JP7214624B2 - Transmitting device and method, and receiving device and method - Google Patents

Description

TECHNICAL FIELD The present technology relates to a transmitting device and method and a receiving device and method, and more particularly to a transmitting device and method and a receiving device and method capable of suppressing deterioration in communication quality.

Conventional signal multiplexing methods include frequency division multiplexing (FDM), time division multiplexing (TDM), spectrum spreading, and the like (see, for example, Patent Document 1). A method of chirp-modulating a phase-modulated signal has also been devised as a method of modulating a transmission signal (see, for example, Patent Document 2). In order to multiplex more signals by these methods, more accurate frequency control and time control are required. Therefore, it was considered to control them using GNSS signals.

Patent No. 3270902 JP-A-08-307375

However, reception of GNSS signals is not always good. Not only when the GNSS signal cannot be received, but also when the received GNSS signal is of low quality, the error in the generated time information and frequency information increases due to the use of interpolation formulas, etc., and communication quality may decrease. there were.

The present disclosure has been made in view of such circumstances, and is intended to suppress deterioration in communication quality.

A transmission device according to one aspect of the present technology includes a setting unit that sets a transmission control frequency for controlling a transmission frequency of a transmission signal based on a reception status of a GNSS signal, and the transmission control set by the setting unit. a transmission control unit that controls the transmission frequency of the transmission signal based on the transmission frequency; and a transmission unit that transmits the transmission signal at the transmission frequency controlled by the transmission control unit , wherein the setting unit When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency of the oscillator is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is sent to the transmission signal. If the received GNSS signal is of lower quality than the reference value, the oscillation frequency is corrected with the previous correction value, and the corrected oscillation frequency is set as the transmission control frequency. It is a transmitting device that

The setting unit further sets the time obtained from the GNSS signal as the time information when the received GNSS signal is of higher quality than a predetermined reference value, and the received GNSS signal is higher than the reference value. If the quality is low, the time obtained by counting at the timing synchronized with the oscillation frequency of the oscillator can be set as the time information.

The transmission control section can control the transmission section to transmit the transmission signal at a predetermined transmission timing known to the receiving side based on the time information set by the setting section.

When the quality of the received GNSS signal is higher than a predetermined reference value, the setting unit uses the time obtained from the GNSS signal to set the time obtained by counting at the timing synchronized with the oscillation frequency. can be corrected.

A GNSS receiver for receiving the GNSS signal may be further provided, and the setting unit may be configured to set the transmission control frequency based on the reception status of the GNSS signal by the GNSS receiver. can.

A transmission method according to one aspect of the present technology corrects the oscillation frequency of a transmitter using a frequency obtained from the GNSS signal received this time when the quality of the received GNSS signal is higher than a predetermined reference value, The corrected oscillation frequency is set as a transmission control frequency for controlling the transmission frequency of a transmission signal, and when the received GNSS signal is of lower quality than the reference value, the oscillation frequency is adjusted to the previous correction. and set the corrected oscillation frequency as the transmission control frequency, control the transmission frequency of the transmission signal based on the set transmission control frequency, and perform the transmission at the transmission frequency. A transmission method for transmitting a signal.

A receiving device according to another aspect of the present technology includes a setting unit that sets a reception control frequency for controlling a reception frequency of a signal transmitted from a transmission side based on a reception status of a GNSS signal; a reception control unit that controls the reception frequency of the signal based on the set reception control frequency; and a reception unit that receives the signal at the reception frequency controlled by the reception control unit , The setting unit corrects the oscillation frequency of the oscillator using the frequency obtained from the GNSS signal received this time when the quality of the received GNSS signal is higher than a predetermined reference value, and corrects the oscillation frequency after correction. frequency is set as the frequency for reception control, and when the received GNSS signal is of lower quality than the reference value, the oscillation frequency is corrected with the previous correction value, and the corrected oscillation frequency is used for the reception control. It is a receiving device that is set as a frequency for use .

The setting unit further sets the time obtained from the GNSS signal as the time information when the quality of the received GNSS signal is higher than a predetermined reference value, and the received GNSS signal is higher than the reference value. If the quality is low, the time obtained by counting at the timing synchronized with the oscillation frequency of the oscillator can be set as the time information.

The reception control section can control the reception section to receive the signal at a predetermined reception timing known to the transmission side based on the time information set by the setting section.

When the quality of the received GNSS signal is higher than a predetermined reference value, the setting unit uses the time obtained from the GNSS signal to set the time obtained by counting at the timing synchronized with the oscillation frequency. can be corrected.

A GNSS receiver for receiving the GNSS signal may be further provided, and the setting unit may be configured to set the reception control frequency based on the reception status of the GNSS signal by the GNSS receiver. can.

A reception method according to another aspect of the present technology corrects the oscillation frequency of a transmitter using a frequency obtained from the GNSS signal received this time when the quality of the received GNSS signal is higher than a predetermined reference value. and setting the corrected oscillation frequency as a reception control frequency for controlling the reception frequency of a signal transmitted from the transmission side, and if the received GNSS signal is lower in quality than the reference value, the oscillation frequency The frequency is corrected with the previous correction value, the corrected oscillation frequency is set as the reception control frequency, the reception frequency of the signal is controlled based on the set reception control frequency, and the reception is performed. A receiving method for receiving said signal at a frequency.

In the transmission device and method of one aspect of the present technology, when the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency of the oscillator is corrected using the frequency obtained from the GNSS signal received this time. and the corrected oscillation frequency is set as the transmission control frequency for controlling the transmission frequency of the transmission signal, and if the received GNSS signal is of lower quality than the reference value, the oscillation frequency value, the corrected oscillation frequency is set as the transmission control frequency, the transmission frequency of the transmission signal is controlled based on the set transmission control frequency, and the transmission signal is transmitted at that transmission frequency. be.

In the receiving device and method of another aspect of the present technology, when the quality of the received GNSS signal is higher than a predetermined reference value, the oscillation frequency of the oscillator uses the frequency obtained from the GNSS signal received this time. The corrected oscillation frequency is set as the reception control frequency for controlling the reception frequency of the signal transmitted from the transmission side, and if the received GNSS signal is of lower quality than the reference value, the oscillation The frequency is corrected with the previous correction value, the corrected oscillation frequency is set as the reception control frequency, the reception frequency of the signal is controlled based on the set reception control frequency, and the signal is received.

According to the present technology, signals can be transmitted or received. Further, according to the present technology, it is possible to suppress deterioration in communication quality.

It is a figure which shows the main structural examples of a position notification system. FIG. 3 is a diagram showing an example of how signals are transmitted and received; FIG. 5 is a diagram illustrating an example of how time information is calculated using GNSS signals; 2 is a block diagram showing a main configuration example of a transmission device; FIG. FIG. 11 is a flowchart for explaining an example of the flow of transmission processing; FIG. 1 is a block diagram showing a main configuration example of a high-sensitivity receiver; FIG. FIG. 11 is a flowchart for explaining an example of the flow of reception processing; FIG. FIG. 4 is a diagram illustrating an example of how frequency information is calculated using GNSS signals; 2 is a block diagram showing a main configuration example of a transmission device; FIG. FIG. 11 is a flowchart for explaining an example of the flow of transmission processing; FIG. 1 is a block diagram showing a main configuration example of a high-sensitivity receiver; FIG. FIG. 11 is a flowchart for explaining an example of the flow of reception processing; FIG. 1 is a diagram showing a main configuration example of an anti-theft system; FIG. It is a block diagram which shows the main structural examples of a computer.

Hereinafter, a form for carrying out the present disclosure (hereinafter referred to as an embodiment) will be described. The description will be given in the following order.
1. Transmission/reception control based on GNSS signals 2 . First embodiment (transmitting device/time control)
3. Second Embodiment (High Sensitivity Receiver/Time Control)
4. Third Embodiment (Transmitter/Frequency Control)
5. Fourth Embodiment (High Sensitivity Receiver/Frequency Control)
6. others

<1. Transmission and reception control based on GNSS signals>
<Location notification system>
FIG. 1 is a diagram showing a main configuration example of a position notification system, which is one embodiment of a signal transmission/reception system to which the present technology is applied. A location notification system 100 shown in FIG. 1 is a system in which a transmitting device 101 notifies its own location. This system is used, for example, to monitor and manage the location of objects. As shown in FIG. 1, the position notification system 100 has devices such as a transmitter 101, a highly sensitive receiver 102, a server 104, a terminal device 105, and the like. The number of transmission devices 101, high-sensitivity reception devices 102, servers 104, and terminal devices 105 is arbitrary, and each may be plural.

The transmitting device 101 is an embodiment of a transmitting device to which the present technology is applied, and transmits, for example, identification information that identifies itself, location information that indicates its location, etc. as a radio signal. The high-sensitivity receiving device 102 is an embodiment of a receiving device to which the present technology is applied, receives the radio signal, acquires identification information, location information, etc. of the transmitting device 101, and transmits them via the network 103. and supplies it to the server 104 . In other words, the high-sensitivity receiver 102 functions as a relay station that relays information transmitted from the transmitter 101 and transmits the information to the server 104 . The server 104 manages the position of each transmission device 101 by linking the position information to the identification information. A terminal device 105 operated by a user who wants to know the location of the transmitting device 101 accesses the server 104 via the network 103, supplies the identification information of the desired transmitting device 101, and requests its location information. Server 104 supplies location information corresponding to the requested identification information to terminal device 105 . The terminal device 105 acquires the position information and notifies the user of the position of the transmission device 101 by, for example, displaying it together with map data or the like.

By having such a transmitting device 101 carried (including possessed or worn) by an object whose position is to be monitored (managed), the server 104 can indirectly manage the position of the position monitored (managed) object. can be done. In the example of FIG. 1 , the user targets an elderly person 111 for location monitoring, and causes the elderly person 111 to carry the transmission device 101 . As described above, the location of transmitting device 101 is managed by server 104 and provided to terminal device 105 . Therefore, the user can operate the terminal device 105 to grasp the position of the elderly person 111 carrying the transmission device 101 .

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

The location information of the transmitting device 101 may be any information as long as it indicates the location of the transmitting device 101, and may be generated in any manner. For example, the transmitting device 101 may receive GNSS signals from GNSS (Global Navigation Satellite System) satellites and obtain its own location information (eg, latitude and longitude) based on the GNSS signals. Also, for example, the transmitting device 101 may identify its own position using a dedicated positioning system other than GNSS. Furthermore, this position information may be generated by a device other than the transmitting device 101, such as the high-sensitivity receiving device 102, the server 104, or a separately provided dedicated information processing device (server or the like).

For example, the GNSS signal received by the transmitting device 101 may be supplied to another device, and the other device may obtain the position information of the transmitting device 101 from the GNSS signal. Also, for example, the transmitting device 101 supplies information obtained using a dedicated positioning system other than GNSS to another device, and the other device obtains the location information of the transmitting device 101 based on the information. may Also, for example, another device may obtain the position information of the transmitting device 101 based on the communication status between the transmitting device 101 and the high-sensitivity receiving device 102 . For example, by identifying the high-sensitivity receiver 102 that has received the signal from the transmitter 101 , it may be determined that the transmitter 101 is located within the communicable range of the high-sensitivity receiver 102 . Furthermore, more detailed position information of the transmitting device 101 may be obtained based on the signal strength, delay time, etc. of the received signal received by the high-sensitivity receiving device 102 . Further, for example, the position information of the transmitting device 101 may be obtained by triangulation or the like using the position information of a plurality of high-sensitivity receiving devices 102 that have received the signal from the transmitting device 101 .

The installation position of the high-sensitivity receiver 102 is arbitrary. For example, it may be the roof of the building 112 such as a building, condominium, house, or the like. The buildings 112 are suitable because they are numerous in urban areas where there is a high possibility that a location monitoring target (for example, an elderly person 111) carrying the transmitting device 101 will be active, and they are easy to install. In particular, when the position monitoring target is a person, the home of the position monitoring target is more likely to be located in the vicinity of the house, which is preferable. In terms of securing an installation site, it is easier to obtain consent than when the location notification service provider independently secures a site and installs the high-sensitivity receiving device 102 .

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

The network 103 is an arbitrary communication network, and may be a wired communication network, a wireless communication network, or both. Also, the network 103 may be composed of one communication network, or may be composed of a plurality of communication networks. For example, the Internet, public telephone networks, wide area communication networks for wireless mobiles such as 3G lines and 4G lines, WANs (Wide Area Networks), LANs (Local Area Networks), communications conforming to the Bluetooth (registered trademark) standard wireless communication network, communication path for short-range wireless communication such as NFC (Near Field Communication), communication path for infrared communication, standards such as HDMI (registered trademark) (High-Definition Multimedia Interface) and USB (Universal Serial Bus) The network 103 may include a communication network or communication path of any communication standard, such as a wired communication network conforming to the .

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 each transmission device 101 . The server 104 can also manage users who are permitted to provide the location information of the transmitting device 101 . For example, the server 104 can provide the location information of each transmitting device 101 only to users who are permitted to obtain the location information of that transmitting device 101 .

As described above, the server 104 manages the location of the transmitting device 101 by relaying information provided from the transmitting device 101 by the high-sensitivity receiving device 102 and supplying it to the server 104 . In other words, the server 104 can manage the position of the transmitting device 101 when the transmitting device 101 is located within the communicable range of any of the high-sensitivity receiving devices 102 . In other words, if the position of transmitting device 101 is out of the communicable range of any high-sensitivity receiving device 102, server 104 cannot manage the position. Therefore, the wider the range of communication between the high-sensitivity receiving device 102 and the transmitting device 101 , the more accurately the server 104 can manage the location of the transmitting device 101 .

Here, more accurate management means managing the position of transmitting device 101 in a wider range (that is, reducing the area where the position of transmitting device 101 cannot be managed). In order to widen the range in which the position of the transmitting device 101 can be managed, the farther the transmitting device 101 and the high-sensitivity receiving device 102 can transmit and receive radio signals, The wider the communicable range), the better. The method of transmitting and receiving radio signals between the transmitting device 101 and the high-sensitivity receiving device 102 is arbitrary and may conform to any communication standard. ) may be used to allow long-distance communication to take place in a manner that allows it.

For example, if the time and frequency at which the transmitting device 101 transmits a radio signal are known (known by the high-sensitivity receiving device 102), the high-sensitivity receiving device 102 detects the radio signal at the known time and frequency. Since it is only necessary to do so, detection becomes easier. Therefore, reception sensitivity can be improved. In other words, the communicable range of the high-sensitivity receiver 102 can be further expanded. It should be noted that if the accuracy of such time and frequency control is reduced, detection becomes more difficult, and reception sensitivity may be reduced. In other words, it is possible to improve reception sensitivity by improving control accuracy of time and frequency.

Further, in such a position notification system 100, as shown in FIG. 2, one high-sensitivity receiver 102 receives radio signals from a plurality of transmitters 101 (transmitters 101-1 to 101-N). A case of receiving a signal is conceivable. In such a case, it is necessary to multiplex each radio signal so as not to interfere with each other so that the high-sensitivity receiver 102 can identify and receive the radio signal from each transmitter 101 . Conventional signal multiplexing methods include frequency division multiplexing (FDM), time division multiplexing (TDM), spectrum spreading, etc., as described in Patent Document 1, for example. rice field. Also, as a method of modulating a transmission signal, a method of chirp-modulating a phase-modulated signal has been devised, as described in Patent Document 2, for example.

In general, as the communicable range expands, the number (N) of transmitters 101 shown in FIG. 2 increases, so more signals need to be multiplexed. However, in order not to reduce the communication quality, it is necessary to multiplex the signals so that the signals are not mixed. In other words, in order to multiplex more signals, the time and frequency must be controlled more accurately (more finely) so that the signals are not mixed. In other words, more signals can be multiplexed by improving the time and frequency control accuracy.

<Time control>
For example, when performing time-division multiplexing in the position notification system 100 shown in FIG. 1, it is assumed that an accuracy of about 10 μs is required for time control. However, it has been difficult to achieve such accuracy with oscillators that are generally built into the transmitter 101 and the high-sensitivity receiver 102 . Therefore, it was conceived to use GNSS (Global Navigation Satellite System) signals to control the time.

GNSS (Global Navigation Satellite System) is a system in which multiple navigation satellites transmit radio waves to an unspecified number of people on the ground, and a receiver that receives the signals is used to know the position and course of the system. A GNSS signal is a navigation signal transmitted by that navigation satellite.

For example, in this GNSS, as shown in FIG. 3A, a receiver on the earth 120 receives GNSS signals from four navigation satellites (navigation satellites 121 to 124), Suppose you do Here, let the position of the navigation satellite 121 be (X1, Y1, Z1) and its satellite time be T1. Let the position of the navigation satellite 122 be (X2, Y2, Z2) and its satellite time be T2. Further, let the position of the navigation satellite 123 be (X3, Y3, Z3) and its satellite time be T3. Further, let the position of the navigation satellite 124 be (X4, Y4, Z4) and its satellite time be T4. Let the position of the receiver be (Xu, Yu, Zu) and the time of the receiver be Tu.

The receiver calculates its own position from the synchronization information of the spreading code (C/A code) of the GNSS signal. For example, in the receiver, the GNSS signal S1 from the navigation satellite 121, the GNSS signal S2 from the navigation satellite 122, the GNSS signal S3 from the navigation satellite 123, and the GNSS signal S4 from the navigation satellite 124 are received at the times shown in B in FIG. and In this case, the relationship between the reception times of each GNSS signal can be expressed by times T1, T2, T3, T4, and Tu. A simultaneous equation holds.

{(X1-Xu) ² +(Y1-Yu) ² +(Z1-Zu) ² } ^1/2 = C・(Tu-T1) (1)
{(X2-Xu) ²⁺ (Y2-Yu) ²⁺ (Z2-Zu) ² } ^1/2 = C・(Tu-T2) (2)
{(X3-Xu) ²⁺ (Y3-Yu) ²⁺ (Z3-Zu) ² } ^1/2 = C・(Tu-T3) (3)
{(X4-Xu) ²⁺ (Y4-Yu) ²⁺ (Z4-Zu) ² } ^1/2 = C・(Tu-T4) (4)

By solving the above simultaneous equations, the receiver position (Xu, Yu, Zu) and the receiver time Tu can be obtained. In other words, if GNSS signals can be received with sufficient quality from four or more navigation satellites, the position of the receiver and receiver time can be obtained.

Such navigation satellites have high-precision cesium oscillators, and can obtain more accurate time information than oscillators normally built in receivers and the like. Therefore, generally, the time information (receiver time) obtained by the receiver based on the GNSS signal as described above is more accurate than the time information obtained by using the oscillator built into the receiver.

The information obtained from the GNSS signal also contains advance information to correct for "leap seconds." The receiver can obtain more accurate time information by inserting a "leap second" based on this information.

Therefore, the transmission device 101 and the high-sensitivity reception device 102 in the position notification system 100 can improve the accuracy of time control during signal transmission/reception by using the time information obtained from such GNSS signals. That is, higher quality communication can be realized.

However, reception of GNSS signals is not always good. If the quality of the received GNSS signal is not sufficient and the coordinates and time of each navigation satellite observed contain errors, the accuracy of the receiver position (Xu, Yu, Zu) and receiver time Tu will also be reduced. In addition, when the number of GNSS signals that could be received is insufficient, that is, when the number of GNSS signals that the receiver was able to receive with sufficient quality is 3 or less, the receiver uses an interpolation formula to determine the position of the receiver. and receiver time. Therefore, there is a risk that the accuracy of the obtained receiver position and receiver time may be reduced. As a result, the accuracy of time control may be reduced. If the accuracy of time control is reduced, signals may be mixed in time-division multiplexing, or reception sensitivity may be reduced due to an increase in error in the time of signal transmission/reception, resulting in a decrease in communication quality.

Therefore, information for controlling the transmission of the transmission signal is set based on the GNSS signal or the oscillation frequency of the oscillator, the transmission of the transmission signal is controlled based on the set information, and the transmission signal is transmitted according to the transmission control. to send. By doing so, it is possible to suppress a decrease in the accuracy of time control and a decrease in communication quality.

<2. First Embodiment>
<Time control of transmitter>
FIG. 4 is a block diagram showing a main configuration example of the transmission device 101. As shown in FIG. As shown in FIG. 4, the transmission device 101 includes a reference value setting unit 211, a GNSS reception unit 212, a correction determination unit 213, an oscillator 214, a clock counter 215, a clock unit 216, a transmission schedule control unit 217, and a transmission control unit 218. , an oscillator 219 and a transmitter 220 .

The reference value setting unit 211 performs processing related to setting of a reference value for determination of transmission time control. The reference value setting unit 211 can be realized by any configuration. For example, the reference value setting unit 211 may be configured by a circuit, LSI (Large Scale Integration), system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the reference value setting unit 211 may have a CPU and a memory, and the CPU (Central Processing Unit) may use the memory to execute a program to perform the above processing.

The GNSS receiver 212 performs processing related to reception of GNSS signals. The GNSS receiver 212 can be implemented with any configuration. For example, the GNSS receiver 212 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the GNSS receiver 212 may be configured with an antenna, a receiver circuit, a signal processing circuit, and the like.

The correction determination unit 213 performs processing related to determination regarding transmission time control. Correction determination unit 213 can be realized by an arbitrary configuration. For example, the correction determination unit 213 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the correction determination unit 213 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

Oscillator 214 oscillates at a predetermined oscillation frequency and generates a signal at that oscillation frequency. Oscillator 214 can be implemented with any configuration. For example, the oscillator 214 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the oscillator 214 may be composed of an oscillation circuit or the like. The oscillation method of this oscillator 214 is arbitrary.

The clock counter 215 performs processing related to time generation based on the signal generated by the oscillator 214 . The clock counter 215 can be realized by any configuration. For example, the clock counter 215 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the clock counter 215 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The clock unit 216 performs processing related to generation of time information used to control transmission timing. The clock unit 216 can be realized by any configuration. For example, the clock unit 216 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the clock unit 216 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The transmission schedule control unit 217 performs processing related to transmission schedule control. The transmission schedule control section 217 can be realized by any configuration. For example, the transmission schedule control unit 217 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the transmission schedule control unit 217 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The transmission control unit 218 performs processing related to transmission control. The transmission control section 218 can be realized by any configuration. For example, the transmission control unit 218 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the transmission control unit 218 may have a CPU and memory, and the CPU may use the memory to execute the program, thereby performing the above-described processing.

The oscillation unit 219 performs processing related to transmission frequency setting. Oscillator 219 can be realized by any configuration. For example, the oscillator 219 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the oscillator 219 may be configured by an oscillator circuit or the like. Note that the oscillation method of the oscillation unit 219 is arbitrary.

The transmission unit 220 performs processing related to transmission. Transmitter 220 can be realized by any configuration. For example, the transmission unit 220 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the transmission section 220 may be composed of a signal processing circuit, a transmission circuit, an antenna, and the like.

In the transmission device 101 having such a configuration, the clock unit 216 generates a transmission signal based on the GNSS signal received by the GNSS reception unit 212 or the oscillation frequency of the oscillator 214 (the frequency of the signal generated by the oscillator 214). Sets the time information that is information for controlling the transmission of Transmission control section 218 (and transmission schedule control section 217) controls transmission of the transmission signal based on the time information. Transmitting section 220 transmits the transmission signal according to the control, that is, at the transmission time specified by the time information.

When the GNSS signal received by the GNSS receiver 212 is of high quality, time information obtained based on the GNSS signal is more accurate than time information obtained based on the oscillation frequency of the oscillator 214 . However, if the GNSS signal received by the GNSS receiver 212 is of low quality, the time information obtained based on the GNSS signal may be less accurate than the time information obtained based on the oscillation frequency of the oscillator 214. Therefore, as described above, by appropriately using both the GNSS signal and the oscillation frequency of the oscillator 214 to set the time information, even if the reception quality of the GNSS signal is not sufficient, the accuracy of time control can be reduced. can be suppressed. That is, the transmission signal can be transmitted more accurately at the desired timing (transmission time).

Note that this transmission time is a known timing for the receiving side. In other words, by doing so, the transmitting device 101 can prevent the transmission time from deviating from the known timing for the receiving side. In other words, the transmission device 101 sets the reception time (timing at which the signal is received) of the high-sensitivity reception device 102 more accurately to the timing corresponding to the transmission time of the transmission signal (that is, the timing suitable for receiving the transmission signal). ).

Also, in time division multiplexing, the transmission device 101 suppresses a decrease in the accuracy of time control even when the reception quality of the GNSS signal is not sufficient by doing as described above, and prevents signals from being mixed with each other. More signals can be multiplexed.

Therefore, even when the reception quality of the GNSS signal is not sufficient, the transmission device 101 can suppress a decrease in the reception sensitivity of the high-sensitivity reception device 102, and can suppress a decrease in communication quality.

The clock unit 216 can select the GNSS signal or the oscillation frequency according to the reception status of the GNSS signal, and use the selected one to set the time information. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

The clock unit 216 sets time information using the received GNSS signal when the quality of the received GNSS signal is higher than a predetermined reference value, and when the received GNSS signal is of lower quality than the reference value, Time information can be set using the oscillation frequency. More specifically, when the quality of the received GNSS signal is higher than a predetermined reference value, the clock unit 216 sets the time obtained from the GNSS signal as the time information, and the received GNSS signal corresponds to the reference value. If the quality is lower than the value, the time obtained by counting in the clock counter 215 in synchronization with the oscillation frequency can be set as the time information. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

Transmission control section 218 (and transmission schedule control section 217) controls transmission section 220 to transmit a transmission signal based on the time information set by clock section 216 at a predetermined transmission timing known to the receiving side. can be sent in Therefore, since the transmission signal can be transmitted at a more accurate transmission time, deterioration of communication quality can be suppressed. Also, even when the transmission signal is time-division multiplexed, the transmission control section 218 can transmit each signal at a more accurate transmission timing by using the time information set by the clock section 216. , more signals can be multiplexed while preventing signals from being mixed with each other, and reduction in communication quality can be suppressed.

By the way, the oscillator 214 oscillates at an oscillation frequency and generates a signal at that frequency. Oscillator 214 provides its signal to watch counter 215 . The clock counter 215 performs counting in synchronization with the frequency of the signal supplied from the oscillator 214 (that is, oscillation frequency), and sets the time based on the oscillation frequency (also called oscillator generation time). The clock counter 215 supplies the oscillator generation time to the clock section 216 . The clock unit 216 can set time information using the oscillator generation time as described above.

Such a clock counter 215 synchronizes with the oscillation frequency given by the oscillator 214 using the time obtained from the GNSS signal in the correction determination unit 213 when the received GNSS signal is of higher quality than a predetermined reference value. It is possible to correct the time obtained by counting at the timing. This makes it possible to make the time based on the oscillation frequency more accurate, so even if the reception quality of the GNSS signal is not sufficient, it is possible to set more accurate time information and suppress deterioration of communication quality. can.

The GNSS receiver 212 receives, for example, GNSS signals. The clock unit 216 can set time information based on the GNSS signal or the oscillation frequency received by the GNSS receiver unit 212 . Also, the correction determination unit 213 determines, for example, whether the quality of the GNSS signal received by the GNSS reception unit 212 is sufficiently high based on the reference value set by the reference value setting unit 211. . Then, when determining that the GNSS signal is of sufficiently high quality, the correction determining unit 213 sets the time (correction-inclusive time) based on the GNSS signal received by the GNSS receiving unit 212, for example. The correction determination unit 213 supplies the time based on this GNSS signal to the clock counter 215 and clock unit 216 . The clock unit 216 can generate time information from the time based on this GNSS signal, as described above. Also, the clock counter 215 can correct the time based on the oscillation frequency using the time based on the GNSS signal, as described above.

<Transmission process flow>
An example of the flow of transmission processing executed by the transmission device 101 will be described with reference to the flowchart of FIG. When the transmission process is started, the reference value setting unit 211 sets a correction application determination reference value used as a threshold in the determination by the correction determination unit 213 in step S101. Any method can be used to set this reference value. For example, a predetermined value may be set, or may be specified by a user or the like, or may be set according to, for example, the external environment or the internal environment. The reference value setting unit 211 supplies the set correction application determination reference value to the correction determination unit 213 .

In step S102, the GNSS receiver 212 receives a GNSS signal. The GNSS signal contains various information such as time information and position information of the navigation satellite that transmitted the GNSS signal. The GNSS reception unit 212 supplies the information included in the received GNSS signal to the correction determination unit 213 as reception information. In step S103, correction determination section 213 determines the quality of the received information. The correction determination unit 213 determines (evaluates) the quality of received information based on information such as the number of satellites that can receive GNSS signals, CNR (Carrier to Noise ratio) of each satellite, Doppler frequency, altitude, leap second, etc. . Then, in step S104, correction determining section 213 determines whether or not the quality of the received information is high using the correction application determination reference value set by reference value setting section 211 as a threshold. If the quality of the received information exceeds the correction application determination reference value and is determined to be of sufficiently high quality, the process proceeds to step S105.

In step S<b>105 , the correction determination section 213 sets the time (correction included time) based on the GNSS signal using the received information, and supplies the corrected time to the clock counter 215 and the clock section 216 . This corrected time is based on the time information of the navigation satellite as described above, and is more accurate than the time based on the oscillation frequency. In other words, the time includes a correction for the time based on the oscillation frequency.

In step S106, the clock unit 216 sets the corrected time as time information. The clock unit 216 supplies the set time information to the transmission schedule control unit 217 . If the received GNSS signal is of sufficiently high quality, the corrected time obtained based on the GNSS signal is also sufficiently accurate. Therefore, the clock unit 216 can set more accurate time information by using the accurate corrected time. Therefore, transmitting device 101 can suppress deterioration in communication quality by transmitting a transmission signal based on the more accurate time information.

In step S107, the clock counter 215 corrects its own count value, ie, the oscillator generation time, with the corrected time generated by the process of step S105. Therefore, the clock counter 215 can make the oscillator generation time (count value) more accurate by correcting the oscillator generation time using the correct corrected time. Therefore, even when the reception quality of the GNSS signal is not sufficient, the transmission device 101 can set more accurate time information, and can suppress deterioration in communication quality.

When the process of step S107 is completed, the process proceeds to step S110. If it is determined in step S104 that the quality of the received information does not exceed the correction application determination reference value and is not of sufficiently high quality (low quality), the process proceeds to step S108.

In step S 108 , the clock counter 215 generates oscillator generation time from the oscillation frequency of the oscillator 214 . In step S109, the clock unit 216 sets the oscillator generation time generated by the process of step S108 as time information. That is, when the reception quality of the GNSS signal is low, the time information is set using the time based on the oscillation frequency generated inside the transmitting device 101 without depending on the GNSS signal. Therefore, even if the reception quality of the GNSS signal is not sufficient, the transmission device 101 can suppress the accuracy of the time information from decreasing due to the use of the interpolation formula, etc., and can suppress the deterioration of the communication quality.

When the processing of step S109 ends, the processing proceeds to step S110. In step S110, the transmission schedule control unit 217 sets the transmission timing for transmitting the transmission signal based on the time information supplied from the clock unit 216 and a preset transmission schedule (also known to the receiving side). do. This transmission timing is timing known to the receiving side. By setting the transmission timing using the time information set as described above, the transmission schedule control section 217 can set the transmission timing to a more accurate time. Therefore, reduction in communication quality can be suppressed. The transmission schedule control section 217 supplies the set transmission timing to the transmission control section 218 .

In step S111, the transmission control section 218 controls the oscillation section 219 and the transmission section 220 to transmit the transmission signal at the transmission timing set in step S110. The oscillator 219 oscillates at a predetermined oscillation frequency (for example, 920 MHz band) under the control of the transmission controller 218 and supplies the signal of the oscillation frequency to the transmitter 220 . The transmission section 220 generates a transmission signal and transmits the transmission signal at the above-described transmission timing at the oscillation frequency of the oscillation section 219 under the control of the transmission control section 218 . Therefore, even if the reception quality of the GNSS signal is not sufficient, the transmission section 220 can transmit the transmission signal at more accurate transmission timing, thereby suppressing deterioration in communication quality.

Any method of generating the transmission signal may be used. Also, the content of the transmission signal is arbitrary. For example, time information, location information, etc. of the transmitting device 101 may be included. Also, the transmission signal may be time-division multiplexed and transmitted. Even in that case, the transmission unit 220 transmits the transmission signal under the control of the transmission control unit 218, so that the transmission signal can be transmitted at more accurate transmission timing even when the reception quality of the GNSS signal is not sufficient. This allows more signals to be multiplexed while keeping the signals from mixing. Therefore, reduction in communication quality can be suppressed.

When the process of step S111 ends, the transmission process ends. By executing each process as described above, the transmitting device 101 can suppress deterioration in communication quality.

<3. Second Embodiment>
<Time control of receiver>
In the high-sensitivity receiver 102, as in the case of the transmitter 101, it is possible to perform more accurate time control by using the GNSS signal. If there is an error in the coordinates or time of the navigation satellite, there is a risk that the communication quality will be reduced.

Therefore, based on the GNSS signal or the oscillation frequency of the oscillator, information for controlling the reception of the signal transmitted from the transmitting side is set, the signal reception is controlled based on the set information, and the reception is performed. to receive the signal according to the control. By doing so, it is possible to suppress a decrease in control accuracy and a decrease in communication quality.

FIG. 6 is a block diagram showing a main configuration example of the high-sensitivity receiver 102. As shown in FIG. As shown in FIG. 6, the high-sensitivity receiving device 102 includes a reference value setting unit 311, a GNSS receiving unit 312, a correction determining unit 313, an oscillator 314, a clock counter 315, a clock unit 316, a reception schedule control unit 317, and a reception control unit. It has a section 318 , an oscillating section 319 and a receiving section 320 .

The reference value setting unit 311 performs processing for setting a reference value for determining control of reception time. The reference value setting unit 311 can be realized by any configuration. For example, the reference value setting unit 311 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the reference value setting unit 311 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The GNSS reception unit 312 performs processing related to reception of GNSS signals. The GNSS receiver 312 can be implemented with any configuration. For example, the GNSS receiver 312 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the GNSS receiver 312 may be configured with an antenna, a receiver circuit, a signal processing circuit, and the like.

The correction determination unit 313 performs processing related to determination regarding reception time control. Correction determination unit 313 can be realized by an arbitrary configuration. For example, the correction determination unit 313 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the correction determination unit 313 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above-described processing.

Oscillator 314 oscillates at a predetermined oscillation frequency and generates a signal at that oscillation frequency. Oscillator 314 can be implemented with any configuration. For example, the oscillator 314 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the oscillator 314 may be composed of an oscillation circuit or the like. The oscillation method of this oscillator 314 is arbitrary.

The clock counter 315 performs processing related to time generation based on the signal generated by the oscillator 314 . The clock counter 315 can be realized by any configuration. For example, the clock counter 315 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the clock counter 315 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The clock unit 316 performs processing related to generation of time information used for control of reception timing. The clock section 316 can be realized by any configuration. For example, the clock unit 316 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the clock unit 316 may have a CPU and a memory, and the CPU may use the memory to execute the program, thereby performing the above processing.

The reception schedule control unit 317 performs processing related to reception schedule control. Reception schedule control section 317 can be realized by an arbitrary configuration. For example, the reception schedule control unit 317 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the reception schedule control unit 317 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The reception control unit 318 performs processing related to reception control. The reception control section 318 can be realized by any configuration. For example, the reception control unit 318 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the reception control unit 318 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The oscillation unit 319 performs processing related to reception frequency setting. Oscillator 319 can be realized by any configuration. For example, the oscillator 319 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the oscillator 219 may be configured by an oscillator circuit or the like. Note that the oscillation method of the oscillation unit 319 is arbitrary.

The receiving unit 320 performs processing related to reception. Receiving section 320 can be realized by an arbitrary configuration. For example, the receiver 320 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the receiving section 320 may be configured with an antenna, a receiving circuit, a signal processing circuit, and the like.

In the highly sensitive receiver 102 having such a configuration, the clock unit 316, based on the GNSS signal received by the GNSS receiver 312 or the oscillation frequency of the oscillator 314 (the frequency of the signal generated by the oscillator 314), Sets time information, which is information for controlling signal reception. Reception control section 318 (and reception schedule control section 317) controls signal reception based on the time information. Receiving section 320 transmits the received signal according to the control, that is, at the reception time designated by the time information. This reception time is a time corresponding to the transmission time of the transmission device 101 . In other words, by doing so, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress a decrease in the accuracy of control, thereby suppressing a decrease in communication quality.

The clock unit 316 can select the GNSS signal or the oscillation frequency according to the reception status of the GNSS signal, and use the selected one to set the time information. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

Clock unit 316 sets time information using the received GNSS signal when the quality of the received GNSS signal is higher than a predetermined reference value, and when the received GNSS signal is of lower quality than the reference value, Time information can be set using the oscillation frequency. More specifically, when the quality of the received GNSS signal is higher than a predetermined reference value, the clock unit 316 sets the time obtained from the GNSS signal as the time information, and the received GNSS signal corresponds to the reference value. If the quality is lower than the value, the time obtained by counting in synchronization with the oscillation frequency in the clock counter 315 can be set as the time information. Therefore, even if the reception quality of the GNSS signal is not sufficient, it is possible to suppress a decrease in the accuracy of time control, thereby suppressing a decrease in communication quality.

The reception control unit 318 (and the reception schedule control unit 317) controls the reception unit 320 to receive the signal at a predetermined reception timing known to the transmission side based on the time information set by the clock unit 316. can be made Therefore, it is possible to receive signals at more accurate reception timings, thereby suppressing deterioration in communication quality.

By the way, the oscillator 314 oscillates at the oscillation frequency and generates a signal at that frequency. Oscillator 314 provides its signal to watch counter 315 . The clock counter 315 performs counting in synchronization with the frequency of the signal supplied from the oscillator 314 (that is, oscillation frequency), and sets the time based on the oscillation frequency (also called oscillator generation time). The clock counter 315 supplies the oscillator generation time to the clock section 316 . The clock unit 316 can set time information using the oscillator generation time as described above.

Such a clock counter 315 synchronizes with the oscillation frequency given by the oscillator 314 using the time obtained from the GNSS signal in the correction determination unit 313 when the received GNSS signal is of higher quality than a predetermined reference value. It is possible to correct the time obtained by counting at the timing. This makes it possible to make the time based on the oscillation frequency more accurate, so even if the reception quality of the GNSS signal is not sufficient, it is possible to set more accurate time information and suppress deterioration of communication quality. can.

The GNSS receiver 312 receives, for example, GNSS signals. The clock unit 316 can set time information based on the GNSS signal or the oscillation frequency received by the GNSS receiver unit 312 . Further, the correction determination unit 313 determines, for example, whether the quality of the GNSS signal received by the GNSS reception unit 312 is sufficiently high based on the reference value set by the reference value setting unit 311. . Then, when determining that the GNSS signal is of sufficiently high quality, the correction determining unit 313 sets the time (correction-inclusive time) based on the GNSS signal received by the GNSS receiving unit 312, for example. The correction determination unit 313 supplies the time based on this GNSS signal to the clock counter 315 and clock unit 316 . The clock unit 316 can generate time information from the time based on this GNSS signal, as described above. Also, the clock counter 315 can correct the time based on the oscillation frequency using the time based on the GNSS signal, as described above.

<Flow of reception processing>
An example of the flow of reception processing executed by the high-sensitivity reception device 102 will be described with reference to the flowchart of FIG. When the reception process is started, the reference value setting unit 311 sets a correction application determination reference value used as a threshold in the determination by the correction determination unit 313 in step S201. Any method can be used to set this reference value. For example, a predetermined value may be set, or may be specified by a user or the like, or may be set according to, for example, the external environment or the internal environment. The reference value setting unit 311 supplies the set correction application determination reference value to the correction determination unit 313 .

In step S202, the GNSS receiver 312 receives a GNSS signal. The GNSS signal contains various information such as time information and position information of the navigation satellite that transmitted the GNSS signal. The GNSS reception unit 312 supplies the information included in the received GNSS signal to the correction determination unit 313 as reception information. In step S203, correction determination section 313 determines the quality of the received information. The correction determination unit 313 determines (evaluates) the quality of received information based on information such as the number of satellites that can receive GNSS signals, CNR (Carrier to Noise ratio) of each satellite, Doppler frequency, altitude, leap second, etc. . Then, in step S204, correction determination section 313 determines whether or not the quality of the received information is high using the correction application determination reference value set by reference value setting section 311 as a threshold. If it is determined that the quality of the received information exceeds the correction application determination reference value and is of sufficiently high quality, the process proceeds to step S205.

In step S<b>205 , the correction determination unit 313 sets the time based on the GNSS signal (corrected time) using the received information, and supplies the corrected time to the clock counter 315 and clock unit 316 . This corrected time is based on the time information of the navigation satellite as described above, and is more accurate than the time based on the oscillation frequency. In other words, the time includes a correction for the time based on the oscillation frequency.

In step S206, clock unit 316 sets the corrected time as time information. The clock unit 316 supplies the set time information to the reception schedule control unit 317 . If the received GNSS signal is of sufficiently high quality, the corrected time obtained based on the GNSS signal is also sufficiently accurate. Therefore, the clock unit 316 can set more accurate time information by using the accurate corrected time. Therefore, the high-sensitivity receiver 102 can suppress deterioration of communication quality by receiving signals based on the more accurate time information.

In step S207, the clock counter 315 corrects its own count value, ie, the oscillator generation time, with the corrected time generated in step S205. Therefore, the clock counter 315 can make the oscillator generation time (count value) more accurate by correcting the oscillator generation time using the correct corrected time. Therefore, even when the reception quality of the GNSS signal is not sufficient, the high-sensitivity reception device 102 can set more accurate time information, and can suppress deterioration in communication quality.

When the processing of step S207 ends, the processing proceeds to step S210. If it is determined in step S204 that the quality of the received information does not exceed the correction application determination reference value and is not of sufficiently high quality (low quality), the process proceeds to step S208.

In step S<b>208 , the clock counter 315 generates oscillator generation time from the oscillation frequency of the oscillator 314 . In step S209, the clock unit 316 sets the oscillator generation time generated by the process of step S208 as time information. That is, when the reception quality of the GNSS signal is low, the time information is set using the time based on the oscillation frequency generated inside the high-sensitivity receiving device 102 without relying on the GNSS signal. Therefore, even when the reception quality of the GNSS signal is not sufficient, the high-sensitivity receiving device 102 can suppress a decrease in the accuracy of time information due to the use of an interpolation formula, etc., and can suppress a decrease in communication quality. .

When the process of step S209 ends, the process proceeds to step S210. In step S210, the reception schedule control unit 317 determines the reception timing for receiving the signal based on the time information supplied from the clock unit 316 and the reception schedule (predetermined reception schedule) corresponding to the known transmission schedule. set. This reception timing is the timing corresponding to the transmission timing in the transmission device 101, that is, the timing suitable for receiving the signal transmitted at the transmission timing. By setting the reception timing using the time information set as described above, the reception schedule control unit 317 sets the reception timing to a more accurate time even when the reception quality of the GNSS signal is not sufficient. can do. Therefore, reduction in communication quality can be suppressed. The reception schedule control section 317 supplies the set reception timing to the reception control section 318 .

In step S211, the reception control section 318 controls the oscillation section 319 and the reception section 320 to receive the transmission signal transmitted from the transmission device 101 at the reception timing set in step S210. The oscillator 319 oscillates at a predetermined oscillation frequency (for example, 920 MHz band) under the control of the reception controller 318 and supplies the signal of the oscillation frequency to the receiver 320 . Under the control of the reception control unit 318, the reception unit 320 receives a signal at the oscillation frequency of the oscillation unit 319 at the reception timing described above (that is, receives a signal transmitted at the same frequency as the oscillation frequency of the oscillation unit 319). ).

By receiving signals in this way under the control of the reception control unit 318, the reception unit 320 can receive signals at more accurate reception timing even when the reception quality of the GNSS signals is not sufficient. Therefore, reduction in communication quality can be suppressed.

When the received signal is time-division multiplexed, the receiver 320 receives the signal under the control of the reception controller 318, so that the GNSS signal can be multiplexed even if the reception quality of the GNSS signal is not sufficient. Therefore, it is possible to suppress the deterioration of the identification accuracy of each signal. That is, it is possible to more accurately receive signals in which more signals are multiplexed. Therefore, reduction in communication quality can be suppressed.

The receiving unit 320 extracts identification information, location information, etc. of the transmitting device 101 from the received signal and supplies it to the server 104 .

When the process of step S211 ends, the reception process ends. By executing each process as described above, the high-sensitivity receiving apparatus 102 can suppress deterioration in communication quality.

<4. Third Embodiment>
<Frequency control>
The transmitting device 101 can control not only the transmission time as described above but also the transmission frequency in transmitting the transmission signal. When frequency division multiplexing is performed as described above, more signals can be multiplexed by improving the control accuracy of the frequency of the transmission signal. For example, when performing frequency division multiplexing in the position notification system 100 shown in FIG. 1, it is assumed that frequency control accuracy is required to be approximately 10 Hz. However, it has been difficult to achieve such accuracy with oscillators that are generally built into the transmitter 101 and the high-sensitivity receiver 102 . Therefore, as in the case of time control described above, it was considered to control the frequency using the GNSS signal.

For example, as shown in FIG. 8, let Vs be the vector of the velocity of the navigation satellite (satellite velocity), fd be the Doppler frequency, Vu be the vector of the velocity of the receiver (receiver velocity), and Let D be the vector up to and let e (=D/|D|) be the unit vector in that direction. Using these, the relative velocity Vd of the receiver with respect to the navigation satellite can be expressed as in the following equation (5).

Vd=((Vs-Vu)・e) (5)

Also, if the speed of light is C, the Doppler frequency of the navigation satellite is fd, the carrier frequency of the GNSS signal is fc, and the wavelength is λ, then the relative velocity Vd of the receiver with respect to the navigation satellite is given by the following equation (6 ) can be expressed as

Vd=C・fd/fc=fd・λ (6)

In the example of A in FIG. 3, the satellite velocity of the navigation satellite 121 is Vs1 (=(VX1, VY1, VZ1)) and the Doppler frequency is fd1. Let Vs2 (=(VX2, VY2, VZ2)) be the satellite velocity of the navigation satellite 122, and fd2 be the Doppler frequency. Furthermore, the satellite velocity of the navigation satellite 123 is Vs3 (=(VX3, VY3, VZ3)), and the Doppler frequency is fd3. Further, the satellite velocity of the navigation satellite 124 is Vs4 (=(VX4, VY4, VZ4)), and the Doppler frequency is fd4.

A unit vector directed from the navigation satellite 121 to the receiver is e1 (=(eX1, eY1, eZ1)). A unit vector directed from the navigation satellite 122 to the receiver is e2 (=(eX2, eY2, eZ2)). A unit vector directed from the navigation satellite 123 to the receiver is e3 (=(eX3, eY3, eZ3)). A unit vector directed from the navigation satellite 124 to the receiver is e4 (=(eX4, eY4, eZ4)).

Information about these navigation satellites is known from orbital information, carrier synchronization of receivers, and the like. Therefore, from equations (5) and (6), by solving the following simultaneous equations of equations (7) to (10), the receiver velocity Vu (=(VXu, VYu, VZu)) and the oscillator frequency , the offset dfu can be obtained.

(VX1-VXu)・eX1+(VY1-VYu)・eY1+(VZ1-VZu)・eZ1=C・(fd1-dfu)/fc (7)
(VX2-VXu)・eX2+(VY2-VYu)・eY2+(VZ2-VZu)・eZ2=C・(fd2-dfu)/fc (8)
(VX3-VXu)・eX3+(VY3-VYu)・eY3+(VZ3-VZu)・eZ3=C・(fd3-dfu)/fc (9)
(VX4-VXu)・eX4+(VY4-VYu)・eY4+(VZ4-VZu)・eZ4=C・(fd4-dfu)/fc (10)

Secondly, the exact Xtal oscillation frequency is also known. If you can receive GNSS signals from 5 or more satellites, you can solve with the least squares method.

Such navigation satellites have high-precision cesium oscillators, and can obtain more accurate frequencies than oscillators normally built in receivers and the like. Therefore, in general, the frequency obtained based on the GNSS signal in the receiver as described above is more accurate than the oscillation frequency of the oscillator built into the receiver (the frequency does not fluctuate).

Therefore, in the position notification system 100, the transmission device 101 and the high-sensitivity reception device 102 use frequencies obtained from such GNSS signals, thereby improving the accuracy of frequency control during signal transmission/reception. That is, higher quality communication can be realized.

However, reception of GNSS signals is not always good. If the quality of the received GNSS signal is not sufficient and errors are included in the satellite velocity, Doppler frequency, carrier frequency, etc. of each navigation satellite observed, the accuracy of the receiver oscillator frequency offset will also be reduced. In addition, when the number of GNSS signals that could be received is insufficient, that is, when the number of GNSS signals that the receiver was able to receive with sufficient quality is 3 or less, the receiver uses an interpolation formula to determine the position of the receiver. and receiver time. Therefore, the accuracy of the obtained oscillator frequency offset of the receiver may be reduced. As a result, the accuracy of frequency control may be reduced. If the accuracy of frequency control is reduced, signals may be mixed in frequency division multiplexing, or reception sensitivity may be reduced due to an increase in error in the time of signal transmission/reception, resulting in reduced communication quality.

Therefore, information for controlling the transmission of the transmission signal is set based on the GNSS signal or the oscillation frequency of the oscillator, the transmission of the transmission signal is controlled based on the set information, and the transmission signal is transmitted according to the transmission control. to send. By doing so, it is possible to suppress a decrease in accuracy of frequency control and a decrease in communication quality.

<Frequency control of transmitter>
FIG. 9 is a block diagram showing a main configuration example of the transmission device 101 when performing frequency control. As shown in FIG. 9, in this case, transmitting apparatus 101 has correction determining section 413 in place of correction determining section 213 in FIG. has an oscillation frequency calculator 416.

The correction determination unit 413 performs processing related to determination regarding transmission frequency control. Correction determination unit 413 can be realized by an arbitrary configuration. For example, the correction determination unit 413 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the correction determination unit 413 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

The oscillation frequency calculator 416 performs processing related to setting of the transmission frequency after correction (transmission frequency including error). Oscillation frequency calculator 416 can be realized by an arbitrary configuration. For example, the oscillation frequency calculator 416 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the oscillation frequency calculation unit 416 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

In the transmission device 101 having such a configuration, the oscillation frequency calculation unit 416, based on the GNSS signal received by the GNSS reception unit 212 or the oscillation frequency of the oscillator 214 (the frequency of the signal generated by the oscillator 214), A transmission control frequency (also referred to as an error-inclusive transmission frequency), which is information for controlling transmission of a transmission signal, is set. The transmission control section 218 controls transmission of the transmission signal based on the transmission control frequency. Oscillating section 219 oscillates according to the control, that is, at a transmission frequency based on the designated transmission control frequency, and transmitting section 220 transmits a transmission signal at that transmission frequency. By doing so, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress a decrease in control accuracy. That is, the transmission signal can be transmitted more accurately at a desired frequency (transmission frequency).

Note that this transmission frequency is a frequency known to the receiving side. In other words, by doing so, the transmitting apparatus 101 can prevent the transmission frequency from deviating from the frequency known to the receiving side. In other words, the transmitting device 101 can enable the high-sensitivity receiving device 102 to match the reception frequency more accurately with the frequency of the transmission signal.

Also in the case of frequency division multiplexing, time division multiplexing using chirp modulation, etc., the transmission apparatus 101 can improve the accuracy of frequency control even when the reception quality of the GNSS signal is not sufficient. More signals can be multiplexed while reducing attenuation and preventing signals from intermingling.

Therefore, even when the reception quality of the GNSS signal is not sufficient, the transmission device 101 can suppress a decrease in the reception sensitivity of the high-sensitivity reception device 102, and can suppress a decrease in communication quality.

The oscillation frequency calculator 416 can select the GNSS signal or the oscillation frequency according to the reception status of the GNSS signal, and use the selected one to set the transmission control frequency. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

When the quality of the received GNSS signal is higher than a predetermined reference value, the oscillation frequency calculation unit 416 sets the error-inclusive transmission frequency using the GNSS signal, and the received GNSS signal is lower in quality than the reference value. , the error-inclusive transmission frequency can be set using the oscillation frequency. More specifically, when the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency calculator 416 adjusts the frequency (oscillation frequency) of the signal supplied from the oscillator 214 to the GNSS signal received this time. The frequency error obtained from the signal can be used for correction and set as the transmission control frequency. On the other hand, if the received GNSS signal is of lower quality than its reference value, the oscillation frequency calculator 416 sets the frequency of the signal supplied from the oscillator 214 (oscillation frequency) to the frequency used in the previous correction. It can be corrected using a correction value and set as the transmission control frequency. Since the previous correction value was obtained when the GNSS signal was of high quality, using this value enables more accurate transmission control than when using the correction value obtained from the low-quality GNSS signal this time. frequency is obtained. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

The transmission control section 218 controls the oscillation section 219 to oscillate at a transmission frequency based on the transmission control frequency set by the oscillation frequency calculation section 416 . The transmission control section 218 can then control the transmission section 220 to transmit the transmission signal at that transmission frequency. Therefore, it is possible to transmit a transmission signal at a more accurate transmission frequency, and suppress deterioration in communication quality.

Also, when the transmission signal is frequency division multiplexed, the transmission control section 218 transmits the multiplexed signals at a transmission frequency based on the transmission control frequency set by the oscillation frequency calculation section 416. Can be set to exact frequency. Further, even when time division multiplexing using chirp modulation is applied to the transmission signal, the transmission control section 218 causes the transmission signal to be transmitted at the transmission frequency based on the transmission control frequency set by the oscillation frequency calculation section 416. , the bandwidth of each signal can be made narrower. Therefore, it is possible to multiplex more signals while preventing signals from being mixed with each other, thereby suppressing a decrease in communication quality.

The GNSS receiver 212 receives, for example, GNSS signals. The oscillation frequency calculator 416 can set the transmission control frequency based on the GNSS signal or the oscillation frequency received by the GNSS receiver 212 . Also, the correction determination unit 213 determines, for example, whether the quality of the GNSS signal received by the GNSS reception unit 212 is sufficiently high based on the reference value set by the reference value setting unit 211. . Then, when determining that the GNSS signal is of sufficiently high quality, the correction determining unit 213 sets the frequency (frequency error) based on the GNSS signal received by the GNSS receiving unit 212, for example. The correction determination section 213 supplies the frequency error based on this GNSS signal to the oscillation frequency calculation section 416 . The oscillation frequency calculator 416 can generate the transmission control frequency from the frequency error based on this GNSS signal, as described above.

<Transmission process flow>
An example of the flow of transmission processing executed by the transmission device 101 in this case will be described with reference to the flowchart of FIG. When the transmission process is started, the processes of steps S301 to S304 are executed in the same manner as the processes of steps S101 to S104 in FIG. However, the processing of steps S303 and S304 is performed by the correction determination unit 413 . If it is determined in step S304 that the quality of the received information exceeds the correction application determination reference value and is of sufficiently high quality, the process proceeds to step S305.

In step S<b>305 , the correction determination unit 413 uses the received information to set the frequency (frequency error) based on the GNSS signal, and supplies the frequency error to the oscillation frequency calculation unit 416 . This frequency error is a correction value based on information such as the satellite velocity of the navigation satellite, as described above.

In step S306, the oscillation frequency calculator 416 corrects the oscillation frequency obtained in the oscillator 214 by the frequency error set in step S305, and sets the corrected frequency as the error-inclusive transmission frequency. The oscillation frequency calculator 416 supplies the transmission frequency including the error to the transmission controller 218 .

If the received GNSS signal is of sufficiently high quality, the frequency error obtained based on that GNSS signal is also sufficiently accurate. Therefore, the oscillation frequency calculator 416 can set a more accurate error-inclusive transmission frequency by correcting the oscillation frequency using the accurate frequency error. Therefore, transmitting apparatus 101 can suppress deterioration in communication quality by transmitting a transmission signal at a transmission frequency based on the more accurate error-inclusive transmission frequency.

When the processing of step S306 ends, the processing proceeds to step S308. If it is determined in step S304 that the quality of the received information does not exceed the correction application determination reference value and is not of sufficiently high quality (low quality), the process proceeds to step S307.

In step S307, the oscillation frequency calculator 416 corrects the oscillation frequency of the oscillator 214 with the same frequency error as the previous time. The oscillation frequency calculator 416 supplies the transmission frequency including the error to the transmission controller 218 . That is, when the reception quality of the GNSS signal is low, the oscillation frequency is corrected using the frequency error based on the high-quality GNSS signal without relying on the low-quality GNSS signal. Therefore, even if the reception quality of the GNSS signal is not sufficient, the transmission device 101 can suppress the deterioration of the accuracy of the frequency due to the use of the interpolation formula, etc., and can suppress the deterioration of the communication quality.

When the process of step S307 is completed, the process proceeds to step S308. In step S308, the transmission control unit 218 controls the oscillation unit 219 and the transmission unit 220 to transmit the transmission signal at the transmission frequency based on the transmission frequency including the error obtained by the processing in step S306 or S307. The oscillator 219 oscillates at the transmission frequency under the control of the transmission controller 218 and supplies the signal of the transmission frequency to the transmitter 220 . The transmission section 220 generates a transmission signal and transmits the transmission signal at the frequency (transmission frequency) of the signal supplied from the oscillation section 219 under the control of the transmission control section 218 . Note that this transmission frequency is a frequency known to the receiving side. Therefore, even if the reception quality of the GNSS signal is not sufficient, the transmission section 220 can transmit the transmission signal at a more accurate transmission frequency, thereby suppressing deterioration in communication quality.

Any method of generating the transmission signal may be used. Also, the content of the transmission signal is arbitrary. For example, time information, location information, etc. of the transmitting device 101 may be included. Also, the transmission signal may be frequency division multiplexed and transmitted. Even in this case, the transmission unit 220 transmits the transmission signal under the control of the transmission control unit 218, so that the transmission signal can be transmitted at a more accurate transmission frequency even when the reception quality of the GNSS signal is not sufficient. , more signals can be multiplexed while avoiding mixing of the signals. Therefore, reduction in communication quality can be suppressed.

Also, the transmission signal may be time-division multiplexed using chirp modulation. Even in that case, the transmission section 220 can narrow the bandwidth of each signal by transmitting the transmission signal under the control of the transmission control section 218 . Therefore, more signals can be multiplexed while avoiding mixing of signals. Therefore, reduction in communication quality can be suppressed.

When the process of step S308 ends, the transmission process ends. By executing each process as described above, the transmitting device 101 can suppress deterioration in communication quality.

<5. Fourth Embodiment>
<Frequency control of receiver>
In the high-sensitivity receiver 102, as in the case of the transmitter 101, more accurate frequency control can be performed by using the GNSS signal. If there is an error in the navigation satellite speed, Doppler frequency, carrier frequency, etc., there is a risk that the accuracy of frequency control will be reduced and the communication quality will be reduced.

Therefore, based on the GNSS signal or the oscillation frequency of the oscillator, information for controlling the reception of the signal transmitted from the transmitting side is set, the signal reception is controlled based on the set information, and the reception is performed. to receive the signal according to the control. By doing so, it is possible to suppress a decrease in accuracy of frequency control and a decrease in communication quality.

FIG. 11 is a block diagram showing a main configuration example of the high-sensitivity receiver 102 when performing frequency control. As shown in FIG. 11, in this case, high-sensitivity receiver 102 has correction determination section 513 instead of correction determination section 313 in FIG. has an oscillation frequency calculator 516 instead of the .

Correction determination section 513 performs processing related to determination regarding control of the reception frequency. Correction determination unit 513 can be realized by an arbitrary configuration. For example, the correction determination unit 513 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the correction determination unit 513 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above processing.

Oscillation frequency calculator 516 performs processing related to setting of the reception frequency after correction (error-inclusive reception frequency). Oscillation frequency calculator 516 can be realized by an arbitrary configuration. For example, the oscillation frequency calculator 516 may be configured by a circuit, LSI, system LSI, processor, module, unit, set, device, apparatus, system, or the like. Also, a plurality of them may be combined. At that time, for example, the same type of configuration such as multiple circuits and multiple processors may be combined, or different types of configuration such as a circuit and LSI may be combined. For example, the oscillation frequency calculator 516 may have a CPU and a memory, and the CPU may use the memory to execute a program to perform the above-described processing.

In the high-sensitivity receiving device 102 having such a configuration, the oscillation frequency calculation unit 516 generates a to set a reception control frequency (also referred to as an error-inclusive reception frequency), which is information for controlling signal reception. The reception control unit 318 controls reception of the signal (transmitted from the transmission device 101) based on the reception control frequency. Oscillating section 319 oscillates according to the control, that is, at a reception frequency based on the designated reception control frequency, and receiving section 320 receives a signal at that reception frequency. By doing so, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the reduction in accuracy of frequency control. That is, it is possible to receive a signal at a desired frequency (receiving frequency) more accurately.

Note that this reception frequency is a frequency (frequency known to the transmitting side) corresponding to the transmission frequency of the transmission signal transmitted from the transmission device 101 . In other words, by doing so, the high-sensitivity receiver 102 can prevent the reception frequency from deviating from the frequency suitable for receiving the transmission signal transmitted from the transmitter 101 .

In addition, when frequency division multiplexing, time division multiplexing using chirp modulation, or the like is applied to the signal to be received, the high-sensitivity receiving apparatus 102 is configured as described above so that the reception quality of the GNSS signal is insufficient. Even in such a state, it is possible to suppress a decrease in the identification accuracy of each multiplexed signal. That is, it is possible to more accurately receive signals in which more signals are multiplexed. Therefore, reduction in communication quality can be suppressed.

Therefore, even when the reception quality of the GNSS signal is not sufficient, the high-sensitivity reception device 102 can suppress a decrease in reception sensitivity and a decrease in communication quality.

The oscillation frequency calculation unit 516 can select the GNSS signal or the oscillation frequency according to the reception status of the GNSS signal, and use the selected one to set the reception control frequency. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency calculator 516 sets the error-inclusive reception frequency using the GNSS signal, and the received GNSS signal is lower in quality than the reference value. , the error-inclusive reception frequency can be set using the oscillation frequency. More specifically, when the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency calculator 516 adjusts the frequency (oscillation frequency) of the signal supplied from the oscillator 314 to the GNSS signal received this time. A frequency error obtained from the signal can be used for correction, and it can be set as the reception control frequency. On the other hand, if the received GNSS signal is of lower quality than the reference value, the oscillation frequency calculator 516 sets the frequency (oscillation frequency) of the signal supplied from the oscillator 314 to the frequency used for the previous correction. It can be corrected using a correction value and set as the reception control frequency. Since the previous correction value was obtained when the GNSS signal was of high quality, using this value enables more accurate reception control than when using the correction value obtained from the low-quality GNSS signal this time. frequency is obtained. Therefore, even when the reception quality of the GNSS signal is not sufficient, it is possible to suppress the decrease in the accuracy of the control, so it is possible to suppress the decrease in the communication quality.

The reception control section 318 can control the oscillation section 319 to oscillate at the reception frequency based on the reception control frequency set by the oscillation frequency calculation section 516 . The reception control section 318 can then control the reception section 320 to receive the signal at that reception frequency. Therefore, signals can be received at a more accurate reception frequency, and deterioration in communication quality can be suppressed.

The reception control unit 318 also controls the oscillation frequency calculation unit 516 when the received signal is frequency-division multiplexed or when time-division multiplexing using chirp modulation is applied to the received signal. By receiving at the reception frequency based on the reception control frequency set by , it is possible to suppress the reduction in the identification accuracy of each multiplexed signal. That is, reduction in communication quality can be suppressed.

The GNSS receiver 312 receives, for example, GNSS signals. The oscillation frequency calculator 516 can set the reception control frequency based on the GNSS signal or the oscillation frequency received by the GNSS receiver 312 . Further, the correction determination unit 513 determines, for example, whether the quality of the GNSS signal received by the GNSS reception unit 312 is sufficiently high based on the reference value set by the reference value setting unit 311. . Then, when determining that the GNSS signal is of sufficiently high quality, the correction determining unit 513 sets the frequency (frequency error) based on the GNSS signal received by the GNSS receiving unit 312, for example. The correction determination section 513 supplies the frequency error based on this GNSS signal to the oscillation frequency calculation section 516 . The oscillation frequency calculator 516 can generate the reception control frequency from the frequency error based on this GNSS signal, as described above.

<Flow of reception processing>
An example of the flow of reception processing executed by the high-sensitivity reception device 102 in this case will be described with reference to the flowchart of FIG. When the reception process is started, the processes of steps S401 to S404 are executed in the same manner as the processes of steps S201 to S204 in FIG. However, the processing of steps S403 and S404 is performed by the correction determination unit 513 . If it is determined in step S404 that the quality of the received information exceeds the correction application determination reference value and is of sufficiently high quality, the process proceeds to step S405.

In step S<b>405 , the correction determination unit 513 uses the received information to set the frequency (frequency error) based on the GNSS signal, and supplies the frequency error to the oscillation frequency calculation unit 516 . This frequency error is a correction value based on information such as the satellite velocity of the navigation satellite, as described above.

In step S406, oscillation frequency calculation section 516 corrects the oscillation frequency obtained in oscillator 314 by the frequency error set in step S405, and sets the corrected frequency as the reception frequency including error. The oscillation frequency calculator 516 supplies the received frequency including the error to the reception controller 318 .

If the received GNSS signal is of sufficiently high quality, the frequency error obtained based on that GNSS signal is also sufficiently accurate. Therefore, oscillation frequency calculation section 516 can set a more accurate received frequency including error by correcting the oscillation frequency using the accurate frequency error. Therefore, high-sensitivity receiving apparatus 102 can suppress deterioration in communication quality by receiving signals at reception frequencies based on the more accurate error-incorporated reception frequencies.

When the processing of step S406 ends, the processing proceeds to step S408. If it is determined in step S404 that the quality of the received information does not exceed the correction application determination reference value and is not of sufficiently high quality (low quality), the process proceeds to step S407.

In step S407, the oscillation frequency calculator 516 corrects the oscillation frequency of the oscillator 314 with the same frequency error as the previous time. That is, when the reception quality of the GNSS signal is low, the oscillation frequency is corrected using the frequency error based on the high-quality GNSS signal without relying on the low-quality GNSS signal. Therefore, even when the reception quality of the GNSS signal is not sufficient, the high-sensitivity receiving device 102 can suppress a decrease in the accuracy of time information due to the use of an interpolation formula, etc., and can suppress a decrease in communication quality. .

When the process of step S407 is completed, the process proceeds to step S408. In step S408, the reception control unit 318 controls the oscillation unit 319 and the reception unit 320 to receive the signal at the reception frequency based on the error-inclusive reception frequency obtained by the processing in step S406 or S407. Oscillating section 319 oscillates at the reception frequency under the control of reception control section 318 and supplies a signal at the reception frequency to reception section 320 . The receiving unit 320 receives a signal at the frequency (receiving frequency) of the signal supplied from the oscillating unit 319 under the control of the receiving control unit 318 (that is, receives the signal transmitted at the same frequency as the oscillation frequency of the oscillating unit 319). receive).

By receiving signals in this manner under the control of the reception control unit 318, the reception unit 320 can receive signals at more accurate reception frequencies even when the reception quality of the GNSS signals is not sufficient. Therefore, reduction in communication quality can be suppressed.

When frequency division multiplexing, time division multiplexing using chirp modulation, or the like is applied to the signal to be received, the reception unit 320 receives the signal according to the control of the reception control unit 318, whereby the GNSS signal is received. Even if the quality is not sufficient, it is possible to suppress the reduction in the identification accuracy of each multiplexed signal. That is, it is possible to more accurately receive signals in which more signals are multiplexed. Therefore, reduction in communication quality can be suppressed.

The receiving unit 320 extracts identification information, location information, etc. of the transmitting device 101 from the received signal and supplies it to the server 104 .

When the process of step S408 ends, the reception process ends. By executing each process as described above, the high-sensitivity receiving apparatus 102 can suppress deterioration in communication quality.

<6. Others>
<Transmit/receive control/time frequency control>
The present technology may be applied only to the transmission device 101, may be applied only to the high-sensitivity reception device 102, or may be applied to both the transmission device 101 and the high-sensitivity reception device 102. may Also, the present technology may be applied to a transmitting/receiving device having a transmitting function and a receiving function. In that case, the present technology may be applied only to the transmission function, may be applied only to the reception function, or may be applied to both the transmission function and the reception function.

Also, the transmission device 101 may perform both time control and frequency control for signal transmission. In that case, the present technology may be applied only to time control, may be applied only to frequency control, or may be applied to both time control and frequency control. Also, the high-sensitivity receiver 102 may perform both time control and frequency control for signal reception. In that case, the present technology may be applied only to time control, may be applied only to frequency control, or may be applied to both time control and frequency control.

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

For example, the present technology can also be applied to an anti-theft system 800 for preventing theft of automobiles, motorcycles, etc., as shown in FIG. In the anti-theft system 800, the transmitter 101 is installed on an object whose position the user monitors, such as a car 801 or a motorcycle 802 owned by the user. As in the case of the position notification system 100, the transmitting device 101 appropriately notifies the high-sensitivity receiving device 102 of its own position information (that is, the position information of the car 801 and the motorcycle 802). In other words, the user can access the server 104 from the terminal device 105 and grasp the positions of the car 801 and the motorcycle 802 as in the case of the position notification system 100 . Therefore, even if the user is stolen, the user can grasp the position of the automobile 801 or the motorcycle 802, so that the automobile 801 or the motorcycle 802 can be recovered easily.

Also in the case of such an anti-theft system 800, by applying the present technology described above in each embodiment to the transmitting device 101 and the high-sensitivity receiving device 102, it is possible to suppress deterioration in communication quality, position information (that is, the position information of the automobile 801 and the motorcycle 802) can be notified to the high-sensitivity receiver 102 more accurately. In other words, the user can more easily and accurately ascertain the position of the automobile 801 or the motorcycle 802 even if it is stolen.

<Other communication systems>
Any information can be sent and received. For example, the transmission device 101 may transmit transmission information including images, sounds, measurement data, identification information of devices, setting information of parameters, control information such as commands, and the like. Also, the transmission information may include a plurality of types of information such as image and sound, identification information, setting information and control information.

Also, the transmitting device 101 may be capable of transmitting transmission information including information supplied from other devices, for example. For example, the transmission device 101 can transmit images, light, brightness, saturation, electricity, sound, vibration, acceleration, velocity, angular velocity, force, temperature (not temperature distribution), humidity, distance, area, volume, shape, flow rate, Generate and transmit transmission information including information (sensor output) output from various sensors that detect or measure arbitrary variables such as time, time, magnetism, chemical substances, or odors, or the amount of change thereof. You may make it

In other words, for example, the present technology can perform three-dimensional shape measurement, space measurement, object observation, movement deformation observation, biological observation, authentication processing, monitoring, autofocus, imaging control, lighting control, tracking processing, input/output control, electronic device control, It can be applied to a system used for any purpose such as actuator control.

In addition, the present technology can be applied to systems in any field such as transportation, medical care, crime prevention, agriculture, livestock industry, mining, beauty, factories, home appliances, 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 mobile device with a camera function, or the like. In addition, for example, this technology can be applied to an in-vehicle system that captures images of the front, back, surroundings, and interior of a vehicle for safe driving such as automatic stopping, recognition of the driver's condition, etc., and monitoring of running vehicles and roads. The present invention can also be applied to systems used for transportation, such as a monitoring camera system for monitoring distance between vehicles and a distance measuring system for distance measurement between vehicles. Furthermore, for example, the present technology can also be applied to a security system that uses surveillance cameras for crime prevention, cameras for personal authentication, and the like. Also, for example, the present technology can be applied to a system used for sports that uses various sensors that can be used for sports, such as a wearable camera. Furthermore, for example, the present technology can also be applied to systems used for agriculture that use various sensors such as cameras for monitoring the state of fields and crops. Further, for example, the present technology can also be applied to a system for livestock industry that uses various sensors for monitoring the state of livestock such as pigs and cattle. Furthermore, the present technology can be applied to systems that monitor natural conditions such as volcanoes, forests, and oceans, weather observation systems that observe weather, temperature, humidity, wind speed, hours of sunshine, etc. It can also be applied to a system for observing the ecology of wildlife such as genus, amphibians, mammals, insects and plants.

<Communication device>
Furthermore, the specifications of radio signals and information to be transmitted and received are arbitrary. In the above, an example in which the present technology is applied to the transmitting device 101 and the high-sensitivity receiving device 102 has been described, but the present technology may be applied to any transmitting device, any receiving device, and any transmitting/receiving device. can be done. That is, the present technology can be applied to any communication device or communication system.

<Computer>
The series of processes described above can be executed by hardware or by software. Moreover, it is also possible to execute some of the processes by hardware and others by software. When executing a series of processes by software, a program that constitutes the software is installed in the computer. Here, the computer includes, for example, a computer built into dedicated hardware and a general-purpose personal computer capable of executing various functions by installing various programs.

FIG. 14 is a block diagram showing a configuration example of hardware of a computer that executes the series of processes described above 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 interconnected via a bus 904 .

Input/output interface 910 is also connected to 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, mouse, microphone, touch panel, 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 is composed of, for example, a hard disk, a RAM disk, a nonvolatile memory, or the like. The communication unit 914 is composed of, for example, a network interface. Drive 915 drives removable media 921 such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory.

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

A program executed by the computer (CPU 901) can be applied by being recorded on a removable medium 921 such as a package medium, for example. In that case, the program can be installed in the storage unit 913 via the input/output interface 910 by loading the removable medium 921 into the drive 915 . The program can also be provided via wired or wireless transmission media such as local area networks, the Internet, and digital satellite broadcasting. In that case, the program can be received by the communication unit 914 and installed in the storage unit 913 . Alternatively, 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 are possible without departing from the gist of the present technology.

For example, the present technology can be applied to any configuration that constitutes a device or system, such as a processor as a system LSI (Large Scale Integration), a module using multiple processors, a unit using multiple modules, etc. It can also be implemented as a set or the like with additional functions (that is, a configuration of part of the device).

In this specification, a system means a set of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Therefore, 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 both 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 configuration described above as a plurality of devices (or processing units) may be collectively configured as one device (or processing unit). Further, it is of course possible to add a configuration other than the above to the configuration of each device (or each processing unit). Furthermore, part of the configuration of one device (or processing unit) may be included in the configuration of another device (or other processing unit) as long as the configuration and operation of the system as a whole are substantially the same. .

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

Also, for example, the above-described program can be executed in any device. In that case, the device should have the necessary functions (functional blocks, etc.) and be able to obtain the necessary information.

Further, for example, each step described in the flowchart above can be executed by one device, or can be shared by a plurality of devices and executed. Furthermore, when one step includes a plurality of processes, the plurality of processes included in the one step can be executed by one device or shared by a plurality of devices. In other words, a plurality of processes included in one step can also be executed as processes of a plurality of steps. Conversely, the processing described as multiple steps can also be collectively executed as one step.

A computer-executed program may be such that the processing of the steps described in the program is executed in chronological order according to the order described herein, in parallel, when called, etc. may be executed individually at required timings. That is, as long as there is no contradiction, 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.

Each of the techniques described in this specification can be implemented independently and singly unless inconsistent. Of course, it is also possible to use any number of the present techniques in combination. For example, part or all of the present technology described in any embodiment can be combined with part or all of the present technology described in other embodiments. Also, part or all of any of the techniques described above may be implemented in conjunction with other techniques not described above.

The present technology can also take the following configurations.
(1) a setting unit that sets information for controlling transmission of the transmission signal based on the GNSS signal or the oscillation frequency of the oscillator;
a transmission control unit that controls transmission of the transmission signal based on the information set by the setting unit;
and a transmission unit that transmits the transmission signal under the control of the transmission control unit.
(2) The transmitting device according to (1), wherein the setting unit selects the GNSS signal or the oscillation frequency according to the reception status of the GNSS signal, and uses the selected one to set the information.
(3) The setting unit
setting the information using the GNSS signal if the received GNSS signal is of higher quality than a predetermined reference value;
(2), wherein the information is set using the oscillation frequency when the received GNSS signal is of lower quality than the reference value.
(4) the information includes time information;
The setting unit
when the quality of the received GNSS signal is higher than a predetermined reference value, setting the time obtained from the GNSS signal as the time information;
The transmission according to (3) is configured to set, as the time information, a time obtained by counting at a timing synchronized with the oscillation frequency when the received GNSS signal is of lower quality than the reference value. Device.
(5) The transmission control unit controls the transmission unit to transmit the transmission signal at a predetermined transmission timing known to the receiving side based on the time information set by the setting unit. 4) The transmitter according to 4).
(6) When the quality of the received GNSS signal is higher than a predetermined reference value, the setting unit uses the time obtained from the GNSS signal to count at the timing synchronized with the oscillation frequency. The transmitter according to (4) or (5), wherein the time is corrected.
(7) the information includes a transmission control frequency;
The setting unit
When the quality of the received GNSS signal is higher than a predetermined reference value, the oscillation frequency is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is used for the transmission control. set as frequency,
When the quality of the received GNSS signal is lower than the reference value, the oscillation frequency is corrected with a previous correction value, and the corrected oscillation frequency is set as the transmission control frequency. The transmitter according to any one of (3) to (6).
(8) The transmission device according to (7), wherein the transmission control section controls the transmission section to transmit the transmission signal at a transmission frequency based on the transmission control frequency set by the setting section.
(9) further comprising a GNSS receiver that receives the GNSS signal;
The transmitting device according to any one of (1) to (8), wherein the setting unit is configured to set the information based on the GNSS signal or the oscillation frequency received by the GNSS receiving unit.
(10) setting information for controlling the transmission of the transmission signal based on the GNSS signal or the oscillation frequency of the oscillator;
performing transmission control of the transmission signal based on the set information;
A transmission method, wherein the transmission signal is transmitted according to the transmission control.
(11) a setting unit that sets information for controlling reception of a signal transmitted from a transmitting side based on a GNSS signal or an oscillation frequency of an oscillator;
a reception control unit that controls reception of the signal based on the information set by the setting unit;
and a receiver that receives the signal under the control of the reception controller.
(12) The receiving device according to (11), wherein the setting unit selects the GNSS signal or the oscillation frequency according to the reception status of the GNSS signal, and uses the selected one to set the information.
(13) The setting unit
setting the information using the GNSS signal if the received GNSS signal is of higher quality than a predetermined reference value;
(12), wherein the information is set using the oscillation frequency when the received GNSS signal is of lower quality than the reference value.
(14) the information includes time information;
The setting unit
when the quality of the received GNSS signal is higher than a predetermined reference value, setting the time obtained from the GNSS signal as the time information;
(13) Reception according to (13), configured to set, as the time information, a time obtained by counting at a timing synchronized with the oscillation frequency when the received GNSS signal is of lower quality than the reference value. Device.
(15) The reception control unit controls the reception unit to receive the signal at a predetermined reception timing known to the transmission side based on the time information set by the setting unit. ).
(16) When the quality of the received GNSS signal is higher than a predetermined reference value, the setting unit uses the time obtained from the GNSS signal to count at timing synchronized with the oscillation frequency. The receiving device according to (14) or (15), wherein the time is corrected.
(17) the information includes a reception control frequency;
The setting unit
When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is used for the reception control. set as frequency,
When the quality of the received GNSS signal is lower than the reference value, the oscillation frequency is corrected with a previous correction value, and the corrected oscillation frequency is set as the reception control frequency. The receiving device according to any one of (13) to (16).
(18) The receiving device according to (17), wherein the reception control section controls the reception section to receive the signal at a reception frequency based on the reception control frequency set by the setting section.
(19) further comprising a GNSS receiver that receives the GNSS signal;
The receiving device according to any one of (11) to (18), wherein the setting unit is configured to set the information based on the GNSS signal or the oscillation frequency received by the GNSS receiving unit.
(20) setting information for controlling reception of the signal transmitted from the transmitting side based on the GNSS signal or the oscillation frequency of the oscillator;
performing reception control of the signal based on the set information;
A reception method for receiving the signal according to the reception control.

100 position notification system, 101 transmitting device, 102 high-sensitivity receiving device, 103 network, 104 server, 111 elderly person, 211 reference value setting unit, 212 GNSS receiving unit, 213 correction determining unit, 214 oscillator, 215 clock counter, 216 clock 217 transmission schedule control unit 218 transmission control unit 219 oscillation unit 220 transmission unit 311 reference value setting unit 312 GNSS reception unit 313 correction determination unit 314 oscillator 315 clock counter 316 clock unit 317 reception Schedule control unit 318 Reception control unit 319 Oscillation unit 320 Reception unit 413 Correction determination unit 416 Oscillation frequency calculation unit 513 Correction determination unit 516 Oscillation frequency calculation unit 800 Anti-theft system

Claims (12)

a setting unit that sets a transmission control frequency for controlling the transmission frequency of a transmission signal based on the reception status of the GNSS signal;
a transmission control unit that controls the transmission frequency of the transmission signal based on the transmission control frequency set by the setting unit;
a transmission unit that transmits the transmission signal at the transmission frequency controlled by the transmission control unit ;
The setting unit
When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency of the oscillator is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is sent to the transmission signal. Set as control frequency,
When the quality of the received GNSS signal is lower than the reference value, the oscillation frequency is corrected with the previous correction value, and the corrected oscillation frequency is set as the transmission control frequency.
transmitter. The setting unit further
setting the time obtained from the GNSS signal as time information when the quality of the received GNSS signal is higher than a predetermined reference value;
The transmission device according to claim 1, wherein when the received GNSS signal is of lower quality than the reference value , the time obtained by counting at a timing synchronized with the oscillation frequency of a transmitter is set as the time information . The transmission control unit controls the transmission unit to transmit the transmission signal to a predetermined reception side at a known transmission timing based on the time information set by the setting unit.
The transmitting device according to claim 2 . When the quality of the received GNSS signal is higher than a predetermined reference value, the setting unit uses the time obtained from the GNSS signal to set the time obtained by counting at the timing synchronized with the oscillation frequency. to correct
The transmitting device according to claim 2 . further comprising a GNSS receiver that receives the GNSS signal;
The setting unit is configured to set the transmission control frequency based on the reception status of the GNSS signal by the GNSS reception unit.
The transmitting device according to claim 1 . When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency of the oscillator is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is used as the transmission signal. set as the transmission control frequency for controlling the transmission frequency of
when the quality of the received GNSS signal is lower than the reference value, correcting the oscillation frequency with the previous correction value, setting the corrected oscillation frequency as the transmission control frequency,
controlling the transmission frequency of the transmission signal based on the set transmission control frequency;
transmit the transmit signal on the transmit frequency
Send method. a setting unit for setting a reception control frequency for controlling the reception frequency of a signal transmitted from a transmission side based on the reception status of a GNSS signal;
a reception control unit that controls the reception frequency of the signal based on the reception control frequency set by the setting unit ;
a receiver that receives the signal at the reception frequency controlled by the reception controller ;
with
The setting unit
When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency of the oscillator is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is set to the received signal. Set as control frequency,
When the quality of the received GNSS signal is lower than the reference value, the oscillation frequency is corrected with the previous correction value, and the corrected oscillation frequency is set as the reception control frequency.
receiving device. The setting unit further
setting the time obtained from the GNSS signal as time information when the quality of the received GNSS signal is higher than a predetermined reference value;
When the quality of the received GNSS signal is lower than the reference value, the time obtained by counting at the timing synchronized with the oscillation frequency of the oscillator is set as the time information.
The receiving device according to claim 7 . 9. The reception control unit according to claim 8, wherein the reception control unit controls the reception unit to receive the signal at a predetermined reception timing known to the transmission side based on the time information set by the setting unit. receiver. When the quality of the received GNSS signal is higher than a predetermined reference value, the setting unit uses the time obtained from the GNSS signal to set the time obtained by counting at the timing synchronized with the oscillation frequency. to correct
The receiving device according to claim 8. further comprising a GNSS receiver that receives the GNSS signal;
The setting unit is configured to set the reception control frequency based on the reception status of the GNSS signal by the GNSS reception unit.
The receiving device according to claim 7 . When the received GNSS signal is of higher quality than a predetermined reference value, the oscillation frequency of the oscillator is corrected using the frequency obtained from the GNSS signal received this time, and the corrected oscillation frequency is sent from the transmitting side. Set as a reception control frequency for controlling the reception frequency of the transmitted signal,
when the quality of the received GNSS signal is lower than the reference value, correcting the oscillation frequency with the previous correction value, setting the corrected oscillation frequency as the reception control frequency,
controlling the reception frequency of the signal based on the set reception control frequency;
receive said signal at said receive frequency
receiving method.

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