| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical transmitter and an optical transmission system which achieve an increase of communication capacity while suppressing high price and high power consumption.SOLUTION: The optical transmitter performs transmission by executing multiple value/high-order modulation with respect to a downlink signal in a plurality of hierarchies with different capacities. At this time, the optical transmitter performs user multiplexing by using the hierarchies by referring to a correspondence table in which destination addresses of optical receivers included in individual ONUs and receivable hierarchies are associatedly stored, and by determining a hierarchy of modulation of each frame according to a destination address. |
