Qpsk demodulator for obtaining phase by arithmetic operation
CA 2180908 C · Owner: Doi, Masayuki · Inventors: Doi, Masayuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A QPSK demodulator that can be made smaller in size and lower in cost by restricting a storage capacity needed for a TAN-1 ROM to a minimum. Values of I and Q channel base band signals obtained by converting and quantizing a received signal is approximated to a nearest one of values on (2N-3 + 1) segment lines represented by Q=(n/2N-3)I where n=0, 1, ... 2N-3, with a phase accuracy of positive N bits. Data corresponding to the approximated segment line is previously stored in a TAN-1 ROM as phase arithmetic data. An address decoder converts each base band signal into an address. An arithmetic circuit obtains phase data, for obtaining a QPSK demodulated signal, by performing a predetermined …
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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 July 10, 1996 and granted June 27, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 10, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 10, 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
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.