diff --git a/ofdm/fdet_eval.m b/ofdm/fdet_eval.m index 4124cf8..d67490e 100644 --- a/ofdm/fdet_eval.m +++ b/ofdm/fdet_eval.m @@ -4,40 +4,36 @@ function fdet_eval(f_true, phi_true, knoise_dB, p) fs = 48000; N = 1024; -K = 20; +K = 40; f_min = p(1); f_max = p(2); f_step = p(3); -% Adaption rate -mu = 0.01; - % 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); -last_mag = 0; - % 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 - 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; + 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; 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; subplot(4,1,1) @@ -50,5 +46,5 @@ subplot(4,1,3) plot(1:lge(f), f); grid; legend('f'); 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');