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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
View File
@@ -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; fs = 48000;
N = 1024; N = 1024;
K = numFrames; K = 100;
phi_true = 1;
f_min = p(1);
f_max = p(2);
f_step = p(3);
% Adaption rate % Adaption rate
mu = 20.0; mu = 0.001;
% 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);
% Initial guess last_mag = 0;
X = fft(x_true, N);
[v maxk] = max(abs(X));
f_est = (maxk-1)*fs/N; % * (1+angle(X(maxk)))
% Initial guess
f_est = fdet_coarse(x_true, N, fs, f_min, f_step, f_max)
Xm = zeros(N, 1);
for k=1:K for k=1:K
xp = x_true((k-1)*N+1:k*N); 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)' + 0));
x_est = exp(-j*(2*pi*f_est/fs*(0:N-1)'+phi_est));
dmod(k) = sum(xp.*x_est); 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_est = f_est + mu*err(k);
f(k) = f_est; f(k) = f_est;
phi(k) = phi_est;
end; end;
f_true = f_true
f_est = f_est f_est = f_est
mean_fest = mean(f(K/2+1:K)) mean_fest = mean(f(K/2+1:K))
error_ppm = 1E6*(1-mean_fest/f_true) error_ppm = 1E6*(1-mean_fest/f_true)
close all; close all;
subplot(4,1,1) 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) subplot(4,1,2)
plot(1:lge(f), err, '-*'); grid; plot(1:lge(f), err, '-'); grid; legend('error');
subplot(4,1,3) subplot(4,1,3)
plot(1:lge(f), f); grid; plot(1:lge(f), f); grid; legend('f');
subplot(4,1,4) subplot(4,1,4)
plot(1:lge(f), angle(dmod)); grid; plot(1:lge(f), phi, '-*'); grid; legend('phi');
ofdm/ofdm_tx.m
+11 -5
View File
@@ -5,9 +5,9 @@ close all;
WITH_RCWIN = 1; WITH_RCWIN = 1;
WITH_FREQ_REF = 1; WITH_FREQ_REF = 1;
WITH_TIME_REF = 1; WITH_TIME_REF = 0;
WITH_GAIN_REF = 1; WITH_GAIN_REF = 0;
WITH_DATA = 1; WITH_DATA = 0;
M_QAM = 4; M_QAM = 4;
RCWIN_ROLLOFF = 0.1; RCWIN_ROLLOFF = 0.1;
@@ -90,7 +90,11 @@ ofdm_params_drm(DRM_MODE_D) = struct('mode', 'MODE_D', 'nu', 112, 'ng', 88, 'nsp
ofdm_params_drm(DRM_MODE_E) = struct('mode', 'MODE_E', 'nu', 27, 'ng', 3, 'nspf', 40, 'W', W1024(DRM_MODE_E), 'Z', Z1024(DRM_MODE_E), 'Q', Q1024(DRM_MODE_E)); ofdm_params_drm(DRM_MODE_E) = struct('mode', 'MODE_E', 'nu', 27, 'ng', 3, 'nspf', 40, 'W', W1024(DRM_MODE_E), 'Z', Z1024(DRM_MODE_E), 'Q', Q1024(DRM_MODE_E));
ofdm_params = ofdm_params_drm(DRM_MODE_B); ofdm_params = ofdm_params_drm(DRM_MODE_B);
ofdm_spec_occ = ofdm_spec_occ_drm(DRM_MODE_B, SPEC_OCC_10k); ofdm_spec_occ = ofdm_spec_occ_drm(DRM_MODE_B, SPEC_OCC_5k0);
ofdm_params_mode = ofdm_params.mode
ofdm_spec_occ_kmin = ofdm_spec_occ.kmin
ofdm_spec_occ_kmax = ofdm_spec_occ.kmax
T = 4/fa; T = 4/fa;
Tu = ofdm_params.nu * T Tu = ofdm_params.nu * T
@@ -112,6 +116,8 @@ k_fft = sqrt(N_fft);
xv = []; xv = [];
xt = zeros(1, Nt); xt = zeros(1, Nt);
ofdm_spec_occ.kmin
ofdm_spec_occ.kmax
figure; figure;
for k=1:N_frames for k=1:N_frames
for s=0:ofdm_params.nspf-1, for s=0:ofdm_params.nspf-1,
@@ -153,7 +159,7 @@ for k=1:N_frames
end; end;
xv = [xv xs(1:Ng+Nu)]; xv = [xv xs(1:Ng+Nu)];
Xs = fft(xs(Ng+1:Ng+Nu), N_fft)/k_fft; Xs = fft(xs(Ng+1:Ng+Nu), N_fft)/k_fft;
plot(fa*(0:N_fft/8-1)/N_fft, abs(Xs(1:N_fft/8)), '-*'); grid; plot(0:N_fft-1, abs(Xs(1:N_fft)), '-*'); grid;
pause (0.001); pause (0.001);
end; end;
end; end;