Echo cancelling device, communication device, and echo cancelling method having the error signal generating circuit
View Patent ↗Provided is an echo canceller capable of realizing an excellent echo cancellation performance even in a double talk state. An echo canceller ( 10 ) comprises: an adaptive filter ( 20 ); a subtractor ( 30 ); and an error signal generating circuit ( 40 ). The adaptive filter ( 20 ) synthesizes a spurious echo signal (y′(k)) from a receiving signal (x(k)) before being delivered from a speaker ( 3 ). The subtractor ( 30 ) subtracts the spurious echo signal (y′(k)) from an input signal (yin(k)) received by a microphone ( 2 ) so as to generate an echo cancellation signal (p(k)) The error signal generating circuit ( 40 ) generates an error signal (s(k−1)) by removing a spurious voice signal (r(k−1)) corresponding to a voice signal (v(k)) of a talker from the echo cancellation signal (p(k)). The adaptive filter ( 20 ) updates a characteristic of the adaptive filter ( 20 ) so that an amplitude of the error signal (s(k−1)) becomes smaller.
1. An echo cancelling device, comprising:
an adaptive filter which synthesizes a spurious echo signal from a receiving signal;
a first subtractor which generates an echo cancellation signal based on said receiving signal including a voice signal of a speaker and the spurious echo signal; and
an error signal generating circuit which generates an error signal based on an input signal and said echo cancellation signal.
2. An echo cancelling device according to claim 1 , wherein said error signal generating circuit includes:
a residual echo suppressor which generates a residual echo cancellation signal by removing a difference between said echo signal and said spurious echo signal from said echo cancellation signal;
a noise suppressor which generates the spurious voice signal based on the residual echo cancellation signal; and
a second subtractor which generates the error signal by subtracting the spurious voice signal from said echo cancellation signal.
3. A communication device, comprising:
a microphone which receives an input signal;
a speaker which delivers a receiving signal; and
an echo cancelling device that includes:
an adaptive filter which synthesizes a spurious echo signal from said receiving signal;
a first subtractor which generates an echo cancellation signal based on said receiving signal including a voice signal of the speaker and the spurious echo signal; and
an error signal generating circuit which generates an error signal based on the input signal and said echo cancellation signal.
4. A communication device according to claim 3 , wherein
the error signal generating circuit includes:
a residual echo suppressor which generates a residual echo cancellation signal by removing a difference between the echo signal and the spurious echo signal from said echo cancellation signal;
a noise suppressor which generates the spurious voice signal based on the residual echo cancellation signal; and
a second subtractor which generates the error signal by subtracting the spurious voice signal from said echo cancellation signal.
5. An echo cancelling method, comprising:
synthesizing, by an adaptive filter, a spurious echo signal from a receiving signal;
generating an echo cancellation signal based on said receiving signal including a voice signal of a speaker and the spurious echo signal;
generating an error signal based on an input signal and said echo cancellation signal.
6. An echo cancelling method according to claim 5 , wherein
said generating said error signal includes:
generating a residual echo cancellation signal by removing a difference between said echo signal and said spurious echo signal from said echo cancellation signal;
generating the spurious voice signal based on the residual echo cancellation signal; and
generating the error signal by subtracting the spurious voice signal from said echo cancellation signal.
7. An echo canceller, comprising:
an adaptive filter which generates a spurious echo signal from a receiving signal;
a subtractor which generates an echo cancellation signal based on said receiving signal including a voice signal of a speaker and the spurious echo signal; and
an error signal generating circuit which delivers an error signal based on an input signal and said echo cancellation signal by removing a difference between said echo signal and said spurious echo signal from said echo cancellation signal.
8. An echo canceller according to claim 7 , wherein said adaptive filter updates a characteristic of the adaptive filter such that an amplitude of said error signal becomes small.
9. An echo canceller according to claim 7 , wherein the error signal generating circuit generates the error signal by removing the spurious echo signal from an echo signal.
10. An echo canceller according to claim 7 , wherein the error signal is unaffected by the voice signal of the speaker.
11. An echo cancelling device according to claim 1 , wherein the error signal generating circuit generates the error signal by removing the spurious echo signal from an echo signal.
12. An echo cancelling device according to claim 1 , wherein the adaptive filter updates a characteristic of the adaptive filter such that an amplitude of said error signal becomes smaller.
13. An echo cancelling device according to claim 1 , wherein the error signal is unaffected by the voice signal of the speaker.
14. A communication device according to claim 3 , wherein the error signal generating circuit generates the error signal by removing the spurious echo signal from an echo signal.
15. A communication device according to claim 3 , wherein the adaptive filter updates a characteristic of the adaptive filter such that an amplitude of said error signal becomes smaller.
16. A communication device according to claim 3 , wherein the error signal is unaffected by the voice signal of the speaker.
17. An echo cancelling method according to claim 5 , wherein the generating the error signal comprises removing the spurious echo signal from an echo signal.
18. An echo cancelling method according to claim 5 , wherein the adaptive filter updates a characteristic of the adaptive filter such that an amplitude of said error signal becomes smaller.
19. An echo cancelling method according to claim 5 , wherein the error signal is unaffected by the voice signal of the speaker.