COMMUNICATION DEVICE, COMMUNICATION SYSTEM, AND METHOD FOR CONTROLLING COMMUNICATION DEVICE

Abstract

To realize low power consumption and suppression of unnecessary radiation.SOLUTION: In a communication device that communicates a baseband signal contactlessly with another communication device, the baseband signal is a signal in which a known pattern is inserted during an idle period between the communication device and the other communication device, and the communication device includes a transmission unit that stops outputting a transmission signal for transmission to the other communication device during a period in which the reception strength of a received signal received from the other communication device is less than a first threshold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a communication device , communication systems and a control method for a communication device. [Background technology]

[0002] In recent years, proximity communication systems have become known that use electromagnetic coupling between nearby couplers (hereafter referred to as couplers) to communicate without contact. If the application of proximity communication systems can make communication between electronic circuit boards or modules wireless, it will be possible to reduce the number of parts, such as connectors and harnesses, at the connection points, which has the advantage of simplifying the manufacturing process.

[0003] Patent Document 1 discloses a communication system that communicates binary baseband signals in a non-contact manner using electric field coupling. In this communication system, couplers provided on a transmitter and a receiver are arranged facing each other and in close proximity, and wireless communication is achieved using the electric field coupling that occurs between the couplers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-29785 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 does not mention transmission control when communication devices (transmitter and receiver) are separated to the extent that they cannot communicate (hereinafter referred to as "separate"). If the communication devices continue to transmit even when they are separated from each other beyond the distance at which they can communicate (hereinafter referred to as "close"), transmission power will be wasted and unnecessary radiation will occur.

[0006] One possible method is to periodically check communication between communication devices (ACK response check), and if an ACK response is received, it is determined that they are in close proximity and communication can begin. However, this requires transmission to check communication even when the devices are far apart, which wastes power and generates unnecessary radiation.

[0007] The present disclosure aims to achieve low power consumption and suppression of unnecessary radiation. [Means for solving the problem]

[0008] A communication device transmits baseband signals to other communication devices in a contactless manner. full duplex A communication device for communicating, a first transmitting coupler coupled to a first receiving coupler of the other communication device, a second receiving coupler coupled to a second transmitting coupler of the other communication device, and a second transmitting coupler coupled to the second receiving coupler, During a period in which the reception strength of the signal received from the other communication device is less than a first threshold, via the first transmit coupler Send Belief Transmitter that stops outputting signals and Has. [Effects of the Invention]

[0009] It is possible to achieve low power consumption and suppress unnecessary radiation. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a close-proximity communication system. [Figure 2] FIG. 2 is a diagram for explaining changes in the time axis of a signal. [Figure 3] 10 is a flowchart illustrating a control method for the close proximity communication system. [Figure 4] FIG. 1 is a diagram illustrating an example of the configuration of a close-proximity communication system. [Figure 5] 10 is a flowchart illustrating a control method for the close proximity communication system. [Figure 6] FIG. 2 illustrates a transmit coupler, a receive coupler, a transmit circuit, and a receive circuit. [Figure 7] 1A and 1B are diagrams illustrating an example of the structure of a coupler. [Figure 8]FIG. 10 is a diagram showing the dimensions of couplers and the distance between couplers. [Figure 9] FIG. 10 is a diagram showing a simulation result of differences in interference characteristics. [Figure 10] 10 is a flowchart illustrating a control method for the close proximity communication system. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) Hereinafter, a first embodiment will be described with reference to the drawings. Note that this embodiment describes one specific example, and is not limited to what is described here.

[0012] 1 is a diagram showing an example of the configuration of a close-proximity communication system 30 according to the first embodiment. The close-proximity communication system 30 includes a module 31, a module 32, a communication terminal 33, and a communication terminal 34. In the close-proximity communication system 30, communication between the communication terminal 33 and the communication terminal 34 is performed in a contactless manner using the modules 31 and 32. The communication terminal 33 and the module 31 are communication devices, and the communication terminal 34 and the module 32 are other communication devices.

[0013] Module 31 and module 32 are each a proximity communication module. Module 31 has a transmission coupler (transmission coupler) 12 and a reception coupler (reception coupler) 13. Module 32 has a transmission coupler 22 and a reception coupler 23. Module 31 and module 32 communicate binary baseband signals in a contactless manner through electric field coupling between transmission coupler 12 and reception coupler 23, and electric field coupling between transmission coupler 22 and reception coupler 13.

[0014] Ethernet signal 37 is a signal between communication terminal 33 and transceiver 10, and is a signal conforming to the Ethernet standard (signal conforming to 1000BASE / 100BASE / 10BASE). Ethernet signal 38 is a signal between communication terminal 34 and transceiver 20, and is a signal conforming to the Ethernet standard (signal conforming to 1000BASE / 100BASE / 10BASE).

[0015] The baseband signal communicated between module 31 and module 32 via electric field coupling is an SGMII (Serial Gigabit Media Independent Interface) signal. Transceiver 10 converts between Ethernet signal 37 and SGMII signals 110 and 114. Transceiver 20 converts between Ethernet signal 38 and SGMII signals 120 and 124.

[0016] SGMII is one of the PHY interfaces for Gigabit Ethernet, and is a standard that uses two pairs of LVDS differential buses (upstream and downstream) to communicate 1.25 Gbps data in full duplex (a format in which two pairs of communication paths are used for bidirectional communication, upstream and downstream). SGMII continues to output a known 8B10B-encoded pattern even during the idle period (the period when no valid packet communication is taking place between communication terminal 33 and communication terminal 34) in which it is in an idle state from the time of power-on.

[0017] Module 31 includes a transceiver 10, a transmission circuit 11, a transmission coupler 12, a reception coupler 13, a reception circuit 14, a reception intensity measurement unit 15, and a transmission control unit 16. Module 32 includes a transceiver 20, a transmission circuit 21, a transmission coupler 22, a reception coupler 23, a reception circuit 24, a proximity detection unit 25, and a transmission control unit 26.

[0018] First, we will explain the operation of each component of the module 31. The transceiver 10 is connected to the communication terminal 33 via a cable. The transceiver 10 converts the Ethernet signal 37 output by the communication terminal 33 into an SGMII signal 110, and outputs the SGMII signal 110 to the transmitting circuit 11. The transceiver 10 also converts the SGMII signal 114 output by the receiving circuit 14 into an Ethernet signal 37, and outputs the Ethernet signal 37 to the communication terminal 33.

[0019] The transmission circuit 11 is a transmission unit, and stops outputting a transmission signal 111 to the transmission coupler 12 while a control signal 116 output from the transmission control unit 16 is at a low level. Furthermore, while the control signal 116 is at a high level, the transmission circuit 11 outputs the input SGMII signal 110 to the transmission coupler 12 as a transmission signal 111. The transmission coupler 12 is electric field coupled to the reception coupler 23 included in the module 32, and wirelessly transmits the transmission signal 111 to the reception coupler 23.

[0020] The receiving coupler 13 is electrically coupled to the transmitting coupler 22 of the module 32, wirelessly receives the transmitting signal 121 wirelessly transmitted by the transmitting coupler 22 as a receiving signal 113, and outputs the receiving signal 113 to the receiving circuit 14 and the receiving intensity measuring unit 15.

[0021] The receiving circuit 14 performs waveform shaping on the received signal 113, restores the signal as an SGMII signal 114, and outputs the SGMII signal 114 to the transceiver 10. The receiving circuit 14 is configured by, for example, a hysteresis comparator.

[0022] The reception intensity measurement unit 15 measures the signal intensity of the received signal 113 and outputs a measurement signal 115 corresponding to the signal intensity to the transmission control unit 16. For example, the measurement signal 115 is an analog value proportional to the signal intensity of the received signal 113. The reception intensity measurement unit 15 is configured, for example, with a detection circuit (a rectifier circuit and a low-pass filter). In this case, the cutoff frequency of the low-pass filter is set to a value sufficiently lower than the minimum frequency of the SGMII signal. Specifically, the SGMII signal is coded using 8B10B coding, and does not contain five or more consecutive bits of "0" or "1". In other words, since the SGMII signal is 1.25 Gbps, the minimum frequency is 125 MHz. Therefore, it is desirable that the above-mentioned low-pass filter be a low-pass filter that can sufficiently cut frequencies lower than 125 MHz.

[0023] If the measurement signal 115 is less than the threshold value A, the transmission control unit 16 determines that the module 31 is separated from the module 32, and outputs a low-level control signal 116 to the transmission circuit 11. On the other hand, if the measurement signal 115 is equal to or greater than the threshold value A, the transmission control unit 16 determines that the module 31 is close to the module 32, and outputs a high-level control signal 116 to the transmission circuit 11.

[0024] The threshold value A is set to a value higher than the signal strength of the measurement signal 115 (i.e., the received signal 113) when module 31 is separated from module 32, and lower than the signal strength of the measurement signal 115 when module 31 is close to module 32.

[0025] Next, we will explain the operation of each component of the module 32. The transceiver 20 is connected to the communication terminal 34 via a cable. The transceiver 20 converts an Ethernet signal 38 output by the communication terminal 34 into an SGMII signal 120, and outputs the SGMII signal 120 to the transmitting circuit 21. The transceiver 20 also converts an SGMII signal 124 output by the receiving circuit 24 into an Ethernet signal 38, and outputs the Ethernet signal 38 to the communication terminal 34.

[0026] The transmission circuit 21 is a transmitter, and stops outputting the transmission signal 121 to the transmission coupler 22 while the control signal 126 output by the transmission control unit 26 is at a low level. Furthermore, while the control signal 126 output by the transmission control unit 26 is at a high level, the transmission circuit 21 outputs the input SGMII signal 120 to the transmission coupler 22 as the transmission signal 121. The transmission coupler 22 is electric field coupled to the reception coupler 13 included in the module 31, and wirelessly transmits the transmission signal 121 to the reception coupler 13.

[0027] The receiving coupler 23 is electrically coupled to the transmitting coupler 12 of the module 31 , wirelessly receives the transmitting signal 111 output by the transmitting coupler 12 as a receiving signal 123 , and outputs the receiving signal 123 to the receiving circuit 24 .

[0028] The receiving circuit 24 performs waveform shaping on the received signal 123, restores the signal as an SGMII signal 124, and outputs the SGMII signal 124 to the transceiver 20. Like the receiving circuit 14, the receiving circuit 24 is configured by, for example, a hysteresis comparator.

[0029] The proximity detection unit 25 detects the proximity of the module 31 and outputs a proximity detection signal 125 to the transmission control unit 26. The proximity detection signal 125 is at a high level while it is detecting proximity to the module 31, and is at a low level while it is detecting separation from the module 31. The detection method of the proximity detection unit 25 may be any known method. For example, the proximity detection unit 25 can detect the proximity of the module 31 by a change in a medium such as light, infrared, a magnetic field, an electric field, or contact.

[0030] The transmission control unit 26 receives the proximity detection signal 125, and outputs a low-level control signal 126 to the transmission circuit 21 during a period when the proximity detection signal 125 is at a low level (a period when the proximity detection unit 25 detects separation from the module 31). On the other hand, the transmission control unit 26 outputs a high-level control signal 126 to the transmission circuit 21 during a period when the proximity detection signal 125 is at a high level (a period when the proximity detection unit 25 detects proximity to the module 31).

[0031] [Explanation of each signal waveform and operation flow] Next, the operation of the close-proximity communication system 30 in this embodiment will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a diagram showing the waveforms of the signals in Fig. 1 on the time axis. Fig. 3(a) is a flowchart showing a control method when module 31 is started (powered on). Fig. 3(b) is a flowchart showing a control method when module 32 is started (powered on).

[0032] Hereinafter, the operation of transmission control unit 16 and transmission control unit 26 will be mainly explained from time T0 to T6 shown in Fig. 2. First, the operation from when module 31 and module 32 start up until when modules 31 and 32 move from a state where they are separated from each other to a state where they are close to each other will be explained.

[0033] 2, modules 31 and 32 start up at time T0. At this time, modules 31 and 32 are separated from each other. For ease of explanation, the start times of modules 31 and 32 are both set to time T0, but they may be different.

[0034] The transceiver 10 starts outputting a known pattern during an idle period as an SGMII signal 110 to the transmission circuit 11. The transceiver 20 starts outputting a known pattern during an idle period as an SGMII signal 120 to the transmission circuit 21.

[0035] At time T0, the processes of steps S10 and S11 in Fig. 3(a) are executed by the module 31. In step S10 in Fig. 3(a), the transmission control unit 16 outputs a low-level control signal 116 to the transmission circuit 11. When the transmission circuit 11 receives the low-level control signal 116, it stops outputting the transmission signal 111.

[0036] In step S11 of FIG. 3(a), the transmission control unit 16 waits until the measurement signal 115 becomes equal to or greater than the threshold value A. When the modules 31 and 32 are spaced apart from each other, the measurement signal 115 is less than the threshold value A. When the measurement signal 115 is less than the threshold value A, the transmission control unit 16 outputs a low-level control signal 116 to the transmission circuit 11. When the transmission circuit 11 receives the low-level control signal 116, it stops outputting the transmission signal 111.

[0037] Meanwhile, at time T0, the processes of steps S20 and S21 in Fig. 3(b) are executed by the module 32. In step S20 in Fig. 3(b), the transmission control unit 26 outputs a low-level control signal 126 to the transmission circuit 21. When the transmission circuit 21 receives the low-level control signal 126, it stops outputting the transmission signal 121.

[0038] 3(b), the transmission control unit 26 waits until the proximity detection signal 125 becomes high level. When the modules 31 and 32 are separated from each other, the proximity detection signal 125 is low level. When the proximity detection signal 125 is low level, the transmission control unit 16 outputs a low level control signal 126 to the transmission circuit 21. When the transmission circuit 21 receives the low level control signal 126, it stops outputting the transmission signal 121.

[0039] 2, module 31 and module 32 come close to each other. The proximity detector 25 detects the proximity of module 31 and changes the proximity detection signal 125 from low level to high level. When the proximity detection signal 125 changes from low level to high level, the transmission controller 26 proceeds to step S22 in FIG. 3(b).

[0040] At time T2 in Fig. 2 and step S22 in Fig. 3(b), the transmission control unit 26 changes the control signal 126 from low level to high level. When the control signal 126 becomes high level, the transmission circuit 21 uses the SGMII signal 120 as the transmission signal 121 and starts outputting the transmission signal 121 to the transmission coupler 22. The transmission coupler 22 wirelessly transmits the transmission signal 121 to the reception coupler 13. At step S23 in Fig. 3(b), the transmission control unit 26 waits until the proximity detection signal 125 becomes low level.

[0041] Through the above operations, the transmission circuit 21 starts outputting the SGMII signal 120 to the transmission coupler 22 as a transmission signal 121. The reception coupler 13 receives the transmission signal 121 wirelessly transmitted from the transmission coupler 22 as a reception signal 113. The reception circuit 14 restores the reception signal 113 to an SGMII signal 114 and starts outputting the SGMII signal 114 to the transceiver 10. The signal strength of the reception signal 113 increases.

[0042] At time T3 in FIG. 2 and step S11 in FIG. 3(a), when the measurement signal 115 output by the reception intensity measurement unit 15 becomes equal to or greater than threshold A, the transmission control unit 16 proceeds to step S12. In step S12, the transmission control unit 16 changes the control signal 116 from low level to high level. When the control signal 116 becomes high level, the transmission circuit 11 starts outputting the transmission signal 111 to the transmission coupler 12, using the SGMII signal 110 as the transmission signal 111. The transmission coupler 12 wirelessly transmits the transmission signal 111 to the reception coupler 23. In step S13 in FIG. 3(a), the transmission control unit 16 waits until the measurement signal 115 becomes less than threshold A.

[0043] Through the above operations, the transmission circuit 11 starts outputting the SGMII signal 110 as the transmission signal 111 to the transmission coupler 12. The reception coupler 23 receives the transmission signal 111 wirelessly transmitted from the transmission coupler 12 as a reception signal 123. The reception circuit 24 restores the reception signal 123 to an SGMII signal 124 and outputs the SGMII signal 124 to the transceiver 20.

[0044] As a result of the above-described operations, modules 31 and 32 are triggered by their proximity to each other to start outputting transmission signals 111 and 121. As a result, SGMII signals are transmitted in full duplex, and communication between communication terminals 33 and 34 is achieved according to the Ethernet standard.

[0045] Next, the operation when the module 31 and the module 32 move from a state in which they are close to each other to a state in which they are separated from each other will be described.

[0046] 2, module 31 and module 32 move away from each other. The proximity detector 25 detects that module 31 has moved away, and outputs a low-level proximity detection signal 125. In step S23 of FIG. 3(b), when the proximity detection signal 125 changes from high to low, the transmission controller 26 returns to step S20.

[0047] 2 and step S20 in FIG. 3(b), the transmission control unit 26 changes the control signal 126 from high to low. When the control signal 126 is low, the transmission circuit 21 stops outputting the transmission signal 121 to the transmission coupler 22. As a result, the signal strength of the reception signal 113 decreases.

[0048] 2 and step S13 in FIG. 3(a), when the measurement signal 115 output by the reception intensity measurement unit 15 becomes less than the threshold A, the transmission control unit 16 returns to step S10. In step S10, the transmission control unit 16 changes the control signal 116 from high level to low level. When the control signal 116 is low level, the transmission circuit 11 stops outputting the transmission signal 111 to the transmission coupler 12.

[0049] As described above, according to this embodiment, the proximity communication system 30 can stop outputting the transmission signals 111 and 121 when the modules 31 and 32 are separated from each other, thereby achieving low power consumption and suppression of unnecessary radiation.

[0050] Although the baseband signal has been described as an SGMII signal, it is not limited to this. For example, any standard, such as 1000BASE-X or 100BASE-FX, can be applied as long as the baseband signal is a full-duplex baseband signal in which a known pattern is inserted during idle periods. Furthermore, the baseband signal may be a PAM-modulated ternary or higher value signal instead of a binary signal.

[0051] Although the configuration has been described in which the communication terminal 33 and the transceiver 10, and the communication terminal 34 and the transceiver 20 are connected via Ethernet, this is not limiting. For example, the communication terminals 33 and 34 may be IC chips that implement the MAC layer or higher of Ethernet, and the communication terminals 33, 34 may be connected to the transceivers 10, 20 via MII or GMII. As described above, the baseband signal may be a different baseband signal that is not related to the Ethernet standard, such as SGMII, 1000BASE-X, or 100BASE-FX.

[0052] Furthermore, the transmission circuits 11 and 21 have been described as being configured to output the SGMII signals 110 and 120 as the transmission signals 111 and 121 without modification, but this is not limiting. For example, the transmission circuits 11 and 21 may be configured to perform waveform amplification, frequency correction (emphasis), and jitter cleaning on the SGMII signals 110 and 120 and output them as the transmission signals 111 and 121.

[0053] Furthermore, although the receiver circuits 14 and 24 have been described as hysteresis comparators, the present invention is not limited to this. The receiver circuits 14 and 24 may be configured in any known manner as long as they can restore the receive signals 113 and 123 that have passed through the receive couplers 13 and 23.

[0054] Also, for convenience of explanation, the transmission control unit 26 has been described as being configured to generate the control signal 126 in response to the proximity detection signal 125, but the transmission control unit 26 may be omitted and the transmission circuit 21 may be configured to use the proximity detection signal 125 as the control signal 126.

[0055] Furthermore, the coupling between the transmitting coupler 12 and the receiving coupler 23 and the coupling between the transmitting coupler 22 and the receiving coupler 13 have been described as electric field coupling, but this is not limited to this and may also be a structure using magnetic field coupling or electromagnetic field coupling (coupling of both electric and magnetic fields).

[0056] Furthermore, the reception intensity measurement unit 15 has been described as a means for detecting the presence or absence of the reception signal 113 by measuring the signal intensity of the reception signal 113 output by the reception coupler 13, but this is not limited thereto. The reception intensity measurement unit 15 may have any configuration as long as it can ultimately determine the presence or absence of the reception signal 113 received when the module 32 is close. For example, if a hysteresis comparator is used as the reception circuit 14, the reception intensity measurement unit 15 may determine the presence or absence of the reception signal 113 by detecting the AC component of the output signal of the hysteresis comparator. Specifically, the threshold is set so that the reception signal 113 when the module 32 is far away is equal to or less than the threshold of the hysteresis comparator. As a result, when the module 32 is far away, the hysteresis comparator outputs a DC signal, and when the module 32 is close, the hysteresis comparator outputs an AC signal (1.25 Gbps signal output). For this reason, the reception intensity measuring unit 15 may be configured to determine the presence or absence of the reception signal 113 by determining a change in the output of a hysteresis comparator.

[0057] As described above, module 31 is a communication device that wirelessly communicates full-duplex baseband signals with module 32. Module 32 is a communication device that wirelessly communicates full-duplex baseband signals with module 31. The baseband signal is a signal into which a known pattern is inserted during an idle period between module 31 and module 32. For example, the baseband signal is a signal conforming to the SGMII standard, the 100BASE-FX standard, or the 1000BASE-X standard.

[0058] 3(a), the transmission circuit 11 stops outputting the transmission signal 111 to be transmitted to the module 32 during a period in which the reception strength of the reception signal 113 received from the module 32 is below a threshold. Furthermore, the transmission circuit 11 outputs the transmission signal 111 to be transmitted to the module 32 during a period in which the reception strength of the reception signal 113 is equal to or greater than the threshold. The threshold is a value that is greater than the signal strength of the reception signal 113 when the modules 31 and 32 are separated by a distance that prevents them from communicating with each other, and is smaller than the signal strength of the reception signal 113 when the modules 31 and 32 are separated by a distance that allows them to communicate with each other.

[0059] 3(b), the transmission circuit 21 stops outputting the transmission signal 121 to be transmitted to the module 31 during a period in which the proximity detection unit 25 does not detect the proximity of the module 31. Furthermore, the transmission circuit 21 outputs the transmission signal 121 to be transmitted to the module 31 during a period in which the proximity detection unit 25 detects the proximity of the module 31.

[0060] According to this embodiment, the modules 31 and 32 can stop outputting the transmission signals 111 and 121 when they become separated from each other.

[0061] (Second embodiment) In the first embodiment, the module 32 is configured to start outputting the transmission signal 121 when it detects the proximity of the module 31. However, the module 32 may make an erroneous detection by detecting only the proximity of the module 31. For example, a configuration can be adopted in which a Hall element is used as the proximity detector 25 and a permanent magnet is installed in the module 31, thereby detecting the mutual proximity of the modules 31 and 32. In this case, when a different permanent magnet approaches the Hall element of the proximity detector 25, the module 32 erroneously detects the proximity of the module 31 and starts outputting the transmission signal 121. In other words, the module 32 may generate wasted power and unnecessary radiation due to an erroneous detection.

[0062] Therefore, in the second embodiment, a reception intensity measurement unit is also provided in the module 32. If the signal intensity of the reception signal 123 is below the threshold even after a predetermined period has elapsed since the transmission circuit 21 output the transmission signal 121, the transmission circuit 21 stops outputting the transmission signal 121, thereby making it possible to suppress wasted power and unnecessary radiation due to false detection.

[0063] Fig. 4 is a diagram showing an example of the configuration of a close-proximity communication system 30 according to the second embodiment. In Fig. 4, the same components as those in the first embodiment described in Fig. 1 are assigned the same reference numerals, and their description will be omitted. The close-proximity communication system 30 in Fig. 4 is configured by adding a reception intensity measurement unit 35 to the close-proximity communication system 30 in Fig. 1 and providing a transmission control unit 36 ​​instead of the transmission control unit 26. The module 32 has a transceiver 20, a transmission circuit 21, a transmission coupler 22, a reception coupler 23, a reception circuit 24, a proximity detection unit 25, a reception intensity measurement unit 35, and a transmission control unit 36.

[0064] The reception intensity measurement unit 35 is similar to the reception intensity measurement unit 15, and measures the signal intensity of the reception signal 123 and outputs a measurement signal 135 corresponding to the signal intensity to the transmission control unit 36. The transmission control unit 36 ​​receives the proximity detection signal 125 and outputs a low-level control signal 126 to the transmission circuit 21 while the proximity detection signal 125 is at a low level (while the proximity detection unit 25 detects that the module 31 is moving away). When the proximity detection signal 125 changes from a low level to a high level (when the proximity detection unit 25 detects that the module 31 is approaching), the transmission control unit 36 ​​outputs a high-level control signal 126 to the transmission circuit 21. When a predetermined time has elapsed since the proximity detection signal 125 became a high level and the measurement signal 135 is less than the threshold A, the transmission control unit 36 ​​outputs a low-level control signal 126 to the transmission circuit 21. Here, if the measurement signal 135 is less than the threshold value A, the transmission control unit 36 ​​determines that the module 31 is not in proximity, that is, that the proximity detection unit 25 has made a false detection, and outputs a low-level control signal 126 to the transmission circuit 21. Furthermore, if the measurement signal 135 is equal to or greater than the threshold value A after a predetermined time has elapsed since the proximity detection signal 125 became high, the transmission control unit 36 ​​maintains the high-level control signal 126.

[0065] 5 is a flowchart showing a control method at the time of startup of the module 32. When the module 32 is started, it starts the processing of FIG.

[0066] In step S20, the transmission control unit 36 ​​outputs a low-level control signal 126 to the transmission circuit 21. When the transmission circuit 21 receives the low-level control signal 126, it stops outputting the transmission signal 121.

[0067] In step S21, the transmission control unit 36 ​​waits until the proximity detection signal 125 becomes high level. When the modules 31 and 32 are separated from each other, the proximity detection signal 125 is low level. When the proximity detection signal 125 is low level, the transmission control unit 16 outputs a low level control signal 126 to the transmission circuit 21. When the transmission circuit 21 receives the low level control signal 126, it stops outputting the transmission signal 121.

[0068] When the module 31 approaches, the proximity detector 25 changes the proximity detection signal 125 from low level to high level. When the proximity detection signal 125 changes from low level to high level, the transmission controller 26 proceeds to step S22.

[0069] In step S22, the transmission control unit 36 ​​changes the control signal 126 from low level to high level. When the control signal 126 is high level, the transmission circuit 21 outputs the SGMII signal 120 to the transmission coupler 22 as a transmission signal 121. The transmission coupler 22 wirelessly transmits the transmission signal 121 to the reception coupler 13.

[0070] In step S30, the transmission control unit 36 ​​waits for a predetermined time after the proximity detection signal 125 changes from low level to high level, and then proceeds to step S31.

[0071] In step S31, if the measurement signal 135 is equal to or greater than threshold A after a predetermined time has elapsed since the proximity detection signal 125 changed from low level to high level, the transmission control unit 36 ​​maintains the control signal 126 at a high level and proceeds to step S23. If the measurement signal 135 is less than threshold A after a predetermined time has elapsed since the proximity detection signal 125 changed from low level to high level, the transmission control unit 36 ​​proceeds to step S32.

[0072] Here, threshold A is a value that is greater than measurement signal 135 (=reception intensity of received signal 123) when module 31 and module 32 are separated from each other, and smaller than measurement signal 135 when module 31 and module 32 are close to each other.

[0073] The predetermined time is the time from when the transmission circuit 21 of the module 32 starts to output the transmission signal 121 to when the transmission circuit 11 of the module 31 starts to output the transmission signal 111. Specifically, the predetermined time is the time from time T2 to time T3 in Fig. 2. In other words, if the measurement signal 135 is less than the threshold A after the predetermined time has elapsed, this means that the modules 31 and 32 are separated from each other and the proximity detection in step S21 is a false detection.

[0074] In step S32, the transmission control unit 36 ​​outputs a low-level control signal 126 to the transmission circuit 21. When the transmission circuit 21 receives the low-level control signal 126, it stops outputting the transmission signal 121. After that, the process proceeds to step S23.

[0075] In step S23, the transmission control unit 26 waits until the proximity detection signal 125 becomes low level, and when the proximity detection signal 125 changes from high level to low level, the process returns to step S20.

[0076] 5, the transmission control unit 36 ​​has been described as maintaining the control signal 126 at a low level until the proximity detection unit 25 detects separation when the measurement signal 135 is below threshold A, but the present invention is not limited to this. For example, after determining that the measurement signal 135 is below threshold A, the transmission control unit 36 ​​checks the measurement signal 135 at regular intervals while the proximity detection unit 25 detects proximity. Then, when the measurement signal 135 becomes equal to or greater than threshold A, the transmission control unit 36 ​​can change the control signal 126 from a low level to a high level.

[0077] As described above, the transmission circuit 21 stops outputting the transmission signal 121 to be transmitted to the module 31 during a period in which the proximity detection unit 25 does not detect the proximity of the module 31. Furthermore, when the proximity detection unit 25 detects the proximity of the module 31, the transmission circuit 21 starts outputting the transmission signal 121 to be transmitted to the module 31. Furthermore, when the reception strength of the reception signal 123 received from the module 31 is less than threshold A after the predetermined time has elapsed in step S30, the transmission circuit 21 stops outputting the transmission signal 121 to be transmitted to the module 31.

[0078] The predetermined time in step S30 is the time from when the transmission circuit 21 starts outputting the transmission signal 121 to when the module 31 starts transmitting. The threshold value A is a value that is greater than the signal strength of the reception signal 123 when the modules 31 and 32 are separated by a distance that prevents them from communicating with each other, and is smaller than the signal strength of the reception signal 123 when the modules 31 and 32 are separated by a distance that allows them to communicate with each other.

[0079] According to this embodiment, the transmission circuit 21 can stop outputting the transmission signal 121 even if the proximity detection in step S21 is a false detection, and as a result, it is possible to suppress wasted power and unnecessary radiation caused by the false detection.

[0080] (Third embodiment) In the third embodiment, the second embodiment is further expanded, and the output from the transmitting circuit is detected by a receiving coupler within the same module to determine whether the proximity detection is a false detection, and if it is a false detection, the output of the transmitting circuit is immediately stopped.

[0081] First, we will explain the signal strength received by a receiving coupler due to the output of a transmitting circuit in the same module, which fluctuates depending on the proximity / separation of the modules, using Figures 6 to 9. Hereinafter, a signal received by a receiving coupler due to the output of a transmitting circuit in the same module will be called an interference signal.

[0082] 6 is a diagram showing a specific example of the configuration of the transmitter circuit 11, transmitter coupler 12, receiver coupler 13, receiver circuit 14, transmitter circuit 21, transmitter coupler 22, receiver coupler 23, and receiver circuit 24 shown in FIGS. 1 and 4. The transmitter coupler 12 has two conductors 12a and 12b and two feed ports P12a and P12b. The receiver coupler 13 has two conductors 13a and 13b and two feed ports P13a and P13b. The transmitter coupler 22 has two conductors 22a and 22b and two feed ports P22a and P22b. The receiver coupler 23 has two conductors 23a and 23b and two feed ports P23a and P23b.

[0083] Each of the SGMII signals 110, 114, 120, and 124 is a differential signal and is shown by two lines. The input / output terminals of the transmission circuits 11 and 21 and the reception circuits 14 and 24 are shown by two ports (suffixed with + and -, respectively).

[0084] The power feed ports P12a and P12b are connection ends between the transmitter circuit 11 and the conductors 12a and 12b. The power feed ports P13a and P13b are connection ends between the receiver circuit 14 and the conductors 13a and 13b. The power feed ports P22a and P22b are connection ends between the transmitter circuit 21 and the conductors 22a and 22b. The power feed ports P23a and P23b are connection ends between the receiver circuit 24 and the conductors 23a and 23b.

[0085] When modules 31 and 32 are close to each other, conductors 12a and 12b are close to conductors 23a and 23b, and conductors 13a and 13b are close to conductors 22a and 22b, and they are coupled by an electric field component.

[0086] Meanwhile, there is also some degree of electric field coupling between the transmitting coupler 12 and receiving coupler 13 in the same module 31, and there is also some degree of electric field coupling between the transmitting coupler 22 and receiving coupler 23 in the same module 32. This electric field coupling generates an interference signal between the transmitting coupler 12 and receiving coupler 13, and an interference signal between the transmitting coupler 22 and receiving coupler 23. The signal strength of this interference signal is greater when modules 31 and 32 are far apart than when modules 31 and 32 are close to each other. Below, we will specifically explain, using simulation results, how the strength of the interference signal changes depending on whether modules 31 and 32 are close to each other.

[0087] 7(a) and 7(b) are diagrams showing examples of the structures of the transmission couplers 12 and 22 and the reception couplers 13 and 23 used in the simulation. FIG. 7(a) is a perspective view of the structures of the transmission couplers 12 and 22 and the reception couplers 13 and 23 used in the simulation. FIG. 7(b) is a diagram of FIG. 7(a) viewed from the positive direction of the Z axis of the coordinate system. Note that the same reference numerals in FIG. 7(a) are assigned as those in FIG. 6. The upper part of FIG. 7(a) shows the transmission coupler 12 and reception coupler 13 of the module 31. The lower part of FIG. 7(b) shows the transmission coupler 22 and reception coupler 23 of the module 32. The conductors 12a, 12b, 13a, 13b, 22a, 22b, 23a, and 23b are formed from copper patterns on a 1 mm-thick glass epoxy substrate. Conductors 12a, 12b, 13a, 13b, 22a, 22b, 23a, and 23b are connected to feed ports P12a, P12b, P13a, P13b, P22a, P22b, P23a, and P23b through vias. Differential port D1 is a port for differential signals between feed ports P12a and P12b. Differential port D2 is a port for differential signals between feed ports P13a and P13b.

[0088] 8(a) and 8(b) show the dimensions X1, Y1, and SP of the transmitting coupler and receiving coupler shown in FIG. 7(b), and the values ​​of the distances G1 and CL between the transmitting and receiving couplers. FIG. 8(a) shows the values ​​when modules 31 and 32 are close to each other, with the distance G1 between the couplers of different modules 31 and 32 being 2 mm. FIG. 8(b) shows the values ​​when modules 31 and 32 are far from each other, with the distance G1 between the couplers of different modules 31 and 32 being ∞ (no opposing modules).

[0089] 9 is a diagram showing the simulation results of the interference characteristics (Sdd21 from differential port D1 to differential port D2) in the transmitting couplers 12 and 22 and the receiving couplers 13 and 23 in FIGS. 7(a) and 7(b). In the simulation, the differential impedance of the differential ports D1 and D2 is 100Ω. The vertical axis of the graph in FIG. 9 represents gain, and the horizontal axis of the graph in FIG. 9 represents frequency.

[0090] The dotted line in Fig. 9 shows the interference characteristics when modules 31 and 32 shown in Fig. 8(a) are close to each other, and the solid line in Fig. 9 shows the interference characteristics when modules 31 and 32 shown in Fig. 8(b) are separated from each other.

[0091] 9, the interference characteristic when modules 31 and 32 are close to each other is -31.59 dB @ 1 GHz. The interference characteristic when modules 31 and 32 are far from each other is -27.97 dB. In other words, the strength of the interference signal increases by about 3.6 dB (voltage ratio 1.5 times) when modules 31 and 32 are far from each other compared to when modules are close to each other.

[0092] In this embodiment, the proximity communication system 30 detects a change in the intensity of the interference signal, determines that the proximity detection is erroneous, and stops output of the transmission signal from the transmission circuit.

[0093] The specific operation will be described below. The configuration of the close proximity communication system 30 of this embodiment is the same as that of the second embodiment, except for the operation of the transmission control unit 36 ​​of the second embodiment.

[0094] 10 is a flowchart showing a control method at the time of startup of the module 32. When the module 32 is started, it starts the process of FIG.

[0095] In steps S20 to S22, the module 32 performs the same processes as steps S20 to S22 in Fig. 5. In step S22, the transmission control unit 36 ​​changes the control signal 126 from low level to high level. This causes the transmission circuit 21 to start outputting the transmission signal 121.

[0096] Immediately after this, the process proceeds from step S22 to step S40. The period from S22 to S40 is the period from when the transmission circuit 21 of module 32 starts outputting the transmission signal 121 to when the transmission circuit 11 of module 31 starts outputting the transmission signal 111, at least when the modules 31 and 32 are close to each other.

[0097] In step S40, the transmission control unit 36 ​​determines whether the measurement signal 135 is less than the threshold value B. If the measurement signal 135 is less than the threshold value B, the transmission control unit 36 ​​proceeds to step S30, and if the measurement signal 135 is equal to or greater than the threshold value B, the transmission control unit 36 ​​proceeds to step S32.

[0098] Here, threshold B is a value that is smaller than the measurement signal 135 (= the strength of the interference signal) when module 31 and module 32 are separated from each other, and is greater than the measurement signal 135 (= the strength of the interference signal) when module 31 and module 32 are close to each other.

[0099] If the measurement signal 135 is greater than or equal to the threshold value B immediately after the transmission circuit 21 starts outputting (the period until the transmission circuit 11 of the opposing module 31 starts outputting), this means that the opposing module 31 is far away, i.e., the proximity detection is a false detection.

[0100] Thereafter, in steps S30 to S32 and S23, the module 32 performs the same processes as in steps S30 to S32 and S23 in FIG.

[0101] Note that, in the above description, the transmission control unit 36 ​​operates to maintain the control signal 126 at a low level until the proximity detection unit 25 detects separation when it determines in step S40 that the measurement signal 135 is equal to or greater than threshold B, but this is not limiting. For example, after determining that the measurement signal 135 is equal to or greater than threshold B, the transmission control unit 36 ​​may check the measurement signal 135 at regular intervals while the proximity detection unit 25 is detecting separation, and when the measurement signal 135 becomes less than threshold B, the process may proceed to step S30 and subsequent steps.

[0102] Furthermore, in this embodiment, steps S30 and S31 in FIG. 10 are not necessarily required, and steps S30 and S31 may be deleted.

[0103] As described above, the transmission circuit 21 stops outputting the transmission signal 121 to be transmitted to the module 31 during a period when the proximity detection unit 25 does not detect the proximity of the module 31. Furthermore, when the proximity detection unit 25 detects the proximity of the module 31, the transmission circuit 21 starts outputting the transmission signal to be transmitted to the module 31. Furthermore, before the predetermined time in step S30 has elapsed, if the signal strength of the interference signal (received signal) 123 caused by the output of the transmission signal 121 is equal to or greater than threshold value B, the transmission circuit 21 stops outputting the transmission signal 121 to be transmitted to the module 31. Furthermore, after the predetermined time has elapsed since the start of outputting the transmission signal 121, if the reception strength of the received signal 123 received from the module 31 is less than threshold value A, the transmission circuit 21 stops outputting the transmission signal 121 to be transmitted to the module 31.

[0104] The threshold value B is a value that is smaller than the signal strength of the interference signal when the modules 31 and 32 are separated by a distance that prevents them from communicating with each other, and is greater than the signal strength of the interference signal when the modules 31 and 32 are separated by a distance that allows them to communicate with each other.

[0105] According to this embodiment, the module 32 can stop outputting the transmission signal 121 earlier than in the second embodiment even when the proximity detector 25 makes a false detection. As a result, the module 32 can further reduce wasted power and unnecessary radiation caused by a false detection.

[0106] (Other embodiments) The present disclosure can also be realized by a process in which a program that realizes one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device read and execute the program. The present disclosure can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0107] It should be noted that the above-described embodiments merely illustrate specific examples of implementing the present disclosure, and the technical scope of the present disclosure should not be construed as being limited by these embodiments. In other words, the present disclosure can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0108] 10, 20 transceiver, 11, 21 transmission circuit, 12, 22 transmission coupler, 13, 23 reception coupler, 14, 24 reception circuit, 15 reception intensity measurement unit, 16, 26 transmission control unit, 25 proximity detection unit, 31, 32 module

Claims

1. A communication device that performs full-duplex communication of baseband signals with another communication device in a non-contact manner, a first transmitting coupler coupled to a first receiving coupler of the other communication device; a second receiving coupler coupled to a second transmitting coupler of the other communication device; a transmitting unit that stops outputting a signal transmitted through the first transmitting coupler during a period in which a reception strength of a signal received from the other communication device through the second transmitting coupler and the second receiving coupler is less than a first threshold; A communication device comprising:

2. 2. The communication device according to claim 1, wherein the transmitter outputs a signal to be transmitted via the first transmitter coupler during a period in which the reception strength of the reception signal is equal to or greater than the first threshold.

3. The communication device described in claim 1 or 2, characterized in that the first threshold is greater than the signal strength of the received signal when the communication device and the other communication device are separated by a distance that prevents them from communicating with each other, and is smaller than the signal strength of the received signal when the communication device and the other communication device are separated by a distance that allows them to communicate with each other.

4. 4. The communication device according to claim 1, wherein the baseband signal is a signal into which a known pattern is inserted during an idle period between the communication device and the other communication device.

5. A communication device that performs full-duplex communication of baseband signals with another communication device in a non-contact manner, a first transmitting coupler coupled to a first receiving coupler of the other communication device; a second receiving coupler coupled to a second transmitting coupler of the other communication device; a proximity detection unit that detects the proximity of the other communication device; a transmitting unit that stops outputting a signal to be transmitted via the first transmitting coupler during a period in which the proximity detector does not detect the proximity of the other communication device, and that stops outputting the signal to be transmitted via the first transmitting coupler during a period in which the proximity detector detects the proximity of the other communication device, if the reception strength of a signal received from the other communication device is less than a first threshold value after outputting the signal to be transmitted via the first transmitting coupler; A communication device comprising:

6. 6. The communication device according to claim 5, wherein the transmitting unit further stops output of the signal transmitted through the first transmitting coupler when a signal strength of an interference signal caused by output of the signal is equal to or greater than a second threshold.

7. the first transmit coupler has two conductors; the second receive coupler has two conductors; The communication device according to any one of claims 1 to 6, characterized in that the two conductors of the first transmitting coupler transmit signals of different polarities in a differential signal from each conductor, and the two conductors of the second receiving coupler receive signals of different polarities in a differential signal from each conductor.

8. The communication device according to any one of claims 1 to 7, characterized in that the degree of coupling between the first transmitting coupler and the second receiving coupler when the communication device and the other communication device are separated by a distance such that they cannot communicate with each other is smaller than the degree of coupling between the first transmitting coupler and the second receiving coupler when the communication device and the other communication device are separated by a distance such that they can communicate with each other.

9. 9. The communication device according to claim 1, wherein the baseband signal is a signal conforming to the SGMII standard, the 100BASE-FX standard, or the 1000BASE-X standard.

10. A communication system having a first communication device and a second communication device that communicate baseband signals with each other in a non-contact, full-duplex manner, the first communication device, a first transmitting coupler coupled to a first receiving coupler of the second communication device; a second receiving coupler coupled to the second transmitting coupler of the second communication device; a first transmitting unit that stops outputting a signal transmitted via the first transmitting coupler during a period in which a reception strength of a reception signal received from the second communication device via the second transmitting coupler and the second receiving coupler is less than a first threshold; the second communication device, the first receiving coupler coupled to the first transmitting coupler of the first communication device; the second transmit coupler coupled to the second receive coupler of the first communication device; a proximity detection unit that detects proximity of the first communication device; a second transmitting unit that stops outputting a signal to be transmitted via the second transmitting coupler during a period when the proximity detecting unit does not detect the proximity of the first communication device, and that outputs a signal to be transmitted via the second transmitting coupler during a period when the proximity detecting unit detects the proximity of the second communication device.

11. A control method for a communication device that performs full-duplex communication of baseband signals with another communication device in a non-contact manner, comprising: The communication device a first transmitting coupler coupled to a first receiving coupler of the other communication device; a second receiving coupler coupled to a second transmitting coupler of the other communication device; outputting a transmission signal to the other communication device; a first transmitting coupler that receives a signal from the other communication device via the second transmitting coupler and the second receiving coupler, and the first transmitting coupler receives a signal from the other communication device via the second transmitting coupler;

12. A control method for a communication device that performs full-duplex communication of baseband signals with another communication device in a non-contact manner, comprising: The communication device a first transmitting coupler coupled to a first receiving coupler of the other communication device; a second receiving coupler coupled to a second transmitting coupler of the other communication device; Detecting the proximity of the other communication device; a control method for a communication device, comprising: stopping output of a signal to be transmitted via the first transmission coupler during a period when proximity of the other communication device is not detected; and, during a period when proximity of the other communication device is detected, outputting the signal to be transmitted via the first transmission coupler, and then stopping output of the signal to be transmitted via the first transmission coupler if a reception strength of a reception signal received from the other communication device is less than a first threshold.

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