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:
Jun. 25, 2013
Filed:
Feb. 18, 2009
Satomi Shioiri, Tokyo, JP;
Toshiharu Ito, Tokyo, JP;
Kiyoshi Fukuchi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Transmission-side communication apparatususing a DQPSK (differential quadrature phase-shift keying) scheme is provided with: optical carrier generation sectionwhich generates an optical carrier the frequency of which switches among a plurality of different frequencies within one symbol period; and modulation sectionwith which DQPSK-modulates the optical carrier generated by the optical carrier generation means in accordance with a modulation signal at an interval of the symbol period. There are provided: single delay interference sectionwhich receives an optical signal obtained by DQPSK-modulating an optical carrier the frequency of which switches among a plurality of different frequencies within one symbol period and outputs an output light obtained by causing the optical signaland a delay optical signal thereof to interfere with each other; and photoelectric conversion sectionwhich converts the output light outputted by the delay interference means to an electric signal.