| 摘要 |
PURPOSE:To demodulate transmitted data without any error even when disturbed by a signal which is as high as some of frequencies of a signal by using the signal having plural frequencies for a modulating carrier. CONSTITUTION:A modulating circuit performs modulation by generating the signal of iota3 frequencies by a multifrequency signal generator 14 on a time- division basis and inverting or not inverting the phase of the output signal of the multifrequency signal generator synchronized with a clock signal from an input terminal 12 with input data from an input terminal 11 by using a data converter 13 and an exclusive OR gate 15. The clock in one period contains a series of plural wavelengths outputted from the multifrequency signal generator. A demodulating circuit receives this modulated wave and the input signal is delayed through a delay line 22 by a time (one period of clock signal) corresponding to one bit of data; and this delay output and input signal are ORed exclusively and passed through a low-pass filter 24 which removes the high-frequency component of the exclusive OR output, thus demodulating the data signal. |
