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:
Mar. 26, 2024
Filed:
May. 29, 2019
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
[Problem] To reduce a filter penalty caused by narrowing of an optical signal band due to optical filters having a multiplexing/demultiplexing function in an optical transmission line between transponder units. [Solution] In an optical transmission systemA, transponder unitstoandtoconnected by optical fibersin which optical filters having a multiplexing/demultiplexing function of an optical signal are interposed include a transmission unitthat transmits the optical signal obtained by modulating laser light from a laser light sourcewith an electric signal from a communication apparatus to the optical fibers, and a reception unitthat receives the optical signal from the optical fibersand converts the received optical signal into an electric signal. The reception unitincludes a BER measurement unit that measures a BER, based on a received signal, and feeds the measured BER back to a transmitting side. The transmission unitincludes a frequency shift control unit that performs frequency shift control of making a center frequency of the laser light match a center frequency of the received optical signal so that the fed back BER is minimized.