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. 28, 2011
Filed:
Feb. 06, 2008
Zhenning Tao, Beijing, CN;
Lei LI, Beijing, CN;
Jens C. Rasmussen, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The present invention provides a digital phase estimator, a digital phase locked loop and an optical coherent receiver. The optical coherent receiver comprises a local oscillator laser, for supplying a local oscillator optical signal; an optical 90 degree frequency mixer, for mixing a received optical signal with the local oscillator optical signal; first and second balancing photoelectric detectors, for converting the optical signals outputted from the optical 90 degree frequency mixer into baseband electrical signals; first and second A/D converters, for respectively converting output signals from the first and the second balancing photoelectric detectors into digital signals; a digital phase locked loop, for compensating a phase difference between a carrier signal of the received optical signal and the local oscillator optical signal, and outputting the compensated signal; and a data recovering unit, for recovering data from the compensated signal.