- TX: process data at symbol rate

- RX: removed kdown stuff (hardcode to 4), fixed redundant down sampling for base band processing

git-svn-id: http://moon:8086/svn/matlab/trunk@37 801c6759-fa7c-4059-a304-17956f83a07c

ofdm/ofdm_rx.m

@@ -5,25 +5,22 @@ function [x] = ofdm_rx(filename, foff, knoise_dB, with_cir)
 %          ofdm_rx('xv.wav', 0, -400, 0)
 %       or ofdm_rx('yv.wav', 0, -400, 0)
 
+close all;
+
 drm_mode = 'B';
 drm_bw = '10k';
 
 [ofdm_drm_params, ofdm_spec_occ] = drm_params(drm_mode, drm_bw);
 
-close all;
 pre_mix = 0;
-Kdown = 4;
-fs = 48000/Kdown;
-fc = fs/4;
-N = 1024/Kdown;
-Ng = 256/Kdown;
+fs = 12000;
+N = 256;
+Ng = 64;
 [carrier_pilot, phi_pilot, mag_pilot] = getRefFreq(drm_mode);
 [carrier_time, phi_time, mag_time] = getRefTime(drm_mode);
 
 h_cir = [0 0 .1 -.2 .5 .2 -.1 0 0 ];
 
-close all;
-
 % Generate signal
 [xwav fs_ nbits] = wavread(filename);
 
@@ -37,10 +34,12 @@ elseif (ndim == 1)
     x = xwav.*exp(-j*(2*pi*(0.25-foff/fs_)*(0:len-1)'));
     hlp = FIRCalcLowpass(12000/fs_, 33);
     x = filter(hlp, 1, x);
+	
+	% Downsample
+	x = x(1:4:length(x));
 else
     error('Cannot read file!');
 end
-x = x(1:Kdown:length(x));
 
 if with_cir
     x = filter(h_cir, 1, x);
@@ -53,7 +52,7 @@ wavwrite(xout,fs,nbits,'ofdm_rx.wav');
 x = x +  sqrt(0.5)*10^(knoise_dB/20)*(randn(size(x)) + j*randn(size(x)));
 
 
-K = fix((length(x)-Ng)/(N+Ng));
+K = fix((length(x))/(N+Ng))-1;
 
 % Timing coarse
 cp_off_ = [];