| 摘要 |
PURPOSE:To discriminate and receive a transmission data signal with a high selectivity by transmitting an original signal of a clock for data signal and a carrier as the reference of data transmission to the data transmitter side from the data receiver side. CONSTITUTION:An output A (original signal) of an oscillator 1 is converted to an optical signal A' on the side of a data receiver 100, and this signal is inputted to an optical receiver 3 of a data transmitter 200 by space propagation to output a signal A'' having the same repeat frequency as the output A of the oscillator 1. The signal A'' has the frequency divided by a frequency divider 6 and is outputted as a carrier B', and the signal A'' has the frequency divided by a frequency divider 7 and is outputted as a clock C'. Data stored in a data memory 13 is read out as transmission data D by the clock C'. The carrier B' is modulated in a data modulator 12 by transmission data D, and a modulation output E is converted to an optical signal E' by an optical transmitter 11 and is sent to the data receiver 100. In the data receiver 100, the optical signal E' is converted to an electric signal E'' by an optical receiver 10, and the electric signal E'' is detected and demodulated in a synchronous detector 9 by a reference wave C which is generated by dividing the frequency of the output A of the oscillator 1 by a frequency divider 5. |
