利用小波变换对信号进行降噪的matlab代码
时间: 2023-09-09 21:06:09 浏览: 42
以下是利用小波变换对信号进行降噪的matlab代码示例:
```matlab
% 加载信号
load noisysignal.mat
% 指定小波基和迭代层数
wname = 'db4';
level = 6;
% 对信号进行小波变换
[c, l] = wavedec(noisysignal, level, wname);
% 提取出各层小波系数
cD1 = detcoef(c, l, 1);
cD2 = detcoef(c, l, 2);
cD3 = detcoef(c, l, 3);
cD4 = detcoef(c, l, 4);
cD5 = detcoef(c, l, 5);
cD6 = detcoef(c, l, 6);
% 计算各层小波系数的阈值
thrD1 = wthrmngr('dw2ddenoLVL', cD1);
thrD2 = wthrmngr('dw2ddenoLVL', cD2);
thrD3 = wthrmngr('dw2ddenoLVL', cD3);
thrD4 = wthrmngr('dw2ddenoLVL', cD4);
thrD5 = wthrmngr('dw2ddenoLVL', cD5);
thrD6 = wthrmngr('dw2ddenoLVL', cD6);
% 小波系数阈值处理
cD1thr = wthresh(cD1, 'h', thrD1);
cD2thr = wthresh(cD2, 'h', thrD2);
cD3thr = wthresh(cD3, 'h', thrD3);
cD4thr = wthresh(cD4, 'h', thrD4);
cD5thr = wthresh(cD5, 'h', thrD5);
cD6thr = wthresh(cD6, 'h', thrD6);
% 重构滤波后的信号
denoisedsignal = waverec(cD1thr, cD2thr, cD3thr, cD4thr, cD5thr, cD6thr, l, wname);
% 绘制原始信号和滤波后信号的对比
figure;
subplot(2,1,1);
plot(noisysignal);
title('Original Signal');
subplot(2,1,2);
plot(denoisedsignal);
title('Denoised Signal');
```
希望这个代码能够对你有所帮助。如果你有其他问题,也欢迎再次向我提问。