- come and go

git-svn-id: http://moon:8086/svn/matlab/trunk@33 801c6759-fa7c-4059-a304-17956f83a07c
2015-04-19 18:47:46 +00:00
parent 626f3141cb
commit 792f9c50f8
8 changed files with 174 additions and 150 deletions
@@ -0,0 +1,39 @@
+function cfo_fine_eval(f, kn)
+
+Kdown = 4;
+fs = 48000/Kdown;
+
+N = 1024/Kdown;
+K = 100;
+n = (0:K*N-1)';
+
+phi = pi/2;
+x = cos(f/fs*2*pi.*n + phi) + kn*randn(K*N, 1);
+
+Xlast = [];
+phi_x_ = [];
+phi_z_ = [];
+Zm = ones(N, 1);
+for k=1:K-1,
+    xp = x((k-1)*N+1:k*N);
+    X = fft(xp);
+    if (~isempty(Xlast))
+        Z = Xlast .* conj(X);
+        [v, bin] = max(abs(Z(1:N/2)));
+        phi_x_ = [phi_x_ 0.5*angle(X(bin))/pi/N*fs];
+        phi_z_ = [phi_z_ 0.5*angle(Z(bin))/pi/N*fs];
+    end
+    Xlast = X;
+    
+end
+df = -mean(phi_z_)
+f_est = (bin-1)/N*fs + df
+
+figure(1)
+plot(abs(Z)); grid;
+
+figure(2)
+plot(phi_x_); grid; ylabel('phi_x');
+
+figure(3)
+plot((bin-1)/N*fs - phi_z_); grid; ylabel('d_f');