jens
51bcd1a549
git-svn-id: http://moon:8086/svn/matlab/trunk@16 801c6759-fa7c-4059-a304-17956f83a07c
51 lines
1.1 KiB
Matlab
51 lines
1.1 KiB
Matlab
function fdet_eval(f_true, phi_true, knoise_dB, p)
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%
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% Example: fdet_eval(1200, pi/4, -10, [1100 1350 1])
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fs = 48000;
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N = 1024;
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K = 40;
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f_min = p(1);
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f_max = p(2);
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f_step = p(3);
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% Generate signal
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x_true = exp(j*(2*pi*f_true/fs*(0:K*N-1)'+phi_true)) + sqrt(10^(knoise_dB/10))*randn(K*N,1);
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% Initial guess
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f_coarse = fdet_coarse(x_true, N, fs, f_min, f_step, f_max)
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phi_est = 0;
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f_est = f_coarse;
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for k=1:K
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f(k) = f_est;
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xp = x_true((k-1)*N+1:k*N);
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x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)' + phi_est));
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dmod(k) = sum(xp.*x_est);
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f_f = angle(dmod(k))/N*fs/(2*pi);
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err(k) = f_f;
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f_est = f_est + f_f;
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dphi_est = 2*pi*mod(f_est/fs*N, 1);
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phi_est = phi_est + dphi_est;
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end;
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f_est = f_est
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error_ppm = 1E6*(1-f_est/f_true)
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close all;
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subplot(4,1,1)
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plot(1:lge(f), real(dmod)/N, 1:lge(f), imag(dmod)/N, 1:lge(f), abs(dmod)/N); grid; legend('Re', 'Im', 'abs()');
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subplot(4,1,2)
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plot(1:lge(f), err, '-'); grid; legend('error');
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subplot(4,1,3)
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plot(1:lge(f), f); grid; legend('f');
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subplot(4,1,4)
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plot(1:lge(f), angle(dmod), '-*', 1:lge(f), diff(angle([0 dmod])), 'r-*'); grid; legend('phi', 'dphi');
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