The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 09, 2016
Filed:
Nov. 28, 2014
Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;
FUJITSU LIMITED, Kawasaki, JP;
Abstract
An apparatus includes: a photodetector configured to create a first electric-signal from an optical signal; a power-measuring unit configured to measure power of the optical signal according to the first electric-signal; a noise calculating unit configured to calculate noise corresponding to a specified target optical signal-to-noise ratio (OSNR) according to the power of the optical signal, the power having been measured by the power-measuring unit, the specified target optical signal-to-noise ratio, and information representing characteristics of the photodetector; a noise generating unit configured to add the noise calculated by the noise calculating unit to the first electric-signal to generate a second electric-signal; an OSNR measuring unit configured to measure an optical signal-to-noise ratio according to the second electric-signal; and a calibration coefficient calculating unit configured to calculate a calibration coefficient used to obtain the target optical signal-to-noise ratio from the optical signal-to-noise ratio measured by the OSNR measuring unit.