Compatible licensed and unlicensed band portable handset unit for tdma wireless communication system
CA 2206473 C · Owner: Noerpel, Anthony Robert · Inventors: Noerpel, Anthony Robert; Chang, Li Fung; Sollenberger, Nelson Ray
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a TDM/TDMA portable radio communications system (5) a portable handset, (201) is compatible for operation in FDD mode and TDD mode. In the FDD mode different frequencies are used to separate a downlink transmission to a portable (201) from a port (204) from an uplink transmission from a port (204) to a portable (201). In the TDD mode, uplink and downlink transmissions are separated in different time-slots but at the same frequency. The handset (201) includes common transmit and receive circuitry (300) that operates at fixed IF frequencies separated by the fixed FDD frequency difference between corresponding uplink and downlink signals. In the FDD mode afrequency synthesizer (301), which …
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 December 15, 1995 and granted January 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 15, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 15, 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.