Techniques for simultaneous communications of analog frequency-modulated and digital modulated signals using postcanceling scheme
CA 2217429 C · Owner: Sundberg, Carl-Erik Wilhelm · Inventors: Papadopoulos, Haralabos C.; Sundberg, Carl-Erik Wilhelm
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a system for simulcasting a digitally modulated signal and an analog FM signal over the same FM frequency band, the composite signal is received and applied to a conventional FM receiver, and a digital receiver in accordance with the invention. An extended Kalman filter is employed in the digital receiver to estimate the analog FM signal based on a version of the recovered FM signal from the FM receiver, and a discrete version of the composite signal whose spectrum has been translated and is at an intermediate carrier frequency. The estimated FM signal, which is in a discrete form, is subtracted from the discrete version of the composite signal. The resulting signal, which is an …
Read the whole patent
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 October 6, 1997 and granted April 17, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 6, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 6, 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.