signal_denoising1.m

给出小波去噪的理论

load leleccum;
indx = 1:1024; 
x = leleccum(indx);
% 产生含噪信号
init=2055615866; 
randn('seed',init); 
nx = x + 18*randn(size(x));  
% 获取消噪的阀值
[thr,sorh,keepapp] = ddencmp('den','wv',nx);   
% 对信号进行消噪
xd = wdencmp('gbl',nx,'db4',2,thr,sorh,keepapp);
subplot(2,2,1);
plot(x);
title('原始信号');
subplot(2,2,2);
plot(nx);
title('含噪信号');
subplot(2,2,3)
plot(xd);
title('消噪后的信号');