| 摘要 |
PURPOSE: To obtain an optical transmission system which may occupies a narrow band as an equalized amplifying circuit and is sufficiently tolerant of mark rate variation by converting an NRZ code received signal into a differential equalizing and amplifying circuit and performing DC regeneration and timing extraction. CONSTITUTION: The equalizing and amplifying circuit 2 inputs the NRZ code received signal to a differentiating circuit 24 to generate the differential equalized signal. A DC regenerating circuit has a logic circuit 31 which outputs the logic plus and logic minus signals of the differential equalized signal from the circuit 2 and a flip-flop circuit which is set with the logic plus signal and reset with the logic minus signal. At the input terminal of a timing discriminating circuit 4, a full-wave rectifier circuit 42 is provided to rectify the differential equalized signal. Consequently, the DC regenerating circuit which may have a narrow band and is highly practical is obtained as the equalizing and amplifying circuit and the optical transmission equipment is obtained which is sufficiently tolerant of mark rate variation and can be IC-implemented. |
