- fdet_wav: mix down

git-svn-id: http://moon:8086/svn/matlab/trunk@23 801c6759-fa7c-4059-a304-17956f83a07c

ofdm/fdet_wav.m

@@ -1,7 +1,13 @@
 function fdet_wav(filename, p)
+%
+% Example: fdet_wav('drm-15435-if.wav', [900 1000 10])
+% Example: ofdm_tx(40, 1)
+%          fdet_wav('xv.wav', [700 800 1])
+%       or fdet_wav('yv.wav', [700 800 1])
 
 close all;
 fs = 48000;
+fc = fs/4;
 N = 1024;
 Ng = 256;
 
@@ -12,7 +18,15 @@ omega_step = p(3)/fs;
 % Generate signal
 [xwav fs nbits] = wavread(filename);
 
-x = xwav(:, 1) + j*xwav(:, 2);
+[len ndim] = size(xwav);
+
+if (ndim > 1)
+    fprintf('Mode: Baseband\n');
+    x = xwav(:, 1) + j*xwav(:, 2);
+else
+    fprintf('Mode: Passband\n');
+    x = xwav.*exp(-j*(2*pi*fc/fs*(0:len-1)'));
+end
 
 [omega, err, dmod, omega_coarse, omega_est] = fdet(x, N, Ng, omega_min, omega_step, omega_max);
 

ofdm/ofdm_tx.m

@@ -164,7 +164,7 @@ for k=1:N_frames
 end;
 
 % Modulate on carrier
-yc = 0.5*exp(i*2*pi.*(0:length(xv)-1)*fc/fa) .* xv;
+yc = 0.5*exp(j*2*pi.*(0:length(xv)-1)*fc/fa) .* xv;
 yv = real(yc) + imag(yc);
 
 xv = conj(xv');