LMS自适应维纳滤波器

 1 %-- 14-10-25 下午3:36 --%
 2 %功能：LMS自适应噪声抵消
 3 % Inputs:
 4 % Outputs:
 5 clc;
 6 clear;
 7 [ref,fs] =wavread(‘in.wav‘);
 8 apm = 1;   %噪声幅度
 9 firLen = 160;  %定义滤波器长度
10 mu = 0.002;      %迭代步长
11 a = zeros(1,firLen);   %产生一行160列向量
12 dataLen = length(ref);   %赋值ref信号向量
13 eout = zeros(1,dataLen);   %产生一列dataLen长的向量且赋值
14 e=zeros(1,dataLen);
15 firIn = zeros(1,firLen);
16 firOut=zeros(1,dataLen);
17 noise = apm*rand(1,dataLen);  %产生随机噪声
18 near = ref‘+noise;   %在原始音频基础上加入噪声
19 for i=firLen:dataLen
20 firOut(i) = a*(near(i-firLen+1:i))‘;  %fir滤波，实现横向滤波器操作
21 e(i) = ref(i)-firOut(i);  %求误差信号
22 a = a+2*mu*e(i)*(near(i-firLen+1:i));   %lms 系数更新
23 eout(i) = e(i)*e(i);
24 end
25 wavwrite(firOut,fs,‘firOut.wav‘);
26 wavwrite(eout,fs,‘eout.wav‘);
27 wavwrite(near,fs,‘speech_noise.wav‘);
28 wavplay(firOut,fs);
29 figure(1)
30 subplot(411);
31 plot(ref);
32 title(‘原始信号‘);
33 subplot(412);
34 plot(near);
35 title(‘语音加噪信号‘);
36 subplot(413);
37 plot(noise);
38 title(‘噪声信号‘);
39 subplot(414);
40 plot(firOut);
41 title(‘自适应消噪信号‘);