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. 14, 2000
Filed:
Mar. 18, 1997
Toshiyuki Akiyama, Tokorozawa, JP;
Hitachi Denshi Kabushiki Kaisha, Tokyo, JP;
Abstract
Transmission method and apparatus allow two channel simultaneous transmission of information codes having a transmission rate of 1.5 Mbps necessary for the transmission of motion pictures or semi-motion pictures through a 2.4 GHz small power communication band (ISM band). Carrier frequencies f.sub.fa and f.sub.hb of the two channels are set to different values from each other, QPSK modulation is demodulated in a receiver and then inverse-spread of the spectrum spread is conducted, and a low pass filter having a root roll-off characteristic is inserted to a succeeding stage of a spectrum spread circuit of a transmitter and a preceding stage of the spectrum inverse-spread circuit of the receiver.