OPTICAL POWER DISTRIBUTION ESTIMATION APPARATUS, OPTICAL POWER DISTRIBUTION ESTIMATION METHOD, AND COMPUTER PROGRAM
An optical power distribution estimation device includes: an optical power distribution estimation unit that estimates an optical power distribution on the basis of a reception signal based on an optical signal transmitted from an optical transmission device and received via an optical transmission line and a transmission signal restored based on the reception signal; a spatial response function calculation unit that calculates a spatial response function on the basis of the transmission signal and a dispersion value of the optical transmission line; and a digital filter application unit that obtains an ideal output by applying a digital filter based on the spatial response function to the optical power distribution.
1 . An optical power distribution estimation device comprising:
an optical power distribution estimator configured to estimate an optical power distribution on a basis of a reception signal based on an optical signal transmitted from an optical transmission device and received via an optical transmission line and a transmission signal restored based on the reception signal;
a spatial response function calculator configured to calculate a spatial response function on a basis of the transmission signal and a dispersion value of the optical transmission line; and
a digital filter applicator configured to obtain an ideal output by applying a digital filter based on the spatial response function to the optical power distribution.
2 . The optical power distribution estimation device according to claim 1 , wherein
the digital filter applicator obtains the ideal output by designing the digital filter by using the spatial response function calculated by the spatial response function calculator and convolving the designed digital filter with the optical power distribution.
3 . The optical power distribution estimation device according to claim 1 , wherein
the optical power distribution estimator estimates the optical power distribution by using a method based on a correlation method as an estimation algorithm for the optical power distribution.
4 . The optical power distribution estimation device according to claim 3 , wherein
the optical power distribution estimator includes
a partial wavelength dispersion applicator configured to apply, to a signal, partial wavelength dispersion corresponding to a distance from the optical transmission device to an optical power measurement position,
a nonlinear operator configured to perform, on the signal to which the partial wavelength dispersion has been applied, nonlinear operation using a linear term obtained by Taylor-expanding a mathematical expression used for phase rotation,
a residual dispersion applicator configured to apply residual wavelength dispersion corresponding to a distance from the optical power measurement position to an optical reception device to the signal subjected to the nonlinear operation by the nonlinear operator, and
a correlation calculator configured to estimate the optical power distribution of the optical transmission line by obtaining, for each optical power measurement position, a correlation between the signal to which the residual wavelength dispersion has been applied and the reception signal based on the optical signal transmitted from the optical transmission device and received via the optical transmission line.
5 . The optical power distribution estimation device according to claim 1 , wherein
the optical power distribution estimator estimates the optical power distribution by using a method based on the least squares method as an estimation algorithm for the optical power distribution.
6 . An optical power distribution estimation method comprising:
estimating an optical power distribution on a basis of a reception signal based on an optical signal transmitted from an optical transmission device and received via an optical transmission line and a transmission signal restored based on the reception signal;
calculating a spatial response function on a basis of the transmission signal and a dispersion value of the optical transmission line; and
obtaining an ideal output by applying a digital filter based on the spatial response function to the optical power distribution.
7 . A non-transitory storage medium that stores a program for making a computer perform processes, the processes comprising:
estimating an optical power distribution on a basis of a reception signal based on an optical signal transmitted from an optical transmission device and received via an optical transmission line and a transmission signal restored based on the reception signal;
calculating a spatial response function on a basis of the transmission signal and a dispersion value of the optical transmission line; and
obtaining an ideal output by applying a digital filter based on the spatial response function to the optical power distribution.