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. 25, 2003
Filed:
Jun. 14, 1999
Applicant:
Inventors:
Hitoshi Takeshita, Tokyo, JP;
Hirofumi Shimomura, Tokyo, JP;
Tatsuya Shiragaki, Tokyo, JP;
Naoya Henmi, Tokyo, JP;
Assignee:
NEC Corporation, , JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B 1/008 ;
U.S. Cl.
CPC ...
H04B 1/008 ;
Abstract
A signal quality monitoring method with reliability is disclosed. After extracting a clock signal from the light signal, a decision region is set for each bit of the light signal. The decision region is defined by a plurality of threshold amplitudes corresponding respectively to threshold phases which are produced with respect to the clock signal. The quality of the light signal is monitored depending on whether an amplitude of the light signal falls into the decision region at timings of the N threshold phases.