摘要
考虑到扬声器的非线性特性,将实际房间声学系统模拟为一个无记忆非线性系统与一个动态线性系统相级联,并分别采用多项式函数和限幅函数模拟扬声器系统的非线性特性,通过在声回波对消的归一化最小均方算法中引入相应的非线性预处理,改善房间声回波对消的效果。计算机仿真证明,考虑了扬声器非线性影响并在算法中进行相应非线性预处理后的房间声回波对消比未经非线性预处理的声回波对消有更好的对消效果。
For the nonlinearity of a loudspeaker, a real room acoustic system is simulated as a cascaded one by a memoryless nonlinear system and a dynamic linear system. Polynomial function and hard-clipping function are adopted to simulate the nonlinearity of the loudspeaker system, and the introduction of corresponding nonlinear pre-processing into the Normalized Least-Mean-Square （NLMS） algorithm of acoustic echo cancellation is proposed, thus to improve the effects of the acoustic echo cancellation. Simulation results proves that if the affects of the speaker nonlinearity have been taken into consideration and corresponding nonlinear pre-processing is applied to the algorithm, the much better effects can be obtained.
出处
《通信技术》
2008年第7期57-59,共3页
Communications Technology
关键词
声回波对消
非线性预处理
多项式函数
限幅函数
acoustic echo cancellation
nonlinear pre-processing
polynomial function
hard-clipping function
