Telephonic communications – Echo cancellation or suppression
Patent
1996-12-23
2000-10-10
Eisenzopf, Reinhard J.
Telephonic communications
Echo cancellation or suppression
379410, 370291, H04M 100
Patent
active
061309435
ABSTRACT:
A method and an apparatus suppresses echo in telephone communication systems having a send path and a receive path. A first filter is coupled to the send path carrying a voice signal. The first filter removes a first set of frequencies but allows either fundamental frequencies or second harmonics in the voice signal to pass through. Thus, the first filter preserves the fundamental frequencies or the second harmonics in the voice signal. A complementary filter is coupled to the receive path carrying the echo. The complementary filter is used to remove the remaining frequencies that are present in the echo. By operating jointly in a complementary way, the first filter and the complementary filter removes the echo.
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Appiah Charles N.
Eisenzopf Reinhard J.
MCI Communications Corporation
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