| 摘要 |
PROBLEM TO BE SOLVED: To provide an information sending/receiving device and an information sending/receiving method that vary a communication parameter to enhance the power efficiency and that attains stable information communication and to provide an information carrying device and an information carrying method. SOLUTION: An information carrying device detection means 7 of an information sending receiving device IRT detects the presence of the information carrying device on the basis of an antenna terminal voltage 8a monitored by a terminal voltage monitor section R8 and a transmission power control means 6 reduces transmission power in a detection standby state and increases the transmission power at information communication after the detection. When no response comes from the information carrying device, the means 6 increases the transmission power of the information sending/receiving device IRT or/and a modulation degree control means 5 increases the degree of modulation of a command. When the response comes therefrom but normal communication is not available, a response modulation degree revision instruction transmission means 4 transmits a response modulation degree revision command to the information carrying device. |
