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:
Mar. 27, 2001
Filed:
Jul. 09, 1998
Tatsumasa Yoshida, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A frequency-modulated signal transmitter and frequency modulation method are provided wherewith the linearity of an FM modulated signal is secured even when the level of frequency modulation after FM modulation is low. A level-subtraction circuit,is provided between a speech processing circuit,and a frequency modulator circuit,for subtracting the signal level of the speech-processed signal D,from the speech processing circuit. The level-subtraction circuit comprises a level-subtraction stage,, to which the speech-processed signal is input, that outputs a level-subtracted voice signal to the FM modulator circuit, and an average FM noise level setting stage,for setting the average level (±Esn) of the FM noise generated in the frequency modulator circuit and outputting that average FM noise level (±Esn) to the level-subtraction stage. In the level-subtraction stage, a signal in which the signal D,and the average FM noise level (±Esn) have been added is obtained as a level-regulated voice signal, which level-regulated voice signal is sent as the modulating signal to the FM modulator circuit. The level subtraction may be implemented by either analog or digital processing.