非平稳时变随机噪声的数字滤波器设计与仿真

非平稳噪声的统计参数是时变的,频率滤波器不能实现对它的抑制,传统的自适应抵消器方法是基于最小均方误差准则(LMS)实现滤波的。针对LMS自适应算法中的固定步长导致收敛速度慢、失调量大的缺点,提出了变步长方法。采用最小二乘准则(LS),根据输入信号信噪比的变化来调整步长,并对滤波器的收敛速度、滤波性能进行了数据仿真,验证了该算法的有效性,实现了对时变非平稳噪声的有效抑制。

Digital Filter Design and Simulation for Non-stationary Random Noise

Due to the time variant property of statistic parameters of unsteady stochastic noise,frequency filter is not suitable to suppress this kind of noise.Traditional adaptive filter for restraining this noise is realized based on LMS algorithm,which of some drawbacks,such as slow convergence and great maladjustment due to its fixed step.We propose an improved noise canceller with LS algorithm,whose step changes in accordance with input SNR.Simulation experiments are conducted and the results indicate that the proposed algorithm is more efficient for its faster convergence and better filtering performances.