Communication system for multicasting delay-adjusted signals on same radio frequencies to adjoining cells
CA 2199922 C · Owner: Nec Corporation · Inventors: Anzai, Makoto; Kurokami, Yuzo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a cellular radio communication system a downlink signal is, multicast from a cental station and multiple base stations receive the multicast downlink signal via transmission links and respectively transmit the downlink signal on radio waves of same frequencies so that a cluster of adjoining areas is illuminated with the radio waves. A mobile station having a tapped-delay line equalizer receives signals from the base stations via multipath fading channels and equalizes the received signals. Interference between the transmitted signals is avoided by adjusting the relative propagation delay times of the transmission links so that the signals received by the mobile station occur within the …
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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 13, 1997 and granted May 1, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 13, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 13, 2019.
- 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.