Abstract: An apparatus includes: a first measurer configured to measure first phase data indicating a temporal variation in a phase of a non-transferred signal that is an optical signal modulated by an optical phase modulation scheme and output from a transmitting device to an optical transmission path as the non-transferred signal; a second measurer configured to second phase data indicating a temporal variation in the phase of the optical signal transferred by the optical transmission path as a transferred signal on a side of a receiving device; a generator configured to generate differential data indicating a difference between the first phase data and the second phase data; and an extractor configured to use the differential data to extract, from the optical signal on the side of the receiving device, optical phase noise generated due to the optical transmission path.

Abstract: An apparatus includes: a first measurer configured to measure first phase data indicating a temporal variation in a phase of a non-transferred signal that is an optical signal modulated by an optical phase modulation scheme and output from a transmitting device to an optical transmission path as the non-transferred signal; a second measurer configured to second phase data indicating a temporal variation in the phase of the optical signal transferred by the optical transmission path as a transferred signal on a side of a receiving device; a generator configured to generate differential data indicating a difference between the first phase data and the second phase data; and an extractor configured to use the differential data to extract, from the optical signal on the side of the receiving device, optical phase noise generated due to the optical transmission path.

Abstract: A control device includes: a first computing circuit which manipulates a parameter that changes a first characteristic in a processing device on the basis of a result of detecting the first characteristic of the processing device; an updating control circuit which stops the first computing circuit from manipulating the parameter when updating a function of the first computing circuit; an acquisition circuit which acquires relationship information indicating a relationship between an amount to be manipulated for the parameter and the amount of change in a second characteristic of the processing device that changes the first characteristic; and a second computing circuit which manipulates the parameter by an amount to be manipulated based on the relationship information acquired by the acquisition circuit and the amount of change in a result of detecting the second characteristic, while the first computing circuit is stopped from manipulating the parameter by the updating control circuit.

Abstract: A demodulating unit demodulates a differential M-phase shift keying signal light by causing delay and interference. A phase-error detecting unit detects an error of a control phase amount of the delay and the interference caused by the demodulating unit. A control unit adjusts the control phase amount to a predetermined phase amount based on the error. A data processing unit monitors an error state of data signal that is demodulated by the demodulating unit. The control unit changes the control phase amount from the predetermined amount when the error state is in a predetermined state, and determines a reception state of the differential M-phase shift keying signal light based on an error that is detected after the control phase amount is changed.

Abstract: A demodulating unit demodulates a differential M-phase shift keying signal light by causing delay and interference. A phase-error detecting unit detects an error of a control phase amount of the delay and the interference caused by the demodulating unit. A control unit adjusts the control phase amount to a predetermined phase amount based on the error. A data processing unit monitors an error state of data signal that is demodulated by the demodulating unit. The control unit changes the control phase amount from the predetermined amount when the error state is in a predetermined state, and determines a reception state of the differential M-phase shift keying signal light based on an error that is detected after the control phase amount is changed.