corresponding to the least common multiple of the value of the second frequency in the modulated analog signal and the value of the data rate of the second digital data used in the FSK modulation unit 144A of the transmission device 1) The sampling data is acquired and stored.

  Here, for example, “first frequency in modulated analog signal” = “1800 (Hz)”, “second frequency in modulated analog signal” = “1200 (Hz)”, and “data rate of second digital data” ”=“ 4800 (bps) ”,“ sampling rate ”=“ 14400 (Hz) ”is used, and when the binary signal shown in FIG. 6B is generated in SB3, FIG. (B) Data corresponding to the time indicated by the alternate long and short dash line ("0" or "1") is acquired as sampling data. Specifically, in the case of FIG. 6B, “111100001111000000111111” is acquired and stored as sampling data from the left side to the right side of FIG. 6B. For example, when the binary signal shown in FIG. 7B is generated in SB3, “1110001110001110000111000” is acquired and stored as sampling data in the same manner from the left side to the right side of FIG. 7B. To do.

  Returning to FIG. 4, in SB5, the determination unit 242C determines which of the first wireless signal and the second wireless signal the wireless communication unit 21 has received. Specifically, the determination is made based on the sampling data acquired and stored in SB4 and the collation data stored in the storage unit 22 of the receiving device 2 in FIG. As a specific determination method, any method can be used, but the following method can also be used.

  Specifically, this determination method is a method for determining by focusing on the number of continuous data (hereinafter referred to as data continuous number), and corresponds to the first radio signal in the collation data stored in the storage unit 22. In this method, the number of continuous data and the number of continuous data corresponding to the second radio signal are specified, the number of continuous data in the sampling data is specified, and the identification results are collated. Specifically, in the case of determining by applying this determination method in the collation data of FIG. 2, first, the item “reference data string” = “corresponding to the item“ wireless signal ”=“ first wireless signal ”of FIG. 111100001111 ”and the item“ reference data string ”=“ 00000011111 ”are acquired, and“ the number of consecutive data corresponding to the first radio signal ”=“ 4 ”or“ 6 ”is specified based on the acquisition result. Next, the item “reference data string” = “000” and the item “reference data string” = “111” corresponding to the item “wireless signal” = “second wireless signal” in FIG. 2 are acquired, and based on the acquisition result Thus, “the number of consecutive data corresponding to the second radio signal” = “3” is specified. Next, the number of consecutive data in the sampling data is specified, and when the specified result includes “4” or “6” and “3” is not included, the first radio signal is received. If the specified result includes “3”, it is determined that the second radio signal has been received. Here, for example, with respect to “1111000011111000000111111” which is the sampling data shown in the description of SB4, since the continuous number is “4” or “6”, it is determined that the first radio signal has been received. For the sampling data “1110001110001110000111000” shown in the description of SB4, since the continuous number is “3”, it is determined that the second radio signal has been received. As described above, since the first digital data and the second digital data include preamble data (that is, data in which “0” and “1” are alternately repeated) as described above, as described above, Using this determination method, it is possible to reliably determine which signal of the first wireless signal or the second wireless signal the wireless communication unit 21 has received.

  Returning to FIG. 4, in SB6, the acquisition unit 243 acquires the demodulated digital data, stores the acquired demodulated digital data in the storage unit 22, and then ends the acquisition process. Here, “demodulated digital data” is a set of data discretized into two values (for example, “0” and “1”), and is obtained by demodulating a radio signal received wirelessly at SB1. Specifically, it is used to generate the first digital data used to generate the first wireless signal wirelessly received at SB1 or the second wireless signal received wirelessly at SB1. The data is composed of the same data string as the second digital data. Specifically for SB6, demodulated digital data is acquired from the sampling data acquired and stored in SB4 based on the determination result of SB5, and the acquired demodulated digital data and the determination result of SB5 are combined. “Combination data” which is data is stored in the storage unit 22. An arbitrary method can be used as a specific method for acquiring the demodulated digital data, but the following method can also be used.

  Specifically, this acquisition method pays attention to the item “data” and the item “reference data string” of the collation data in FIG. 2, and the sampling data stored in the storage unit 22 and the data of the item “reference data string” This is a technique for acquiring demodulated digital data by performing matching based on the above. When this method is used, for example, when it is determined that the first wireless signal is received in SB5, attention is paid to the item “data” and the item “reference data string” in the collation data in FIG. 2, and “111100001111” in the sampling data. ”And the inverted data“ 0000011110000 ”of this data are converted to“ 0 ”, and“ 00000011111 ”and the inverted data of this data“ 111111000000 ”are converted to“ 1 ”to obtain demodulated digital data, “Combination data” which is data obtained by combining the acquired demodulated digital data and “SB5 determination result” = “first wireless signal” is stored in the storage unit 22. Further, for example, when it is determined that the second wireless signal is received in SB5, paying attention to the item “data” and the item “reference data string” in the collation data of FIG. 2, “000”, “111” in the sampling data The demodulated digital data is acquired by converting each into “0” and “1”, and the acquired demodulated digital data and “SB5 determination result” = “second radio signal” are combined data “ The combination data ”is stored in the storage unit 22.

(Processing-Output processing)
Next, output processing of the receiving device 2 will be described. This output processing is started when one demodulated digital data is acquired in SB 6 of FIG. 4 and the demodulated digital data is stored in the storage unit 22.

  First, in SC1 of FIG. 5, the control unit 24 determines whether or not new demodulated digital data has been acquired. Specifically, referring to the storage unit 22, it is determined whether or not new combination data is stored in the storage unit 22 of FIG. If “combination data” is not newly stored in the storage unit 22, it is determined that new demodulated digital data has not been acquired (NO in SC1), and SC1 is repeatedly executed. If a predetermined waiting time elapses after starting the output process while SC1 is repeatedly executed, it is assumed that spoofing communication described later may be performed, and the output process is terminated. Good. Here, the “predetermined waiting time” is a predetermined time for detecting the possibility of spoofed communication, and specifically, the time from the start to the end of the transmission process in FIG. Is a time set to be sufficiently longer than, for example, “2 minutes” or the like (the “predetermined waiting time” in “(alarm output)” of “variation” described later) The same shall apply). Further, when “combination data” is newly stored in the storage unit 22 due to the execution of the acquisition process of FIG. 4 after starting the output process, it is determined that the demodulated digital data has been newly acquired ( If YES in SC1, the process proceeds to SC2. Here, “spoofing communication” is communication performed illegally in the communication system 100 of FIG. 1. For example, a spoofed communication device other than the transmission device 1 is used to illegally transmit a radio signal to the reception device 2. Examples include wireless communication to be transmitted.

  Returning to FIG. 5, in SC2, the collation unit 244 collates the demodulated digital data acquired by the acquisition unit 243. Specifically, first, “combination data” (hereinafter referred to as pre-startup combination data) stored in the storage unit 22 in FIG. 1 before starting the output process, and SC1 in FIG. 5 after starting the output process. The “combination data” stored in the storage unit 22 (hereinafter referred to as “combination data after start-up”) is acquired from the storage unit 22. Here, for example, a time stamp indicating the time when the data is stored is attached to each combination data. By comparing the start time of the output process with the time indicated by the type stamp, The combination data and the combination data after start-up are identified and acquired. Next, “demodulated digital data” and “determination result of SB5” included in the acquired combination data before start-up and combination data after start-up are specified. Next, the “demodulated digital data” of the specified combination data before start-up is compared with the “demodulated digital data” of the specified combination data after start-up to determine whether the respective data match each other. . Next, the aforementioned “SB5 determination result” of the specified combination data before start-up is compared with the “SB5 determination result” of the specified combination data after start-up, and each data (determination result) is identical to each other. Determine whether you are doing it.

  Returning to FIG. 5, in SC3, the collation unit 244 determines whether to output data. Specifically, it is determined whether or not to output data based on the determination result of SC2 (that is, the collation result). If it is determined in SC2 that the “demodulated digital data” match each other, and if it is determined in SC2 that the “determination results of SB5” do not match each other, normal (or valid) When it is determined that wireless communication has been performed, it is determined that data is to be output (YES in SC3), and the process proceeds to SC4. Also, in cases other than YES of SC3 (that is, when it is determined in SC2 that the “demodulated digital data” do not match each other, or in SC2, the “determination results of SB5” match each other. In the case of at least one of the cases), after determining that there is a possibility of unauthorized wireless communication (that is, after determining that there is a possibility of spoofing communication) It is determined that no data is output (YES in SC3), and the output process is terminated.

  Next, in SC4, the processing unit 245 ends the output process after outputting the data. Specifically, data corresponding to the aforementioned “detection result data” is acquired from the “demodulated digital data” specified in SC2, and the door (not shown) and the open / closed state of the door are specified based on the acquired data. Then, the specified door and the open / closed state of the door are displayed on the display constituting the output unit 23 of FIG. Note that the “demodulated digital data” used in SC4 of FIG. 5 includes the combination data before start-up and combination data after start-up specified in SC2 being the same data. Any data may be used.

(Example of processing)
Next, regarding the above-described processing example of “control processing”, a processing example of control processing when normal communication is performed and a processing example of control processing when a pseudo wireless signal is wirelessly transmitted twice by spoofing communication explain. Here, the “pseudo wireless signal” is a signal that is illegally transmitted by spoofing communication, and is a signal having the same function as the first wireless signal, for example.

(Processing example-normal communication)
When normal communication is performed, the first wireless signal is wirelessly transmitted in SA4 of the transmission process of FIG. 4, and the acquisition process (SB1 to SB6) is performed on the wirelessly transmitted first wireless signal. The output process is started. Next, the second wireless signal is wirelessly transmitted in SA7 of the transmission processing in FIG. 4, and acquisition processing (SB1 to SB6) is performed on the wirelessly transmitted second wireless signal. Then, “demodulation digital data” = “data sequence of first digital data” and “SB5 determination result” = “first wireless signal” pre-startup combination data, and “demodulation digital data” = “ The combination data after the start-up that is “data string of second digital data” and “result of determination of SB5” = “second radio signal” is stored in the storage unit 22 of FIG. 1 and the output processing of FIG. In SC3, it is determined that data is output (YES in SC3), and SC4 is executed.

(Processing example-spoofing communication)
When spoofing communication is performed in which a pseudo wireless signal is wirelessly transmitted twice, the first pseudo wireless signal is wirelessly transmitted, and an acquisition process (SB1 to SB6) is performed on the wireless wirelessly transmitted pseudo wireless signal. 5 is started. Next, the second pseudo wireless signal is wirelessly transmitted, and acquisition processing (SB1 to SB6) is performed on the wireless wirelessly transmitted pseudo wireless signal. Then, “demodulation digital data” = “data sequence of first digital data” and “SB5 determination result” = “first wireless signal” pre-startup combination data, and “demodulation digital data” = “ The combination data after the start-up of “first digital data data string” and “SB5 determination result” = “first wireless signal” is stored in the storage unit 22 of FIG. 1 and the output process of FIG. In SC3, it is determined that data is not output (NO in SC3), and SC4 is not executed.

  Thus, only when the first radio signal and the second radio signal, which are two radio signals that are generated by different modulation schemes and include the same data string, are received by radio, SC4 in FIG. Therefore, it is possible to enhance the security of communication by preventing the same processing as when normal communication is performed by unauthorized communication such as spoofing communication.

(Effect of Embodiment 1)
As described above, according to the present embodiment, both the first radio signal generated by the MSK modulation and the FM modulation based on the first digital data and the second radio signal generated by the FSK modulation based on the second digital data. Since the wireless communication is performed between the transmission device 1 and the reception device 2 using the above-described signal, for example, the first digital signal is transmitted using a predetermined spoofing communication device that performs wireless communication using only one type of communication method. Since it is difficult to store both the data and the second digital data, it is possible to prevent the predetermined spoofing communication device from impersonating the transmission device 1 and to perform wireless communication between the transmission device 1 and the reception device 2. It becomes possible to strengthen security.

  In addition, since the data acquired from the first wireless signal and the second wireless signal are collated and the process is performed based on the collation result, for example, the process is performed only when two valid data are prepared. It is possible to prevent unauthorized processing from being performed based only on unauthorized data from the spoofed communication device, and to improve the reliability of the communication system 100.

(Embodiment 2)
Next, a second embodiment will be described. In this embodiment, “first data” is encrypted data, “second data” is data for decrypting the first data, and “receiving device” is encrypted data. A case will be described in which control is performed based on the decoded data. The configuration of the second embodiment is substantially the same as the configuration of the first embodiment except where otherwise specified, and the same configuration as that of the first embodiment is used in the first embodiment. The same reference numerals are attached as necessary, and the description thereof is omitted.

(Constitution)
First, the configuration of the communication system according to the present embodiment will be described. FIG. 8 is a schematic diagram showing a configuration of a communication system according to the present embodiment. As shown in FIG. 8, the communication system 300 is a system that performs communication, and includes a transmission device 3 and a reception device 4, and these devices can communicate wirelessly.

(Configuration-Transmitter)
First, the configuration of the transmission device 3 will be described. The transmission device 3 is a wireless signal transmission unit that wirelessly transmits a wireless signal, and is a door opening / closing sensor that detects an open / closed state of a door (not shown) and outputs a detection result. As illustrated in FIG. 11, a wireless communication unit 12, a storage unit 33, and a control unit 34.

(Configuration-Transmitter-Storage unit)
The storage unit 33 is a storage unit that stores a program and various data necessary for the operation of the transmission device 3. The storage unit 33 stores key data. “Key data” is key information used for encrypting or decrypting data, and specifically, a binary number corresponding to a predetermined number of character strings or a predetermined number of digits (that is, “ 0 ”and“ 1 ”binary). And this key data shall be memorize | stored when a user inputs a character string or a numerical value etc. via an input means not shown.

(Configuration-Transmitter-Control unit)
The control unit 34 is a control unit that controls the transmission device 3. In terms of functional concept, the control unit 34 includes a first data generation unit 341, a first signal generation unit 142, a second data generation unit 343, and a second signal generation unit 144.

(Configuration-Transmitting device-Control unit-First data generation unit)
The first data generation unit 341 is a data generation unit that generates first digital data (first data). Specifically, the first data generation unit 341 encrypts “detection result data” that is data for specifying the detection result of the detection unit 11. The first digital data including the encrypted detection result data and the preamble data described in the first embodiment is generated.

(Configuration-Transmitting device-Control unit-Second data generation unit)
The second data generation unit 343 is data generation means for generating second digital data (second data), specifically, “key data” stored in the storage unit 33 of the transmission device 3, and second data Second digital data including preamble data of the same data sequence as preamble data of one digital data is generated. The specific processing contents by each unit of the control unit 34 will be described later.

(Configuration-Receiver)
Next, the configuration of the receiving device 4 will be described. The receiving device 4 is a radio signal receiving unit that receives and controls the first radio signal and the second radio signal from the transmitting device 3, and is an output device that displays and outputs information, as shown in FIG. As shown, the wireless communication unit 21, the storage unit 22, the output unit 23, and the control unit 44 are provided.

(Configuration-Receiver-Controller)
The control unit 44 is a control unit that controls the receiving device 4. The control unit 44 includes a demodulation unit 241, an analysis unit 242, an acquisition unit 443, a decoding unit 444, and a processing unit 445 in terms of functional concept. The acquisition unit 443 is an acquisition unit that acquires data transmitted by the first wireless signal and the second wireless signal wirelessly received by the wireless communication unit 21 based on the analysis result of the analysis unit 242. The decoding unit 444 is a decoding unit that decodes the data acquired by the acquisition unit 443. The processing unit 445 is a processing unit that performs processing based on the decoding result of the decoding unit 444. The specific processing contents by each unit of the control unit 44 will be described later.

(processing)
Next, a control process executed by the communication system 300 configured as described above will be described. The “control process” is a process for performing control related to the communication system 300, is a process performed based on the first radio signal and the second radio signal from the transmission device 3, and the specific processing content is arbitrary. However, as in the case of the first embodiment, the process of displaying the door open / closed state (not shown) on the output unit 23 of the receiving device 4 and outputting it will be described as the control process. The “control processing” described here will be described as including “transmission processing”, “acquisition processing”, and “output processing” in the same manner as the “control processing” in the first embodiment.

  FIG. 9 is a flowchart of transmission processing and acquisition processing of the communication system 300. FIG. 10 is a flowchart of output processing of the communication system 300.

(Processing-Transmission processing)
First, transmission processing of the transmission device 3 will be described. First, in SD1 of FIG. 9, the first data generation unit 341 generates first digital data. Specifically, first, “detection result data”, which is data for specifying the detection result of the detection unit 11, is encrypted with predetermined data using the key data stored in the storage unit 33 of the transmission device 3 of FIG. 8. Encrypt using the method. Here, the “predetermined encryption method” is a predetermined method, which is an encryption method using key data. Specifically, data is encrypted using key data. Any method including a known method can be used as long as the encrypted data can be decrypted using the key data used for encryption. Next, encrypted detection result data (hereinafter, encrypted detection result data) and preamble data are included, and first digital data of “1200” (bps) is generated.

  Returning to FIG. 9, the first wireless signal is generated by performing the same processing as SA2 and SA3 of FIG. 4 in SD2 and SD3, and the same processing as SA4 of FIG. 4 is performed in SD4 of FIG. 9. The generated first wireless signal is wirelessly transmitted.

  Returning to FIG. 9, in SD5, the second data generation unit 343 generates second digital data. Specifically, the key data stored in the storage unit 33 of the transmission device 3 in FIG. 8 and the preamble data of the same data string as the preamble data of the first digital data generated in SD1 are included, and “4800” is included. Second digital data (bps) is generated.

  Returning to FIG. 9, the second radio signal is generated in SD6 by performing the same process as SA6 in FIG. 4, and the second radio signal is generated in SD7 in FIG. 9 by performing the same process as SA7 in FIG. 4. Two wireless signals are transmitted wirelessly.

(Processing-Acquisition processing)
Next, the acquisition process of the receiving device 4 will be described. After performing the same processing as SB1 to SB5 in FIG. 4 in SE1 to SE5 in FIG. 9, the same processing as SB6 in FIG. 4 is performed in SE6 in FIG. 9, thereby demodulating digital data described in the first embodiment. Is acquired, and the acquired demodulated digital data is stored in the storage unit 22 of the receiving device 4 of FIG. 8, and then the acquisition process is terminated. Specifically, for SE6 in FIG. 9, for example, when the first wireless signal is wirelessly received in SE1, the acquisition unit 443 acquires the “encryption detection result data” described above and acquires the obtained “encryption code”. For example, when the second wireless signal is wirelessly received in SE1, the above-mentioned “key data” is acquired, and the acquired “key data” is stored.

(Processing-Output processing)
Next, output processing of the receiving device 4 will be described. This output process is started when both the “encryption detection result data” and the “key data” are acquired by the acquisition process described above and both the acquired data are stored in the storage unit 22.

  First, in SF1 of FIG. 10, the decoding unit 444 performs data decoding. Specifically, first, “encryption detection result data” and “key data” stored in the storage unit 22 are acquired by performing an acquisition process. Next, the obtained “encrypted detection result data” is decrypted by a predetermined decryption method using the obtained “key data”, thereby obtaining the detection result data. Here, the “predetermined decryption method” is a predetermined method and is a method corresponding to the predetermined encryption method used in the transmission apparatus 3, and specifically, the predetermined encryption method. Any method including a publicly known method can be used as long as the data encrypted by the encryption method can be decrypted by using the key code used in the predetermined encryption method.

  Next, in SF2, the processing unit 445 ends the output process after outputting the data. Specifically, data corresponding to the “detection result data” acquired in SF1 is acquired, and a door (not shown) and opening / closing of the door are opened based on the acquired data in the same manner as in the case of SC4 in FIG. The state is specified, and the specified door and the open / closed state of the door are displayed on the display constituting the output unit 23 of FIG. 8 and output.

  As described above, the first radio signal and the second radio signal, which are two radio signals generated by different modulation schemes and including “encryption detection result data” and “key data”, are received by radio. Since the SF2 of FIG. 10 can be executed only in such a case, it is possible to prevent the same processing as when normal communication is performed by unauthorized communication such as spoofing communication, and strengthen communication security. It becomes possible.

(Effect of Embodiment 2)
As described above, according to the present embodiment, the encryption detection result data out of the encryption detection result data and the key data acquired from the first radio signal and the second radio signal is decrypted based on the key data, Since the process is performed based on the result of the decryption, for example, the process is performed only when two valid data are prepared, and the unauthorized process is performed based only on the unauthorized data from the predetermined spoofing communication device. This can be prevented and the reliability of the communication system 300 can be improved.

(Embodiment 3)
Next, Embodiment 3 will be described. In this embodiment, “first data” is data specifying a frequency band of wireless communication, “second data” is data including detection result data, and “receiving device” is a wireless signal. A case of performing control for switching the frequency band to be received will be described. The configuration of the third embodiment is substantially the same as the configuration of the first embodiment unless otherwise specified, and the same configuration as that of the first embodiment is used in the first embodiment. The same reference numerals are attached as necessary, and the description thereof is omitted.

(Constitution)
First, the configuration of the communication system according to the present embodiment will be described. FIG. 11 is a schematic diagram showing a configuration of a communication system according to the present embodiment. As shown in FIG. 11, a communication system 500 is a system for performing communication, and includes a transmission device 5 and a reception device 6, and these devices can communicate wirelessly.

(Configuration-Transmitter)
First, the configuration of the transmission device 5 will be described. The transmission device 5 is a wireless signal transmission unit that wirelessly transmits a wireless signal, and is a door open / close sensor that detects an open / closed state of a door (not shown) and outputs a detection result. As illustrated in FIG. 11, a wireless communication unit 12, a storage unit 53, and a control unit 54.

(Configuration-Transmitter-Storage unit)
The storage unit 53 is a storage unit that stores a program and various data necessary for the operation of the transmission device 5. The storage unit 53 stores switching frequency data. “Switching frequency data” is frequency band specifying information for specifying a frequency band to be switched to receive a radio signal, and specifically, a first radio signal and a second radio signal, which will be described later, transmitted by the transmission device 5 by radio. Among the radio signals, the data specifies the frequency band of the second radio signal transmitted second, and is binary (ie, “0”, “1” binary) data. And this switching frequency data shall be memorize | stored when a user inputs via an input means not shown.

(Configuration-Transmitter-Control unit)
The control unit 54 is a control unit that controls the transmission device 5. The control unit 54 includes a first data generation unit 541, a first signal generation unit 542, a second data generation unit 543, and a second signal generation unit 544 in terms of functional concept.

(Configuration-Transmitting device-Control unit-First data generation unit)
The first data generation unit 541 is data generation means for generating first digital data (first data). Specifically, the “switching frequency data” stored in the storage unit 53 and the first embodiment are described. The first digital data including the preamble data described in (1) is generated.

(Configuration-Transmitter-Control unit-First signal generation unit)
The first signal generation unit 542 is a first radio signal generation unit that generates a first radio signal to be described later, and includes an MSK modulation unit 142A and an FM modulation unit 542B, as shown in FIG.

  The FM modulation unit 542B is a first radio signal generation unit that performs FM modulation based on the modulated analog signal generated by the MSK modulation unit 142A and generates a first radio signal. The “first radio signal” generated by the FM modulation unit 542B is a signal generated by modulation, and specifically, a radio signal generated by the FM modulation unit 542B. The frequency band of the first radio signal is set to a frequency band different from the channel of the second radio signal described later, and the FM modulation unit 542B is set to a channel different from the channel of the second radio signal described later. In the following, it is assumed that the first wireless signal for wireless communication is generated.

(Configuration-Transmitting device-Control unit-Second data generation unit)
The second data generation unit 543 is a data generation unit that generates second digital data (second data), specifically, “detection result data” that is data for specifying a detection result of the detection unit 11; Second digital data including preamble data of the same data string as preamble data of the first digital data is generated.

(Configuration-Transmitter-Control unit-Second signal generation unit)
The second signal generation unit 544 is a second radio signal generation unit that generates a second radio signal described later, and includes an FSK modulation unit 544A as shown in FIG.

  The FSK modulation unit 544A is a second radio signal generation unit that performs FSK modulation based on the second digital data generated by the second data generation unit 543 and generates a second radio signal. The “second radio signal” generated by the FSK modulation unit 544A is a signal generated by modulation, specifically, a radio signal generated by the FSK modulation unit 544A, which has the first FSK frequency. The signal includes a signal and a signal having a second FSK frequency, which is a frequency different from the first FSK frequency. The first FSK frequency and the second FSK frequency in the second radio signal are set to a frequency of a channel different from the channel of the first radio signal described above, and the FSK modulation unit 544A and the channel of the first radio signal described above are set. Will be described below as generating a second wireless signal for wireless communication on different channels. The specific processing contents by each unit of the control unit 54 will be described later.

(Configuration-Receiver)
Next, the configuration of the receiving device 6 will be described. The receiving device 6 is a wireless signal receiving means that receives and controls the first wireless signal and the second wireless signal from the transmitting device 5, and is an output device that displays and outputs information, as shown in FIG. As shown, a wireless communication unit 61, a storage unit 62, an output unit 23, and a control unit 64 are provided.

(Configuration-Receiver-Wireless communication unit)
The wireless communication unit 61 is a communication unit that performs wireless communication with the transmission device 5, and in particular, is a reception unit that wirelessly receives a first wireless signal or a second wireless signal. For example, a communication circuit and a channel for wireless communication A changeover switch or the like is provided. Here, the “channel switching switch” is a switch for switching a channel (that is, a frequency band) in which the wireless communication unit 61 performs wireless communication. By switching the channel switching switch, the wireless communication unit 61 receives the channel switching switch. The channel (that is, frequency band) of the radio signal that can be switched can be switched.

(Configuration-receiving device-storage unit)
The storage unit 62 is a storage unit that stores a program and various data necessary for the operation of the receiving device 6. The storage unit 62 stores verification data and initial frequency data.

  The “collation data” is the same data as the “collation data” stored in the storage unit 22 of the receiving device 2 in FIG.

  “Initial frequency data” is information for specifying a frequency band to be switched to receive a radio signal immediately after starting activation of “control processing” to be described later. Of the first radio signal and the second radio signal to be transmitted, this is data specifying the frequency band of the first radio signal transmitted first. And this initial frequency data shall be memorize | stored when a user inputs via an input means not shown.

(Configuration-Receiver-Controller)
The control unit 64 is a control unit that controls the receiving device 6. The control unit 64 includes a demodulation unit 241, an analysis unit 242, an acquisition unit 643, a switching unit 644, and a processing unit 645 in terms of functional concept. The acquisition unit 643 is an acquisition unit that acquires data transmitted by the first wireless signal and the second wireless signal wirelessly received by the wireless communication unit 61 based on the analysis result of the analysis unit 242. The switching unit 644 is a switching unit that switches a frequency band for receiving a wireless signal in the wireless communication unit 61. The processing unit 645 is a processing unit that performs processing based on the acquisition result of the acquisition unit 643. The specific processing contents by each unit of the control unit 64 will be described later.

(processing)
Next, control processing executed by the communication system 500 configured as described above will be described. The “control process” is a process for controlling the communication system 500, is a process performed based on the first radio signal and the second radio signal from the transmission device 5, and the specific processing content is arbitrary. However, as in the case of the first embodiment, the process of displaying the door open / closed state (not shown) on the output unit 23 of the receiving device 6 and outputting it will be described as a control process. The “control processing” described here includes “transmission processing” and “acquisition output processing”, and “transmission processing” is processing corresponding to “transmission processing” in the first embodiment. The “acquisition output processing” will be described as processing corresponding to “acquisition processing” and “output processing” in the first embodiment.

  FIG. 12 is a flowchart of transmission processing and acquisition output processing of the communication system 500.

  First, in SG1 of FIG. 12, the first data generation unit 541 of the transmission device 5 generates first digital data. Specifically, the first digital data of “1200” (bps) is generated including the switching frequency data and the preamble data stored in the storage unit 53 of the transmission device 5 of FIG.

  Returning to FIG. 12, in SG2 and SG3, the first signal generation unit 542 of the transmission device 5 generates the first radio signal by performing the same processing as SA2 and SA3 in FIG.

  Returning to FIG. 12, in SG4, the control unit 54 of the transmission device 5 wirelessly transmits the first wireless signal. Specifically, the first radio signal generated in SG3 is transmitted via the radio communication unit 12 of the transmission device 5.

  On the other hand, in SH <b> 1, the switching unit 644 of the receiving device 6 switches the frequency band for receiving the radio signal in the radio communication unit 61. Specifically, the initial frequency data stored in the storage unit 62 of the receiving device 6 of FIG. 11 is acquired, and the frequency band (here, the frequency band of the first radio signal) specified by the acquired initial frequency data is acquired. The channel switch of the wireless communication unit 61 is switched to switch the channel of the wireless communication unit 61 so that the wireless signal can be received wirelessly. Any method can be used for channel switching. For example, a channel table in which each frequency band of a radio signal and a channel number corresponding to each frequency band are associated with each other is stored in the reception device 6. The channel number corresponding to the frequency band specified by the initial frequency data stored in the storage unit 62 and with reference to the channel table is specified by the initial frequency data stored in the storage unit 62 of the receiving device 6, and the specified channel number You may make it switch to these channels.

  Returning to FIG. 12, in SH <b> 2, the control unit 64 of the reception device 6 determines whether or not a wireless signal is wirelessly received. Specifically, it is determined whether or not a radio signal has been received via the radio communication unit 61 whose channel has been switched in SH1. And when it determines with not having received the radio signal (NO of SH2), SH2 is repeatedly performed. If it is determined that a radio signal has been received by receiving the first radio signal from the transmission device 5 in FIG. 11 (YES in SH2), the process proceeds to SH3.

  Returning to FIG. 12, in SH3, the demodulation unit 241 and the analysis unit 242 of the reception device 6 perform demodulation and analysis of the wireless signal wirelessly received in SH2. Specifically, the same processing as SB2 to SB5 in FIG. 4 is performed.

  Returning to FIG. 12, in SH4, the acquisition unit 643 of the reception device 6 performs the same processing as SB6 in FIG. 4 (or SE6 in FIG. 9), so that in the first radio signal wirelessly received in SH2, The “switching frequency data” is acquired, and the acquired “switching frequency data” is stored in the storage unit 62 of the receiving device 6.

  Returning to FIG. 12, in SH <b> 5, the switching unit 644 of the receiving device 6 switches the frequency band for receiving the radio signal in the radio communication unit 61. Specifically, the “switching frequency data” acquired and stored in SH4 is acquired from the storage unit 62 of the receiving device 6 in FIG. 11, and the frequency band (here, the second frequency data) specified by the acquired initial frequency data is acquired. The channel switch of the wireless communication unit 61 is switched so that the wireless signal in the frequency band of the wireless signal can be received wirelessly, and the channel of the wireless communication unit 61 is switched in the same manner as in SH1 of FIG.

  On the other hand, in SG5, the second data generation unit 543 of the transmission device 5 generates second digital data. Specifically, it includes “detection result data” that is data for specifying the detection result of the detection unit 11, and preamble data of the same data string as the preamble data of the first digital data generated in SG1, “4800”. Second digital data (bps) is generated.

  Next, in SG6, the second signal generation unit 544 of the transmission device 5 generates the second radio signal by performing the same processing as SA6 in FIG.

  Returning to FIG. 12, in SG7, the control unit 54 of the transmission device 5 wirelessly transmits the second wireless signal. Specifically, the second radio signal generated in SG 6 is transmitted via the radio communication unit 12 of the transmission device 5.

  On the other hand, in SH6, the control unit 64 of the reception device 6 determines whether or not a wireless signal is wirelessly received. Specifically, it is determined whether or not a wireless signal has been received via the wireless communication unit 61 whose channel has been switched in SH5. And when it determines with not having received the radio signal (NO of SH6), SH6 is repeatedly performed. Further, when it is determined that the radio signal is received by receiving the second radio signal from the transmission device 5 in FIG. 11 (YES in SH6), the process proceeds to SH7.

  Returning to FIG. 12, in SH7, the demodulation unit 241 and the analysis unit 242 of the reception device 6 perform demodulation and analysis of the radio signal wirelessly received in SH6 in the same manner as in SH3.

  Next, in SH8, the acquisition unit 643 of the receiving device 6 performs the same processing as in SH4, thereby acquiring “detection result data” in the second wireless signal wirelessly received in SH6, and acquiring the acquired “ The “detection result data” is stored in the storage unit 62 of the receiving device 6.

  Next, in SH9, the processing unit 645 of the receiving device 6 ends the acquisition output process after outputting the data. Specifically, data corresponding to the “detection result data” acquired in SH8 is acquired, and a door (not shown) and opening / closing of the door are opened based on the acquired data in the same manner as in the case of SC4 in FIG. The state is specified, and the specified door and the open / closed state of the door are displayed on the display constituting the output unit 23 of the receiving device 6 in FIG.

  In this way, SH9 of FIG. 12 is executed only when the first radio signal and the second radio signal, which are two radio signals generated by different modulation schemes and having different communication channels, are received by radio. Therefore, it is possible to enhance the security of communication by preventing the same processing as when normal communication is performed by unauthorized communication such as spoofing communication.

(Effect of Embodiment 3)
As described above, according to the present embodiment, the transmission device 5 wirelessly transmits the first radio signal corresponding to the first digital data including the switching frequency data in the first radio signal or the second radio signal. After transmitting, the second wireless signal is wirelessly transmitted, and the receiving device 6 switches the frequency band based on the switching frequency data. For example, the wireless communication is performed while switching the frequency band of the received wireless signal, It is possible to prevent the reception device 6 from performing wireless communication with a predetermined spoofing communication device, and to further enhance the security of wireless communication performed between the transmission device 5 and the reception device 6.

[Modifications to Embodiment]
Although the embodiments of the present invention have been described above, specific configurations and means of the present invention are arbitrarily modified and improved within the scope of the technical idea of the present invention described in the claims. be able to. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above contents, and may vary depending on the implementation environment and details of the configuration of the invention. May be solved, or only some of the effects described above may be achieved.

(About distribution and integration)
Further, each of the electrical components described above is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific forms of distribution and integration of each unit are not limited to those shown in the drawings, and all or a part thereof may be functionally or physically distributed or integrated in arbitrary units according to various loads or usage conditions. Can be configured. For example, in each embodiment, the functions of the transmission device and the reception device may be configured by being distributed among a plurality of devices, or the devices may be integrated. Specifically, the detection unit, the first data generation unit, and the second data generation unit of the transmission device in each embodiment are provided in an external device that is a device other than the transmission device of each embodiment, In addition, in the transmission device of each embodiment, the detection unit, the first data generation unit, or the second data generation unit may be omitted. In this case, the external device transmits the first digital data and the second digital data to the transmission device of each embodiment, and the transmission device of each embodiment receives the transmitted data and receives the received data. The first wireless signal and the second wireless signal may be generated based on the above and wirelessly transmitted.

(About shape, numerical value, structure, time series)
In addition, regarding the constituent elements illustrated in the respective embodiments and drawings, the shape, numerical value, or the structure of a plurality of constituent elements or the mutual relationship in time series are arbitrarily modified and changed within the scope of the technical idea of the present invention. It can be improved.

(About wireless signals and digital data)
In Embodiment 1 described above, the case where the second radio signal is transmitted after the first radio signal is transmitted in the transmission process of FIG. 4 is not limited to this. For example, the first radio signal may be transmitted after the second radio signal is transmitted. Further, in the communication system 100 according to the first embodiment, the transmitter 1 is provided with a first radio transmitter dedicated to the first radio signal and a second radio transmitter dedicated to the second radio signal. On the other hand, a first radio receiving unit dedicated to the first radio signal and a second radio receiving unit dedicated to the second radio signal are provided, and the transmitting apparatus 1 transmits the first radio signal and the second radio signal at the same timing. , Wirelessly transmitted via the first wireless transmission means and the second wireless transmission means, and the reception device 2 receives the first wireless signal and the second wireless signal from the transmission device 1 at the same timing as the first wireless reception means. And you may make it radio-receive via a 2nd radio | wireless receiving means. Note that the communication system 300 according to the second embodiment may also be configured in the same manner as this modification.

  In the second embodiment, the case where the first digital data includes the encryption detection result data and the second digital data includes the key data has been described. However, the present invention is not limited to this. For example, the first digital data may include key data, and the second digital data may include encryption detection result data.

  In the third embodiment, the first digital data includes the switching frequency data, the second digital data includes the detection result data, and the second wireless signal is transmitted after the first wireless signal is transmitted. However, the present invention is not limited to this. For example, the first digital data may include the detection result data and the second digital data may include the switching frequency data, and the first wireless signal may be transmitted after the second wireless signal is transmitted. .

(About alarm output)
Further, in each of the above embodiments, if there is a possibility that spoofing communication is being performed, an alarm indicating that there is a possibility that spoofing communication is being performed is output to the output unit in the receiving device of each embodiment. It may be displayed on a display that constitutes and output. Specifically, in the first embodiment, a predetermined waiting time (for example, 2 minutes) elapses after the output process is started while SC1 is repeatedly executed in the case of “SC1 NO” in FIG. In such a case, an alarm may be output in the case of an alarm, or an alarm may be output in the case of “NO in SC3”. Also, in the second embodiment, specifically, in the acquisition process of FIG. 9, a predetermined waiting time (for example, 2 minutes or the like) is acquired after acquiring one of “encryption detection result data” and “key data”. ) An alarm may be output when the other data has not yet been acquired despite the elapse of time, or an alarm may be output when decoding cannot be performed in SF1 of FIG. In the third embodiment, specifically, the second radio signal is received at SH6 even though a predetermined waiting time (for example, 2 minutes) has elapsed after receiving the first radio signal at SH2 in FIG. If not, an alarm may be output.

(About each device of the communication system)
In each of the above embodiments, the case where the “transmission device” in each embodiment is a “door open / close sensor” and the “reception device” in each embodiment is an “output device” has been described. It is not limited to this. For example, it is assumed that the “transmission device” in each embodiment is a “sensor”, the “reception device” in each embodiment is a “disaster prevention receiver”, and each embodiment is a “sensor”. When the “transmitting device” senses an abnormality, a notification signal (wireless signal) including “self ID” and “notice of abnormality” is wirelessly used instead of the “detection result data” in each embodiment. The “receiving device” of each embodiment, which is a “disaster prevention receiver”, wirelessly receives the notification signal and analyzes the wirelessly received notification signal to identify the source of the notification signal And you may make it alert | report an abnormality. In this case, the “reception device” of each embodiment which is a “disaster prevention receiver” may be configured to notify the occurrence of an abnormality to the outside, or only the inside without notifying the occurrence of the abnormality to the outside. You may comprise so that it may alert | report. Further, for example, it is assumed that the “transmission device” in each embodiment is a “human sensor” and the “reception device” in each embodiment is an “output device”, which is the same as the processing in each embodiment. Processing may be performed so that the detection result of the human sensor is output by the output device.

(About dedicated equipment)
In the first embodiment, the demodulator 241 of the receiver 2 in FIG. 1 demodulates both the first radio signal and the second radio signal, and the analyzer 242 of the receiver 2 analyzes the signal. Although it has been described that the acquisition unit 243 acquires data after the execution, the present invention is not limited to this. For example, in the receiving device 2, the demodulator 241 and the analyzer 242 are omitted, and the first dedicated demodulator that demodulates only the first radio signal by an arbitrary method including a known method, and the second radio signal only. Is provided with a second dedicated demodulator that demodulates the signal using an arbitrary method including a known method, and the wireless signal received by the wireless communication unit 21 is input to both the first dedicated demodulator and the second dedicated demodulator. Thus, the acquisition unit 243 acquires the data of the demodulation result of the first dedicated demodulator as data transmitted by the first radio signal, and the demodulation of the second dedicated demodulator as data transmitted by the second radio signal. You may comprise so that the data of a result may be acquired. Note that the receiving apparatus 4 according to the second embodiment and the receiving apparatus 6 according to the third embodiment are also configured to demodulate using the first dedicated demodulator and the second dedicated demodulator in the same manner as this modification. May be.

(About sampling rate)
In the first embodiment, as the sampling rate used in sampling section 242B of receiving apparatus 2 in FIG. 1, the value of the first frequency in the modulated analog signal generated in MSK modulating section 142A of transmitting apparatus 1 The case where a value corresponding to a common multiple of the value of the second frequency in the modulated analog signal and the value of the data rate of the second digital data used in the FSK modulation unit 144A has been described. Not limited. For example, the sampling rate used in the sampling unit 242B of the receiving device 2 is set to a value that is sufficiently large (for example, about 100 times) with respect to the frequency value of the demodulated signal generated in the demodulating unit 241 of the receiving device 2. May be. Note that the sampling rates of the second and third embodiments may be set similarly.

(About logic)
Further, as various digital data or binary signals in the above embodiments, data or signals in which logical values “1” and “0” are exchanged may be used.

(About radio signal determination)
In the above-described embodiment, the description has been given of the case where the determination is made by paying attention to the “number of continuous data” in the determination of SC5 in FIG. For example, each of the first radio signal and the second radio signal includes data including a bit string and information that can identify the type of each signal, and the included data (that is, the type of each signal is changed). The determination may be made based on a bit string or information that can be identified.

(Appendix)
The communication system of Supplementary Note 1 is a communication system including a transmission device and a reception device, wherein the transmission device performs first modulation by FM modulation based on a modulated signal generated by MSK modulation based on first data. The first radio signal generating means for generating a signal, the second radio signal generating means for generating a second radio signal by FSK modulation based on the second data, and the first radio signal generating means of the transmitter Transmitting means for wirelessly transmitting the first wireless signal and the second wireless signal generated by the second wireless signal generating means of the transmitting device, wherein the transmitting device of the transmitting device includes the transmitting device of the transmitting device. A receiving means for wirelessly receiving the first wireless signal and the second wireless signal transmitted wirelessly, and the first wireless signal and the second wireless signal wirelessly received by the receiving means of the receiving device Based on, and a control means for controlling.

  The communication system according to supplementary note 2 is the communication system according to supplementary note 1, wherein the control means of the receiving device is based on the first radio signal and the second radio signal wirelessly received by the receiving means of the receiving device. Acquisition means for acquiring the first data and the second data, verification means for verifying the first data and the second data acquired by the acquisition means of the reception device, and the verification means of the reception device And a processing means for performing processing according to the first data and the second data based on the collation result.

  The communication system according to supplementary note 3 is the communication system according to supplementary note 1, wherein one of the first data and the second data is encrypted data, and the first data or the second data The other data is data for decoding the one data, and the control means of the receiving device is configured to receive the first wireless signal and the first wireless signal received wirelessly by the receiving means of the receiving device. The acquisition unit of the receiving device acquires the one data and the other data based on two radio signals, and the acquisition unit of the receiving device acquires the other data acquired by the acquisition unit of the receiving device. Decoding means for decoding said one data, and processing means for performing processing according to said one data based on a result of decoding by said decoding means of said receiving device Provided.

  The communication system according to supplementary note 4 is the communication system according to supplementary note 1, wherein the transmission means of the transmission device wirelessly transmits one of the first radio signal and the second radio signal, The first radio signal or the second radio signal is configured to wirelessly transmit the other radio signal, and one of the first data and the second data corresponds to the one radio signal. The data includes frequency band specifying information for specifying a frequency band of the other radio signal, and the control unit of the receiving device transmits the one radio signal wirelessly transmitted by the receiving unit of the receiving device. Included in the one data acquired by the acquisition unit of the reception device and the acquisition unit of acquiring the one data based on the one radio signal received wirelessly Based on the frequency band specific information which includes a switching means for switching a frequency band for receiving a radio signal in the receiving means of the receiving device.

(Additional effects)
According to the communication system according to attachment 1, both signals of the first radio signal generated by the MSK modulation and the FM modulation based on the first data and the second radio signal generated by the FSK modulation based on the second data Since the wireless communication is performed between the transmission device and the reception device using, for example, the first data and the second data using a predetermined spoofing communication device that performs wireless communication using only one type of communication method. It is difficult to memorize both of them, so that the predetermined spoofing communication device can be prevented from impersonating the transmission device, and security of wireless communication performed between the transmission device and the reception device can be enhanced. Become.

  According to the communication system described in the supplementary note 2, the first data and the second data acquired from the first radio signal and the second radio signal are collated, and processing is performed based on the collation result. Processing is performed only when data (that is, one data and the other data) is prepared, and unauthorized processing based on only unauthorized data from a predetermined spoofing communication device is prevented, It becomes possible to improve the reliability of the communication system.

  According to the communication system according to attachment 3, one of the first data and the second data acquired from the first radio signal and the second radio signal is decoded based on the other data, Since processing is performed based on the result, for example, processing is performed only when two legitimate data (that is, one data and the other data) are prepared, and illegal data from a predetermined spoofing communication device. It is possible to prevent an unauthorized process from being performed based only on this, and to improve the reliability of the communication system.

  According to the communication system according to attachment 4, the transmission device wirelessly transmits one of the first radio signal and the second radio signal corresponding to one data including the frequency band specifying information. After that, the other radio signal is transmitted wirelessly, and the receiving apparatus switches the frequency band based on the frequency band specifying information included in the one data. For example, the wireless signal is transmitted while switching the frequency band of the received radio signal. It is possible to further enhance the security of wireless communication performed between the transmission device and the reception device by performing communication to prevent the reception device from performing wireless communication with a predetermined spoofing communication device. become.

DESCRIPTION OF SYMBOLS 1 Transmission apparatus 2 Reception apparatus 3 Transmission apparatus 4 Reception apparatus 5 Transmission apparatus 6 Reception apparatus 11 Detection part 12 Wireless communication part 13 Storage part 14 Control part 21 Wireless communication part 22 Storage part 23 Output part 24 Control part 33 Storage part 34 Control part 44 control unit 53 storage unit 54 control unit 61 wireless communication unit 62 storage unit 64 control unit 100 communication system 141 first data generation unit 142 first signal generation unit 142A MSK modulation unit 142B FM modulation unit 143 second data generation unit 144 second 2 signal generation unit 144A FSK modulation unit 241 demodulation unit 242 analysis unit 242A waveform shaping unit 242B sampling unit 242C determination unit 243 acquisition unit 244 collation unit 245 processing unit 300 communication system 341 first data generation unit 343 second data generation unit 443 acquisition Unit 444 Decoding unit 445 Processing unit 5 00 communication system 541 first data generation unit 542 first signal generation unit 542B FM modulation unit 543 second data generation unit 544 second signal generation unit 544A FSK modulation unit 643 acquisition unit 644 switching unit 645 processing unit t1 time t2 time t3 time t4 hours t5 hours t6 hours t7 hours t8 hours t9 hours t10 hours t11 hours t12 hours t13 hours t14 hours t15 hours t16 hours t17 hours t18 hours t19 hours t20 hours t21 hours t22 hours t23 hours t24 hours

Claims (4)

A communication system comprising a transmission device and a reception device,
The transmitter is
First radio signal generating means for generating a first radio signal by FM modulation based on a modulated signal generated by MSK modulation based on first data;
Second radio signal generating means for generating a second radio signal by FSK modulation based on the second data;
Transmitting means for wirelessly transmitting the first wireless signal generated by the first wireless signal generating means of the transmitting apparatus and the second wireless signal generated by the second wireless signal generating means of the transmitting apparatus; Prepared,
The receiving device is:
Receiving means for wirelessly receiving the first wireless signal and the second wireless signal wirelessly transmitted by the transmitting means of the transmitting device;
Control means for performing control based on the first wireless signal and the second wireless signal wirelessly received by the receiving means of the receiving device;
Communications system. The control means of the receiving device includes:
Obtaining means for obtaining the first data and the second data based on the first wireless signal and the second wireless signal wirelessly received by the receiving means of the receiving device;
Collating means for collating the first data and the second data acquired by the acquiring means of the receiving device;
Processing means for performing processing in accordance with the first data and the second data based on a matching result of the matching means of the receiving device;
The communication system according to claim 1. One data of the first data or the second data is encrypted data, and the other data of the first data or the second data decrypts the one data. Data for
The control means of the receiving device includes:
Obtaining means for obtaining the one data and the other data based on the first wireless signal and the second wireless signal wirelessly received by the receiving means of the receiving device;
Decoding means for decoding the one data obtained by the obtaining means of the receiving device based on the other data obtained by the obtaining means of the receiving device;
Processing means for performing processing according to the one data based on a result of decoding by the decoding means of the receiving device;
The communication system according to claim 1. The transmission means of the transmission device wirelessly transmits one of the first radio signal and the second radio signal, and then transmits the other radio of the first radio signal and the second radio signal. Configured to transmit signals wirelessly,
One data corresponding to the one radio signal of the first data or the second data includes frequency band specifying information for specifying a frequency band of the other radio signal,
The control means of the receiving device includes:
An acquisition means for acquiring the one data based on the one radio signal wirelessly received when the one radio signal wirelessly transmitted by the reception means of the receiving device is received;
Switching means for switching a frequency band for receiving a radio signal in the receiving means of the receiving device based on the frequency band specifying information included in the one data acquired by the acquiring means of the receiving device; Prepare
The communication system according to claim 1.

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