MULTI-VALUE MODULATION OPTICAL TRANSMITTER/RECEIVER AND MULTI-VALUE MODULATION OPTICAL TRANSMITTING/RECEIVING METHOD

PROBLEM TO BE SOLVED: To obtain a low-power-consumption and high-speed multi-value modulation optical transmitter/receiver which easily achieves an optical receiving circuit corresponding to a plurality of modulation systems. SOLUTION: A digital signal processing optical transceiver (20) has: a receiving front end (30) which divides an optical receiving signal from a communication channel into four channels in total, an I channel and a Q channel of an X polarization component, and an I channel and a Q channel of a Y polarization component; and a digital signal processing part (50) which performs signal point determination to the signals of four channels, determines that the modulation system is two-phase phase modulation when only two signal points exist, selects two channels of an I channel component of the X polarization and an I channel component of the Y polarization to perform signal processing, determines that the modulation system is four-phase phase modulation when four signal points exist, and selects the four channels, the I channel components and Q channel components of each of the X polarization, Y polarization to perform the signal processing. COPYRIGHT: (C)2011,JPO&INPIT