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:
Oct. 11, 1994
Filed:
Mar. 08, 1993
Katsumi Takahashi, Kodaira, JP;
Takashi Kurokawa, Hachioji, JP;
Nobuo Sekiguchi, Kodaira, JP;
Kazuo Suzuka, Sayama, JP;
Sakari Ohira, Sendai, JP;
Kiyoyuki Isawa, Kawasaki, JP;
Fujio Sumi, Tokyo, JP;
Kenichi Suzuki, Yokohama, JP;
Hitachi Denshi Kabushiki Kaisha, Tokyo, JP;
Tohoki Electric Power Co., Inc., Sendai, JP;
Fuji-Tekku Kabushiki Kaisha, Tokyo, JP;
Abstract
A voice transmission method and apparatus in a duplex radio system are disclosed in which a voice signal to be transmitted in a constant period of time is subjected to 1/N time compression, N being a numeral not smaller than 2.0. The time-compressed voice signal is supplied to a transmitter as a modulating signal and a transmitting operation is performed by the transmitter in synchronism with a period of time when the modulating signal is inputted to the transmitter. A receiving operation of receiving a time-compressed and modulated signal transmitted from the transmitter to demodulate it is performed by a receiver in a period of time other than the period of time when the transmitting operation is performed. A demodulated signal is subjected to N-ple time expansion to obtain a reproduced receive voice signal, and both the transmitting operation and the receiving operation are repeated at the constant period of time. In the voice transmission method and apparatus, a predetermined band of a signal corresponding to said signal to be transmitted, which is in a voice band, is extracted with a predetermined band width. The extracted signal is shifted to any band which is in the voice band and is other than the extracted band. A signal corresponding to the shifted signal is supplied to the transmitter as the modulating signal.