Patents Assigned to Teleliaison
  • Patent number: 5177781
    Abstract: A method and device for recognizing a signature of dialing pulse present in a communication signal isolate from the latter signal the signature. The so isolated signature is correlated with a statistic model obtained from a large number of dialing pulse signatures to determine whether the isolated signature corresponds to a dialing pulse. During this correlation, a first complex function representative of the isolated signature is calculated and correlated with a second complex function representative of the statistic model. The result of the correlation is normalized and whether the isolated signature is a signature of dialing pulse is decided in function of this normalization. The method and device can be used to convert into a tone frequency signal a series of dialing pulse signatures present in the communication signal and corresponding to a dialed digit.
    Type: Grant
    Filed: September 21, 1990
    Date of Patent: January 5, 1993
    Assignee: Teleliaison
    Inventors: Michel Ponton, Yves Lemieux, Normand Girard, Marc Gareau