goldxcorr.m

自适应滤波原理_西蒙.赫金_Matlab_源代码 希望能够对学习自适应滤波技术的朋友有所帮助

%-------------------------------------------------------------------------
%  Compute cross-correlation of two oversampled Gold sequences
%  functions.
%-------------------------------------------------------------------------

%--- compute maximal length sequence of length 2^7-1 ---
N = 7;
m = 2^N -1;   % length
G1seq = [ones(1,N-1), -1];
for n=N+1:m 
    G1seq(n)=G1seq(n-N)*G1seq(n-3); 
end
G2seq = [ones(1,N-1), -1];
for n=N+1:m 
    G2seq(n)=G2seq(n-N)*G2seq(n-5)*G2seq(n-4)*G2seq(n-3)*G2seq(n-2)*G2seq(n-1); 
end
G3seq = [1, -ones(1,N-1)];
for n=N+1:m 
    G3seq(n)=G3seq(n-N)*G3seq(n-5)*G3seq(n-4)*G3seq(n-3)*G3seq(n-2)*G3seq(n-1); 
end

Goldseq1 = G1seq.*G2seq;
Goldseq2 = G1seq.*G3seq;

%--- oversample by 4 ---
osMseq1 = ones(4,1)*Goldseq1;
osMseq1 = osMseq1(:);
osMseq2 = ones(4,1)*Goldseq2;
osMseq2 = osMseq2(:);

%--- compute auto-correlation ---
h12 = xcorr([osMseq1' osMseq1' osMseq1'], osMseq2');
plot([-3*4*127:3*4*127-2]-507,(h12)/(4*127)); grid on
axis([-500 500 -.25 1])
ylabel('Normalized Cross-correlation')
xlabel('Delay(samples)')