LMS算法滤除心电工频干扰

1、信号处理基础ECG心电图信号干扰消除实验报告姓名:xxxxxx班级:xx班学号:xxxxxxxxxx一、实验要求interference cancellationGiven a received signal r(k which consist of a source signal s(k and a sinusoidal interference with known frequency. The task is to extract s(k from r(k. Notice that the amplitude and phase of the sinusoid is unknown. A

2、 well-known application is to remove 50/60 Hz power line interference in the recording of the electrocardiogram (ECG. 二、Matlab仿真结果 三、结果分析维纳滤波器参数是固定的,适合于平稳随机信号。卡尔曼滤波器参数是时变的,适合于非平稳随机信号。然而,只有在信号和噪声的统计特性先验已知的情况下,这两种滤波技术才能获得最优滤波。在实际应用中,常常无法得到信号和噪声统计特性的先验知识。在这种情况下,自适应滤波技术能够获得极佳的滤波性能,因而具有很好的应用价值。本程序是基于LMS算

3、法的自适应滤波,从上图可以看出,滤波效果也是很不错的。四、源代码av=1;f0=0.2;s,d=generateDemoECG(av,f0;% 生成模拟ECG信号;N=length(s;f0=50;fs=500;t=1:N;n1=100*sin(2*pi*f0*t/fs+20;d=n1+s; % 生成加50HZ干扰模拟ECG信号;%*LMS算法滤波*x1=sin(2*pi*f0*t/fs;x2=cos(2*pi*f0*t/fs;t=(0:0.001:1;w0(1=0;w1(1=0;mu=0.007;y(1=w0(1*x1(1+w1(1*x2(1;e(1=d(1-y(1;w0(2=w0(1+2*

4、mu*e(1*x1(1;w1(2=w1(1+2*mu*e(1*x2(1;for n=2:Ny(n=w0(n*x1(n+w1(n*x2(n;e(n=d(n-y(n;w0(n+1=w0(n+2*mu*e(n*x1(n;w1(n+1=w1(n+2*mu*e(n*x2(n;endr=d-w0(600*x1-w1(600*x2; %滤波后心电信号er=e.*e;%误差功率figure(1subplot(2,1,1plot(s(1:2000title('模拟ECG信号'xlabel('时间t/ms'ylabel('电压'subplot(2,1,2plot(r

5、(1:2000title('滤波后模拟ECG信号'xlabel('时间t/ms'ylabel('电压'figure(2subplot(2,1,1plot(w0(1:1000title('w0 逼近曲线'subplot(2,1,2plot(w1(1:1000title('w1 逼近曲线'figure(3subplot(1,1,1semilogy(er(1:2000;title('误差功率'generateDemoECG.m ECG 信号产生文件，将本文件代码放到 MATLAB 工作路径下 functi

6、on x2,x3=generateDemoECG(av,af pv=0.1*208;qv=0.1*208;rv=1*208;sv=0.2*208;tv=0.2*208;st=0.1*208; x2(1:100=0;x2(101:150=pv-pv*cos(0:49 * 2*pi/50; x2(151:170=0;x2(171:175 = -1:5*qv/5;x2(176:190=-qv+1:15*(rv+qv/15; x2(191:210=rv- 1:20*(rv+sv/20;x2(210:219=-sv + 1:10*(sv+st/10; x2(220:259=st;x2(260:359=tv-tv*cos(1:100*2*pi/100 + st- 1:100*st/100;x2(360:500=0; x2(501:1000=x2(1:500;x2(1001:2000=x2(1:1000;x2(2001:4000=x2(1:2000;x2(400