Communication device and communication method

1. A communication device for communicating with an external device using a human body as a signal transmission path, comprising:

an electric field strength measuring unit configured to measure a noise level from a detected received electric field strength at the time of no signal after the received electric field strength is detected by the communication device when a transmission signal to be output to the external device is absent;

a transmission output determination unit configured to determine an output level of the transmission signal to be transmitted to the external device on the basis of the measured noise level; and

an output execution unit configured to output a transmission signal of the determined output level to the external device.

2. The communication device according to claim 1 ,

wherein the received electric field strength at the time of no signal is a received electric field strength of the moment when the human body is in contact with the external device in a state in which the transmission signal directed to the external device is not started up.

3. The communication device according to claim 1 ,

wherein the transmission output determination unit determines a high output level when the measured noise level is high, and determines a low output level when the measured noise level is low.

4. The communication device according to claims 1 ,

wherein the output execution unit outputs the transmission signal including information of the measured noise level or the determined output level to the external device.

5. The communication device according to claim 4 ,

wherein the external device is a communication module mounted on the human body), and

wherein the mounted communication module includes:

a transmission output determination unit configured to determine an output level of a transmission signal to be returned to the communication device on the basis of the information of the measured noise level or the determined output level; and

an output execution unit configured to output a transmission signal of the determined output level to the communication device.

6. The communication device according to claim 5 ,

wherein the transmission output determination unit determines a high output level when the measured noise level or the determined output level is high, and determines a low output level when the measured noise level or the determined output level is low.

7. The communication device according to claims 1 ,

wherein a received electric field strength of a transmission signal returned from the external device is further detected,

wherein the electric field strength measuring unit measures a received signal level from the detected received electric field strength of the transmission signal, and

wherein the transmission output determination unit re-determines an output level of a transmission signal to be transmitted to the external device on the basis of the measured received signal and a noise level before or after the received signal is detected.

8. A communication method for communication between a first communication module and a second communication module using a human body as a signal transmission path, comprising:

detecting, by the first communication module, a received electric field strength at the time of no signal as the moment when the human body is in contact with the second communication module in a state in which a transmission signal is not started up when the transmission signal is output to the second communication module;

measuring, by the first communication module, a noise level from the detected received electric field strength at the time of no signal;

following, by the first communication module, a high/low state of the measured noise level and determining an output level of a transmission signal to be transmitted to the second communication module;

outputting, by the first communication module, a transmission signal of the determined output level to the second communication module along with information of the measured noise level or the determined output level;

following, by the second communication module, a high/low state of the information of the measured noise level or the determined output level and determining an output level of a transmission signal to be returned to the first communication module; and

outputting, by the second communication module, a transmission signal of the determined output level to the first communication module.