Spread spectrum cdma communications system
CA 2091784 C · Owner: Interdigital Technology Corporation · Inventors: Schilling, Donald L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A spread spectrum CDMA communications system for communicating data and/or digitized voice between a plurality or users to a plurality of PCN units. The spread spectrum communications system is located within a same geographical region as occupied by an existing FDMA, proposed TDMA or any other mobile cellular system. The spread spectrum CDMA communications system includes a plurality of PCN-base stations and a plurality of PCN units. A PCN-base station has a comb filter (333) for notch filtering predetermined channels of the mobile cellular system a , device for converting the format of the data into a form suitable for communicating over radio waves a spread spectrum modulator , for …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 3, 1991 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 3, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 3, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.