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git-svn-id: http://moon:8086/svn/matlab/trunk@16 801c6759-fa7c-4059-a304-17956f83a07c
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jens
2015-04-04 17:34:24 +00:00
parent 57ae533570
commit 51bcd1a549
1 changed files with 16 additions and 20 deletions
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ofdm/fdet_eval.m
+16 -20
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@@ -4,40 +4,36 @@ function fdet_eval(f_true, phi_true, knoise_dB, p)
fs = 48000; fs = 48000;
N = 1024; N = 1024;
K = 20; K = 40;
f_min = p(1); f_min = p(1);
f_max = p(2); f_max = p(2);
f_step = p(3); f_step = p(3);
% Adaption rate
mu = 0.01;
% Generate signal % Generate signal
x_true = exp(j*(2*pi*f_true/fs*(0:K*N-1)'+phi_true)) + sqrt(10^(knoise_dB/10))*randn(K*N,1); x_true = exp(j*(2*pi*f_true/fs*(0:K*N-1)'+phi_true)) + sqrt(10^(knoise_dB/10))*randn(K*N,1);
last_mag = 0;
% Initial guess % Initial guess
f_est = fdet_coarse(x_true, N, fs, f_min, f_step, f_max) f_coarse = fdet_coarse(x_true, N, fs, f_min, f_step, f_max)
Xm = zeros(N, 1); phi_est = 0;
f_est = f_coarse;
for k=1:K for k=1:K
xp = x_true((k-1)*N+1:k*N);
x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)' + 0));
dmod(k) = sum(xp.*x_est);
mag = abs(dmod(k))/N;
err(k) = mag-last_mag;
err(k) = sin(1*err(k));
last_mag = mag;
phi(k) = angle(dmod(k));
f_est = f_est + mu*err(k);
f(k) = f_est; f(k) = f_est;
xp = x_true((k-1)*N+1:k*N);
x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)' + phi_est));
dmod(k) = sum(xp.*x_est);
f_f = angle(dmod(k))/N*fs/(2*pi);
err(k) = f_f;
f_est = f_est + f_f;
dphi_est = 2*pi*mod(f_est/fs*N, 1);
phi_est = phi_est + dphi_est;
end; end;
f_est = f_est f_est = f_est
mean_fest = mean(f(K/2+1:K))
error_ppm = 1E6*(1-mean_fest/f_true) error_ppm = 1E6*(1-f_est/f_true)
close all; close all;
subplot(4,1,1) subplot(4,1,1)
@@ -50,5 +46,5 @@ subplot(4,1,3)
plot(1:lge(f), f); grid; legend('f'); plot(1:lge(f), f); grid; legend('f');
subplot(4,1,4) subplot(4,1,4)
plot(1:lge(f), phi, '-*'); grid; legend('phi'); plot(1:lge(f), angle(dmod), '-*', 1:lge(f), diff(angle([0 dmod])), 'r-*'); grid; legend('phi', 'dphi');