Patent ID: 11923897
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 2:
3. A non-transitory computer-readable medium having computer-executable instructions that, upon execution of the instructions by a processor of a computer, cause the computer to perform:
a data preprocessing step of reducing the number of data using random sampling with respect to constellation data in which an amplitude and a phase of optical communication data are represented by a polar coordinate diagram and performing distribution calculation and a resolution reduction, thereby forming reduced constellation data;
a learning step of learning a dictionary matrix in sparse coding using the reduced constellation data processed in the data preprocessing step; and
a recognition step of calculating a sparse coefficient using the reduced constellation data processed in the data preprocessing step and the dictionary matrix generated in the learning step and estimating a factor causing degradation of the optical communication using the calculated sparse coefficient, where the factor is one of a phase error of bias in a modulator, an imbalanced state of I/O gain or an imbalanced state of I/O skew.