WO2018180529A1

WO2018180529A1 - Signal processing device and method

Info

Publication number: WO2018180529A1
Application number: PCT/JP2018/010163
Authority: WO
Inventors: 敏宏藤木
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2017-03-28
Filing date: 2018-03-15
Publication date: 2018-10-04
Also published as: JPWO2018180529A1; JP7187439B2

Abstract

The present technology pertains to a signal processing device and method for enabling control of a transmission device that performs one-way communication. The present invention detects modulation of antenna power, performs a predetermined process on the basis of the detection result of modulation of antenna power, and transmits a signal including a payload. Alternatively, the present invention modulates antenna power. The present disclosure is applicable to, for example, a signal processing device, a transmission device, a reception device, a transmission/reception device, a communication device, an information processing device, an electronic apparatus, a computer, a program, a recording medium, a system, and the like.

Description

Signal processing apparatus and method

The present technology relates to a signal processing device and method, and more particularly, to a signal processing device and method that can control a transmission device that performs one-way communication.

Conventionally, there has been a method of controlling other communication devices by transmitting control information in a communication system that performs communication between devices (for example, see Patent Document 1). For example, Patent Literature 1 describes a method for causing another communication device to update an encryption key by transmitting a key update message.

JP 2009-10933 A

However, in the case of a system that performs one-way data transmission (one-way communication) from a transmission device to a reception device, the transmission device does not have a function of receiving a signal, so control information is transmitted to the transmission device, etc. It was difficult to control the transmitter from the outside.

The present disclosure has been made in view of such a situation, and makes it possible to control a transmission device that performs one-way communication.

A signal processing device according to an aspect of the present technology includes a detection unit that detects modulation of antenna power, a processing unit that performs predetermined processing based on a detection result of the modulation of antenna power by the detection unit, and a signal including a payload. It is a signal processing apparatus provided with the transmission part which transmits.

The detection unit can detect the modulation of the antenna power based on the change in the antenna power for each partial section obtained by dividing the antenna power measurement period into a plurality of sections.

The detection unit can detect the modulation of the antenna power based on the change in the power value of the antenna power for each partial section.

The detection unit can detect the modulation of the antenna power based on the pattern of the change in the power value of the antenna power for each partial section.

The detection unit can detect the modulation of the antenna power based on the change in the phase of the antenna power for each partial section.

As the processing, the processing unit sets identification information for identifying whether or not the detection unit has detected an antenna power modulation, and the transmission unit transmits a signal including the payload and the identification information. be able to.

When the detection unit detects the modulation of the antenna power, the processing unit sets the value of the identification information to a value indicating that the modulation of the antenna power is detected as the processing. The encryption key used for encrypting the payload is updated at a predetermined timing after information transmission, and the transmission unit transmits a signal including the payload and the identification information set by the processing unit. it can.

When the predetermined number of times that the antenna power modulation is not detected within a predetermined period, the processing unit can control the transmission unit to stop transmission of the payload as the processing.

When the detection unit detects the modulation of the antenna power, the processing unit can acquire the encryption key information used for encrypting the payload included in the modulated antenna power as the processing. .

The detection unit can detect the modulation of the antenna power based on the antenna power received in the carrier sense for confirming the usage status of the frequency band used for signal transmission by the transmitter.

The signal processing method according to one aspect of the present technology is a signal processing method of detecting a modulation of the antenna power, performing a predetermined process based on the detection result of the antenna power modulation, and transmitting a signal including a payload.

A signal processing device according to another aspect of the present technology is a signal processing device including a power modulation unit that modulates antenna power.

The power modulation unit can modulate the antenna power so that the antenna power changes for each partial section obtained by dividing the antenna power measurement period in the transmission apparatus into a plurality of sections.

The power modulation unit can change the power value of the antenna power for each partial section.

The power modulation unit can change the power value of the antenna power for each partial section with a predetermined pattern.

The power modulation unit can change the phase of the antenna power for each partial section.

A receiving unit that receives the signal transmitted from the transmitting device and receives identification information that identifies whether the signal includes a payload and whether or not modulation of antenna power is detected by the transmitting device. be able to.

The reception unit decrypts a payload encrypted using an encryption key, and when the received identification information value is a value indicating that antenna power modulation is detected by the transmission device, a predetermined timing is obtained. The encryption key can be updated at.

The reception unit is transmitted from the transmission device when it has occurred a predetermined number of times that the identification information having a value indicating that modulation of antenna power is detected by the transmission device within a predetermined period of time. The reception of the signal can be stopped.

The signal processing method according to another aspect of the present technology is a signal processing method for modulating antenna power.

In the signal processing apparatus and method according to one aspect of the present technology, the modulation of the antenna power is detected, a predetermined process is performed based on the detection result of the antenna power modulation, and a signal including the payload is transmitted.

In the signal processing apparatus and method according to another aspect of the present technology, the antenna power is modulated.

According to this technology, the signal can be processed. According to the present technology, it is possible to control a transmission device that performs one-way communication.

It is a figure explaining the example of the mode of the transmitter control using the modulation | alteration of antenna power. It is a figure explaining the example of the mode of the encryption key update using the modulation | alteration of antenna power. It is a figure explaining the example of the mode of modulation of antenna power. It is a figure explaining the example of the mode of modulation of antenna power. It is a figure which shows the main structural examples of a position notification system. It is a block diagram which shows the main structural examples of a highly sensitive receiver. It is a block diagram which shows the main structural examples of a transmitter. It is a flowchart explaining the example of the flow of an encryption key update process. It is a flowchart explaining the example of the flow of an encryption key update process. It is a flowchart explaining the example of the flow of control processing. It is a block diagram which shows the main structural examples of a highly sensitive receiver. It is a block diagram which shows the main structural examples of a transmitter. It is a figure which shows the main structural examples of an antitheft system. And FIG. 20 is a block diagram illustrating a main configuration example of a computer.

Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. 1. Information transmission using antenna power modulation First embodiment (position notification system)
3. Second embodiment (DPSK modulation)
4). Other

<1. Information transmission using antenna power modulation>
<Control of one-way communication transmitter>
2. Description of the Related Art Conventionally, in a communication system that performs communication between devices, for example, as described in Patent Document 1, a communication device is controlled from the outside, such as by causing another communication device to update an encryption key by transmitting a key update message. A method was considered.

However, in the case of a system that performs unidirectional data transmission (one-way communication) from the transmission device to the reception device, the transmission device does not have a function of receiving signals, and therefore, control is performed by transmitting control information from the outside. I couldn't.

For example, in a wireless communication system, generally, data exchanged between a transmitter and a receiving station is required to be encrypted in order to reduce the possibility of wiretapping or tampering with communication. Also, in order to further reduce the possibility of tapping and tampering with communication, it is desirable to be able to change the encryption key used for the encryption. However, a transmitter that performs one-way communication cannot receive data (downlink) from a receiving station because the direction of data transmission is one-way (uplink). Therefore, it has been difficult to update the encryption key of such a transmitter through communication.

In order to update the encryption key of such a one-way communication transmitter, for example, it is considered to use a communication means of another standard such as USB (Universal Serial Bus) (registered trademark) or bluetooth (registered trademark). It is done. However, when there are a large number of transmitters, all the transmitters must be collected in one place, which requires complicated work. In particular, many IoT devices are assumed to be disposable, and it has been difficult to collect all transmitters.

As a method for updating the encryption key of the transmitter in one-way communication, for example, a method in which the transmitter periodically generates and changes the encryption key using date / time information and the like can be considered. However, in this method, the encryption key generation rule must be fixed. In general, since it is difficult to completely prevent the leakage of the encryption key generation rule, if this generation rule is fixed, it becomes difficult to generate a secret encryption key after the leakage. Further, in this method, since the encryption key is periodically updated, the update timing of the encryption key is likely to be leaked. Therefore, if the generation rule is leaked due to observation or the like, it becomes clear to the third party how and when the encryption key is generated, and it becomes difficult to reduce the possibility of wiretapping or tampering with communication. There was a fear.

Also, in a wireless communication system, stopping transmission from a transmitter that is no longer necessary is important not only from the viewpoint of security but also from the viewpoint of effective use of frequency bands (resources). For example, a signal from a transmitter that is not managed has a high possibility of being vulnerable, so that the possibility of eavesdropping or tampering is increased. Further, the vulnerability of the communication is analyzed from the signal, and there is a possibility that it is used for wiretapping or tampering with other communication of the wireless communication system. In addition, since signal transmission from a transmitter that is no longer necessary is naturally unnecessary, there is a possibility that the usage rate of the band may be unnecessarily high due to the signal.

<Use of antenna power measurement>
Therefore, the antenna power is modulated in the receiving apparatus. Further, the transmitting device detects the modulation of the antenna power, performs a predetermined process based on the detection result of the antenna power modulation, and transmits a signal including the payload. In this way, information can be supplied from the outside to the transmission device using the antenna power measurement function of the transmission device. In other words, information can be supplied from the outside to the transmission device without the need for signal transmission. Therefore, even when the transmission device does not have a signal reception function, the transmission device can be controlled from the outside.

<Control using carrier sense>
For example, as shown in FIG. 1, the update of the encryption key may be requested from the outside using the carrier sense function. The carrier sense is a function that determines whether or not there is another radio wave in the frequency band in which the transmitter 1 transmits, and determines that transmission is possible if it is lower than a certain antenna power level. This function is a means for confirming that the communication by other radio is not disturbed, and only the antenna power measurement is performed. That is, data bits cannot be received even if carrier sensing is simply performed.

Transmitter 1 is in a carrier sense state and monitors surrounding antenna power. The receiving station 2 applies a weak power modulation to a frequency band where the transmitter 1 performs carrier sense so that it does not become an interference wave of other communications. This power modulation is performed based on specific rules. It is also assumed that the timing for applying power modulation is predetermined. The transmitter 1 and the receiving station 2 share such information in advance. The transmitter 1 performs carrier sense at the predetermined timing, and detects power modulation based on the specific rule. When the modulation is successfully detected, the transmitter 1 receives a predetermined instruction (command) from the receiving station 2 and performs processing corresponding to the instruction. The contents of this instruction are predetermined and are shared by the transmitter 1 and the receiving station 2. That is, the transmitter 1 executes a predetermined process that is determined in advance. By doing in this way, the transmitter 1 which does not have a signal reception function can be controlled from the outside using a carrier sense function.

<Encryption key update using carrier sense>
Using such a method, the receiving station 2 may instruct the transmitter 1 to update the encryption key used for encrypting communication data. An example in that case is shown in FIG. In this example, the key update command is received with one month as one segment.

First, a predetermined rule (a pseudo-random number sequence for detecting a key update command) and a time (year / month / day / time) are determined in advance between the transmitter 1 and the receiving station 2. The receiving station 2 performs transmission (downlink) for minutely modulating the antenna power at the timing when the transmitter 1 performs carrier sense. The transmitter 1 integrates and detects the antenna power fine modulation for this key update command. When the integrated value exceeds a certain threshold value, the transmitter 1 sets fill-up information prepared in the payload to be transmitted, and notifies the receiving station 2 of it (uplink).

The fill-up information may be any information as long as it indicates that the integrated value has reached the threshold value (an instruction from the receiving station 2 has been accepted). For example, the fill-up information may include a fill-up flag (fill-up flag) that indicates whether or not the integrated value has reached a threshold value. The bits constituting the fill-up flag are also referred to as fill-up bits. For example, the fill-up flag takes a value “0” when the integrated value has not reached the threshold value, and a fill-up flag composed of 1-bit fill-up bit that has the value “1” when the integrated value has reached the threshold value. It may be configured by.

The receiving station 2 determines that the key update command has reached the transmitter 1 when the fill-up information is set in the payload. After this state is reached, the encryption key is updated simultaneously at both the transmitter 1 and the receiving station 2 at a predetermined time.

For example, the transmitter 1 integrates the antenna power minute modulation from the first day of the month to the last day in the calendar, and compares the accumulated value with a threshold value. The transmitter 1 transmits fill-up information having a value corresponding to the comparison result to the receiving station 2. That is, when the integrated value reaches the threshold during the one month, the transmitter 1 updates the value of the fill-up information and transmits it to the receiving station 2. When it is determined that the integrated value has reached the threshold based on the fill-up information, the receiving station 2 updates the encryption key at the time when the month changes. At the same time, the transmitter 1 also updates the encryption key.

By doing so, in the transmitter 1 and the receiving station 2 that perform one-way communication, the encryption key used for payload encryption can be updated using the carrier sense function.

<Modulation rule>
FIG. 3 shows a modulation rule for transmission antenna power at the receiving station 2. A random value obtained from a predetermined pseudo-random number sequence generator is represented as prbs. For example, as shown on the left side of FIG. 3A, when the random number value prbs = '0', the receiving station 2 is in the latter half of the first half of the antenna power measurement period (also referred to as a carrier sense period). Modulate with a modulation pattern that increases the antenna power. For example, the receiving station 2 does not transmit the modulation signal that slightly increases the antenna power around the transmitter 1 in the first half of the carrier sense interval, and transmits the modulation signal in the second half of the carrier sense interval. . In this way, the receiving station 2 can modulate the antenna power around the transmitter 1 into a waveform as shown on the left side of FIG.

Further, for example, when the random value prbs = '1', the receiving station 2 is in the latter half of the first half of the antenna power measurement period (also referred to as a carrier sense section) as shown on the right side of FIG. Modulates with a modulation pattern that lowers the antenna power. For example, the receiving station 2 transmits a modulation signal that slightly increases the antenna power around the transmitter 1 in the first half of the carrier sense interval, and does not transmit the modulation signal in the second half of the carrier sense interval ( Stop sending). In this way, the receiving station 2 can modulate the antenna power around the transmitter 1 into a waveform as shown on the right side of FIG.

FIG. 3B shows the relationship between the random value prbs and the modulated antenna power. It is assumed that the difference between the power value in the first half and the power value in the second half of this carrier sense section is sufficiently small so as not to affect other communications.

FIG. 4 shows the antenna power in the transmitter 1. Here, in order to detect the key update command, the transmitter 1 samples the air power value in the first half A and the second half B of the carrier sense period, and calculates the difference δ (= PB−PA). If δ is a positive value, the determination value Δ = + 1, and if δ is a negative value, Δ = −1. Similarly to the case of the receiving station 2, the transmitter 1 assumes that the output of a predetermined pseudo-random number sequence is prbs. When prbs = '0', the transmitter polarity is positive (addition) and prbs = '1'. In this case, the determination value Δ is integrated with the integration polarity being negative (subtraction).

4B and 4C show the state of this integration. As shown in FIG. 4B, the integrated value increases every time the number of power measurements increases. Further, as shown in FIG. 4C, when the determination value Δ and the predetermined pseudo-random number sequence are related, a large integrated value can be obtained. However, the antenna power difference δ, which is the basis of the determination value, is small and is not always correct because it is affected by the environment (weather, ionosphere, etc.), and other radios affect the antenna power. The calculation example of C in FIG. 4 is a table showing that the integration can be performed without error. In practice, the integration process is often disturbed as shown in B of FIG.

In the payload (data) transmitted from the transmitter 1, a fill-up bit field (flag) indicating whether a preset threshold value has been exceeded is prepared. The transmitter 1 sets a fill-up flag when the integrated value exceeds the threshold value, clears this after integrating a predetermined period, and resets the integrator. If a plurality of integration trials fails, the transmitter 1 stops transmission and disables the transmission function. When the integration trial is successful even once, the key update in the transmitter 1 and the receiving station 2 is simultaneously performed at a predetermined timing as described above.

繰り返し Repeat this integration trial and if it fails to detect the key update signal a predetermined number of times in succession, it is considered that the expiration date has expired. Specifically, the transmitter 1 stops the transmission, and the receiving station 2 considers that the transmitter 1 has been abolished, and does not perform the receiving operation for the transmitter 1 thereafter.

<Influence of antenna power by other transmitters>
In addition, the influence of the antenna power by the other transmitters 1 is random. Further, since the transmitter 1 integrates for a long time (= a large number of times), the influence of other transmitters 1 can be suppressed. Further, the integrated value may be reset after a certain period (for example, integrated value = 0) in order to reduce the influence of the accumulation of “dust” over a long period of time. For example, the integration may be detected once per minute. In this case, it is accumulated 43200 times in 30 days. If the integrated value does not exceed the threshold value within 30 days, the integrated value is reset and the integration is performed again in the next 30 days.

Note that if the integrated value does not exceed the threshold value, the fill-up flag from the transmitter 1 side is not raised, so the encryption key of the receiving station 2 is not updated (of course, the encryption key of the transmitter 1 is not updated). Accordingly, since both the transmitter 1 and the receiving station 2 remain the old encryption key information, data communication between the transmitter 1 and the receiving station 2 can be continued.

<2. First Embodiment>
<Location notification system>
Next, a more specific application example of the present technology will be described. FIG. 5 is a diagram illustrating a main configuration example of a position notification system which is an embodiment of a signal transmission / reception system to which the present technology is applied. The position notification system 100 shown in FIG. 5 is a system in which the transmission apparatus 101 notifies its own position. This system is used, for example, for monitoring and managing a target position. As illustrated in FIG. 5, the position notification system 100 includes devices such as a transmission device 101, a high sensitivity reception device 102, a server 104, and a terminal device 105. The number of the transmission device 101, the high sensitivity receiving device 102, the server 104, and the terminal device 105 is arbitrary, and may be plural.

The transmission apparatus 101 is an embodiment of a transmission apparatus to which the present technology is applied, and transmits, for example, identification information for identifying itself, position information indicating its own position, and the like as a radio signal. The high-sensitivity receiving apparatus 102 is an embodiment of a receiving apparatus to which the present technology is applied. The high-sensitivity receiving apparatus 102 receives the wireless signal, acquires identification information, position information, and the like of the transmitting apparatus 101, and transmits them through the network 103. To the server 104. That is, the high sensitivity receiving apparatus 102 functions as a relay station that relays the information transmitted from the transmitting apparatus 101 and transmits it to the server 104. The server 104 manages the position of each transmission apparatus 101 by managing the position information associated with the identification information. A terminal device 105 operated by a user who wants to know the position of the transmission apparatus 101 accesses the server 104 via the network 103, supplies identification information of the desired transmission apparatus 101, and requests the position information. The server 104 supplies position information corresponding to the requested identification information to the terminal device 105. The terminal device 105 acquires the position information and notifies the user of the position of the transmission device 101 by displaying the position information together with map data, for example.

The server 104 can indirectly manage the position of the position monitoring (management) target by carrying (including carrying or wearing) such a transmission apparatus 101 by a target whose position is to be monitored (managed). Can do. In the example of FIG. 1, the user targets the elderly person 111 for position monitoring, and the elderly person 111 carries the transmission device 101. As described above, the position of the transmission device 101 is managed by the server 104 and provided to the terminal device 105. Therefore, the user can grasp the position of the elderly person 111 who is carrying the transmission device 101 by operating the terminal device 105.

Note that the position monitoring target is arbitrary. For example, it may be a child, an animal such as a dog or a cat, or a company employee. The transmission device 101 may be configured as a dedicated device, but may be incorporated in a portable information processing device such as a mobile phone or a smartphone, for example.

The position information of the transmission apparatus 101 may be any information as long as it indicates the position of the transmission apparatus 101, and may be generated in any manner. For example, the transmission apparatus 101 may receive a GNSS signal from a GNSS (Global Navigation Satellite System) satellite, and obtain its position information (for example, latitude and longitude) based on the GNSS signal. Further, for example, the transmitting apparatus 101 may specify its own position using a dedicated position specifying system other than GNSS.

Further, the position information is generated in a device other than the transmission device 101, such as the high-sensitivity reception device 102, the server 104, or a dedicated information processing device (such as a server) provided separately. May be. For example, the GNSS signal received by the transmission apparatus 101 may be supplied to another apparatus, and the other apparatus may obtain the position information of the transmission apparatus 101 from the GNSS signal. In addition, for example, the transmission apparatus 101 supplies information obtained using a dedicated position specifying system other than GNSS to another apparatus, and the other apparatus obtains position information of the transmission apparatus 101 based on the information. May be.

Further, for example, another device may obtain the position information of the transmission device 101 based on the communication status between the transmission device 101 and the high sensitivity reception device 102. For example, by specifying the high sensitivity receiving device 102 that has received the signal from the transmitting device 101, it may be specified that the transmitting device 101 is located within the communicable range of the high sensitivity receiving device 102. Further, more detailed position information of the transmission apparatus 101 may be obtained based on the signal strength, delay time, and the like of the received signal received by the high sensitivity receiving apparatus 102. Further, for example, the position information of the transmission apparatus 101 may be obtained by trigonometry or the like using the position information of a plurality of high sensitivity reception apparatuses 102 that have received signals from the transmission apparatus 101.

The installation position of the high sensitivity receiver 102 is arbitrary. For example, the roof or the roof of a building 112 such as a building, apartment, or house may be used. There are many buildings 112 in urban areas where there is a high possibility that a position monitoring target (for example, an elderly person 111) carrying the transmission device 101 is active, and it is preferable because the buildings 112 are easy to install. In particular, when the position monitoring target is a person, the home of the position monitoring target is more preferable because the position monitoring target is more likely to be located in the vicinity thereof. Further, in terms of securing the installation location, it is easier to obtain an agreement than when the location notification service provider independently secures the location and installs the high sensitivity receiver 102.

In addition to this, the high-sensitive receiving device 102 may be installed on a movable object (also referred to as a moving body) such as an automobile, a motorcycle, or a bicycle. That is, the position of the high sensitivity receiving apparatus 102 may be variable.

The network 103 is an arbitrary communication network, may be a wired communication network, a wireless communication network, or may be configured by both of them. Further, the network 103 may be configured by a single communication network or may be configured by a plurality of communication networks. For example, communication conforming to the Internet, public telephone network, so-called 3G and 4G wireless mobile wide area networks, WAN (Wide Area Network), LAN (Local Area Network), Bluetooth (registered trademark) standards , Wireless communication network for near field communication such as NFC (Near Field Communication), infrared communication path, HDMI (High-Definition Multimedia Interface) and USB (Universal Serial Bus) standards The network 103 may include a communication network or a communication path of an arbitrary communication standard such as a wired communication network complying with the standard.

The server 104 and the terminal device 105 are information processing devices that process information. The server 104 and the terminal device 105 are communicably connected to the network 103, and can communicate with other communication devices connected to the network 103 via the network 103 to exchange information.

The server 104 manages the position of the transmission device 101. The server 104 can also manage users who are permitted to provide location information of the transmission apparatus 101. For example, the server 104 can provide the position information of each transmission apparatus 101 only to users who are permitted to acquire the position information of the transmission apparatus 101.

As described above, the information provided from the transmission apparatus 101 is relayed by the high-sensitivity reception apparatus 102 and supplied to the server 104, whereby the server 104 manages the position of the transmission apparatus 101. That is, the server 104 can manage the position of the transmission device 101 in a state where the transmission device 101 is located within the communicable range of any of the high sensitivity reception devices 102. In other words, if the position of the transmission apparatus 101 is out of the communicable range of any of the high sensitivity receiving apparatuses 102, the server 104 cannot manage the position. Therefore, the server 104 can manage the position of the transmission apparatus 101 more accurately as the communication range network of the high sensitivity reception apparatus 102 with the transmission apparatus 101 becomes wider.

Here, more accurate management means that the position of the transmitting apparatus 101 is managed in a wider range (that is, the area where the position of the transmitting apparatus 101 cannot be managed is reduced). In order to make the range in which the position of the transmission apparatus 101 can be managed wider, the transmission apparatus 101 and the high-sensitivity reception apparatus 102 can transmit and receive radio signals farther (for each high-sensitivity reception apparatus 102). A wider communication range is preferable. The method of transmitting and receiving the radio signal between the transmitting apparatus 101 and the high sensitivity receiving apparatus 102 is arbitrary, and may conform to any communication standard. For example, a frequency band including 925 MHz (both 920 MHz band) May be used in a method that enables long-distance communication.

For example, if the time and frequency at which the transmission apparatus 101 transmits a radio signal are known (the high sensitivity reception apparatus 102 knows), the high sensitivity reception apparatus 102 detects the radio signal at the known time and frequency. Detection is easier because it only has to be done. Therefore, reception sensitivity can be improved. That is, the communicable range of the high sensitivity receiving apparatus 102 can be further expanded.

<Configuration of high sensitivity receiver>
FIG. 6 is a block diagram illustrating a main configuration example of the high-sensitivity receiving apparatus 102 which is an embodiment of the signal processing apparatus to which the present technology is applied. As illustrated in FIG. 6, the high sensitivity receiving apparatus 102 includes an antenna 151, an amplification unit 152, a demodulation unit 153, an error correction unit 154 (FEC (Forward Error Correction)), and a CPU (Central Processing Unit) 155. .

The antenna 151 is used for receiving a signal transmitted from the transmission apparatus 101. The amplification unit 152 amplifies the reception signal received via the antenna 151 and supplies the amplified signal to the demodulation unit 153. The amplifying unit 152 can be realized by an arbitrary configuration. For example, the amplification unit 152 may be configured by a circuit, LSI (Large Scale Integration), system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the amplification unit 152 may be configured by an operational amplifier or the like.

The demodulation unit 153 performs processing related to demodulation of the received signal. For example, the demodulation unit 153 demodulates the signal supplied from the amplification unit 152 by a predetermined method corresponding to the modulation performed on the transmission side, and errors the obtained data (data transmitted from the transmission apparatus 101). This is supplied to the correction unit 154. The demodulator 153 can be realized by an arbitrary configuration. For example, the demodulation unit 153 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the demodulation unit 153 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The error correction unit 154 performs processing related to error correction (FEC). For example, the error correction unit 154 performs error correction on the data supplied from the demodulation unit 153, detects and corrects an error, and supplies the error-corrected data to the CPU 155. The error correction unit 154 can be realized by an arbitrary configuration. For example, the error correction unit 154 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the error correction unit 154 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The CPU 155 performs arbitrary processing. For example, the CPU 155 performs processing on the data supplied from the error correction unit 154. That is, the CPU 155 functions as a receiving unit that receives signals via the antenna 151 to the error correction unit 154. For example, the CPU 155 receives the signal transmitted from the transmission apparatus 101, and is identification information that identifies whether the payload included in the signal and the antenna power modulation is detected by the transmission apparatus 101. Receive fill-up information.

In addition, for example, when a predetermined number of times that the CPU 155 has failed to receive fill-up information having a value indicating that the antenna power modulation has been detected by the transmission apparatus 101 within a predetermined period, the CPU 155 Stop receiving the received signal.

Further, for example, when the payload is encrypted, the CPU 155 decrypts the encrypted payload using the encryption key. This encryption key corresponds to the encryption key used when the transmission apparatus 101 encrypts the payload. For example, this encryption key is the same encryption key (common key) as the encryption key of the transmission apparatus 101. Further, the CPU 155 can update this encryption key. For example, when the value of the fill-up information is a value (for example, “1”) indicating that the antenna power modulation is detected by the transmission apparatus 101, the CPU 155 updates the encryption key at a predetermined timing.

The CPU 155 can correctly decrypt the encrypted payload by using such an encryption key. In other words, in order to correctly receive the payload, the encryption key of the transmitting apparatus 101 and the encryption key of the high sensitivity receiving apparatus 102 must correspond correctly. Therefore, when the encryption key of the transmission apparatus 101 is updated, the encryption key of the high sensitivity receiving apparatus 102 must be updated at the same time. And of course, even after updating, both encryption keys need to correspond correctly. That is, both encryption keys need to be updated by the same method at the same timing. That is, it is necessary to generate a new encryption key with the same method at the same timing in both the transmitting apparatus 101 and the high sensitivity receiving apparatus 102 and replace the old encryption key.

Assuming that the encryption key generation rules may be leaked, the possibility of eavesdropping or tampering with communication can be reduced if the encryption key update timing is irregular. Various methods can be considered in order to make the update timings of both encryption keys uniform and irregular, but at least the update can be performed between the transmission device 101 and the high-sensitivity reception device 102. There is a need to be able to notify each other. For example, when the high sensitivity receiving apparatus 102 requests (instructions) to update the encryption key to the transmitting apparatus 101, and the transmitting apparatus 101 responds to the request (instruction), the transmitting apparatus 101 receives the request (instruction). ) Based on the response, the high-sensitivity receiving apparatus 102 can confirm that the encryption key can be updated, and the high-sensitivity receiving apparatus 102 can update the encryption key based on the response. Can be confirmed.

However, since the communication between the transmission device 101 and the high sensitivity receiving device 102 is one-way communication and the transmission device 101 does not have a signal reception function, the encryption key is transferred from the high sensitivity reception device 102 to the transmission device 101 by communication. Cannot request (instruct) update. Therefore, the high sensitivity receiving apparatus 102 requests (instructs) to update the encryption key by modulating the antenna power.

Therefore, the high sensitivity receiving apparatus 102 includes a power modulation unit 156-1, a power modulation unit 156-2, and a power modulation unit 156-3. The power modulation unit 156-1, the power modulation unit 156-2, and the power modulation unit 156-3 are processing units that have the same configuration and perform the same processing. When these do not need to be distinguished from each other, they are referred to as a power modulation unit 156.

The power modulation unit 156 modulates the antenna power in a frequency band in which the high sensitivity receiving apparatus 102 receives a signal. Each power modulation unit 156 modulates the antenna power in different channels of the frequency band. For example, the power modulation unit 156 modulates the antenna power so that the antenna power changes for each partial section obtained by dividing the antenna power measurement period in the transmission apparatus 101 into a plurality of sections. For example, the power modulation unit 156 changes the power value of the antenna power for each partial section. For example, the power modulation unit 156 changes the power value of the antenna power for each partial section with a predetermined pattern. For example, the power modulation unit 156 changes the polarity of the difference value of the power value of the antenna power between successive partial sections with a predetermined pattern. For example, the power modulation unit 156 modulates the antenna power for a period including the measurement period twice or more. For example, the power modulation unit 156 modulates the antenna power so that the power value of the antenna power around the transmission device 101 changes during the measurement period of the antenna power in the transmission device 101.

In FIG. 6, three power modulation units 156 (power modulation unit 156-1, power modulation unit 156-2, and power modulation unit 156-3) are shown, but the number of power modulation units 156 is shown. Is optional. For example, one power modulation unit 156 may be provided for every channel in the frequency band where signal reception is performed.

The power modulation unit 156 can be realized by an arbitrary configuration. For example, the power modulation unit 156 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined.

6, the power modulation unit 156 includes a GNSS reception unit 161, a pseudo random number generation unit 162, a single carrier modulation unit 163, a switch 164, an amplification unit 165, and an antenna 166.

The GNSS receiver 161 receives the GNSS signal transmitted from the GNSS satellite, extracts the time information generated in the GNSS satellite included in the GNSS signal, and supplies it to the pseudo-random number generator 162. The GNSS receiving unit 161 can be realized by an arbitrary configuration. For example, the GNSS receiving unit 161 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the GNSS receiving unit 161 may be configured by an antenna, a receiving circuit, a signal processing circuit, and the like.

The pseudorandom number generator 162 generates a 1-bit pseudorandom number based on the time information supplied from the GNSS receiver 161 and supplies the pseudorandom number to the switch 164. The pseudo random number generation unit 162 can be realized by an arbitrary configuration. For example, the pseudo random number generation unit 162 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the pseudo random number generation unit 162 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

Single carrier modulation section 163 generates a modulation signal for modulating antenna power. That is, the single carrier modulation unit 163 generates a modulation signal that slightly increases the antenna power around the transmission apparatus 101. The single carrier modulation unit 163 supplies the generated modulation signal to the switch 164. The single carrier modulation unit 163 can be realized by an arbitrary configuration. For example, the single carrier modulation unit 163 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the single carrier modulation unit 163 may be configured by a modulation circuit or the like that generates a modulation signal as described above.

The switch 164 controls the supply of the modulation signal supplied from the single carrier modulation unit 163 to the amplification unit 165 (that is, transmission of the modulation signal) based on the pseudo random number supplied from the pseudo random number generation unit 162. Then, a modulation pattern as shown in FIG. 3 is generated. For example, when the pseudo random number (prbs) is “0”, the switch 164 does not transmit the modulation signal by disconnecting between the input and output in the first half of the carrier sense interval, as shown on the left side of FIG. In the second half of the carrier sense period, the input and output are connected to transmit the modulation signal. Further, when the pseudo random number (prbs) is “1”, the switch 164 transmits the modulation signal by connecting the input and output in the first half of the carrier sense period, as shown on the right side of FIG. 3A. In the second half of the carrier sense interval, the input / output is disconnected to prevent the modulation signal from being transmitted. In other words, the modulation pattern is determined by the switch 164, and the polarity of the difference value between the first half power value and the second half power value of the carrier sense section is set.

The switch 164 can be realized by an arbitrary configuration. For example, the switch 164 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined.

The amplifying unit 165 amplifies the modulated signal supplied from the switch 164 and transmits the amplified modulated signal to the air as a radio signal via the antenna 166. That is, the amplification unit 165 functions as a transmission unit that transmits a modulated signal. Thereby, the antenna power around the transmission apparatus 101 is modulated as in the example of FIG. The amplification unit 165 can be realized by an arbitrary configuration. For example, the amplification unit 165 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the amplification unit 165 may be configured by an operational amplifier or the like.

The high-sensitivity receiving apparatus 102 modulates the antenna power for all the channels in the frequency band used for signal reception, using the power modulation unit 156 configured as described above. This modulation means an instruction to update the encryption key to the transmission apparatus 101, and that fact is shared in advance between the transmission apparatus 101 and the high sensitivity receiving apparatus 102 (known). That is, the transmission apparatus 101 receives an instruction from the high sensitivity receiving apparatus 102, that is, an encryption key update instruction by detecting this modulation.

That is, as described above, by modulating the antenna power, the high sensitivity receiving apparatus 102 can instruct the transmitting apparatus 101 not having the signal receiving function to update the encryption key.

<Configuration of transmitter>
FIG. 7 is a block diagram illustrating a main configuration example of the transmission apparatus 101 which is an embodiment of the signal processing apparatus to which the present technology is applied. As illustrated in FIG. 7, the transmission apparatus 101 includes a transmission data generation unit 210, a CPU 211, a memory 212, an encoding unit 213, a modulation unit 214, a transmission unit 215, an amplification unit 216, an antenna 217, a modulation detection unit 218, and An oscillation unit 219 is included.

The transmission data generation unit 210 performs processing related to generation of transmission data. The content of the transmission data is arbitrary. For example, the transmission data generation unit 210 may generate transmission data to be transmitted to the high sensitivity receiving apparatus 102 using sensor data obtained from a sensor or the like. For example, the transmission data generation unit 210 may generate transmission data using the received GNSS signal. The transmission data generation unit 210 supplies the generated transmission data to the CPU 211.

The transmission data generation unit 210 can be realized by an arbitrary configuration. For example, the transmission data generation unit 210 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the transmission data generation unit 210 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The CPU 211 performs processing related to transmission data. For example, the CPU 211 performs processing related to transmission data, such as transmission control based on a carrier sense result, generation of a payload using transmission data, and encryption of the payload. For example, the CPU 211 generates a payload including transmission data, encrypts the payload, sets fill-up information, adds the payload to the payload, and supplies the payload to the memory 212. Further, the CPU 211 performs predetermined processing based on the detection result of the antenna power modulation. For example, the CPU 211 performs predetermined processing such as generation / update of an encryption key used for payload encryption, setting of fill-up information, addition to the payload, stop of signal transmission, and the like.

The memory 212 stores a payload supplied from the CPU 211. Further, the memory 212 supplies the stored payload to the encoding unit 213 at a predetermined timing or based on a request from the encoding unit 213.

The encoding unit 213 encodes the payload by a predetermined method and supplies the encoded payload to the modulation unit 214. The encoding unit 213 can be realized by an arbitrary configuration. For example, the encoding unit 213 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the encoding unit 213 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The modulation unit 214 modulates the encoded payload by a predetermined method and supplies the modulated payload to the transmission unit 215. The modulation unit 214 can be realized by an arbitrary configuration. For example, the modulation unit 214 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the modulation unit 214 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The transmission unit 215 generates a transmission signal by multiplying the carrier signal rejected by the oscillation unit 219 by the signal (payload) supplied from the modulation unit 214. The transmission unit 215 can be realized by an arbitrary configuration. For example, the transmission unit 215 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the transmission unit 215 may be configured by a signal processing circuit, a transmission circuit, or the like.

The amplification unit 216 amplifies the transmission signal. The amplification unit 216 can be realized by an arbitrary configuration. For example, the amplification unit 216 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the amplification unit 216 may be configured by an operational amplifier or the like. The antenna 217 is used for transmitting a transmission signal. The transmission unit 215 transmits the generated transmission signal as a radio signal via the amplification unit 216 and the antenna 217.

The modulation detector 218 performs carrier sense for all channels in the frequency band used for signal transmission. Also, the modulation detector 218 detects the modulation of the antenna power around the transmission apparatus 101 from the received power received at the time of the carrier sense. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the change in the antenna power for each of the partial sections obtained by dividing the carrier sense section (aerial power measurement period). For example, the modulation detection unit 218 detects the modulation of the antenna power based on the change in the power value of the antenna power for each partial section. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the pattern of the change in the power value of the antenna power for each partial section. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the polarity pattern of the difference value of the power value of the antenna power between successive partial sections. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the magnitude of the integrated value of the polarity. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the magnitude of the integrated value of the difference value between the first half power value and the second half power value of the carrier sense section (antenna power measurement period). To do.

The modulation detection unit 218 can be realized by an arbitrary configuration. For example, the modulation detection unit 218 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined.

The oscillation unit 219 oscillates at a predetermined frequency and supplies the oscillation signal as a carrier signal to the transmission unit 215 and the modulation detection unit 218 (reception unit 232). The oscillation unit 219 can be realized by an arbitrary configuration. For example, the oscillating unit 219 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the oscillation unit 219 may be configured by an oscillation circuit or the like. Note that the oscillation method of the oscillation unit 219 is arbitrary.

As shown in FIG. 7, the modulation detection unit 218 includes an amplification unit 231, a reception unit 232, a filter 233, a switch 234, an A / D conversion unit 235, an A / D conversion unit 236, an addition unit 237, a subtraction unit 238, A code comparison unit 239, an amplification unit 240, an amplification unit 241, an integration unit 243, a threshold comparison unit 244, a GNSS reception unit 251, and a pseudo-random number generation unit 252 are included.

The GNSS receiving unit 251 receives a GNSS signal transmitted from a GNSS satellite and extracts time information generated by the GNSS satellite. The GNSS receiver 251 supplies the time information (GNSS time information) to the CPU 211. The CPU 211 can perform arbitrary processing using the GNSS time information. For example, the CPU 211 supplies the GNSS time information to the pseudo random number generation unit 252. Further, the GNSS receiving unit 251 supplies the time information (GNSS information) to an arbitrary processing unit in the transmitting apparatus 101 such as an encoding unit 213, a modulation unit 214, a transmission unit 215, an oscillation unit 219, and the like. it can. Each processing unit in the transmission apparatus 101 can perform processing at timing based on the GNSS information, for example. Thereby, each processing unit can perform processing at a more accurate timing.

The GNSS receiving unit 251 can be realized by an arbitrary configuration. For example, the GNSS receiver 251 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the GNSS receiving unit 251 may be configured with an antenna, a receiving circuit, a signal processing circuit, and the like.

Based on the GNSS time information supplied from the CPU 211, the pseudo random number generator 252 generates a 1-bit pseudo random number (prbs) having the same value as the pseudo random number generated by the high sensitivity receiver 102 (pseudo random number generator 162). Generate. The pseudo random number generation unit 252 supplies the generated pseudo random number to the switch 234. The pseudo random number generation unit 252 can be realized by an arbitrary configuration. For example, the pseudo random number generation unit 252 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the pseudo random number generation unit 252 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The amplifying unit 231 amplifies the received power received via the antenna 217 during carrier sense and supplies the amplified received power to the receiving unit 232. The amplification unit 231 can be realized by an arbitrary configuration. For example, the amplification unit 231 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the amplification unit 231 may be configured by an operational amplifier or the like.

The receiving unit 232 receives the antenna power around the transmitting apparatus 101 via the antenna 217 and the amplifying unit 231 during carrier sense. The receiving unit 232 receives the antenna power for each channel in the frequency band used for signal transmission, using the carrier signal supplied from the oscillating unit 219. The receiving unit 232 supplies the received power to the filter 233. The receiving unit 232 can be realized by an arbitrary configuration. For example, the receiving unit 232 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the receiving unit 232 may be configured by a signal processing circuit, a receiving circuit, or the like.

The filter 233 extracts a component of a desired frequency band included in the supplied reception power and supplies it to the switch 234. The filter 233 can be realized by an arbitrary configuration. For example, the filter 233 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the filter 233 may be configured by a predetermined filter circuit such as a bypass filter, a low-pass filter, or a high-pass filter. Further, for example, the filter 233 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The switch 234 switches the supply destination of the supplied received power according to the value of the pseudo random number supplied from the pseudo random number generator 252. For example, when the value of the pseudo random number is “0”, the switch 234 supplies the reception power in the first half of the carrier sense interval to the A / D conversion unit 236 and converts the reception power in the second half of the carrier sense interval to A / D conversion. The supply destination of the received power is switched so as to be supplied to the unit 235. For example, when the value of the pseudo random number is “1”, the switch 234 supplies the reception power in the first half of the carrier sense interval to the A / D conversion unit 235, and the reception power in the second half of the carrier sense interval is A / D. The supply destination of the received power is switched so as to be supplied to the D conversion unit 236.

The switch 234 can be realized by an arbitrary configuration. For example, the switch 234 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined.

The A / D conversion unit 235 and the A / D conversion unit 236 respectively A / D convert the supplied received power into digital data. The A / D conversion unit 235 and the A / D conversion unit 236 supply digital data of received power to the addition unit 237 and the subtraction unit 238, respectively. Each of the A / D conversion unit 235 and the A / D conversion unit 236 can be realized by an arbitrary configuration. For example, the A / D conversion unit 235 and the A / D conversion unit 236 may be configured by circuits, LSIs, system LSIs, processors, modules, units, sets, devices, apparatuses, systems, or the like, respectively. . A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, each of the A / D conversion unit 235 and the A / D conversion unit 236 may be configured by a predetermined A / D conversion circuit, or may have a CPU and a memory, and the CPU uses the memory. The above process may be performed by executing a program.

The addition unit 237 adds the reception power supplied from the A / D conversion unit 235 and the reception power supplied from the A / D conversion unit 236. That is, the adding unit 237 adds the reception power in the first half and the reception power in the second half of the carrier sense interval, and obtains the power measurement result of the entire carrier sense interval. The adding unit 237 supplies the power measurement result of the entire carrier sense section to the CPU 211. The adding unit 237 can be realized by an arbitrary configuration. For example, the adding unit 237 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the adding unit 237 may include a CPU and a memory, and the CPU may execute the above-described calculation by executing a program using the memory.

When the CPU 211 determines whether or not the frequency band to be used is vacant based on the power measurement result (carrier sense result) of each channel supplied from the adding unit 237 in this way, Controls each processing unit to start transmission. Further, when it is determined that the frequency band is not free, the CPU 211 controls each processing unit so as not to transmit a signal.

The subtraction unit 238 calculates a difference value between the power value of the reception power supplied from the A / D conversion unit 235 and the power value of the reception power supplied from the A / D conversion unit 236.

As described above, since the switch 234 switches the reception power supply destination based on the value of the pseudo random number, the direction of subtraction by the subtraction unit 238 changes according to the value of the pseudo random number. For example, when the value of the pseudo random number is “0”, the subtraction unit 238 subtracts the power value of the reception power in the first half of the carrier sense interval from the power value of the reception power in the second half of the carrier sense interval. For example, when the value of the pseudo random number is “1”, the subtraction unit 238 subtracts the power value of the received power in the second half of the carrier sense section from the power value of the first half of the carrier sense section. That is, the subtracting unit 238 calculates a value obtained by multiplying the difference value obtained by subtracting the power value of the reception power in the first half of the carrier sense section from the power value of the reception power in the second half of the carrier sense section by the code corresponding to the pseudorandom number. . For example, when the value of the pseudo random number is “0”, a value obtained by multiplying the difference value obtained by subtracting the power value of the reception power in the first half of the carrier sense section from the power value of the reception power in the second half of the carrier sense section by “+1” Is obtained. Also, for example, when the value of the pseudo random number is “1”, the difference value obtained by subtracting the power value of the reception power in the first half of the carrier sense section from the power value of the reception power in the second half of the carrier sense section is multiplied by “−1”. The obtained value is obtained.

The subtraction unit 238 supplies the calculated difference value to the code comparison unit 239. The subtraction unit 238 can be realized by an arbitrary configuration. For example, the subtraction unit 238 may be configured by a circuit, an LSI, a system LSI, a processor, a module, a unit, a set, a device, an apparatus, a system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the subtraction unit 238 may include a CPU and a memory, and the CPU may execute the above-described calculation by executing a program using the memory.

The sign comparison unit 239 determines the sign of the difference value (whether positive or negative). The code comparison unit 239 notifies the amplification unit 240 or the amplification unit 241 of the determination result. For example, when it is determined that the sign of the difference value is positive, the sign comparison unit 239 notifies the amplification unit 240 accordingly. For example, when it is determined that the sign of the difference value is negative, the sign comparison unit 239 notifies the amplification unit 241 to that effect.

The code comparison unit 239 can be realized by an arbitrary configuration. For example, the code comparison unit 239 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the code comparison unit 239 may include a CPU and a memory, and the CPU may execute the above process by executing a program using the memory.

The amplification unit 240 supplies the value “+1” to the integration unit 243 in accordance with the notification from the code comparison unit 239. The amplifying unit 241 supplies the value “−1” to the accumulating unit 243 according to the notification from the code comparing unit 239. The amplifying unit 240 can be realized by an arbitrary configuration. For example, the amplification unit 240 may be configured by a circuit, an LSI, a system LSI, a processor, a module, a unit, a set, a device, an apparatus, or a system. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the amplification unit 240 may be configured by an operational amplifier or the like.

The integrating unit 243 integrates the values supplied from the amplifying unit 240 and the amplifying unit 241, and supplies the integrated value to the threshold comparing unit 244. The integration by the integration unit 243 is continued for a predetermined period as in the graph shown in FIG. The integrated value may be supplied to the threshold comparing unit 244 every time the values supplied from the amplifying unit 240 or the amplifying unit 241 are integrated, or supplied to the threshold comparing unit 244 after a predetermined period. You may be made to do. The integration unit 243 can be realized by an arbitrary configuration. For example, the integrating unit 243 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the integrating unit 243 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

The threshold value comparing unit 244 compares the integrated value supplied from the integrating unit 243 with a predetermined threshold value, and supplies the comparison result to the CPU 211. The threshold comparison unit 244 can be realized by an arbitrary configuration. For example, the threshold comparison unit 244 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the threshold comparison unit 244 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

Based on the comparison result, the CPU 211 determines whether the modulation detector 218 has detected the modulation of the surrounding antenna power, that is, whether the encryption key update instruction from the high sensitivity receiver 102 has been received. To do. For example, when the integrated value is equal to or greater than the threshold value, the CPU 211 determines that the modulation of the antenna power is detected by the modulation detection unit 218. In that case, the CPU 211 sets the value of the fill-up information to a value (for example, “1”) indicating that the antenna power modulation is detected, and adds the value to the payload. That is, fill-up information with a value “1” is transmitted. When the integrated value is smaller than the threshold value, it is determined that the modulation detector 218 has not detected the antenna power modulation. In this case, the CPU 211 sets the value of the fill-up information to a value (for example, “0”) indicating that the antenna power modulation is not detected, and adds the value to the payload. That is, fill-up information with a value “0” is transmitted.

Since the high-sensitivity receiving apparatus 102 modulates the antenna power with a modulation pattern corresponding to the pseudo-random number, the subtraction unit 238 obtains the antenna power in a state in which the transmission apparatus 101 correctly detects the antenna power modulation by the high-sensitivity receiving apparatus 102. The sign of the value is positive. In other words, when the sign of the value obtained by the subtracting unit 238 is positive, there is a possibility that the transmitting apparatus 101 has correctly detected the antenna power modulation by the high sensitivity receiving apparatus 102. Furthermore, in other words, when the sign of the value obtained by the subtracting unit 238 is negative, the antenna power is not modulated by the high sensitivity receiver 102 or the transmitter 101 due to other factors such as noise. However, the modulation of the antenna power by the high sensitivity receiver 102 cannot be detected correctly. Therefore, in other words, as the number of times that a positive value is obtained by the subtracting unit 238 increases, the possibility that the transmission apparatus 101 can correctly detect the modulation of the antenna power by the high sensitivity receiving apparatus 102 increases.

Therefore, the CPU 211 determines that the difference value obtained by subtracting the power value of the reception power in the first half of the carrier sense section from the power value of the reception power in the second half of the carrier sense section is multiplied by a sign corresponding to a pseudorandom number. By determining whether or not an encryption key update instruction from the high sensitivity receiver 102 has been received based on the integrated value, the determination can be made more accurately than when the determination is made based on the detection result of one carrier sense interval It can be performed.

In addition, after the integrated value is supplied to the threshold value comparing unit 244, the integrated value of the integrating unit 243 is reset (initialized) by the CPU 211. That is, the integrated value of the integrating unit 243 is set to an initial value (for example, “0”). Thereby, the integration unit 243 can repeatedly perform the same integration for each predetermined period and output the integration value for each period, and the threshold value comparison unit 244 compares the integration value of each period with a common threshold value. be able to. Therefore, the CPU 211 can more easily determine whether or not the surrounding antenna power modulation has been detected.

If the CPU 211 detects that the antenna power modulation is detected based on the comparison result by the threshold comparison unit 244 and determines that an encryption key update instruction has been received, the CPU 211 encrypts the payload at a predetermined timing, for example, at the beginning of the month. Update the encryption key to be used. After that, the CPU 211 encrypts the payload using the updated encryption key (new encryption key).

Note that the timing of this update is shared with the high-sensitivity receiving apparatus 102 (known to both the transmission apparatus 101 and the high-sensitivity receiving apparatus 102), and the high-sensitivity receiving apparatus 102 also uses the encryption key at the same timing. Update. Of course, the encryption key generation rule is common to the transmission apparatus 101 and the high-sensitivity reception apparatus 102. Therefore, the transmitting apparatus 101 and the high sensitivity receiving apparatus 102 can simultaneously acquire new encryption keys corresponding to each other. That is, the transmission apparatus 101 and the high sensitivity receiving apparatus 102 can normally communicate using the new encryption key. Therefore, the transmitter 101 and the high sensitivity receiver 102 can reduce the possibility of wiretapping or tampering with the communication.

<Flow of encryption key update processing>
Next, an example of the flow of the encryption key update process performed in the position notification system 100 will be described with reference to the flowcharts of FIGS. The encryption key update process is a process for updating an encryption key used for encrypting and decrypting the payload of the transmitting apparatus 101 and the high sensitivity receiving apparatus 102. With reference to the flowchart in FIG. 8, an example in which the encryption key is successfully updated will be described.

For example, at the beginning of the month, the CPU 211 of the transmission device 101 resets the integrated value of the integrating unit 243 (step S101).

The power modulation unit 156 of the high sensitivity receiver 102 requests the transmitter 101 to update the encryption key by modulating the antenna power (step S121). On the other hand, the modulation detection unit 218 of the transmission apparatus 101 performs carrier sense and detects the modulation of the surrounding antenna power (step S102).

When it is confirmed by carrier sense that a desired frequency band is free, the transmission unit 215 of the transmission apparatus 101 transmits a transmission signal including an encrypted payload (step S103). Since the integrated value has not reached the threshold at this time, the value of the fill-up information added to this payload is “0” (fillup = 0). On the other hand, the amplification unit 152 of the high sensitivity receiving apparatus 102 receives the transmission signal via the antenna 151 and amplifies it. Further, the demodulating unit 153 demodulates, and the error correcting unit 154 performs error correction. The CPU 155 extracts the encrypted payload and decrypts it using the encryption key. In this way, the payload is received (step S122). Since the value of the fill-up information of this payload is “0”, the update of the encryption key is not yet reserved.

The above processes (steps S102 and S103, and steps S121 and S122) are repeatedly performed during a predetermined period (for example, one month).

Similarly, when the integrated value reaches the threshold value as a result of performing the antenna power modulation (step S123) and the carrier sense (step S104) several times, the CPU 211 of the transmission apparatus 101 sets the value “1”. Fill-up information is added to the payload. The transmission unit 215 of the transmission device 101 transmits the payload (step S105). The high sensitivity receiving apparatus 102 receives the payload as in the case of the processing in step S122 and the like (step S124). Since the value of the fill-up information becomes “1”, the update of the encryption key is reserved.

And since the update of the encryption key is reserved, the CPU 211 of the transmission apparatus 101 updates the encryption key at a known predetermined timing such as the end of the month (step S106). At the same timing, the CPU 155 of the high sensitivity receiving apparatus 102 also updates the encryption key (step S125).

Next, an example of the flow of encryption key update processing when the update of the encryption key fails will be described with reference to the flowchart of FIG.

For example, at the beginning of the month, the CPU 211 of the transmission device 101 resets the integrated value of the integrating unit 243 (step S141).

The power modulation unit 156 of the high sensitivity receiving apparatus 102 requests the transmitting apparatus 101 to update the encryption key by modulating the antenna power (step S161). On the other hand, the modulation detection unit 218 of the transmission apparatus 101 performs carrier sense and detects the modulation of the surrounding antenna power (step S142).

When it is confirmed by carrier sense that a desired frequency band is free, the transmission unit 215 of the transmission apparatus 101 transmits a transmission signal including an encrypted payload (step S143). Since the integrated value has not reached the threshold at this time, the value of the fill-up information added to this payload is “0” (fillup = 0). On the other hand, the amplification unit 152 of the high sensitivity receiving apparatus 102 receives the transmission signal via the antenna 151 and amplifies it. Further, the demodulating unit 153 demodulates, and the error correcting unit 154 performs error correction. The CPU 155 extracts the encrypted payload and decrypts it using the encryption key. In this way, the payload is received (step S162). Since the value of the fill-up information of this payload is “0”, the update of the encryption key is not yet reserved.

The above processing (steps S142 and S143, and steps S161 and S162) is repeatedly performed during a predetermined period (for example, one month).

If the integrated value does not exceed the threshold value in the processes (steps S144 and S145, and steps S163 and S164) performed at the end of the predetermined period, transmission is performed from the transmission device 101 to the high sensitivity reception device 102. The value of the fill-up information added to the added payload remains “0”, and the encryption key update is not reserved.

That is, since the update of the encryption key is not reserved (the integrated value does not exceed the threshold value), the CPU 211 of the transmission apparatus 101 does not update the encryption key at a known predetermined timing such as the end of the month (encryption). (Key update is omitted) (step S146). Further, at the same timing, the CPU 155 of the high sensitivity receiving apparatus 102 also does not update the encryption key (the update of the encryption key is omitted) (step S165).

By executing the encryption key update process as described above, the transmission device 101 and the high sensitivity receiving device 102 perform encryption at the same timing, for example, by updating the encryption key or omitting the update of the encryption key. The same process can be performed for the key update. Therefore, the transmitting device 101 and the high sensitivity receiving device 102 can perform encryption and decryption of information using an encryption key while maintaining a state where information can be normally exchanged. The encryption key can also be updated. Therefore, the possibility of wiretapping or tampering with communication can be reduced.

Further, by executing the encryption key update process as described above, the transmission apparatus 101 and the high sensitivity receiving apparatus 102 can update the encryption key irregularly. Therefore, it is possible to further reduce the possibility of wiretapping or tampering with communication.

That is, the high sensitivity receiving apparatus 102 does not have a signal receiving function and can control the transmitting apparatus 101 that performs one-way communication from the outside.

In the above description, the period of repeating the carrier sense (accumulating period) has been described as one month, but the length of this period is arbitrary.

<Flow of control processing>
The drive of the transmission apparatus 101 may be controlled using the encryption key update process as described above. For example, in the case of disposable, the transmission device 101 that is no longer needed is left unattended, and unnecessary signals are continuously transmitted from the transmission device 101, and the unnecessary signal transmission occupies the frequency band used for communication, It may be an interference wave for other communications. Also for the high-sensitivity receiving apparatus 102, continuing to receive signals transmitted from the unnecessary transmitting apparatus 101 is a wasteful process. Furthermore, since this unnecessary communication does not update the encryption key for a long period of time, the security level is reduced, and there is a possibility that it may be used for wiretapping or tampering of communication.

Therefore, an expiration date may be provided for driving the transmission apparatus 101, and the expiration date may be managed using the encryption key update process described above. For example, the above-described encryption key update processing may be repeatedly executed, and signal transmission by the transmission apparatus 101 may be stopped when the encryption key update fails for a predetermined period (continuously a predetermined number of times). In this case, reception of a signal from the transmission device 101 by the high sensitivity reception device 102 may be stopped.

An example of the flow of control processing for realizing such control will be described with reference to the flowchart of FIG.

When the control process is started, the transmission apparatus 101 performs an encryption key update request process (step S181), and the high sensitivity receiver 102 performs an encryption key update request confirmation process (step S191). With this process, the transmission apparatus 101 resets the integrated value at the expiration date start timing (for example, at the beginning of the month).

When it is determined that a predetermined period (for example, one month) has elapsed and the transmission apparatus 101 has not received an instruction from the high sensitivity reception apparatus 102 (that is, the integrated value has not reached the threshold value), the transmission apparatus 101 Performs encryption key update request processing again (step S182). At this time, since the high sensitivity receiving apparatus 102 has not received the fill-up information of the value “1” from the transmitting apparatus 101, the encryption key update request confirmation process is performed again (step S192).

Further, when a predetermined period (for example, one month) elapses and the encryption key is not updated in the same manner, the transmitting apparatus 101 performs the encryption key update request process again (step S183). On the other hand, the high sensitivity receiving apparatus 102 performs encryption key update request confirmation processing again.

If the encryption key is not updated after a predetermined period (for example, one month), the CPU 211 of the transmission apparatus 101 determines that the expiration date has expired, and controls other processing units as necessary. Signal transmission is stopped (step S184). Further, the CPU 155 of the high-sensitivity receiving apparatus 102 determines that the expiration date of the transmission apparatus 101 that is a communication partner has expired, controls other processing units as necessary, and stops reception from the transmission apparatus 101. (Step S194).

By doing so, unnecessary signal transmission / reception can be stopped, so that reduction in the frequency band utilization efficiency can be suppressed. In addition, it is possible to suppress a decrease in reception sensitivity of other communications. Furthermore, the possibility of wiretapping or tampering with communication can be reduced.

In FIG. 10, when the encryption key update is successful, the number of failed encryption key updates is reset. That is, it is considered that the expiration date has been updated (extended). Further, in FIG. 10, it has been described that the expiration date expires when the encryption key update fails three times in succession, but this number may be any number.

<Application example>
The modulation scheme in the carrier sense section is arbitrary and is not limited to the above example. For example, spread modulation using a pseudo random number sequence may be used. Further, for example, the carrier sense section may be divided into three or more partial sections, and a difference value may be calculated between the partial sections. In the case of the method of calculating the difference value between the first half and the second half of the carrier sense interval described above, only 1-bit information can be supplied to the transmission apparatus 101. By doing so, multiple-bit information is transmitted. The apparatus 101 can be supplied.

Further, the method for calculating each modulated antenna power may be any method as long as it is shared between the modulating side and the detecting side (if known). For example, the carrier sense section is divided into four, the modulation of the antenna power in each partial section is “+1”, “−1”, “+1”, “−1”, and the antenna power in the odd-numbered partial section is added, You may make it subtract the antenna power of the even-numbered partial area. Further, the method of calculating the antenna power of each partial section (for example, whether to add or subtract) may be determined from a pseudo random number. Of course, also in this case, the number of divisions of the carrier sense section is arbitrary, and may be eight divisions, for example.

Further, not only the sign of the difference value but also the magnitude of the difference value may be computerized. That is, Δ = 1 may be changed to Δ = δ. By doing so, more information can be supplied to the transmission apparatus 101.

Further, when the process of supplying information to the transmitting apparatus 101 by the modulation of the antenna power is repeated, such as the repetition of the encryption update process in the control process described above, that is, a plurality of detections of the antenna power modulation (reset of integrated values) When the transmission is performed once, different information may be supplied to the transmission apparatus 101 each time the modulation of the antenna power is detected (the integrated value exceeds the threshold value). That is, for example, the transmission apparatus 101 determines that the A process is instructed for the first time, determines that the B process is instructed for the second time, determines that the C process is instructed for the third time, and so on. As described above, the content (for example, instruction content) of the supplied information may be changed.

Furthermore, one piece of information may be supplied to the transmission apparatus 101 in multiple detections of the modulation of the antenna power. For example, a multi-bit encryption key may be obtained by collecting 1-bit information supplied to the transmission apparatus 101 each time. That is, arbitrary information such as an encryption key can be transmitted using the modulation of the antenna power.

In the above description, it has been described that the transmission apparatus 101 detects the modulation of the antenna power using the received power received in the carrier sense when transmitting the signal. However, the transmission apparatus 101 detects the modulation of the antenna power. For this purpose, carrier sense may be separately performed. In this case, since the transmission apparatus 101 does not perform transmission, the transmission power of the carrier sense band transmitted by the high sensitivity receiving apparatus 102 can be increased.

Also, the encryption key generation method is arbitrary. For example, a value uniquely determined using GPS time information, LFSR (Linear Feed-back Shift Register), or the like may be used as an encryption key, or a predetermined encryption key table may be used as a highly sensitive reception with the transmission device 101. It may be shared with the apparatus 102 and the encryption key may be set based on the table.

Note that the high sensitivity receiving apparatus 102 may broadcast a key update command, that is, simultaneously transmit to all the transmitting apparatuses 101, or may change the modulation of the carrier sense interval for each group, for example. . For example, it is possible to perform a dedicated key update for a group by setting a rule in advance between the transmitting apparatus 101 and the high sensitivity receiving apparatus 102 belonging to a predetermined group. In this case, the modulation of the antenna power is received as noise by the transmission apparatus 101 outside the group.

In the above description, the high-sensitivity receiving apparatus 102 has been described so as to modulate the antenna power around the transmission apparatus 101. However, the present invention is not limited to this, and any apparatus other than the high-sensitivity reception apparatus 102 may receive May be modulated (that is, information is supplied to the transmission apparatus 101).

In the above description, the antenna power is modulated on all channels in the frequency band used for signal transmission / reception. For example, the antenna power is modulated only on one or more representative channels. May be. Further, the channel on which the antenna power is modulated may be variable. Further, the antenna power may be modulated in a band different from the frequency band used for signal transmission / reception.

<3. Second Embodiment>
<DPSK>
In the above description, the power value (magnitude) of the antenna power is modulated. However, the phase of the antenna power may be modulated. Further, differential (difference) phase shift keying (DPSK (Differential Phase-Shift Keying)) may be used.

<Configuration of high sensitivity receiver>
FIG. 11 shows a main configuration example of the high-sensitivity receiving apparatus 102 when the antenna power is modulated by DPSK. As shown in FIG. 11, the high sensitivity receiving apparatus 102 in this case basically has the same configuration as that in FIG. However, in this case, the power modulation unit 156 of the high sensitivity receiving apparatus 102 includes a DPSK unit 311 instead of the single carrier modulation unit 163 and the switch 164.

In this case, for example, the power modulation unit 156 changes the phase of the antenna power for each partial section obtained by dividing the antenna power measurement period in the transmission apparatus 101 into a plurality of sections. For example, the power modulation unit 156 changes the phase of the antenna power for each partial section with a predetermined pattern. For example, the power modulation unit 156 changes the polarity of the phase difference of the antenna power between successive partial sections with a predetermined pattern. For example, the power modulation unit 156 modulates the antenna power for a period including the measurement period twice or more.

The DPSK unit 311 generates a signal having a predetermined frequency, and modulates the signal so as to indicate the value of the pseudorandom number supplied from the pseudorandom number generator 162 by the DPSK method. At this time, the DPSK unit 311 performs modulation so that the phase of the antenna power around the transmission apparatus 101 changes during the measurement period of the antenna power in the transmission apparatus 101 (that is, the carrier sense section). The DPSK unit 311 supplies the modulated signal (modulated signal) to the amplification unit 165. The amplification unit 165 transmits the modulated signal via the antenna 166. By doing so, the high sensitivity receiver 102 can modulate the antenna power by the DPSK method.

The DPSK unit 311 can be realized by an arbitrary configuration. For example, the DPSK unit 311 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the DPSK unit 311 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

<Configuration of transmitter>
FIG. 12 shows a main configuration example of the transmission apparatus 101 when the antenna power is modulated by the DPSK method. As shown in FIG. 12, the transmitting apparatus 101 in this case basically has the same configuration as that in FIG. However, in this case, the modulation detection unit 218 of the transmission apparatus 101 includes a phase difference detection unit 321 instead of the subtraction unit 238.

In this case, for example, the modulation detection unit 218 detects the modulation of the antenna power based on the change in the phase of the antenna power for each partial section obtained by dividing the carrier sense section (aerial power measurement period). For example, the modulation detection unit 218 detects the modulation of the antenna power based on the pattern of the change in the phase of the antenna power for each partial section. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the polarity pattern of the phase difference of the antenna power between successive partial sections. For example, the modulation detection unit 218 detects the modulation of the antenna power based on the magnitude of the integrated value of the polarity.

That is, the phase difference detection unit 321 detects the phase difference between the reception power supplied from the A / D conversion unit 235 and the reception power supplied from the A / D conversion unit 236. The phase difference detection unit 321 can be realized by an arbitrary configuration. For example, the phase difference detection unit 321 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. A plurality of them may be combined. At this time, for example, the same type of configuration such as a plurality of circuits and a plurality of processors may be combined, or different types of configurations such as a circuit and an LSI may be combined. For example, the phase difference detection unit 321 may include a CPU and a memory, and the CPU may execute the above-described processing by executing a program using the memory.

As described above, since the switch 234 switches the reception power supply destination based on the value of the pseudo random number, the direction of subtraction by the subtraction unit 238 changes according to the value of the pseudo random number. For example, when the value of the pseudo random number is “0”, the subtraction unit 238 subtracts the phase of the reception power in the first half of the carrier sense interval from the phase of the reception power in the second half of the carrier sense interval. For example, when the value of the pseudo random number is “1”, the subtracting unit 238 subtracts the phase of the received power in the second half of the carrier sense interval from the phase of the received power in the first half of the carrier sense interval.

That is, the subtracting unit 238 multiplies a difference value (phase difference) obtained by subtracting the phase of the received power in the first half of the carrier sense interval from the phase of the received power in the latter half of the carrier sense interval by a code corresponding to a pseudo random number. calculate. For example, when the value of the pseudo random number is “0”, “+1” is multiplied by a difference value (phase difference) obtained by subtracting the phase of the received power in the first half of the carrier sense interval from the phase of the received power in the latter half of the carrier sense interval. Value is obtained. Further, for example, when the value of the pseudo random number is “1”, “−1” is added to a difference value (phase difference) obtained by subtracting the phase of the received power in the first half of the carrier sense interval from the phase of the received power in the latter half of the carrier sense interval. The value multiplied by is obtained.

The phase difference detection unit 321 supplies the detected phase difference to the code comparison unit 239. The sign comparison unit 239 determines the sign (whether positive or negative) of the phase difference. That is, in this case, the modulation detector 218 detects the modulation of the antenna power based on the magnitude of the integrated value of the polarities of the difference values between the first half phase and the second half phase of the antenna power measurement period. By doing so, the transmission apparatus 101 can detect the modulation of the antenna power by the DPSK method. Also in this case, the CPU 211 makes a determination based on the integrated value, so that the determination can be performed more accurately than when the determination is made based on the detection result of one carrier sense section.

That is, as in the case of the first embodiment, the high sensitivity receiving apparatus 102 can control the transmitting apparatus 101 that does not have a signal receiving function and performs one-way communication from the outside.

<4. Other>
<Anti-theft system>
In the above, the position notification system 100 has been described as an example, but the present technology can be applied to any communication system. For example, the transmission apparatus 101 may be installed not only on a person but also on a moving body.

For example, the present technology can also be applied to an anti-theft system 800 for preventing theft of automobiles, motorcycles and the like as shown in FIG. In the case of this anti-theft system 800, the transmission apparatus 101 is installed in an object whose position is monitored by the user, for example, an automobile 801 or a motorcycle 802 owned by the user. As in the case of the position notification system 100, the transmission apparatus 101 notifies the high-sensitivity reception apparatus 102 of its own position information (that is, position information of the automobile 801 and the motorcycle 802) as appropriate. That is, as in the case of the position notification system 100, the user can access the server 104 from the terminal device 105 and grasp the positions of the automobile 801 and the motorcycle 802. Therefore, since the user can grasp the positions of the automobile 801 and the motorcycle 802 even if the user is stolen, the user can easily retrieve the automobile 801 and the motorcycle 802.

In the case of such an anti-theft system 800 as well, the same effects as those of the position notification system 100 described above can be obtained by applying the present technology described above in each embodiment to the transmission apparatus 101 and the high sensitivity receiving apparatus 102. Can be obtained.

<Other communication systems>
Information transmitted and received between the transmission device 101 and the high sensitivity reception device 102 is arbitrary. For example, the transmission apparatus 101 may transmit transmission information including identification information such as images, sounds, measurement data, devices, parameter setting information, or control information such as commands. The transmission information may include a plurality of types of information such as an image and sound, identification information, setting information, and control information.

Further, the transmission apparatus 101 may be able to transmit transmission information including information supplied from another apparatus, for example. For example, the transmission device 101 may have an image, light, brightness, saturation, electricity, sound, vibration, acceleration, speed, angular velocity, force, temperature (not temperature distribution), humidity, distance, area, volume, shape, flow rate, Generate and send transmission information including information (sensor output) output from various sensors that perform detection or measurement for any variable such as time, time, magnetism, chemical substance, or odor, or the amount of change. You may make it do.

In other words, the present technology, for example, three-dimensional shape measurement, spatial measurement, object observation, moving deformation observation, biological observation, authentication processing, monitoring, autofocus, imaging control, illumination control, tracking processing, input / output control, electronic device control, The present invention can be applied to a system used for any application such as actuator control.

In addition, the present technology can be applied to a system in an arbitrary field such as traffic, medical care, crime prevention, agriculture, livestock industry, mining, beauty, factory, home appliance, weather, and nature monitoring. For example, the present technology can also be applied to a system that captures an image for viewing using a digital camera, a portable device with a camera function, or the like. In addition, for example, this technology monitors in-vehicle systems, traveling vehicles, and roads that photograph the front, rear, surroundings, and interiors of automobiles for safe driving such as automatic stop and recognition of the driver's condition. The present invention can also be applied to a system used for traffic, such as a surveillance camera system that performs a distance measurement between vehicles or the like. Furthermore, for example, the present technology can also be applied to a system provided for security using a security camera for surveillance purposes, a camera for personal authentication purposes, or the like. In addition, for example, the present technology can also be applied to a system provided for sports using various sensors that can be used for sports applications such as a wearable camera. Furthermore, for example, the present technology can also be applied to a system used for agriculture using various sensors such as a camera for monitoring the state of a field or crop. In addition, for example, the present technology can also be applied to a system used for livestock industry that uses various sensors for monitoring the state of livestock such as pigs and cows. Furthermore, the present technology can be applied to systems that monitor natural conditions such as volcanoes, forests, and oceans, meteorological observation systems that observe weather, temperature, humidity, wind speed, sunshine hours, and so on, such as birds, fish, and reptiles. It can also be applied to a system for observing the ecology of wildlife such as moss, amphibians, mammals, insects and plants.

<Other devices>
Furthermore, the specification of the radio signal and information transmitted / received is arbitrary. In the above, an example in which the present technology is applied to the transmission device 101 and the high-sensitivity reception device 102 has been described. Furthermore, the present technology is not limited to a transmission device and a reception device, and can be applied to an arbitrary device such as a transmission / reception device, a communication device, a signal processing device, or an information processing device.

<Computer>
The series of processes described above can be executed by hardware or can be executed by software. Also, some processes can be executed by hardware, and other processes can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer that can execute various functions by installing a computer incorporated in dedicated hardware and various programs.

FIG. 14 is a block diagram showing an example of a hardware configuration of a computer that executes the above-described series of processing by a program.

In a computer 900 shown in FIG. 14, a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, and a RAM (Random Access Memory) 903 are connected to each other via a bus 904.

An input / output interface 910 is also connected to the bus 904. An input unit 911, an output unit 912, a storage unit 913, a communication unit 914, and a drive 915 are connected to the input / output interface 910.

The input unit 911 includes, for example, a keyboard, a mouse, a microphone, a touch panel, an input terminal, and the like. The output unit 912 includes, for example, a display, a speaker, an output terminal, and the like. The storage unit 913 includes, for example, a hard disk, a RAM disk, a nonvolatile memory, and the like. The communication unit 914 includes a network interface, for example. The drive 915 drives a removable medium 921 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

In the computer configured as described above, the CPU 901 loads the program stored in the storage unit 913 into the RAM 903 via the input / output interface 910 and the bus 904 and executes the program, for example. Is performed. The RAM 903 also appropriately stores data necessary for the CPU 901 to execute various processes.

The program executed by the computer (CPU 901) can be recorded and applied to, for example, a removable medium 921 as a package medium or the like. In that case, the program can be installed in the storage unit 913 via the input / output interface 910 by attaching the removable medium 921 to the drive 915. This program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. In that case, the program can be received by the communication unit 914 and installed in the storage unit 913. In addition, this program can be installed in the ROM 902 or the storage unit 913 in advance.

<Supplement>
Embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.

For example, the present technology may be applied to any configuration that constitutes an apparatus or system, for example, a processor as a system LSI (Large Scale Integration), a module that uses a plurality of processors, a unit that uses a plurality of modules, etc. It can also be implemented as a set or the like to which functions are added (that is, a partial configuration of the apparatus).

In this specification, the system means a set of a plurality of constituent elements (devices, modules (parts), etc.), and it does not matter whether all the constituent elements are in the same casing. Accordingly, a plurality of devices housed in separate housings and connected via a network and a single device housing a plurality of modules in one housing are all systems. .

Further, for example, the configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units). Conversely, the configurations described above as a plurality of devices (or processing units) may be combined into a single device (or processing unit). Of course, a configuration other than that described above may be added to the configuration of each device (or each processing unit). Furthermore, if the configuration and operation of the entire system are substantially the same, a part of the configuration of a certain device (or processing unit) may be included in the configuration of another device (or other processing unit). .

Also, for example, the present technology can take a configuration of cloud computing in which one function is shared and processed by a plurality of devices via a network.

Also, for example, the above-described program can be executed in an arbitrary device. In that case, the device may have necessary functions (functional blocks and the like) so that necessary information can be obtained.

Also, for example, each step described in the above flowchart can be executed by one device or can be executed by a plurality of devices. Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus. In other words, a plurality of processes included in one step can be executed as a process of a plurality of steps. Conversely, the processing described as a plurality of steps can be collectively executed as one step.

The program executed by the computer may be such that the processing of steps describing the program is executed in time series in the order described in this specification, or in parallel or when a call is made. It may be executed individually at the required timing. That is, as long as no contradiction occurs, the processing of each step may be executed in an order different from the order described above. Furthermore, the processing of the steps describing this program may be executed in parallel with the processing of other programs, or may be executed in combination with the processing of other programs.

The technologies described in this specification can be implemented independently as long as no contradiction arises. Of course, any of a plurality of present technologies can be used in combination. For example, part or all of the present technology described in any of the embodiments can be combined with part or all of the present technology described in other embodiments. Moreover, a part or all of the arbitrary present technology described above can be implemented in combination with other technologies not described above.

The present technology can also have the following configurations.
(1) a detector that detects the modulation of the antenna power;
A processing unit that performs predetermined processing based on a detection result of the antenna power modulation by the detection unit;
A signal processing apparatus comprising: a transmission unit that transmits a signal including a payload.
(2) The signal processing device according to (1), wherein the detection unit detects the modulation of the antenna power based on a change in the antenna power for each partial section obtained by dividing the antenna power measurement period into a plurality of sections.
(3) The signal processing device according to (2), wherein the detection unit detects modulation of the antenna power based on a change in the power value of the antenna power for each partial section.
(4) The signal processing device according to (3), wherein the detection unit detects modulation of the antenna power based on a pattern of change in the power value of the antenna power for each partial section.
(5) The signal processing device according to (2), wherein the detection unit detects the modulation of the antenna power based on a change in the phase of the antenna power for each partial section.
(6) The processing unit sets identification information for identifying whether or not the detection unit has detected a modulation of antenna power as the processing,
The signal processing apparatus according to any one of (1) to (5), wherein the transmission unit transmits a signal including the payload and the identification information.
(7) When the detection unit detects an antenna power modulation, the processing unit, as the processing,
Setting the value of the identification information to a value indicating that the modulation of the antenna power is detected;
Update the encryption key used for encrypting the payload at a predetermined timing after transmitting the identification information,
The signal processing apparatus according to (6), wherein the transmission unit transmits a signal including the payload and the identification information set by the processing unit.
(8) When the predetermined number of times that the antenna power modulation is not detected within a predetermined period, the processing unit controls the transmission unit to stop transmission of the payload as the processing. ) To (7).
(9) When the detection unit detects the modulation of the antenna power, the processing unit acquires, as the processing, information on an encryption key used for encrypting the payload included in the modulated antenna power. (1) The signal processing device according to any one of (8).
(10) The detection unit detects the modulation of the antenna power based on the antenna power received in the carrier sense for confirming the usage state of the frequency band used by the transmission unit for signal transmission. (1) to (9) The signal processing device according to any one of the above.
(11) detect the modulation of the antenna power,
Perform predetermined processing based on the detection result of the antenna power modulation,
A signal processing method for transmitting a signal including a payload.

(12) A signal processing device including a power modulation unit that modulates antenna power.
(13) The signal processing device according to (12), wherein the power modulation unit modulates the antenna power so that the antenna power changes for each of the partial sections obtained by dividing the antenna power measurement period in the transmitter.
(14) The signal processing device according to (13), wherein the power modulation unit changes a power value of antenna power for each partial section.
(15) The signal processing device according to (14), wherein the power modulation unit changes the power value of the antenna power for each of the partial sections with a predetermined pattern.
(16) The signal processing device according to (12), wherein the power modulation unit changes a phase of the antenna power for each partial section.
(17) A receiving unit that receives the signal transmitted from the transmission device, and receives the identification information that identifies whether the payload and the modulation of the antenna power detected by the transmission device are included in the signal. The signal processing device according to any one of (12) to (16).
(18) The reception unit decrypts a payload encrypted using an encryption key, and when the value of the received identification information is a value indicating that modulation of antenna power is detected by the transmission device, The signal processing device according to (17), wherein the encryption key is updated at a predetermined timing.
(19) When the reception unit has generated a predetermined number of times that the identification information having a value indicating that modulation of antenna power is detected by the transmission device within a predetermined period, The signal processing device according to (17) or (18), wherein reception of the transmitted signal is stopped.
(20) A signal processing method for modulating antenna power.

100 location notification system, 101 transmission device, 102 high sensitivity reception device, 103 network, 104 server, 111 elderly people, 151 antenna, 152 amplification unit, 153 demodulation unit, 154 error correction unit, 155 CPU, 156 power modulation unit, 161 GNSS receiver, 162 pseudo random number generator, 163 single carrier modulator, 164 switch, 165 amplifier, 166 antenna, 210 transmission data generator, 211 CPU, 212 memory, 213 encoder, 214 modulator, 215 transmitter , 216 amplification unit, 217 antenna, 218 modulation detection unit, 219 oscillation unit, 231 amplification unit, 232 reception unit, 233 filter, 234 switch, 235 and 236 A / D conversion unit, 237 addition unit, 238 subtraction unit, 239 code comparison unit, 240 and 241 amplification unit, 243 integration unit, 244 threshold comparison unit, 251 GNSS reception unit, 252 pseudo random number generation unit, 311 DPSK unit , 321 phase difference detector, 800 anti-theft system

Claims

A detector for detecting the modulation of the antenna power;
A processing unit that performs predetermined processing based on a detection result of the antenna power modulation by the detection unit;
A signal processing apparatus comprising: a transmission unit that transmits a signal including a payload.
The signal processing apparatus according to claim 1, wherein the detection unit detects modulation of the antenna power based on a change in the antenna power for each partial section obtained by dividing the antenna power measurement period into a plurality of sections.
The signal processing apparatus according to claim 2, wherein the detection unit detects the modulation of the antenna power based on a change in the power value of the antenna power for each partial section.
The signal processing device according to claim 3, wherein the detection unit detects modulation of the antenna power based on a pattern of a change in the power value of the antenna power for each partial section.
The signal processing device according to claim 2, wherein the detection unit detects the modulation of the antenna power based on a change in the phase of the antenna power for each partial section.
The processing unit sets identification information for identifying whether or not the detection unit has detected a modulation of antenna power as the processing,
The signal processing apparatus according to claim 1, wherein the transmission unit transmits a signal including the payload and the identification information.
When the detection unit detects the modulation of the antenna power, as the processing,
Setting the value of the identification information to a value indicating that the modulation of the antenna power is detected;
Update the encryption key used for encrypting the payload at a predetermined timing after transmitting the identification information,
The signal processing device according to claim 6, wherein the transmission unit transmits a signal including the payload and the identification information set by the processing unit.
The said processing part controls the said transmission part and stops transmission of the said payload as the said process, when the frequency | count that the modulation | alteration of antenna power is not detected within a predetermined period generate | occur | produces the predetermined number of times. Signal processing equipment.
The processing unit acquires information on an encryption key used for encryption of the payload included in the modulated antenna power as the processing when the detection unit detects modulation of the antenna power. A signal processing device according to 1.
The signal processing apparatus according to claim 1, wherein the detection unit detects the modulation of the antenna power based on the antenna power received in carrier sense for confirming a usage state of a frequency band used for signal transmission by the transmission unit.
Detects the modulation of the antenna power,
Perform predetermined processing based on the detection result of the antenna power modulation,
A signal processing method for transmitting a signal including a payload.
A signal processing device including a power modulation unit that modulates antenna power.
The signal processing device according to claim 12, wherein the power modulation unit modulates the antenna power so that the antenna power changes for each partial section obtained by dividing the antenna power measurement period in the transmission device into a plurality of sections.
The signal processing device according to claim 13, wherein the power modulation unit changes a power value of antenna power for each partial section.
The signal processing device according to claim 14, wherein the power modulation unit changes the power value of the antenna power for each partial section according to a predetermined pattern.
The signal processing device according to claim 13, wherein the power modulation unit changes a phase of the antenna power for each of the partial sections.
A receiving unit that receives the signal transmitted from the transmitting device and receives identification information that identifies whether the signal includes a payload and whether or not modulation of antenna power is detected by the transmitting device. The signal processing device according to claim 12.
The reception unit decrypts a payload encrypted using an encryption key, and when the received identification information value is a value indicating that antenna power modulation is detected by the transmission device, a predetermined timing is obtained. The signal processing apparatus according to claim 17, wherein the encryption key is updated.
The reception unit is transmitted from the transmission device when it has occurred a predetermined number of times that the identification information having a value indicating that modulation of antenna power is detected by the transmission device within a predetermined period of time. The signal processing device according to claim 17, wherein reception of the signal is stopped.
A signal processing method for modulating antenna power.