Synchronization of echo cancellers in a voice processing system
View Patent ↗Methods and apparatus for processing a received voice signal from a variable-delay network by a communications system that has at least one echo canceller. An echo canceller determines delay characteristics that are associated with the received voice signal and correspondingly modifies echo cancellation processing. In a variation of the embodiment of the invention, a first echo canceller sends silence descriptor information to a second echo canceller. The second echo canceller reconstructs a voice signal based upon the silence descriptor information and excitation vector information.
1. In a communication system comprising a plurality of echo cancellers coupled to a variable-delay network, a method comprising:
determining, by a first echo canceller of the at least one echo canceller, delay characteristics related to at least one voice signal received via the variable delay network;
determining, by the first echo canceller, that delay characteristics corresponding to the at least one voice signal have changed;
receiving information regarding changes to corresponding delay characteristics corresponding to a second echo canceller of the plurality of echo cancellers; and
modifying, by the first echo canceller, echo cancellation processing on the at least one voice signal in response to the changed delay characteristics.
2. The method of claim 1 , wherein the determining that the delay characteristics have changed further comprises inspecting a jitter buffer used to store the at least one voice signal.
3. The method of claim 1 , wherein the at least one voice signal comprises a plurality of packets, the method further comprising:
correlating the delay characteristics with the plurality of packets,
wherein the element of modifying further comprises discontinuing echo cancellation processing for the plurality of packets.
4. The method of claim 3 , wherein the element of modifying further comprises substituting previously echo cancelled packets for missing packets of the plurality of packets.
5. The method of claim 1 , wherein the element of modifying further comprises adjusting a time domain transfer function used to perform the echo cancellation processing.
6. The method of claim 5 , further comprising:
moving respective h vectors in response to the changed delay characteristics.
7. The method of claim 6 , wherein the adjusting the time domain transfer function anticipates the changed delay characteristics.
8. In a communication system comprising at least one echo canceller coupled to a variable-delay network, a method comprising:
determining, by a first echo canceller of the at least one echo canceller, delay characteristics related to at least one voice signal received via the variable delay network;
determining, by the first echo canceller, that delay characteristics corresponding to the at least one voice signal have changed;
prior to the determining that the delay characteristics have changed, determining that echo cancellation performance has degraded, wherein the echo cancellation performance is indicative of a magnitude of echo; and
modifying, by the first echo canceller, echo cancellation processing on the at least one voice signal in response to the changed delay characteristics.
9. A Communication system coupled to a variable-delay network, the communications system comprising:
means for determining, by a first echo canceller of at least one echo canceller, delay characteristics related to at least one voice signal received via the variable delay network;
means for determining, by the first echo canceller, that delay characteristics corresponding to the at least one voice signal have changed;
means for receiving information regarding changes to corresponding delay characteristics corresponding to a second echo canceller of the at least one echo cancellers; and
means for modifying, by the first echo canceller, echo cancellation processing on the at least one voice signal in response to the changed delay characteristics.