Rapid training echo cancellor for telecommunications system
View Patent ↗Plural echo cancellors each are tuned for different hybrid delays until it is established which echo cancellors are operating to cancel echos. The echo cancellors not so operating are then terminated.
1. Apparatus for canceling echoes over a communications channel, said apparatus comprising:
means for implementing, at the start of a communications session over a communications line, a plurality of echo cancellors to cancel echo on said communications line, said echo cancellors each operating to cancel echoes that arrive during a predetermined bandwidth of time, said predetermined band-widths of time being non-overlapping;
means for training each of said plurality of echo cancellors to produce a cancellation signal that cancels echoes arriving during the predetermined bandwidth of time associated with said echo cancellor; and
means for eliminating, after a predetermined training period, all echo cancellors that produce a cancellation signal below a predetermined threshold.
2. Apparatus of claim 1 wherein said bandwidths of time are equal in width to each other.
3. The apparatus of claim 2 wherein said non-overlapping bandwidths are each approximately 16 milliseconds apart.
4. The apparatus of claim 1 further comprising a graphical user interface for allowing a user to alter the predetermined threshold.
5. A method of canceling echoes in a telecommunications system comprising:
establishing a plurality of non-overlapping echo canceling filters;
training each of said non-overlapping echo canceling filters such that each produces a canceling signal within a predetermined time bandwidth;
eliminating all of said echo cancellors with the exception of those that produce a canceling signal above a predetermined threshold.
6. The method of claim 5 further comprising:
adjusting said predetermined threshold based upon results produced by said method of claim 5 .
7. The method of claim 5 wherein each of said non-overlapping filters occupies a time width of approximately 16 milliseconds.
8. An apparatus comprising:
a plurality of echo cancellors to cancel echo on a communications line, the echo cancellors each operating to cancel echoes that arrive during a predetermined bandwidth of time, the predetermined bandwidths of time being non-overlapping; and
a control circuit in electrical communication with the plurality of echo cancellors to eliminate, after a predetermined training period, all echo cancellors that produce a cancellation signal below a predetermined threshold.
9. The apparatus of claim 8 , wherein said bandwidths of time are equal in width to each other.
10. The apparatus of claim 8 , wherein said non-overlapping bandwidths are each approximately 16 milliseconds in width.
11. The apparatus of claim 8 , further comprising a graphical user interface for allowing a user to alter the predetermined threshold.