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:
Jan. 11, 2011
Filed:
Mar. 27, 2006
Masaru Fuse, Osaka, JP;
Osamu Hirota, Kanagawa, JP;
Masaki Souma, Tokyo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A dynamic range of intensity modulation is set to range from a maximum intensity Smax to a minimum intensity Smin. A difference Δ(=Smax−Smin) between the maximum intensity Smax and the minimum intensity Smin is divided by the number 2M of multilevel signals. Thus, a distance (an intensity difference) between adjacent signals is [Δ/2M]. The number 2M of multilevel signals is selected such that the distance [Δ/2M] between adjacent multilevel signals (between an intensity Sand an intensity S) is sufficiently buried within a range of quantum fluctuations obtained when heterodyne measurements are made or buried within a range of quantum shot noise obtained when a direct detection is made. Bases of a basis group are each positioned for intensity signals so as to have a high intensity and a low intensity between which a distance is set to be a certain value smaller than a middle point intensity [Δ/2]. Note that adjacent bases are set to have an intensity signal transmitting a logical value '1' of transmission data and an intensity signal transmitting a logical value '0' of transmission data in an inverted manner.