| 摘要 |
PURPOSE:To realize a transmission and receiving system strong against noise for a weak radi wave other than the law-regulated radio wave, by transmitting and receiving binary signals while multiplexing them, for example, transmitting composite waves which a frequency mixer outputs at a fixed time interval. CONSTITUTION:Signals according to input states of switches 1-3 are stored in 15-17 and outputted, and switch circuits 7-9 repeat turning-on and off by clock pulse CP11, and then, frequency waves f1-f3 assigned correspondingly to switches 1-3 are supplied to mixer 10 simultaneously at a fixed interval repeatedly and transmitted from antenna 20 on the UHF carrier wave through amplifier 18 and transmitter 19. Next, signals received by 21 have f1-f3 extracted by filters 24-26 after detection in 22 and amplification in 23, and continuously, they pass through amplifiers 27-29 and pulse generation circuits 30-32 and further pass through operation circuit 33-35 and CP generator 36, thus preventing the influence of external noise. |
