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:
Jul. 24, 2012
Filed:
Oct. 20, 2006
Seiichi Noda, Tokyo, JP;
Eisaku Sasaki, Tokyo, JP;
Seiichi Noda, Tokyo, JP;
Eisaku Sasaki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The present invention relates to a modulation and demodulation method of minimizing an error rate and applying it to a differential operation modulo 4. A modulation apparatus includes a Gray coding circuitto which data of (2+1) bits are inputted (where 'n' is an integer more than 1) and which encodes 2 bits of an input signal of (2+1) bits to a Gray code as a signal for allowing four quadrants to be identified, an encoding circuitthat encodes 3 bits of the input signal of (2+1) bits as a signal indicating any one of eight subgroups provided in each of the four quadrants so that an average Hamming distance between adjacent subgroups within its quadrant becomes a minimum, and a mapping circuitthat maps binary data encoded by the Gray coding circuitand the encoding circuiton the four quadrants.