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. 05, 1994
Filed:
Feb. 04, 1993
Yukinobu Ishigaki, Miura, JP;
Takahisa Matsumoto, Yokohama, JP;
Victor Company of Japan, Inc., Yokohama, JP;
Abstract
A spread spectrum communication system comprising a transmitter including an angle modulator, a frequency divider, a spread code generator, and a spread spectrum modulator, and a receiver including a despreading circuit, an angle demodulator, a sync detection circuit, and a clock signal generating circuit. In the transmitter, the spread code generator produces a spread code having correlation with the angle-modulated signal outputted from the angle modulator. In the receiver the despreading circuit despreads the spread spectrum modulation signal sent from the transmitter by a demodulation spread code. The angle demodulator generates a demodulation output by means of a phase-locked loop circuit contained therein. The sync detection circuit detects sync condition on the basis of noise level of a phase detector provided in the phase-locked loop circuit, and generates a sync detection signal when sync condition is established. And, the clock signal generating circuit responds the sync detection signal to switch a demodulation clock from a temporary clock used for capturing a sync time to a regular clock which is equivalent to a modulation clock signal used in the transmitter.