| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a transmission system, which automatically follows a change on a reception side by varying a band by means of changing the number of carriers on a transmission side. SOLUTION: A band variable modulation device 101 changes the number of carriers so that a signal becomes a used band width. A frequency conversion transmission device 102 controls a local oscillating frequency so that the signal becomes the used frequency. A transmission signal which becomes the used frequency/band width is transmitted to a reception side. On the reception side, a band variable demodulation device 104 discriminates among a state where all carriers do not exist, a state only a part of carriers exists, and a state where most scheduled carriers exist, outputs a corresponding switch control signal to a frequency conversion reception device 103, switches a received frequency with the switch control signal, and receives the transmission signal from the transmission side. Thus, the system which automatically searches an idle channel and transmits data with transmission bandwidth corresponding to the idle band is configured.</p> |
