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Expired Canadian patentCanada

Simplified recovery of data signals from quadrature- related carrier signals

CA 1265202 C · Owner: American Telephone And Telegraph Company · Inventors: Debus, Walter, Jr.; Reeve, Howard Clifford, Iii; Siller, Curtis Albert, Jr.

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Abstract From the Canadian patent

Abstract, A technique is presented for simplifying the recovery of two synchronous data signals having a common symbol rate after each signal has respectively modulated a different one of a pair of quadrature-related carrier signals. In the transmitter, the data signal which modulates one of the quadrature-related carrier signals is delayed relative to the data signal which modulates the other quadrature-related carrier signal. This delay is related to an IF frequency chosen at the receiver. After passing through a noisy transmission channel, the quadrature-related carrier signals are coupled in the receiver to a serial combination of an equalizer and analog-to-digital converter. This …

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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 January 30, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 30, 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.
FiledOctober 19, 1987
GrantedJanuary 30, 1990
Term endedJanuary 30, 2007
Patent numberCA 1265202 C
Classification (IPC)H04L27/02 +2 more

Timeline

Timeline From CIPO dates

1988199019921994199619982000200220042006Application filedOct 19, 1987Patent grantedJan 30, 1990Term endedJan 30, 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.