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. 20, 1998
Filed:
May. 26, 1994
Ichiro Kato, Kawasaki, JP;
Canon, Tokyo, JP;
Abstract
Digital data for generating a signal having a prescribed waveform is stored beforehand in the memory on the transmitting side of a communication system. The prescribed waveform is one obtained by combining signals having mutually different frequencies corresponding to the digits of a spread-spectrum code comprising a plurality of digits. When transmission data is inputted, the system generates, for every bit of data, a signal waveform corresponding to the value of the bit, based upon the data stored in the memory. The generated signal is a signal which has undergone spreading. This signal is placed upon a carrier wave and then sent to a transmission line. Like the transmitting side, the receiving side possesses digital data for generating a signal having a prescribed waveform. When a signal is received, the system generates a signal based upon the data possessed, multiplies this by the received signal and effects a conversion into a signal having an intermediate frequency. Signals in a prescribed frequency band are filtered out of the intermediate frequency and data is demodulated from the filtered signal.