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:
Jan. 07, 2020
Filed:
Feb. 27, 2017
Nec Corporation, Tokyo, JP;
Wakako Yasuda, Tokyo, JP;
NEC CORPORATION, Tokyo, JP;
Abstract
A frequency difference compensation unit () generates a carrier recovery signal by compensating for a frequency difference between a local light beam and an optical signal in a plurality of digital signals. A first symbol determination unit () determines the symbol position of the carrier recovery signal in which a frequency difference is compensated for, in accordance with the signal arrangement of multi-value modulation. A second symbol determination unit () determines the symbol position of the carrier recovery signal in which a frequency difference is compensated for, in accordance with a signal arrangement in which the number of multi-values of the multi-value modulation is reduced. A loop filter unit () and a compensation signal generation unit () temporarily generates a compensation signal using a determination result of the second symbol determination unit (), and then regularly generates the compensation signal using a determination result of the first symbol determination unit ().