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:
Dec. 17, 1991
Filed:
Jul. 12, 1989
Christopher J Collier, Carshalton Beeches, GB;
Robert J Murray, Horley, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A transmission system in which a suitably modulated speech or data signal is combined with a low bit rate (100b/s) spread spectrum signal and transmitted simultaneously on the same channel with the modulated speech lying within the bandwidth of the spread spectrum signal. At a receiver the modulated speech or data signal is demodulated and the modulated speech or data signal together with the spread spectrum signal are applied to a multiplier in which the spread spectrum signal is despread. A code synchronizing signal may be included in the modulated signal prior to transmission and when recovered in the receiver, the synchronizing signal is applied to a pseudo-random code generating means. The transmission system may include a text transmission system in which case the low bit rate signal comprises pages of data. A number of pages may be transmitted simultaneously by spreading the data associated with each page by orthogonal psuedo-random codes.