[Rx]

- fixed frame time estimation

git-svn-id: http://moon:8086/svn/matlab/trunk@64 801c6759-fa7c-4059-a304-17956f83a07c

ofdm/cfo_coarse_int.m

@@ -1,7 +1,7 @@
 function [d_bin, valid, Zf] = cfo_coarse_int(x, N, carrier_pilot, bins_search, Zi)
 
 if (~isfield(Zi, 'valid'))
-    Zi = struct('valid', 1, 'Xm', zeros(N, 1), 'Xv', zeros(N, 1), 'Zk', [], 'd_bin', []);
+    Zi = struct('valid', 1, 'Xm', zeros(size(x)), 'Xv', zeros(size(x)), 'Zk', [], 'd_bin', []);
 end
 
 alpha = 0.01;

ofdm/ofdm_rx.m

@@ -61,7 +61,7 @@ cfoCoarseFractional = struct('Z', 0, 'sync_counter', 200, 'sync', 0, 'err', 0, '
 cfoFine = struct('Z', 0, 'sync_counter', 200, 'sync', 0, 'err', 0, 'err_', [], 'df', 0, 'df_', [], 'Xlast', [], 'phi', 0, 'bin_track', 1);
 
 % Frame timing stuff
-frameTiming = struct('Z', 0, 'sync_counter', 20, 'sync', 0, 'kc_max', -1000, 'n_max', 0);
+frameTiming = struct('Z', 0, 'sync_counter', 20, 'sync', 0, 'kc_max', -1000, 'n', 0, 'n_max', 0);
 
 % Equalization stuff
 MIN_ABS_H = 1e-10;
@@ -109,7 +109,7 @@ while(fileRemain > fileChunkSize)
 	if (~isModePassband)
 	    xwav = xwav(:, 1) + j*xwav(:, 2);
 	end
-	xwav = xwav - mean(xwav);
+%	xwav = xwav - mean(xwav);
 
 	x = xwav.*exp(-j*(2*pi*omega_xwav*(0:fileChunkSize-1)' + phi_xwav)); 
 	phi_xwav = mod(phi_xwav + 2*pi*omega_xwav*fileChunkSize, 2*pi);
@@ -163,6 +163,8 @@ while(fileRemain > fileChunkSize)
 					cfoCoarseInteger.sync_counter = cfoCoarseInteger.sync_counter - 1;
 				else
 					cfoCoarseInteger.sync = 1;
+					% Reset buffer to Cp offset
+					buf_recv.setReadIndex(timingCoarse.cp_off);
 				end
 			end
 		end
@@ -182,6 +184,8 @@ while(fileRemain > fileChunkSize)
 				cfoCoarseFractional.df = cfoCoarseInteger.df + mean(cfoCoarseFractional.err_);
 				cfoCoarseFractional.df_ = cfoCoarseInteger.df + cfoCoarseFractional.err_;
 				cfoFine.df = cfoCoarseFractional.df;
+				% Reset buffer to Cp offset
+				buf_recv.setReadIndex(timingCoarse.cp_off);
 			end
 		end
 	end
@@ -203,36 +207,34 @@ while(fileRemain > fileChunkSize)
 				cfoFine.err_ = [cfoFine.err_ cfoFine.err];
 				cfoFine.df = cfoFine.df + 0.1*mean(cfoFine.err(cfoFine.bin_track));
 				cfoFine.df_ = [cfoFine.df_ cfoFine.df];
-				buf_Z.write(X);
 			end
+			buf_Z.write(X);
 			cfoFine.Xlast = X;
 		end
 
+		% Frame timing acquisition
 		bins = c2i(N, carrier_time);
 		skip_syms = ofdm_drm_params.nspf*4;
-		% Frame timing acquisition
+		if (~frameTiming.sync) && (buf_Z.len() >= (N*(1+ofdm_drm_params.nspf+skip_syms)))
-		if (~frameTiming.sync) && (buf_Z.len() >= (N*(ofdm_drm_params.nspf+skip_syms)))
+			
-			buf_Z.setReadIndex(N*skip_syms);
+			if (frameTiming.n < ofdm_drm_params.nspf)
-			for n=0:ofdm_drm_params.nspf-1
 				frameTiming.Z = 0;
-				k = skip_syms+n;
+				Z1 = buf_Z.readAt(N, N*skip_syms);
-				Z = buf_Z.read(N);
+				Z2 = buf_Z.readAt(N, N*(ofdm_drm_params.nspf+skip_syms));
-				if ~isempty(Z)
+				kc = abs(Z1(bins)' * Z2(bins));
-					for m=1:2
+				if valid
-						[kc valid frameTiming.Z] = timing_frame(Z(bins)', bins, ofdm_drm_params.nspf, frameTiming.Z);
+					if kc > frameTiming.kc_max
-						k = k + ofdm_drm_params.nspf;
+						frameTiming.n_max = frameTiming.n;
-					end
+						frameTiming.kc_max = kc;
-					if valid
-						if kc > frameTiming.kc_max
-							frameTiming.n_max = n;
-							frameTiming.kc_max = kc;
-						end
 					end
 				end
-			end
+				frameTiming.n = frameTiming.n + 1;
-			if ~isempty(Z)
+				buf_Z.read(N);
-				buf_Z.setReadIndex(N*(frameTiming.n_max));
+			else
 				frameTiming.sync = 1;
+			
+				% Reset Buffer to frame start
+				buf_Z.setReadIndex(N*(frameTiming.n_max));
 				frame_start = frameTiming.n_max
 			end
 		end

ofdm/timing_frame.m

@@ -1,6 +1,6 @@
 function [kc, valid, Zf] = frame_timing(Z, bins_timing_pilots, sym_per_frame, Zi)
 
-N = length(Z);
+N = length(Z)
 
 if (~isfield(Zi, 'valid'))
     Zi = struct('valid', 1, 'Zk', []);
@@ -11,12 +11,12 @@ if 1
     kc = 0;
     if ~isempty(Zi.Zk)
         Xk = Z .* conj(Zi.Zk);
-        if 0
+        if 1
             plot(0:length(Xk)-1, abs(Xk), '-*'); grid;
             pause (0.01); 
         end
         valid = 1;
-        kc = mean(abs(Xk));
+        kc = mean(abs(Xk))
     end
     Zi.Zk = Z;
 end