OPTICAL TRANSMISSION CHARACTERISTICS ESTIMATION APPARATUS, OPTICAL TRANSMISSION CHARACTERISTICS ESTIMATION METHOD, AND PROGRAM

1 . An optical transmission property estimation device comprising:

a transmission waveform restore configured to restore a transmission signal from a reception signal obtained by receiving an optical signal by a coherent detection system; and

an estimator configured to estimate an optical power distribution in a transmission line by estimating a nonlinear coefficient in a propagation equation of a light wave by a linear least square method based on the restored transmission signal and the reception signal.

2 . The optical transmission property estimation device according to claim 1 , wherein the estimator uses an approximate solution using a perturbation method as a numerical solution of a propagation equation of the light wave.

3 . The optical transmission property estimation device according to claim 1 , further comprising:

a linear solution estimator configured to estimate a linear solution subjected to chromatic dispersion using the restored transmission signal;

a perturbation term estimator configured to estimate a perturbation term by subtracting the linear solution from a signal based on the reception signal; and

a matrix calculator configured to calculate a matrix representing a property of a virtual transmission line using the restored transmission signal,

wherein the estimator estimates the optical power distribution in the transmission line by estimating a nonlinear coefficient in the propagation equation of the light wave by a linear least square method using the perturbation term estimated by the perturbation term estimator and the matrix calculated by the matrix calculator.

4 . The optical transmission property estimation device according to claim 3 , further comprising a chromatic dispersion loader configured to estimate chromatic dispersion received in an optical transmission line and load the estimated chromatic dispersion to the reception signal to generate the signal.

5 . The optical transmission property estimation device according to claim 1 , wherein the estimator estimates an optical power distribution in a transmission line by estimating a nonlinear coefficient in a propagation equation of the light wave by a linear least square method using a pseudo reception signal obtained as a numerical solution of the propagation equation of the light wave using the restored transmission signal and the reception signal.

6 . An optical transmission property estimation method comprising:

restoring a transmission signal from a reception signal obtained by receiving an optical signal by a coherent detection system; and

estimating an optical power distribution in a transmission line by estimating a nonlinear coefficient in a propagation equation of a light wave by a linear least square method based on the restored transmission signal and the reception signal.

7 . A non-transitory storage medium that stores a program for making a computer perform processes, the processes comprising:

restoring a transmission signal from a reception signal obtained by receiving an optical signal by a coherent detection system; and

estimating an optical power distribution in a transmission line by estimating a nonlinear coefficient in a propagation equation of a light wave by a linear least square method based on the restored transmission signal and the reception signal.