| 摘要 |
PURPOSE:To compensate the timing change of linear and nonlinear distortion, by transmitting a pilot signal superimposing on a main signal, and reproducing thrugh integration after gain control with differentiation ar reception side. CONSTITUTION:With a pilot signal superimposing device 2, an input signal is superimposed on a pilot signal of a prescribed amplitude and frequency obtained from a pilot signal generator 1 as an input analog signal and the result is transmitted to a transmission line 4 with a phototransmitter 3. An optical signal is converted into an electric signal at a photo receiver 5 and inputted to a band rejection filter 6 and a BPF7 having the same center frequency as the pilot signal frequency. The output of the filter 6 is inputted to a variable gain circuit 8 via a differentiator 11 and after the loss of the transmission line 4 is compensated with a level detector 9 receiving the output of the BPF7, transmission waveform is reproduced with an integrator 12 and outputted via an amplifier 10. |
