研究自适应多路通信回波信号消除这一目前国内外未能有效解决的热门而棘手的问题。利用交叉学科的优势，采用非线性ＰＩＤ控制技术寻求收敛速度快、运算量相当且适合于多路通信回波信号消除的自适应非线性算法，并探索在数字信号处理芯片上的实时实现问题；为完善自适应多路通信回波信号消除理论与应用技术奠定相应的基础。

Adaptive filtering theory and its application in the multi-channel echo cancellation is studied. Then, aiming at the existing problems in these aspects at present, we seek some relative fast algorithms by exerting geometry rotating transform theory, inverse matrix theory, high order cumulant theory and nolinear rotate transform technique. These fast algorithms have not only good convergence properties, but also have less computational complexity. Moreover, their structures are so simple that they can be realized easily. Applying these algorithms to the adaptive cancellation of multi-channel echo, we obtain good results, which can improve many relative research works inside and outside the country at present.