US 11,742,947 B1
Noise estimation in optical networks
Inwoong Kim, Allen, TX (US); Olga I. Vassilieva, Plano, TX (US); and Paparao Palacharla, Richardson, TX (US)
Assigned to FUJITSU LIMITED, Kawasaki (JP)
Filed by FUJITSU LIMITED, Kawasaki (JP)
Filed on Mar. 9, 2022, as Appl. No. 17/691,045.
Int. Cl. H04B 10/079 (2013.01); H04B 10/077 (2013.01)
CPC H04B 10/07953 (2013.01) [H04B 10/0775 (2013.01)] 20 Claims
OG exemplary drawing
 
15. An optical system comprising:
an optical network that includes a plurality of frequency channels, the optical network including:
an optical filter configured to filter a first optical noise signal on a frequency channel of the plurality of frequency channels to include a notch at a frequency in the frequency channel;
an optical detector configured to:
measure, at the frequency, a first noise level at the frequency in the frequency channel when the first optical noise signal is transmitted at a first power level, and
measure a second noise level at the frequency in the frequency channel, the frequency channel including a second power level, which is different than the first power level, when measuring the second noise level; and
a processor configured to:
determine an intra-channel noise level based on a difference between the first noise level and the second noise level;
apply an adjustment factor to the intra-channel noise level, the adjustment factor determined based on a correlation between non-linear interference noise and intra-channel noise; and
estimate a noise level of an optical data signal transmitted along the frequency channel based on the first noise level and the adjusted intra-channel noise level.