Nec Corporation

Tomoki Yoshihara

Masayuki Takahashi

In order to provide a circuit which can realize high-speed frequency tracking performance while satisfying jitter/wander suppression performance, the circuit controls loop gain of a PLL means, which extracts a clock signal of a SDH signal or an Ethernet signal from an OTN signal, on the basis of a result of processing a jitter/wander component and a frequency change state on the basis of phase comparison data of the PLL means.

Circuit, control system, control method, and computer-readable recording medium for recording program

A polarization multiplexing optical receiver according to the invention includes a polarization splitting unit receiving polarization multiplexed lights which are modulated according to a first input signal and a second input signal including respective identifier, and splitting the polarization multiplexed light into a first polarized received light and a second polarized received light, a pair of photoelectric conversion units, a demodulation unit performing symbol recognition about the first received signal and the second received signal, and outputting a first demodulated signal and a second demodulated signal, an identifier detecting unit detecting the identifiers from the first demodulated signal and the second demodulated signal, and a delay compensation unit calculating a delay difference between the first demodulated signal and the second demodulated signal based on the identifiers, and inserting delay time corresponding to the delay difference into the first demodulated signal or the second demodulated signal.

Polarization multiplexing optical transmission system, polarization multiplexing optical receiver and polarization multiplexing optical transmission method

Growing community of inventors

Minato-ku, Japan

Tomoki Yoshihara