| 摘要 |
There are provided digital communicating method and apparatus for modulating digital signals into chirp signals and performing the communication. In this method, pulses indicative of digital signals of codes "1" and "0" are modulated, the modulated pulse signals are converted into chirp signals, the chirp signals are converted into the optical signals and output as transmission signals, and the digital signals are input and the pulses based thereon are generated. A wave of a predetermined frequency is multiplied by the pulses indicative of "1" and "0" of the digital signals and the modulation is executed. The communication signals can be converted into the chirp signals by the chirp conversion elements using the surface acoustic wave-dispersive delay lines having different converting characteristics by the simple construction. On the reception side, the modulated signals are demodulated by the chirp conversion elements having characteristics opposite to those of the chirp conversion elements on the transmission side. Thus, the code signals of "1" and "0" can be accurately discriminated and the error rate can be reduced. The communication reliability is improved.
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