IntroductionIn the applications of multimedia communication, real-time speech transmission and hand-free telephone conference, echo cancellation is essential to improve the speech quality.

• 引 言在基于IP网络的多媒体通信、因特网上的语音实时传输、电话会议及免提电话通信系统中，回声抵消技术对提高语音传输质量、通话质量方面发挥着不可或缺的重要作用。