PURPOSE: To receive a light stably by utilizing that an optical reception level and a time division multiplex schedule are known and varying a gain of a light receiving circuit or a threshold level of an identification circuit every time slot corresponding to each terminal equipment.
CONSTITUTION: Digital transmission accommodation each subscriber in a predetermined time slot is presumed on the optical communication system in which time division multiplex communication is implemented by means of an optical communication network where one station equipment and plural termianl equipments are interconnected by optical fibers and star couplers. When an optical reception level of each subscriber and the sequence of an accommodated time slot are known in advance, the optical reception system realizing economically high speed response AGC and ATC which has been difficult in a conventional system is obtained by varying the gain of the light receiving circuit at every slot corresponding to each subscriber based on the information or a threshold level Vth of an identification circuit even when a large optical loss is present on each subscriber so as to obtain a prescribed electric signal.
YONEDA ETSUGO
MANO FUMIO
OKADA KENJI
