| 摘要 |
PROBLEM TO BE SOLVED: To accelerate communication from a questioner to a responder and to improve accuracy, without requiring any precise internal reference clock for the responder by demodulating a command or data by discriminating a change in the frequency of transmitted carrier wave, when the difference of count number is settled within a prescribed threshold value. SOLUTION: The number of carrier waves of 1/N of the number of carrier waves, consisting of one bit of digital data transmitted by a questioner 1 and during such time, counting is performed at plural kinds of timing while using a transmitter 10 built in an IC. These plural count numbers are compared and it is discriminated whether the difference of count numbers is more than the threshold value or less than it. By using such transition in the count number, the digital data are demodulated. Therefore, the digital data can be demodulated without being affected by dispersion in the oscillation frequency of the oscillator 10 to be used for a high-speed counter and further, without necessity for a responder 2 to return a signal for synchronism acquisition to the questioner 1, in order for the questioner 1 to match synchronism with the responder 2. |
