| 摘要 |
When using a polarization separator which updates filter coefficients by CMA, since distortion of the constellation of a reproduced received optical signal increases if the optical SNR of the received optical signal is low, this polarization separator comprises a filter means which inputs a first received signal and a second received signal acquired from a polarization division multiplexed signal beam, and a filter coefficient updating means which updates the filter coefficients such that the envelope of the output signal of the filter means is constant, wherein the filter coefficient updating means calculates an output symbol distance, calculates the output symbol movement amount, which is the difference between a first output symbol distance, calculated from the output signal acquired using the first filter coefficient, and a second output symbol distance, calculated from the output signal acquired using the second filter coefficient that updates the first filter coefficient, and calculates an update amount of the filter coefficient such that the change in the output symbol movement amount relative to the first output symbol distance is point-symmetric around a prescribed target value of the first output symbol distance. |
