| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a modulation system converter capable of converting an optical signal modulated by a two-phase phase modulation system into an optical signal modulated based on a four-phase phase modulation system. <P>SOLUTION: The modulation system converter converts an input optical signal modulated by a two-phase phase modulation system into an output optical signal modulated by a four-phase phase modulation system and comprises bit shift means for shifting the input optical signal by 1 bit, phase shift means for rotating the phase of the input optical signal by π/2, amplitude adjustment means for arranging the maximum amplitude of the input optical signal and the maximum amplitude of a shift signal produced by shifting the input optical signal by 1 bit by means of the bit shift means and then rotating the phase by π/2 by means of the phase shift means, and multiplexing means for generating the output optical signal by multiplexing the input optical signal having a maximum amplitude arranged by the amplitude adjustment means and the shift signal. <P>COPYRIGHT: (C)2013,JPO&INPIT |
