US 2004/0071102 A1 · Method and apparatus for echo cancellation

Abstract

The present invention relates to an arrangement and a method for echo cancellation wherein only telecommunications traffic (s6) of a downlink (3), for which echo cancellation is performed, passes through an echo canceller function (1′). Traffic (s5) of an uplink (2) is forwarded via a switch (15) to a near end (B) without passing through the echo canceller function (1′). A signal copy (s9) of traffic (s5) of the uplink is created by the switch (15) and directed to the echo canceller function (1′) in order to serve as a base for an estimated echo signal (e′). The estimated echo signal (e′) is subtracted from the traffic (s6) of the downlink, which is input to the echo canceller function (1′), so as to create an output signal (s8), which is substantially free from echo. The invention makes it possible to reduce the processing capacity required in connection with echo cancellation and provides for a decreased delay of traffic of the uplink (2).

Claims16

Dependent claims

A telecommunications system, which includes means for forwarding traffic in a first direction from at least one far end to at least one near end;

means for forwarding traffic in a second direction from the at least one near end to the at least one far end;
means for echo cancellation, which means for echo cancellation includes an echo canceller function arranged to perform echo cancellation of echo superimposed on the traffic in the second direction so as to make the traffic in the second direction substantially free from echo;
and
a switch,
characterised in that the switch is arranged to forward the traffic in the first direction to the near end, and to produce a copy of the traffic in the first direction, and in that the switch is further arranged to forward the copy to the echo canceller function, for use in the echo cancellation of the echo superimposed on the traffic in the second direction.

2 more elements

A method for echo cancellation in a telecommunications system, which telecommunications system includes means for forwarding traffic in a first direction from at least one far end to at least one near end;

means for forwarding traffic in a second direction from the at least one near end to the at least one far end;
which method includes the steps of receiving in an echo canceller function the traffic in the second direction;
and
performing echo cancellation, in the echo canceller function, of echo superimposed on the traffic in the second direction so as to make the traffic in the second direction substantially free from echo
characterised by the method further including the steps of
receiving the traffic in the first direction in a switch;
the switch producing a copy of the traffic in the first direction;
the switch forwarding the traffic in the first direction to the near end;
and
the switch forwarding the copy to the echo canceller function, for use in the echo cancellation of the echo superimposed on the traffic in the second direction.

7 more elements

Dependencies are inferred from the claim text.

Method and apparatus for echo cancellation

Life of this patent

Method and apparatus for echo cancellation

Life of this patent

Abstract

Claims16