Time shift keying digital communications system
CA 2217066 C · Owner: Erisman, David E. · Inventors: Erisman, David E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A digital modulation technique is disclosed which is unique in that it does not utilize fixed time slots for varying the characteristics of an electromagnetic carrier signal, but actually uses variations of the time slots to transfer the digital information. The modulation is created by using direct digital synthesis techniques (10) to produce a carrier waveform (21) that closely approximates a sine wave carrier signal that can vary the time it takes for each peak to occur. The peaks of the carrier (21) are tightly controlled to occur at exact discrete time slots that correspond to certain base band digital data. The time slot changes occur precisely at the sine wave peaks to minimize 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 April 10, 1995 and granted June 19, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 10, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 10, 2017.
- 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.