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. 14, 1988
Filed:
Feb. 09, 1987
Applicant:
Inventor:
Yasuharu Yoshida, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03C / ; H03K / ;
U.S. Cl.
CPC ...
332 / ; 332 / ; 332 17 ; 329 50 ; 329109 ; 329110 ; 329135 ; 375 39 ;
Abstract
Responsive to a first and a second main data signal and a subdata signal, a multilevel modulator produces a composite modulated signal which comprises a quadrature amplitude modulated component modulated by the first and the second main data signals and represented by a radius on a phase plane and a phase modulated component modulated by the subdata signal are represented by a clockwise and a counterclockwise shift on the phase plane. A multilevel demodulator carries out an inverse operation to reproduce the composite modulated signal into first and second reproduced main data signal and a reproduced subdata signal.