Method and apparatus for multi-channel acoustic echo cancellation and recording medium with the method recorded thereon

A multi-channel acoustic echo canceller for an acoustic systemwhich has N receive channels each containing a loudspeaker for generating a reproduced sound, N being an integer equal to or greater than 2, and at least one pickup channel containing a microphone for picking up an acoustic signal, said N loudspeakers and said microphone being placed in a common sound field, said echo canceller comprising:

• N additive signal generating means for generating low cross-correlated additive signals for N received signals input into said N receive channels, respectively;
• N processed signal generating means for adding said received signals of said N receive channels and said additive signals corresponding thereto to generate processed signals of said N receive channels;
• said N loudspeakers each provided in one of said N receive channels, for reproducing said processed signals of said N receive channels and outputting reproduced sounds;
• said microphone for picking up a combined acoustic echo of said reproduced sounds sneaking thereinto from said N loudspeakers, and for inputting into said at least one pickup channel the combined acoustic echo as an acoustic echo signal;
• means for individually processing said N received signals and said N additive signals to generate an echo replica that simulates said acoustic echo signal in said at least one pickup channel, and
• for subtracting said echo replica from said acoustic echo signal to thereby perform acoustic echo cancellation.

A recording medium on which there is recorded a program for performing, by a computer, multi-channel acoustic echo cancellation in an acoustic system which has N receive channels each containing a loudspeaker for generating a reproduced sound, N being an integer equal to or greater than 2, and at least one pickup channel containing a microphone for picking up an acoustic signal, said N loudspeakers and said microphone being placed in a common sound field, said program comprising the steps of:

• (a) generating low cross-correlated additive signals for N received signals input into said N receive channels, respectively;
• (b) adding said received signals of said N receive channels and said additive signals corresponding thereto to generate processed signals of said N receive channels;
• (c) radiating said processed signals of said N receive channels by said loudspeakers corresponding thereto;
• (d) picking up and combing, by said microphone of said at least one pickup channel a combined, acoustic echo of the reproduced sounds sneaking thereinto from said loudspeakers of said N receive channels, and inputting the combined acoustic echo into said at least one pickup channel as an acoustic echo signal;
• and
• (e) individually processing said N received signals and said N additive signals to generate an echo replica that simulates said acoustic echo signal in said at least one pickup channel, and subtracting said echo replica from said acoustic echo signal to thereby perform acoustic echo cancellation.