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:
Jun. 20, 1989
Filed:
May. 08, 1987
Applicant:
Inventors:
Fumio Ikegami, Uji-shi, Kyoto-fu, JP;
Susumu Yoshida, Kyoto, JP;
Tsutomu Takeuchi, Kyoto, JP;
Sirikiat Ariyavisitakul, Kyoto, JP;
Assignees:
Other;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
375 53 ; 332 / ; 375 86 ; 375101 ;
Abstract
A digital communication system, in which digital information is represented by a quaternary information symbol (11, 01, 00, 10) and the double step phase shift, each step represented by (.pi./4, 3.pi./4, 5.pi./4, 7.pi./4), is performed per 1/2 time slot in correspondence to each information symbol, so that the number of phase shift per unit time in the case of the identical transmission rate can be decreased to 1/2, as compared with a .DELTA..theta./2-DSK system, and expansion of the bandwidth can be decreased to 1/2.