algorithm - 如何为 LMS 算法绘制 MSE

Question

能否请您告诉我如何为下面的 matlab 代码的 LMS 算法绘制 MSE 曲线。提前致谢。

clc
close all
clear all
N=input('length of sequence N = '); % filter length
t=[0:N-1]; 
w0=0.001;  phi=0.1;
d=sin(2*pi*[1:N]*w0+phi); %desired signal 
x=d+randn(1,N)*0.5; % input of the filter
w=zeros(1,N); %initial weight 
mu=input('mu = '); % alpha
for i=1:N
    e(i) = d(i) - w(i)' * x(i);  %error (desired-real output)
    w(i+1) = w(i) + mu * e(i) * x(i); % weight update of the filter
end
for i=1:N
    yd(i) = sum(w(i)' * x(i));
end
subplot(221),plot(t,d),ylabel('Desired Signal'),
subplot(222),plot(t,x),ylabel('Input Signal+Noise'),
subplot(223),plot(t,e),ylabel('Error'),
subplot(224),plot(t,yd),ylabel('Adaptive Desired output');
end  

Answer 1

mean squared error包括计算所需结果和获得结果之间的平方差之和，并将其对样本数进行平均。因此:

MSE=sum((d(:)-yd(:)).^2)./size(d,2);

在你的情况下，你可以用 N 替换 size(d,2)