Simulink中Matlab Function实现归一化LMS滤波器相位问题求助

安全阿岳

2026-7-30

归一化LMS滤波器Simulink实现的相位偏移问题

我在Simulink的Matlab Function模块中实现归一化最小均方（Normalized LMS）滤波器，模块结构如图所示。当前仿真结果显示滤波器虽有滤波效果，但存在恒定相位偏移，我期望实现无相位偏移的滤波效果。

实现代码

Matlab Function模块中的代码如下：

function b = lms_update(ref,cor,adapt,N,mu)
% ref = reference signal, noise signal itself, for filter to produce
% cor = corrupted signal, total signal, to be filtered

% initialization
persistent x w

if isempty(x),x=zeros(N,1);end   % input buffer
if isempty(w),w=zeros(N,1);end % filter weights

epsil = 2.2204460492503131e-016; % epsilon for divided-by-zero

% read new input sample
x(1:N-1,1) = x(2:N,1);
x(N,1)     = cor;

if adapt
    % compute filter output
    xf = flip(x); % flip x
    
    y = w'*xf;

    e = ref - y;

    % update filter weights
    w = w + mu*e*xf/(xf'*xf + epsil);
end

b = w';