jens
792f9c50f8
git-svn-id: http://moon:8086/svn/matlab/trunk@33 801c6759-fa7c-4059-a304-17956f83a07c
40 lines
732 B
Objective-C
40 lines
732 B
Objective-C
function cfo_fine_eval(f, kn)
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Kdown = 4;
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fs = 48000/Kdown;
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N = 1024/Kdown;
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K = 100;
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n = (0:K*N-1)';
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phi = pi/2;
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x = cos(f/fs*2*pi.*n + phi) + kn*randn(K*N, 1);
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Xlast = [];
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phi_x_ = [];
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phi_z_ = [];
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Zm = ones(N, 1);
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for k=1:K-1,
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xp = x((k-1)*N+1:k*N);
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X = fft(xp);
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if (~isempty(Xlast))
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Z = Xlast .* conj(X);
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[v, bin] = max(abs(Z(1:N/2)));
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phi_x_ = [phi_x_ 0.5*angle(X(bin))/pi/N*fs];
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phi_z_ = [phi_z_ 0.5*angle(Z(bin))/pi/N*fs];
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end
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Xlast = X;
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end
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df = -mean(phi_z_)
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f_est = (bin-1)/N*fs + df
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figure(1)
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plot(abs(Z)); grid;
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figure(2)
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plot(phi_x_); grid; ylabel('phi_x');
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figure(3)
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plot((bin-1)/N*fs - phi_z_); grid; ylabel('d_f');
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