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:
Sep. 04, 2001
Filed:
Jul. 16, 1998
Alberto Gutierrez, Plano, TX (US);
Nortel Networks Limited, Montreal, CA;
Abstract
A CDMA communication system supports underlay transmissions and direct spread overlay transmissions such that the overlay transmissions are at least partially orthogonal to underlay transmissions. A base station supports both the underlay transmissions and the overlay transmissions and includes an interface to a mobile switching center, an underlay unit, an overlay unit and at least one radio frequency (RF) unit. The interface receives communications intended for a plurality of mobile stations serviced by the base station. These communications include underlay communications intended for mobile stations (MSs) supporting underlay transmissions and overlay communications intended for MSs supporting overlay transmissions. The underlay unit receives the underlay portion of the communications and produces underlay transmissions. The overlay unit receives the overlay portion of the communications and produces overlay transmissions. Then, the underlay transmissions and the overlay transmissions are received by the at least one RF unit and transmitted via at least one antenna to the plurality of MSs. Each of the MSs receives both the underlay transmissions and the overlay transmissions. However, those MSs supporting the underlay transmissions extract intended underlay communications while the MSs supporting overlay transmissions extract intended overlay communications. The underlay unit and the overlay unit produce the overlay transmissions such that they are at least partially orthogonal to the underlay transmissions. A synchronization unit coupled to the underlay unit and the overlay unit that causes the overlay transmissions to be substantially synchronized with the underlay transmissions. In another construction, differing base stations provide the underlay transmissions and the overlay transmissions.