| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the efficiency of the radio wave resource by transmitting/ receiving data through the use of a single carrier frequency between a plurality of transmitters and a single receiver. SOLUTION: When a first transmitter transmits an FSK modulation signal, the modulated signal of only a carrier frequency fr is transmitted at first and an FSK modulation signal frl or fr2 obtained by FSK-modulating data after prescribed time passes is transmitted. When data transfer terminates, the transmission of the FSK modulated signal is also stopped. A second transmitter 8 to N-th transmitter 9 have the same constitutions as the first transmitter 1. Thus, they transmit the carrier frequency fr at first in the same way as the first transmitter 1 and the FSK modulated signal fr1 of fr2 is transmitted after prescribed time passes. Then, the transmission of the FSK modulated signal terminates with the termination of data. The transmission signal transmitted from the first transmitter 1 is received by a single receiver 10 in a system. The carrier signal is tuned and amplified in a reception circuit 11.</p> |
