Method and apparatus for location finding in a cdma system
CA 2192579 C · Owner: Motorola, Inc. · Inventors: Ghosh, Amitava; Rozanski, Walter Joseph, Jr.; Buford, Kevin Andrew
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for determining the location of a communication unit in a CDMA system includes in a first embodiment sending a location request via a , spread spectrum signal to the subscriber (140) and receiving in return a , subscriber signal including a response message showing a receive time of a particular symbol of the base's spreading sequence and a transmit time of a particular symbol of the subscriber's spreading sequence. The base (130) along with other receiving base(s) (140) also receives a predetermined symbol , of the subscriber spreading sequence and each determines a respective receive time of the predetermined symbol. The received information is then processed …
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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 March 21, 1996 and granted September 7, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 21, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 21, 2018.
- 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
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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.