JP5563880B2 - Communication apparatus and communication method - Google Patents

Description

  The present invention relates to a communication device and a communication method used for human body communication.

  2. Description of the Related Art In recent years, a technology (hereinafter collectively referred to as human body communication) that uses a medium having conductivity such as a human body (hereinafter collectively referred to as a human body) as a transmission path and performs communication within a limited area in the vicinity thereof (See, for example, Patent Document 1 and Non-Patent Document 1 below). In human body communication, a communication path between transmission / reception devices is established when both of the transmission / reception devices are in contact with or close to a human body. Usually, each transmitting / receiving device has a pair of signal electrodes, one of which is electrostatically coupled to the human body and the other to the external environment such as the ground or walls around the human body, forming an apparent closed circuit. Thus, information is transmitted from the transmission device to the reception device. The transmission device transmits information by applying transmission signal power between a pair of signal electrodes and applying an electric potential difference between the signal electrodes to induce an electric field in the vicinity of the human body. The receiving device receives information from the transmitting device by detecting a potential difference generated between the pair of signal electrodes by the electric field induced in the vicinity of the human body by the transmitting device according to the received signal sensitivity.

JP 2004-128536 A

“What is RedTacton?”, [Online], 2008, Nippon Telegraph and Telephone Corporation, [Search March 2, 2010], Internet (URL: http://www.redtacton.com/jp) /info/index.html)

  However, when such a communication device is normally used, the pair of signal electrodes are not electrostatically coupled with only the human body and the external environment, respectively. For example, as shown in FIG. Even the signal electrode on the coupling side has some electrostatic coupling with the human body. Therefore, in the case of a transmission apparatus, even if the transmission signal power applied between the pair of electrodes is the same, the potential difference induced between the pair of electrodes becomes small, and therefore the transmission performance may deteriorate. On the other hand, similarly in the case of the receiving apparatus, there is a problem that even if the received signal sensitivity is the same, the potential difference induced between the pair of signal electrodes is reduced, so that the receiving performance may be lowered. In particular, when a human uses the communication device in his / her hand, the hand may touch both of the pair of signal electrodes at the same time. In such a case, the human body is more coupled to both of the pair of signal electrodes. Because of the increase in size, there has been a problem that the deterioration of communication characteristics may become very large. Further, since the communication device establishes a communication path using electrostatic coupling with the communication medium, for example, the communication device and the communication medium are caused by a slight change in the state of the communication medium such as a human posture or body movement. Since the strength of the electrostatic coupling greatly changes, there is a problem that the communication characteristics fluctuate depending on the posture of the human body and the movement of the body.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a communication device and a communication method capable of realizing stabilization of communication characteristics without significantly increasing power consumption. To do.

In order to solve the above-described problem, a communication device according to the present invention is a communication device on a transmission side in human body communication, and includes a pair of signal electrodes electrostatically coupled to a communication medium and a surrounding environment of the communication medium, and a pair of signal electrodes. Applying means for applying electric power to the measuring means, measuring means for measuring reflected power with respect to the electric power applied by the applying means, detecting means for detecting contact or proximity of the communication medium to the pair of signal electrodes, and a pair of detecting means Based on the presence or absence of detection of contact or proximity of the communication medium to the signal electrode , human body communication based on the determination means for controlling the operation of the measurement means and the reflected power measured by the measurement means operated by the control of the determination means And a transmission power control means for controlling the transmission signal power.

The communication method of the present invention is a communication method on the transmission side in human body communication of a communication device comprising a communication medium and a pair of signal electrodes that are electrostatically coupled to the surrounding environment of the communication medium. An application step of applying power between the signal electrodes, a measurement step of measuring a reflected power with respect to the power applied by the application unit, and a detecting unit contacting or approaching the communication medium to the pair of signal electrodes A detecting step for detecting the detection means , a determining means for controlling the operation of the measuring means based on the presence or absence of detection of contact or proximity of the communication medium to the pair of signal electrodes in the detecting means , and a transmission power control means. , based on the reflected power measured by the measuring means operated by the control of the determination step, and a transmission power control step of controlling transmission signal power in a human body communication It is characterized in that it comprises.

  Here, “human body communication” is a general term for technologies that perform communication within a limited area in the vicinity using a conductive medium such as a human body as a transmission path.

  In these inventions, the measuring unit measures the reflected power based on the presence or absence of control of the transmission signal power in the human body communication determined by the determining unit. As a result, the communication characteristics are improved when there is a high possibility that the communication characteristics are deteriorated, so that the communication characteristics can be stabilized regardless of the coupling state between the communication device and the communication medium. In addition, since the function for controlling the transmission signal power is operated only when the communication characteristics deteriorate, it is possible to suppress a significant increase in power consumption. That is, it is possible to achieve stabilization of communication characteristics without significantly increasing power consumption.

The communication device of the present invention is a communication device on the receiving side in human body communication, and applies power between a pair of signal electrodes that are electrostatically coupled to the communication medium and the surrounding environment of the communication medium, and the pair of signal electrodes. Application means, measurement means for measuring reflected power with respect to the power applied by the application means, detection means for detecting contact or proximity of the communication medium to the pair of signal electrodes, and communication to the pair of signal electrodes in the detection means Based on the presence or absence of detection of contact or proximity of the medium, the reception signal sensitivity in human body communication is determined based on the determination power for controlling the operation of the measurement means and the reflected power measured by the measurement means operated by the control of the determination means. Receiving sensitivity control means for controlling.

The communication method of the present invention is a communication method on the receiving side in human body communication of a communication device comprising a communication medium and a pair of signal electrodes that are electrostatically coupled to the surrounding environment of the communication medium. An application step of applying power between the signal electrodes, a measurement step of measuring a reflected power with respect to the power applied by the application unit, and a detecting unit contacting or approaching the communication medium to the pair of signal electrodes A detection step for detecting the detection means , a determination means for controlling the operation of the measurement means based on the presence or absence of detection of contact or proximity of the communication medium to the pair of signal electrodes in the detection means , and a reception sensitivity control means. , based on the reflected power measured by the measuring means operated by the control of the determination step, a reception sensitivity control step of controlling the reception signal sensitivity in the human body communication It is characterized in that it comprises.

  In these inventions, the measuring means measures the reflected power based on the presence / absence of control of the received signal sensitivity in the human body communication determined by the determining means. As a result, the communication characteristics are improved when there is a high possibility that the communication characteristics are deteriorated, so that the communication characteristics can be stabilized regardless of the coupling state between the communication device and the communication medium. Further, since the function for controlling the received signal sensitivity is operated only when the communication characteristics deteriorate, it is possible to suppress a significant increase in power consumption. That is, it is possible to achieve stabilization of communication characteristics without significantly increasing power consumption.

  In the communication device of the present invention, the determination unit includes a detection unit that detects contact or proximity of the communication medium to the pair of signal electrodes, and controls the operation of the measurement unit based on the detection by the detection unit. Also good. Thereby, the situation where communication characteristics deteriorate can be acquired.

  In the communication apparatus of the present invention, the determination unit may operate the measurement unit when the detection unit detects that the communication medium is in contact with or close to both the pair of signal electrodes.

  This makes it possible to operate a function for reliably controlling transmission signal power or reception signal sensitivity in a situation where communication characteristics deteriorate. Further, it is possible to operate a function for controlling transmission signal power or reception signal sensitivity only when communication characteristics deteriorate.

  In the communication device of the present invention, the determination unit may operate the measurement unit when the detection unit does not detect that the communication medium is in contact with or close to both the pair of signal electrodes.

  This makes it possible to operate a function for reliably controlling transmission signal power or reception signal sensitivity in a situation where communication characteristics deteriorate. Further, it is possible to operate a function for controlling transmission signal power or reception signal sensitivity only when communication characteristics deteriorate.

  Moreover, in the communication apparatus of this invention, the detection means may be comprised by the touch sensor or the proximity sensor. Thereby, the structure which acquires the condition where communication characteristics deteriorate can be constructed | assembled easily.

  In the communication device of the present invention, the determination unit may include a state detection unit that detects the state of the communication device housing, and may control the operation of the measurement unit based on the detection by the state detection unit.

  As a result, it is possible to acquire a situation in which the communication characteristics deteriorate due to the state of the communication device housing.

  In the communication device of the present invention, the state detection unit may include an open / close detection unit that detects opening / closing of the folding of the communication device housing, and the determination unit may be in a state in which the communication device housing is closed by the open / close detection unit. If detected, the measuring means may be operated.

  This makes it possible to operate a function for reliably controlling transmission signal power or reception signal sensitivity in a situation where communication characteristics deteriorate. Further, it is possible to operate a function for controlling transmission signal power or reception signal sensitivity only when communication characteristics deteriorate.

  In the communication device of the present invention, the state detection unit includes a slide detection unit that detects a slide state of the communication device housing, and the determination unit is in a state in which the communication device housing is not slid by the slide detection unit. The measuring means may be operated when the error is detected.

  This makes it possible to operate a function for reliably controlling transmission signal power or reception signal sensitivity in a situation where communication characteristics deteriorate. Further, it is possible to operate a function for controlling transmission signal power or reception signal sensitivity only when communication characteristics deteriorate.

  In the communication device of the present invention, the determination unit includes a time measurement unit that measures a duration of a predetermined detection state in the detection unit or the state detection unit, and the determination unit is configured to have a duration measured by the time measurement unit. Based on this, the measuring means may be operated.

  As a result, when a change in the instantaneous relationship between the communication device and the communication medium that does not cause a decrease in communication characteristics during communication occurs, the operation for stabilizing the communication characteristics is not performed. Therefore, an increase in unnecessary power consumption can be suppressed.

  In the communication device of the present invention, the measurement unit includes a first storage unit that stores the reflected power measured by the measurement unit, and the measurement unit includes the latest reflected power stored in the first storage unit and the The reflected power measured by the measuring means may be compared, and the transmission power control means or the reception sensitivity control means may be operated based on the comparison result.

  Accordingly, unnecessary control can be avoided when there is no need to change the transmission signal power and the reception signal sensitivity, so that an increase in unnecessary power consumption and an increase in control time can be suppressed.

  In the communication device of the present invention, the transmission power control means or the reception sensitivity control means includes the power applied between the pair of signal electrodes by the applying means and the reflected power measured when the power is applied by the measuring means. And calculating means for determining a control value for transmission signal power or reception signal sensitivity, and the measuring means is based on the control value determined by the calculation means for transmitting power control means or reception sensitivity control means. May be operated.

  Thereby, it is possible to control the transmission signal power or the reception signal sensitivity to be ideal for communication using the measurement result of the reflected power.

  In the communication apparatus of the present invention, the transmission power control means or the reception sensitivity control means includes a second storage means for storing control information associated with a control parameter for the reflected power, and the transmission power control means or the reception sensitivity control means. Extracts a control parameter corresponding to the reflected power measured by the measuring unit from the control information stored in the second storage unit, and controls the transmission signal power or the received signal sensitivity based on the extracted control parameter. May be.

  This eliminates the need to calculate the control value of the transmission signal power or the reception signal sensitivity each time, so that the processing time can be increased and the communication time can be shortened.

  According to the communication device and the communication method of the present invention, it is possible to realize stabilization of communication characteristics without significantly increasing power consumption.

It is a figure which shows the outline | summary of the communication system which concerns on 1st Embodiment. It is a functional block diagram which shows the function structure of the communication apparatus of the transmission side. It is a figure which shows the hardware constitutions of the communication apparatus of the transmission side of FIG. It is a functional block diagram which shows the function structure of the communication apparatus of the receiving side. It is a flowchart which shows operation | movement of the communication apparatus of a transmission side. It is a flowchart which shows operation | movement of the communication apparatus of the receiving side. It is a functional block diagram which shows the function structure of the communication apparatus of the transmission side which concerns on 2nd Embodiment. It is a figure explaining arrangement | positioning of the signal electrode of the communication apparatus of the transmission side which concerns on 2nd Embodiment. It is a functional block diagram which shows the function structure of the communication apparatus of the transmission side which concerns on 3rd Embodiment. It is a functional block diagram which shows the function structure of the communication apparatus of the transmission side which concerns on 4th Embodiment. It is a functional block diagram which shows the function structure of the communication apparatus of the transmission side which concerns on 5th Embodiment. It is a figure for demonstrating the example of a calculation for determining the control value of transmission signal power from the measurement result of reflected power. It is a functional block diagram which shows the function structure of the communication apparatus of the transmission side which concerns on 6th Embodiment. It is a figure which shows an example of the data table used for determination of the control value of transmission signal power. It is a schematic diagram explaining human body communication.

(First embodiment)
A first embodiment of the present invention will be described with reference to the accompanying drawings. Where possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[Configuration of Communication System 1]
FIG. 1 is a diagram showing an outline of a communication system according to the first embodiment of the present invention. The communication system 1 is a system in which the communication device 10 and the communication device 20 transmit and receive information via a human body (communication medium) 3 as shown in FIG. The communication device 10 and the communication device 20 have both a function as a transmission device for human body communication and a function as a reception device. Here, for convenience, the communication device 10 is a communication device on the transmission side of the human body communication, the communication device 20. Will be described as a communication device on the receiving side of human body communication. As a matter of course, the communication device 10 and the communication device 20 may be used in a communication system that uses other than the human body 3 as a communication medium.

[Configuration of Communication Device 10]
FIG. 2 is a functional block diagram showing a functional configuration of the communication device on the transmission side. The communication device 10 can transmit information using a conductive medium as a communication medium. As shown in FIG. 2, the communication device 10 includes signal electrodes 11 and 12, a transmission unit (applying means) 13, A transmission power control unit (transmission power control unit) 14, a measurement unit (measurement unit) 17, a detection unit (detection unit) 19, and a determination unit (determination unit) 18 are provided. The communication device 10 provides better communication characteristics by appropriately controlling transmission signal power in human body communication. In order to realize such an effect, each component functions as follows.

  The signal electrode 11 and the signal electrode 12 are signal electrodes configured by a pair (a pair) of two sheets. The signal electrode 11 and the signal electrode 12 are elements for forming a closed circuit by electrostatic coupling with the human body 3 and the surrounding environment of the human body 3.

  The transmission unit 13 applies power between the pair of signal electrodes 11 and 12, applies transmission signal power between the pair of signal electrodes 11 and 12, gives a predetermined potential difference between the electrodes, and generates an electric field near the human body 3. This is a means for transmitting by inducing. The transmission unit 13 can change the transmission signal power based on control information from the transmission power control unit 14 described later, and has a function of transmitting with various transmission signal powers. Note that two means in the transmission unit 13, that is, a means for applying power between the pair of signal electrodes 11 and 12, and a transmission signal power between the pair of signal electrodes 11 and 12, and a predetermined potential difference between the electrodes. And means for transmitting by inducing an electric field in the vicinity of the human body 3 may be provided separately from each other.

  The transmission power control unit 14 is a means for appropriately determining the magnitude of transmission signal power applied by the transmission unit 13 between the pair of signal electrodes 11 and 12. The transmission power control unit 14 has a function of determining the transmission signal power output from the transmission unit 13 based on the magnitude of the reflected power measured by the measurement unit 17 described later. The transmission power control unit 14 realizes desired communication characteristics by increasing the transmission signal power applied between the pair of signal electrodes 11 and 12 when the communication characteristics are deteriorated.

  The measurement unit 17 is a means for measuring the reflected power radiated from between the pair of signal electrodes 11 and 12 when power is applied by the transmission unit 13. The measurement unit 17 does not always operate, and determines whether or not to measure the reflected power based on the presence or absence of control of transmission signal power in human body communication determined by the determination unit 18 described later. In addition, the measurement unit 17 has a function for outputting information about the magnitude of the measured reflected power to the transmission power control unit 14.

  The detection unit 19 is means for detecting whether or not the human body 3 is in contact with or close to the signal electrode 11 and the signal electrode 12. Examples of the detection unit 19 include an inductive type, a capacitance type, an ultrasonic type, an electromagnetic type, an infrared type touch sensor, a proximity sensor, and the like.

  The determination unit 18 is means for determining whether or not transmission signal power is controlled in human body communication. The determination unit 18 has a function of controlling the operation of the measurement unit 17 by transmitting the determination to the measurement unit 17.

  Hereinafter, the control content of the measurement part 17 in the determination part 18 is demonstrated concretely. For example, when the detection unit 19 detects that the human body 3 is in contact with or close to both the signal electrode 11 and the signal electrode 12, the determination unit 18 determines that transmission signal power control in human body communication is necessary. Based on the determination, the measurement unit 17 measures the reflected power with respect to the power applied between the pair of signal electrodes 11 and 12 by the transmission unit 13. The transmission power control unit 14 controls the amount of increase in transmission signal power that the transmission unit 13 applies between the pair of signal electrodes 11 and 12 based on the magnitude of the measured reflected power. Here, when the detection unit 19 detects that the human body 3 is in contact with or close to both the signal electrode 11 and the signal electrode 12, for example, it is conceivable that a human is holding the communication device 10 in his / her hand. In such a case, it is considered that both the signal electrode 11 and the signal electrode 12 and the human body 3 are strongly coupled to deteriorate the communication characteristics. However, in this embodiment, the transmission signal power in the human body communication is increased. Therefore, the communication characteristics can be stabilized.

  For example, when the detection unit 19 detects that the human body 3 is not in contact with or close to both the signal electrode 11 and the signal electrode 12, the determination unit 18 determines that transmission signal power control in human body communication is necessary. To do. Based on the determination, the measurement unit 17 measures the reflected power with respect to the power applied between the pair of signal electrodes 11 and 12 by the transmission unit 13. The transmission power control unit 14 controls the magnitude of transmission signal power applied by the transmission unit 13 between the pair of signal electrodes 11 and 12 based on the measured magnitude of reflected power. Here, when the detection unit 19 detects that the human body 3 is not in contact with or close to both the signal electrode 11 and the signal electrode 12, for example, the communication device 10 may be placed in a bag or the like. In such a case, it is conceivable that the communication characteristics deteriorate due to weak coupling between both the signal electrode 11 and the signal electrode 12 and the human body 3, but in this embodiment, the transmission signal power in the human body communication is reduced. Since the number is increased, communication characteristics can be stabilized.

  For example, the detection unit 19 may detect that the human body 3 is in contact with or close to only one of the signal electrode 11 and the signal electrode 12. In this case, the communication device 10 may be in a state such as being put in a pocket of clothes, for example. However, in this case, since either one of the signal electrode 11 or the signal electrode 12 is in contact with or close to the human body 3 and only one of the signal electrodes is considered to be strongly coupled to the human body 3, the communication characteristics are relatively low. It seems to be stable. Therefore, in such a case, the determination unit 18 does not determine that transmission signal power control in human body communication is necessary, and the measurement unit 17 is also connected between the pair of signal electrodes 11 and 12 by the transmission unit 13. The reflected power with respect to the applied power is not measured.

  In the communication device 10, the components other than the signal electrode 11 and the signal electrode 12 may be configured only by hardware such as a circuit, or a predetermined program is stored in a CPU, a ROM, or the like as shown in FIG. It may be realized by reading and executing. These components are controlled by a control circuit (not shown) constituted by a CPU or the like. Hereinafter, an example of a hardware configuration of the communication apparatus 10 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a hardware configuration of the communication device 10. As shown in FIG. 3, the communication device 10 includes a CPU 31 that executes an operating system, application programs, and the like, a main storage unit 32 that includes a ROM and a RAM, an auxiliary storage unit 33 that includes a hard disk, a memory, and the like. It comprises an input unit 34 for input and an output unit 35 for output of signals. Each function in the communication device 10 described above causes the CPU 31 and the main storage unit 32 to read predetermined software and operate the input unit 34 and the output unit 35 under the control of the CPU 31, and the main storage unit 32 and the auxiliary storage unit. This is realized by causing the data 33 to read / write data.

[Configuration of Communication Device 20]
Here, the communication device 20 that functions as a communication device on the receiving side will be described with reference to FIG. FIG. 4 is a functional block diagram showing a functional configuration of the communication device on the receiving side. The communication device 20 can receive information using a conductive medium as a communication medium. As shown in FIG. 4, as a functional component, the signal electrodes 21 and 22, a transmission unit (application unit) 23, A reception unit 25, a reception sensitivity control unit (reception sensitivity control unit) 26, a measurement unit (measurement unit) 27, a detection unit (detection unit) 29, and a determination unit (determination unit) 28 are provided. The communication device 20 can provide better communication characteristics by appropriately controlling the received signal sensitivity in human body communication. In order to realize such an effect, each component functions as follows.

  The signal electrode 21 and the signal electrode 22 are signal electrodes configured as a pair (a pair) of two sheets. The signal electrode 21 and the signal electrode 22 are elements for forming a closed circuit by electrostatic coupling with the human body 3 and the surrounding environment of the human body 3.

  The transmitter 23 is means for applying power between the pair of signal electrodes 21 and 22. Here, since the communication device 20 functions as a communication device on the receiving side, the power applied by the transmission unit 23 between the pair of signal electrodes 21 and 22 is a test only for measuring the reflected power in the measurement unit 27 described later. Power.

  The receiving unit 25 is a means for performing reception by detecting a potential difference between the pair of signal electrodes 21 and 22 generated by the electric field induced in the human body 3 by the communication device 10. The reception unit 25 can change the reception signal sensitivity based on control information from the reception sensitivity control unit 26 described later, and has a function of receiving with various reception signal sensitivities.

  The reception sensitivity control unit 26 is a means for appropriately determining the reception signal sensitivity when the reception unit 25 detects a potential difference induced between the pair of signal electrodes 21 and 22. The reception sensitivity control unit 26 has a function of determining the reception signal sensitivity in the reception unit 25 based on the magnitude of the reflected power measured by the measurement unit 27 described later. The reception sensitivity control unit 26 realizes desired communication characteristics by increasing reception signal sensitivity for detecting a potential difference between the pair of signal electrodes 21 and 22 when the communication characteristics are deteriorated.

  The measuring unit 27 is a unit that measures the magnitude of reflected power radiated from between the pair of signal electrodes 21 and 22 when power is applied between the pair of signal electrodes 21 and 22 by the transmitting unit 23. The measuring unit 27 does not always operate, and determines whether or not to measure the reflected power based on whether or not the received signal sensitivity is controlled in the human body communication determined by the determining unit 28 described later. The measuring unit 27 has a function for outputting information related to the magnitude of the measured reflected power to the reception sensitivity control unit 26.

  The detection unit 29 is means for detecting whether or not the human body 3 is in contact with or close to the signal electrode 21 and the signal electrode 22. Examples of the detection unit 29 include an inductive type, a capacitance type, an ultrasonic type, an electromagnetic type, an infrared type touch sensor, a proximity sensor, and the like.

  The determination unit 28 is means for determining whether or not the received signal sensitivity is controlled in human body communication. The determination unit 28 has a function of controlling the operation of the measurement unit 27 by transmitting the determination to the measurement unit 27.

  Hereinafter, the control content of the measurement unit 27 in the determination unit 28 will be specifically described. For example, when the detection unit 29 detects that the human body 3 is in contact with or close to both the signal electrode 21 and the signal electrode 22, the determination unit 28 determines that control of received signal sensitivity in human body communication is necessary. The measurement unit 27 measures the reflected power with respect to the power applied between the pair of signal electrodes 21 and 22 by the transmission unit 23 based on the determination. The reception sensitivity control unit 26 controls the amount of increase in reception signal sensitivity when the reception unit 25 detects a potential difference between the pair of signal electrodes 21 and 22 based on the measured magnitude of the reflected power. Here, when the detection unit 29 detects that the human body 3 is in contact with or close to both the signal electrode 21 and the signal electrode 22, it is conceivable that, for example, a human is holding the communication device 20. In such a case, it is considered that both the signal electrode 21 and the signal electrode 22 and the human body 3 are strongly coupled to deteriorate the communication characteristics, but in this embodiment, the received signal sensitivity in the human body communication is increased. Therefore, the communication characteristics can be stabilized.

  For example, when the detection unit 29 detects that the human body 3 is not in contact with or close to both the signal electrode 21 and the signal electrode 22, the determination unit 28 determines that control of received signal sensitivity in human body communication is necessary. To do. The measurement unit 27 measures the reflected power with respect to the power applied between the pair of signal electrodes 21 and 22 by the transmission unit 23 based on the determination. The reception sensitivity control unit 26 controls the amount of increase in reception signal sensitivity when the reception unit 25 detects a potential difference between the pair of signal electrodes 21 and 22 based on the measured magnitude of the reflected power. Here, when the detection unit 29 detects that the human body 3 is not in contact with or in close proximity to both the signal electrode 21 and the signal electrode 22, for example, the communication device 20 may be placed in a bag or the like. In such a case, it is considered that the communication characteristics are deteriorated due to weak coupling between the communication device 20 and the human body 3, but in this embodiment, the received signal sensitivity in the receiving unit 25 is increased in such a case. Since the number is increased, communication characteristics can be stabilized.

  For example, the detection unit 29 may detect that the human body 3 is in contact with or close to only one of the signal electrode 21 and the signal electrode 22. In this case, the communication device 20 may be in a state where it is put in a pocket of clothes, for example. However, in this case, since either one of the signal electrode 21 or the signal electrode 22 is in contact with or close to the human body 3 and only one of the signal electrodes is considered to be strongly coupled to the human body 3, the communication characteristics are relatively stable. It seems to have done. Therefore, in such a case, the determination unit 28 does not determine that control of received signal sensitivity in human body communication is necessary, and the transmission unit 23 applies power between the pair of signal electrodes 21 and 22. Nor.

  The constituent elements other than the signal electrode 21 and the signal electrode 22 may be configured only by hardware such as a circuit, or a predetermined program may be read and executed by a CPU, a ROM, or the like as shown in FIG. It may be realized with. These components are controlled by a control circuit (not shown) constituted by a CPU or the like. Note that the hardware configuration of the communication device 20 is the same as that of the example of the communication device 10 described above, and therefore the description thereof is omitted here.

[Processing in Communication Device 10]
Hereinafter, operations of the communication device 10 and the communication device 20 will be described, and a transmission / reception method (communication method) according to the present embodiment will be described. First, the operation of the communication device 10 on the transmission side will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the communication device on the transmission side.

  In the communication device 10, when the human body communication process is started (S11), the transmission unit 13 starts applying power between the pair of signal electrodes 11 and 12 (S12: application step). Note that the power in this case may be transmission signal power that should be originally communicated, or may be test power for determining whether or not transmission signal power is controlled.

  When the human body communication is continued following the application of the power (S13: NO), the determination unit 18 determines whether or not the transmission signal power is controlled in the human body communication based on the detection result of the detection unit 19. (S14: Determination step).

  For example, when the detection unit 19 detects that the human body 3 is in contact with or close to both the signal electrode 11 and the signal electrode 12, the determination unit 18 determines that control of transmission signal power in human body communication is necessary. Also good. For example, when the detection unit 19 detects that the human body 3 is not in contact with or close to both the signal electrode 11 and the signal electrode 12, the determination unit 18 determines that transmission signal power control in human body communication is necessary. May be. For example, when the detection unit 19 detects that the human body 3 is in contact with or close to only one of the signal electrode 11 and the signal electrode 12, the determination unit 18 does not need to control transmission signal power in human body communication. May be determined.

  Here, when the determination unit 18 determines that control of transmission signal power in human body communication is necessary (S14: YES), the information regarding the determination is output to the measurement unit 17. When the information is input from the determination unit 18, the measurement unit 17 measures the reflected power (S15: measurement step).

  Next, the measurement unit 17 outputs information regarding the magnitude of the measured reflected power to the transmission power control unit 14. The transmission power control unit 14 determines a control value of the transmission signal power in the transmission unit 13 based on the information input from the measurement unit 17 (S16), and outputs the control value to the transmission unit 13. Subsequently, when it is necessary to change the transmission signal power based on the transmission signal power control value determined by the transmission power control unit 14 (S17: YES), the transmission unit 13 changes the transmission signal power (S18). : Transmission power control step).

  On the other hand, when the determination unit 18 determines in step S14 that control of transmission signal power in human body communication is not necessary (S14: NO), and when there is no need to change transmission signal power in the transmission unit 13 in step S17. For (S17: NO), the transmission unit 13 applies transmission signal power between the pair of signal electrodes 11 and 12 with the setting of the power or transmission signal power applied in step S12. Note that while the human body communication is performed, the processing from step S12 to step S18 is repeatedly executed (S13: NO). When the communication ends (S13: YES), the communication device 10 transitions to the initial state and prepares for the next communication.

  In addition, the communication apparatus 10 may perform the process after step S12 except step S13 before communication start. In other words, the communication device 10 may be configured so that the processing after step S12 excluding step S13 is executed before new communication is started. In this case, since the optimal transmission signal power is set using the test signal before the start of communication, communication can be started with the optimally controlled transmission signal power at the start of a new communication. It becomes possible to execute.

[Processing in Communication Device 20]
Next, the operation of the communication device 20 on the receiving side will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the communication device on the receiving side.

  In the communication device 20, when the communication process is started (S21), the receiving unit 25 starts detecting a potential difference between the pair of signal electrodes 21 and 22 (S22). When the human body communication is continued following the detection of the potential difference (S23: NO), the determination unit 28 determines whether or not the received signal sensitivity is controlled in the human body communication based on the detection result of the detection unit 19. (S24: Determination step).

  For example, when the detection unit 29 detects that the human body 3 is in contact with or close to both the signal electrode 21 and the signal electrode 22, the determination unit 28 determines that it is necessary to control the received signal sensitivity in human body communication. Also good. For example, when the detection unit 29 detects that the human body 3 is not in contact with or close to both the signal electrode 21 and the signal electrode 22, the determination unit 28 determines that control of received signal sensitivity in human body communication is necessary. May be. For example, when the detection unit 29 detects that the human body 3 is in contact with or close to only one of the signal electrode 21 and the signal electrode 22, the determination unit 28 does not need to control the received signal sensitivity in human body communication. May be determined.

  Here, when the determination unit 28 determines that control of received signal sensitivity in human body communication is necessary (S24: YES), the determination unit 28 outputs information related to the determination to the transmission unit 23 and the measurement unit 27. The transmitter 23 applies power between the pair of signal electrodes 21 and 22 (S25: application step). Here, since the communication device 20 functions as a communication device on the receiving side, the power applied by the transmission unit 23 is test power only for measuring the reflected power in the measurement unit 27 described later. In addition, when the information is input from the determination unit 28, the measurement unit 27 measures the reflected power (S26: measurement step).

  Next, the measurement unit 27 outputs information related to the magnitude of the measured reflected power to the reception sensitivity control unit 26. The reception sensitivity control unit 26 determines a control value of the reception signal sensitivity in the reception unit 25 based on the information input from the measurement unit 27 (S27), and outputs the control value to the reception unit 25. Subsequently, when it is necessary to change the received signal sensitivity based on the received signal sensitivity control value determined by the received sensitivity control unit 26 (S28: YES), the receiving unit 25 changes the received signal sensitivity (S29). : Reception sensitivity control step).

  On the other hand, when the determination unit 18 determines in step S24 that it is not necessary to control the received signal sensitivity in human body communication (S24: NO), and it is not necessary to change the received signal sensitivity in the receiving unit 25 in step S27. In (S27: NO), the receiving unit 25 detects the potential difference between the pair of signal electrodes 21 and 22 by setting the received signal sensitivity when the potential difference is detected in step S22. Note that while the human body communication is performed, the processing from step S22 to step S29 is repeatedly executed (S23: NO). When the communication ends (S23: YES), the communication device 20 transitions to the initial state and prepares for the next communication.

  Note that the communication device 20 may execute the processes in and after step S24 before starting communication. In other words, the communication device 20 may be configured such that the processing after step S24 is executed before new communication is started. In this case, since reception can be started with optimally controlled reception signal sensitivity at the start of new communication, communication can be executed more stably.

  As described above, according to the present embodiment, the measurement unit 17 measures the reflected power based on the presence or absence of transmission signal power control in human body communication determined by the determination unit 18. As a result, the communication characteristics are improved when there is a high possibility that the communication characteristics are deteriorated, so that the communication characteristics can be stabilized regardless of the coupling state between the communication device 10 and the communication medium. In addition, since the function for controlling the transmission signal power is operated only when the communication characteristics deteriorate, it is possible to suppress a significant increase in power consumption in the communication device 10.

  Further, according to the present embodiment, the measuring unit 27 measures the reflected power based on the presence / absence of control of the received signal sensitivity in the human body communication determined by the determining unit 28. As a result, the communication characteristics are improved when there is a high possibility that the communication characteristics are deteriorated, so that the communication characteristics can be stabilized regardless of the coupling state between the communication device 20 and the communication medium. In addition, since the function for controlling the received signal sensitivity is operated only when the communication characteristics deteriorate, it is possible to suppress a significant increase in power consumption in the communication device 20.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram illustrating a functional configuration of the communication apparatus according to the second embodiment. The communication device 40 is a communication device mounted on a mobile phone terminal body or a mobile terminal, and includes all the components of the communication device 10 in the first embodiment as shown in FIG. There is a further feature in that it is configured to include a detection unit (state detection means) 41. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the following embodiments, the communication device 40 will be described as a transmission-side communication device.

  The state detection unit 41 is configured to be included in the determination unit 18 and has a function of detecting the state of the casing of the mobile phone terminal (communication device). The state of the casing of the mobile phone terminal is, for example, a folding type mobile phone terminal, whether the terminal is in an open state or a closed state, and if it is a slide type mobile phone terminal, the terminal Whether the housing is in a slid state or not slid state, and if the mobile phone terminal is of a folding type and the display rotates, the component side on which the display is mounted is in a rotating state, This is the state. The state detection unit 41 is an open / close detection means (not shown) for detecting whether the terminal is open or closed, and whether the terminal is slid or not slid. A slide detection means (not shown) for detection may be included.

  In the communication device 40 according to the second embodiment, in the determination unit 18 including the state detection unit 41, when the folding cellular phone terminal is in a closed state or when the sliding cellular phone terminal is not slid, The determination unit 18 determines that control of transmission signal power in human body communication is necessary. When the information related to the determination is input from the determination unit 18, the measurement unit 17 measures the reflected power. Thereby, the transmission power control unit 14 can control the transmission signal power at an optimum timing in consideration of a case where the communication characteristics deteriorate. This often occurs when the communication characteristics are deteriorated, for example, when the hand is touching both signal electrodes of the communication device as described above, or when it is placed in a bag. It uses what is known in the rule of thumb. Referring to the drawings, each of the pair of signal electrodes 11 and 12 mounted on the communication device 40 is, for example, a foldable mobile phone terminal as shown in FIG. Since it is often mounted on the surface, when the communication characteristics as described above are deteriorated, the fact that the cellular phone terminal is almost closed is used. Although not shown, in the case of a slide-type mobile phone terminal, each of the pair of signal electrodes 11 and 12 is similarly mounted on the surface of each component that slides on each other. In the case of a decrease, the fact that the mobile phone terminal is not slid is used.

  In the second embodiment, unlike the first embodiment, for example, even when the communication device 40 is in a pocket or the like, the determination unit 18 determines that transmission signal power control in human body communication is necessary, Although there is a high possibility that the measurement unit 17 will measure the reflected power, it is considered that there are few cases where the transmission signal power is actually controlled. This is because when the communication device 40 is in a pocket or the like, the communication characteristics are relatively stable. Therefore, even when the reflected power is measured by the measurement unit 17, the transmission power control unit 14 actually transmits the transmission signal power. This is because it is determined not to change (refer to the process on the “NO” side of step S17 in FIG. 5).

  In addition, even when the communication device 40 is a reception-side communication device, it is obvious that the change in received signal sensitivity can be controlled by the same method as described above.

  According to such a communication device 40, the communication characteristics are optimized by using a function that is very simple and that is already mounted on a commercially available mobile phone terminal, such as the state of the casing of the mobile phone terminal. For this reason, as in the first embodiment, the communication characteristics are improved when there is a high possibility that the communication characteristics are deteriorated, so that the communication characteristics are stabilized regardless of the coupling state between the communication device 40 and the communication medium. Can do. In addition, since the function for controlling the transmission signal power is operated only when there is a high possibility that the communication characteristics are deteriorated, it is possible to suppress a significant increase in power consumption in the communication device 40. In addition, since it is possible to use the function of an existing mobile phone terminal, a desired operation can be realized without increasing the manufacturing cost of the communication device 40.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a block diagram illustrating a functional configuration of the communication apparatus according to the third embodiment. As shown in FIG. 9, the communication device 50 includes all the components of the communication device 10 according to the first embodiment, and the determination unit 18 is configured to include a time measurement unit (time measurement unit) 51. There are additional features. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the following embodiments, the communication device 50 is described as a transmission-side communication device.

  The time measurement unit 51 has a function of measuring the duration of a predetermined detection state in a state detection unit (not shown) included in the detection unit 19 or the determination unit 18. The determination unit 18 determines that control of transmission signal power in human body communication is necessary when the predetermined measurement state is continued for a predetermined time or longer by the time measurement unit 51. When the information related to the determination is input from the determination unit 18, the measurement unit 17 measures the reflected power. For example, the case where the determination part 18 is applied to an example of 1st Embodiment which determines the presence or absence of the measurement of the reflected power in the measurement part 17 based on the detection result from the detection part 19 using a touch sensor is demonstrated. In this case, the determination unit 18 performs human body communication when a state where the detection state of the human body 3 in the touch sensor (whether the human body 3 is detected by the touch sensor) is continuously detected is detected for a predetermined time or longer. It is determined that it is necessary to control the transmission signal power at.

  According to such a communication device 50, for example, when there is a change in the instantaneous relationship between the communication device 50 and the human body 3, such as temporarily removing the communication device 50 from a pocket and holding it in hand. Therefore, it is possible not to control the transmission signal power in human body communication. That is, in the above example, when the communication device 50 is taken out from the pocket and held in the hand, the communication characteristics may be instantaneously reduced, but the transmission power is controlled to such an instantaneous change. Since there is a high possibility that the communication device 50 is unnecessary, an increase in unnecessary power consumption in the communication device 50 can be suppressed.

  Even when the communication device 50 is a device on the receiving side, it is apparent that an increase in unnecessary power consumption can be suppressed by controlling the received signal sensitivity by the same method as described above.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a block diagram illustrating a functional configuration of a communication device according to the fourth embodiment. As shown in FIG. 10, the communication device 60 includes all the components of the communication device 10 according to the first embodiment, and the measurement unit 17 includes a first storage unit (first storage unit) 61. There is a further feature. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the following embodiments, the communication device 60 will be described as a communication device on the transmission side.

  The first storage unit 61 is configured to be included in the measurement unit 17 and has a function of storing the reflected power measured by the measurement unit 17. When the activation signal from the determination unit 18 is input, the measurement unit 17 measures the reflected power and then compares the latest reflected power stored in the first storage unit 61 with the measured reflected power. The transmission power control unit 14 is operated based on the comparison result.

  Here, for example, when the reflected power at the time of the previous measurement (nearest) and the current reflected power coincide with each other, the transmission signal power (control value) controlled by the transmission power control unit 14 based on the reflected power of the measurement unit 17 ) Is the same for the previous time and this time. For this reason, it is not necessary to change the transmission signal power controlled by the transmission power control unit 14 once again based on the reflected power in the current measurement unit 17. In the present embodiment, when the reflected power at the time of the previous measurement (nearest) and the reflected power of this time coincide with each other, control of the transmission signal power in the transmission power control unit 14 is avoided and unnecessary control is not performed. I am doing so.

  According to such a communication device 60, unnecessary control can be avoided, so that unnecessary increase in power consumption and increase in control time can be suppressed.

  Even when the communication device 60 is a communication device on the receiving side, it is possible to suppress an increase in unnecessary power consumption and an increase in control time by controlling the received signal sensitivity by the same method as described above. it can. In this case, for example, the measurement unit 17 avoids control of the reception signal sensitivity in the reception sensitivity control unit 26 when the measurement result of the reflected power at the previous measurement (most recent) and the measurement result of the current reflected power match each other. do it.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a block diagram illustrating a functional configuration of a communication device according to the fifth embodiment. FIG. 12 is a diagram for explaining a calculation example for determining the control value of the transmission signal power from the measurement result of the reflected power. As shown in FIG. 11, the communication device 70 includes all the components of the communication device 10 according to the first embodiment, and the transmission power control unit 14 is configured to include a calculation unit (calculation means) 71. There are additional features. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the following embodiments, the communication device 70 will be described as a transmission-side communication device.

  The calculation unit 71 determines the transmission signal power controlled by the transmission power control unit 14 based on the reflected power measured by the measurement unit 17 and the transmission signal power applied by the transmission unit 13 when the reflected power is measured. It has a function to decide. For example, as shown in FIG. 12, the set value of the transmission signal power applied by the transmission unit 13 is X, the measurement value of the reflected power measured by the measurement unit 17 at that time is Y, and the pair of signal electrodes 11 from the transmission unit 13 If the magnitude of the signal loss up to 12 is L, the transmission signal power radiated from between the pair of signal electrodes 11 and 12 can be calculated by the calculation formula X × L−Y / L (true value). For example, using this calculation formula, the transmission signal power radiated between the pair of signal electrodes 11 and 12 is an ideal value (for example, radiated from the pair of signal electrodes 11 and 12 when no reflection occurs). The set value of the transmission signal power may be controlled to be equal to (transmission signal power).

  According to such a communication apparatus 70, it is possible to control the transmission signal power to be ideal for performing human body communication using the measurement result of the reflected power.

  Further, even when the communication device 70 is a communication device on the receiving side, it is apparent that it is possible to control the received signal sensitivity to an ideal for human body communication by the same method as described above. In this case, the calculation unit (calculation means) 71 may be configured to be included in the reception sensitivity control unit 26 shown in FIG.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a block diagram illustrating a functional configuration of a communication apparatus according to the sixth embodiment. FIG. 14 is a diagram illustrating an example of a data table used for determining a control value of transmission signal power. As illustrated in FIG. 13, the communication device 80 includes all the components of the communication device 10 according to the first embodiment, and the transmission power control unit 14 includes a second storage unit (second storage unit) 81. There is a further feature in this point. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the following embodiments, the communication device 80 will be described as a transmission-side communication device.

  The second storage unit 81 is means for storing a data table (control information) in which a control value (control parameter) of transmission signal power with respect to reflected power is associated. The transmission power control unit 14 has a function of determining a control value of the transmission signal power according to the reflected power measured by the measurement unit 17 and a data table stored in advance in the second storage unit 81. . For example, it is assumed that a data table in which a control value of transmission signal power corresponding to one-to-one with respect to reflected power as illustrated in FIG. 14 is stored in the second storage unit 81. When the reflected power in the measurement unit 17 is “P3”, the transmission power control unit 14 extracts “S3” as the control value of the transmission signal power and transmits the transmission signal based on the extracted control value of the transmission signal power. Control power.

  In the example of the data table illustrated in FIG. 14, it has been described that the reflected power and the control value of the transmission signal power have a one-to-one correspondence. However, the data table is not limited to such an example. For example, a data table in which one transmission signal power control value corresponds to a certain range of reflected power may be used. The data table stored in the second storage unit 81 can be freely created as long as the desired purpose can be achieved.

  According to such a communication apparatus 80, since it is not necessary to calculate the control value of the transmission signal power each time, the processing time can be increased and the communication time can be shortened.

  Further, even when the communication device 80 is a communication device on the receiving side, it is obvious that the processing time can be increased and the communication time can be shortened by the same method as described above. In this case, the second storage unit (second storage unit) 81 may be configured to be included in the reception sensitivity control unit 26 shown in FIG.

  As mentioned above, although this invention was demonstrated in detail based on the said embodiment, it is not limited to this. The present invention can be variously modified without departing from the gist thereof.

  In the above-described embodiments and modifications, the communication device 10 has been described as a communication device on the transmission side of human body communication and the communication device 20 is a communication device on the reception side of human body communication for convenience. May be configured to include a pair of signal electrodes, a measurement unit, a determination unit, a detection unit, a transmission unit, a transmission power control unit, a reception unit, and a reception sensitivity control unit in one communication device.

  DESCRIPTION OF SYMBOLS 1 ... Communication system, 3 ... Human body, 10, 20, 40, 50, 60, 70, 80 ... Communication apparatus, 11, 12 ... Signal electrode, 13 ... Transmission part, 14 ... Transmission power control part, 17 ... Measurement part, DESCRIPTION OF SYMBOLS 18 ... Determination part, 19 ... Detection part, 21, 22 ... Signal electrode, 23 ... Transmission part, 25 ... Reception part, 26 ... Reception sensitivity control part, 27 ... Measurement part, 28 ... Determination part, 29 ... Detection part, 41 ... a state detection unit, 51 ... a time measurement unit, 61 ... a first storage unit, 71 ... a calculation unit, 81 ... a second storage unit.

Claims (11)

A communication device on the transmission side in human body communication,
A pair of signal electrodes electrostatically coupled to the communication medium and the surrounding environment of the communication medium;
Applying means for applying power between the pair of signal electrodes;
Measuring means for measuring the reflected power relative to the power applied by the previous SL applying means,
Detecting means for detecting contact or proximity of the communication medium to the pair of signal electrodes;
Determining means for controlling the operation of the measuring means based on the presence or absence of detection of contact or proximity of the communication medium to the pair of signal electrodes in the detecting means;
Transmission power control means for controlling transmission signal power in the human body communication based on the reflected power measured by the measurement means operated by the control of the determination means ;
A communication apparatus comprising: A communication device on the receiving side in human body communication,
A pair of signal electrodes electrostatically coupled to the communication medium and the surrounding environment of the communication medium;
Applying means for applying power between the pair of signal electrodes;
Measuring means for measuring the reflected power relative to the power applied by the previous SL applying means,
Detecting means for detecting contact or proximity of the communication medium to the pair of signal electrodes;
Determining means for controlling the operation of the measuring means based on the presence or absence of detection of contact or proximity of the communication medium to the pair of signal electrodes in the detecting means;
Receiving sensitivity control means for controlling the received signal sensitivity in the human body communication based on the reflected power measured by the measuring means operated by the control of the determining means ;
A communication apparatus comprising: The determination means according to claim 1 or 2, characterized in that to operate the measuring means when said detecting means said that the communication medium is in contact with or close to both of the pair of signal electrodes detects Communication device. The said determination means operates the said measurement means, when the said detection means does not detect that the said communication medium has contacted or adjoined to both said pair of signal electrodes , Any one of Claims 1-3 characterized by the above-mentioned. The communication apparatus according to claim 1 . It said detecting means, communication device according to any one of claims 1 to 4, characterized in that it is constituted by a touch sensor or proximity sensor. The determination means includes a state detecting means for detecting the state of the communication device housing, it claims 1-5, characterized in that for controlling the operation of said measuring means on the basis of the detection by the state detection means Item 1. The communication device according to item 1. The state detection means includes open / close detection means for detecting opening / closing of folding of the communication device housing,
The communication device according to claim 6 , wherein the determination unit operates the measurement unit when the open / close detection unit detects that the communication device housing is in a closed state. The state detection means includes a slide detection means for detecting a slide state of the communication device housing,
The communication device according to claim 6 , wherein the determination unit operates the measurement unit when the slide detection unit detects that the communication device housing is not slid. The determination unit includes a time measurement unit that measures a duration of a predetermined detection state in the detection unit or the state detection unit,
The communication according to any one of claims 6 to 8 , wherein the determination unit operates the measurement unit when the duration time measured by the time measurement unit is equal to or longer than a predetermined time. apparatus. A communication method on the transmission side in human body communication of a communication device comprising a communication medium and a pair of signal electrodes that are electrostatically coupled to the surrounding environment of the communication medium,
An applying step in which the applying means applies power between the pair of signal electrodes;
Measuring means comprises a measuring step of measuring the reflected power relative to the power applied by the previous SL applying means,
A detecting step for detecting contact or proximity of the communication medium to the pair of signal electrodes;
A determining step for controlling the operation of the measuring means based on the presence or absence of detection of contact or proximity of the communication medium to the pair of signal electrodes in the detecting means ;
A transmission power control step for controlling transmission signal power in the human body communication based on the reflected power measured by the measurement unit operated by the control in the determination step ;
A communication method comprising: A communication method on the receiving side in human body communication of a communication device comprising a communication medium and a pair of signal electrodes that are electrostatically coupled to the surrounding environment of the communication medium,
An applying step in which the applying means applies power between the pair of signal electrodes;
Measuring means comprises a measuring step of measuring the reflected power relative to the power applied by the previous SL applying means,
A detecting step for detecting contact or proximity of the communication medium to the pair of signal electrodes;
A determining step for controlling the operation of the measuring means based on the presence or absence of detection of contact or proximity of the communication medium to the pair of signal electrodes in the detecting means ;
A reception sensitivity control step , wherein the reception sensitivity control means controls the reception signal sensitivity in the human body communication based on the reflected power measured by the measurement means operated by the control in the determination step ;
A communication method comprising:

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