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. 22, 2015
Filed:
Jun. 27, 2013
Hitachi, Ltd., Tokyo, JP;
Nobuhiko Kikuchi, Tokyo, JP;
HITACHI, LTD., Tokyo, JP;
Abstract
The optical signal to noise ratio is improved when the polarization multilevel signal light is demodulated. A optical polarization multilevel signal receiving apparatus is provided with a polarization multilevel receiver configured to generate at least one estimation symbol A1 to AN estimating a state of the symbol A by utilizing a polarization state of at least one polarization multilevel symbol received in a past before the symbol A, a past value of a decision variable, and a decision result, average the estimation symbols A1 to AN and the symbol A to calculate a reference symbol Ar, and use the calculated reference symbol Ar in place of the symbol A to calculate a decision variable corresponding to a polarization state change of the received symbol R, where R is a received symbol and A is at least one past symbol used as a reference for a change.