Analysis And Research Of Nonlinear Preprocessing Solution To Stereophonic Acoustic Echo Cancellation

Acoustic echo cancelers (AECs) are necessary for communication systems such as teleconferencing to reduce echos that result from coupling between the loudspeaker and microphone. With conventional sing-channel (monophonic) systems, such AECs simultaneously reduce the echo and identify the acoustic path so that the echo remains cancelled no matter what happens at the remote transmission room ( such as the change of spatial information, for example , the change of location or direction of speaker of the remote transmission room).To enhance the sound realism in application , two-channel audio is necessary. However, in this case ( stereophonic sound ) the acoustic echo cancellation problem is more difficult to solve because of the necessity to uniquely identify two acoustic paths.In this paper, on the basis of explanation of these problems, we use nonlinear preprocessing to deduce the correlation of the two recorded signals. To analyze and judge correctly the result of de-correlation of every nonlinear preprocessingsolution and the subjective effect of every nonlinear preprocessing solution on speech, it is very important to use factual data of LRM impulsive response. In this paper we test LRM impulsive response in a real room using TMS320C542 and TLC320AC01 in order to get factual data of LRM impulsive response.Using factual data of LRM impulsive response and real speech we analyze and judge every nonlinear preprocessing solution. Spectrum analyses and experiments show that sof t-limiter solution is better than those nonlinear preprocessing solutions proposed in paper[2]...