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Expired Canadian patentCanada

Psk modem system having improved demodulation reliability

CA 1269714 C · Owner: Sumitomo Electric Industries, Ltd. · Inventors: Shibano, Yoshizo

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A modem system is disclosed which has improved reliability of detection of transmitted PSK data using a simple signal delay detection scheme. A transmission signal is produced in which repetitive digital time slots each contain phase encoded "mark" or "space" data. Each time slot includes a reference phase portion at at least one of a front and rear portion of the time slot. The phase of the transmitted signal changes in the remaining portion of each time slot in accordance with applied digital data. For a "mark" data signal the phase changes from a reference phase in a first direction to predetermined phase in a first half of the remaining portion of the time slot and then, back to 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

  • Granted May 29, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 29, 2007.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 13, 1987
GrantedMay 29, 1990
Term endedMay 29, 2007
Patent numberCA 1269714 C
Classification (IPC)H04L27/18 +2 more

Timeline

Timeline From CIPO dates

1988199019921994199619982000200220042006Application filedJuly 13, 1987Patent grantedMay 29, 1990Term endedMay 29, 2007

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.