| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase the frequency band use efficiency of spread spectrum communication and to effectively use radio wave resources. SOLUTION: A tone generator provided to a transmission device, i.e., a tone generator which generates (n) tone signals for an n-level input signal is so constituted that a combination of (i) tones among (m) tones corresponds to the n-level input signal. The same logic with the tone generator of the transmission device is employed to constitute a detector provided to a reception device so that an n-level signal is restored from a combination of (i) arriving tone signals.</p> |
