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:
Apr. 04, 2000
Filed:
Jun. 11, 1998
Toshiyuki Akiyama, Tokorozawa, JP;
Atsushi Miyashita, Tokorozawa, JP;
Seiichi Sano, Higashiyamato, JP;
Nobuo Tsukamoto, Akishima, JP;
Shigeki Moriyama, Tokyo, JP;
Kenichi Tsuchida, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a demodulating method of demodulating amplitude-demodulated signals in an amplitude phase shift keying system for conducting an amplitude modulation by setting signal points as information codes on a complex plane representing a signal space of transmission signals onto circumferences of two concentric circles including a first circle having a first diameter and a second circle having a second diameter smaller than the first diameter on the complex plane, there are obtained, in accordance with an amplitude value of an amplitude component of each symbol of a received amplitude-modulated signal, a first threshold value and a second threshold value having a predetermined relationship with the amplitude value. Next, the amplitude value the an amplitude component of each symbol of the successively received amplitude-modulated signal is compared with the first and second first threshold values to determine an amplitude variation in the amplitude component of each symbol in accordance with a result from the comparison so as to output therefrom a signal representing the determination result as a code obtained by demodulating the amplitude component.