| 摘要 |
The invention relates to a method for determining (1000) an optical signal to noise ratio of a dual polarization optical signal (e.g. QPSK). According to the invention, the method includes the following steps: detecting (11), in said dual polarization optical signal, a modulation signal which modulates, at at least one low amplitude level that is approximately zero and at a high amplitude level, said dual polarization optical signal, and determining (12) said optical signal to noise ratio from a measurement of the power of said modulation signal. |
