| 摘要 |
PURPOSE:To obtain a radio line of FSK modulation with high quality and less transmission power by providing plural sub-channels in a transmission band and increasing/ decreasing the sub-channel number in resonse to the information capacity to be transmitted, the number of reception stations and the line quality for communication. CONSTITUTION:Plural sub-channels SCHf01-f0n are provided in the transmission band of the operating frequency and terminal devices 01-0n at each SCH and modulators- demodulators 11-1n of the FSK system are equipped. An output of the modulators- demodulators is synthesized by a synthesizer/distributor 2, the carrier is modulated and transmitted from a transmitter TX. Further, the signal received by a receiver RX is demodulated by the demodulator 2, distributed to each SCH, demodulated by each modulator-demodulator and transmitted to each terminal device. In case of 1:1 transmission/reception, one set of information is assigned to each SCH by one bit each. In case of >=1:2 transmission/reception, plural SCH number per one reception station is assigned in advance, the same or different kid of data is transmitted/recieved at each SCH, and the number of SCH is increased/decreased depending on the information capacity or the reception station number. In decreasing the SCH number, the shift frequency of the FSK modulation is spread and the line quality is ensured. |
