linelms.m

线性自适应预测滤波算法

function e_prediction=linelms(receive_signal,num_weight)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%receive_signal:为接收信号序列=ss_signal+interference+noise;
%e_prediction:  为预测到的信号值
%num_weight:             抽头系数个数;
%a:             为Laguerre滤波器的极点;
%此为采用线性预测滤波方法抑制窄带干扰的算法
%当a为0时，变为一般的z-1，即传统的滤波器.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
z=receive_signal;                               %接收信号
M=length(z);                                    %接收信号长度
w=0.001*randn(1,num_weight)'; 
e=zeros(1,M);
z_hat=zeros(1,M);
p=zeros(1,M);
u=0.05;
p(num_weight)=2;%norm(z(1:num_weight))^2;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for k=(num_weight+1):M
    X=z(k-1:-1:k-num_weight).';
    xk2=norm(X)^2;
    gama=0.99;
    p(k)=p(k-1)+gama*[xk2-p(k-1)];
    z_hat(k)=w'*X;
    e(k)=z(k)-z_hat(k);
    w=w+u/(p(k)+10)*e(k)*X;
end;
e_prediction=e;