Echo Cancellation Algorithm And Software Implementation Technology For IP Communication

Acoustic echo cancellation is an important problem which needs to be solved in IP speech communication, echo cancellation classical algorithms computational complexity is higher, and at present on the side of technology application mainly use special chips、special device hardware implementation technology. With the improving of communication processor performance、with the development of IP communication terminal technology, the demand which is based on the general CPU to implement software echo cancellation application is very broad, currently business software speech engine technology which supports echo cancellation is confidential, the price is expensive, the paper mainly combines with an actual IMS software terminal echo cancellation technology to implement need, research related improved algorithm and software implementation technology.The paper is on the basis of consulting numerous references, summarizes the echo cancellation causes、classification and technology theory, mainly complete the following work1) research and evaluate the classic LMS and NLMS algorithm, improve the algorithm convergence factor to guarantee system steady-state precision;2) propose a kind of adaptive filter improved method based on adding a auxiliary filter, and solve echo cancellation worse effect which is led by double-talk detection;3) simulate, implement and evaluate the improved algorithm through the Matlab simulation tools.4) multithreading in software echo cancellation technology implementation causes that real-time signal synchronous is hard, lead to some problems,for examples, adaptive filter is difficult to convergence, and combine AEC software technology implementation in Speex speech codec to prove the application.The improved echo cancellation algorithm in the paper can improve echo cancellation effect on the basis of not increasing computing complexity; through improving the real-time speech signal synchronization mechanism, realize software echo cancellation processing engine further in the non-real time system.