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git-svn-id: http://moon:8086/svn/matlab/trunk@13 801c6759-fa7c-4059-a304-17956f83a07c
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jens
2015-04-04 08:33:11 +00:00
parent fc703d1011
commit a63adc66a9
2 changed files with 36 additions and 22 deletions
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ofdm/fdet_eval.m
+25 -17
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@@ -1,46 +1,54 @@
function fdet_eval(f_true, knoise_dB, numFrames)
function fdet_eval(f_true, phi_true, knoise_dB, p)
%
% Example: fdet_eval(1200, pi/4, -10, [1100 1350 1])
fs = 48000;
N = 1024;
K = numFrames;
phi_true = 1;
K = 100;
f_min = p(1);
f_max = p(2);
f_step = p(3);
% Adaption rate
mu = 20.0;
mu = 0.001;
% 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);
% Initial guess
X = fft(x_true, N);
[v maxk] = max(abs(X));
f_est = (maxk-1)*fs/N; % * (1+angle(X(maxk)))
last_mag = 0;
% Initial guess
f_est = fdet_coarse(x_true, N, fs, f_min, f_step, f_max)
Xm = zeros(N, 1);
for k=1:K
xp = x_true((k-1)*N+1:k*N);
phi_est = angle(xp(1));
x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)'+phi_est));
x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)' + 0));
dmod(k) = sum(xp.*x_est);
err(k) = sign(imag(dmod(k)))*(1-real(dmod(k)/abs(dmod(k))))^.5;
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;
phi(k) = phi_est;
end;
f_true = f_true
f_est = f_est
mean_fest = mean(f(K/2+1:K))
error_ppm = 1E6*(1-mean_fest/f_true)
close all;
subplot(4,1,1)
plot(1:lge(f), 1-real(dmod)./abs(dmod), 1:lge(f), imag(dmod)./abs(dmod), 1:lge(f), real(dmod)./abs(dmod)); grid;
plot(1:lge(f), real(dmod)/N, 1:lge(f), imag(dmod)/N, 1:lge(f), abs(dmod)/N); grid; legend('Re', 'Im', 'abs()');
subplot(4,1,2)
plot(1:lge(f), err, '-*'); grid;
plot(1:lge(f), err, '-'); grid; legend('error');
subplot(4,1,3)
plot(1:lge(f), f); grid;
plot(1:lge(f), f); grid; legend('f');
subplot(4,1,4)
plot(1:lge(f), angle(dmod)); grid;
plot(1:lge(f), phi, '-*'); grid; legend('phi');