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:
Sep. 19, 2006
Filed:
Dec. 20, 2000
Applicants:
Antti Pietiläinen, Espoo, FI;
Mikko Söderlund, Helsinki, FI;
Simo Tammela, Espoo, FI;
Inventors:
Assignee:
Nokia Corporation, Espoo, FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F 17/10 (2006.01); H04L 27/26 (2006.01);
U.S. Cl.
CPC ...
Abstract
This invention relates to detecting a pilot tone in an optical fiber. In the method described in the invention, computational complexity is reduced significantly by almost completely removing the need to carry out multipli-cations. To calculate certain spectral components of DFT (Discrete Fourier Transform) only a few multiplications are required. The idea is that for de-tecting one pilot tone, it is adequate to calculate one spectral component of DFT if a specific ratio can be chosen between the pilot tone frequency and the sample rate of the receiver.