Telephonic communications – Line equalization or impedance matching
Reexamination Certificate
2007-05-08
2007-05-08
Singh, Ramnandan (Department: 2614)
Telephonic communications
Line equalization or impedance matching
C379S394000, C333S017300, C333S032000, C333S124000
Reexamination Certificate
active
11060514
ABSTRACT:
A method of selecting an optimum impedance for a loop start trunk line, comprising successively applying respective ones of a plurality of impedance settings to the loop start trunk line, for each impedance setting measuring the impulse response of the trans-hybrid echo path by applying audio test signals to obtain a time-domain trans-hybrid transfer function and deriving a frequency-domain spectrum representative of trans-hybrid loss, and then calculating figure of merit of the transfer function based on the power spectrum. Once all impedance settings have been tested, the optimum impedance is selected as the impedance setting associated with the highest calculated figure of merit.
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Fang Yonghua
Popovic Mirjana
Schulz Dieter
Marger & Johnson & McCollom, P.C.
Mitel Networks Corporation
Singh Ramnandan
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