From f4428bb0e6e9fa7e145aabcf614e046692b00584 Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Sat, 2 May 2015 16:53:32 +0000
Subject: [PATCH] - fixed dF tracking

git-svn-id: http://moon:8086/svn/matlab/trunk@57 801c6759-fa7c-4059-a304-17956f83a07c
---
 ofdm/ofdm_rx.m | 76 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 45 insertions(+), 31 deletions(-)

diff --git a/ofdm/ofdm_rx.m b/ofdm/ofdm_rx.m
index 22ff919..d10bcc2 100644
--- a/ofdm/ofdm_rx.m
+++ b/ofdm/ofdm_rx.m
@@ -157,10 +157,8 @@ for k=1:K,
     Xlast = X;
 end
 
-if ~isempty(cp_off_)
-    figure;
-    plot(0:length(cp_off_)-1, cp_off_, 0:length(cp_off_)-1, cp_off*ones(size(cp_off_)), 'r-'); grid; title('cp_{off}')
-end
+figure;
+plot(0:length(cp_off_)-1, cp_off_, 0:length(cp_off_)-1, cp_off*ones(size(cp_off_)), 'r-'); grid; title('cp_{off}')
 
 df_acq_fine_ = df_acq_fine_';
 
@@ -249,43 +247,58 @@ fac_cell_list = ...
     [23, 35, 47, 65, 77],
     []
 };
-symbol_counter = 0;
-win_count = 0;
+s = 0;
+m = 0;
+
 H_syms = [];
 H_pilots = [];
 sym_out = [];
 kk = 1;
 H_ = [];
-df_track_ = [];
+dw_track_ = [];
+MIN_ABS_H = 1e-10;
+
 for k=start:length(Z_)
     
     %shifted symbol index
-    nn = rem(k-start-1-symbols_to_delay + symbols_per_frame, symbols_per_frame);
-    m = floor(nn/ofdm_drm_params.y);
-    n = rem(nn, ofdm_drm_params.y);
+    n = rem(m+symbols_to_delay-1, ofdm_drm_params.y);
 
-	[carrier_gain, phi_gain, mag_gain] = getRefGain(ofdm_drm_params, ofdm_spec_occ, symbol_counter);
+	[carrier_gain, phi_gain, mag_gain] = getRefGain(ofdm_drm_params, ofdm_spec_occ, s);
     carrier_gain_bins = c2i(N, carrier_gain);
+	H_  = transpose(Z_(carrier_gain_bins, k))./(mag_gain.*exp(j*2*pi*phi_gain/1024));
 
-	if ~isempty(H_pilots)
-		df_track = fs/(2*pi*N)*angle( H_pilots * conj(H2_));
-		df_track_ = [df_track_ df_track];
-	end
-	H2_ = H_;
-	H_= Z_(carrier_gain_bins, k)./(mag_gain.*exp(j*2*pi*phi_gain/1024)).';
-    H_raw(carrier_gain_bins) = H_;
-    H_gain_cell{win_count+1} = transpose(H_);
-    ii = 1+mod(n+(0:frames_per_window-1), frames_per_window);
-    H_gain = [H_gain_cell{ii}];
-    H_gain_carriers_cell{win_count+1} = carrier_gain;
+    H_raw(carrier_gain_bins) = (H_);
+    H_gain_cell{m+1} = (H_);
+    H_gain_carriers_cell{m+1} = carrier_gain;
     
-    str = sprintf('Frame %d, SymCount %d, winCount %d, n=%d', k, symbol_counter, win_count, n);
-    if length(H_gain) == 208
+    str = sprintf('Frame %d, s=%d, m=%d, n=%d', k, s, m, n);
+    if kk > 6
+		ii = 1+mod(m+symbols_to_delay-1+(0:frames_per_window-1), frames_per_window);
+		H_gain = [H_gain_cell{ii}];
 		H_syms = H_gain*W_syms{n+1};
-		H_pilots = H_gain*W_pilots{n+1};
+		H_pilots = (H_gain)*W_pilots{n+1};
 		ZZ = Z_(carrier_indexes, k-symbols_to_delay).';
-    	sym_eq = ZZ ./ H_syms;
+		hhh = H_gain_cell{mod(m-1, frames_per_window)+1};
+		dw_track = angle( (H_pilots) * hhh' + MIN_ABS_H);
+		dw_track_ = [dw_track_ dw_track];
+		
+		% check for too small values
+		rms_H = sqrt( abs( H_syms*H_syms' )/length(H_syms) );
+		MIN_ABS_H = max( rms_H/20, 1e-10 );	%quick and dirty fixed settings
+		H_too_small_index = find( abs(H_syms)<MIN_ABS_H );
+		H_syms( H_too_small_index ) = MIN_ABS_H;
+
+		sym_eq = ZZ ./ H_syms;
 		sym_out(:, kk) = sym_eq;
+		if 0
+			subplot(2, 1, 1)
+			plot(1:length(hhh), abs(hhh), 'b-', 1:length(H_pilots), abs(H_pilots), 'r-'); grid; 
+			subplot(2, 1, 2)
+			plot(1:length(hhh), angle(hhh), 'b-', 1:length(H_pilots), angle(H_pilots), 'r-'); grid; 
+			title(str);
+			pause(0.01);
+		end
+		if 1
         if show_H
 			H_raw(1:2:N) = H_raw(2:2:N);
 			subplot(3, 1, 1)
@@ -304,7 +317,7 @@ for k=start:length(Z_)
 
             pause(0.01);
 		else
-            fac_c = fac_cell_list{mod(symbol_counter-symbols_to_delay, symbols_per_frame)+1};
+            fac_c = fac_cell_list{mod(s-symbols_to_delay, symbols_per_frame)+1};
             if (~isempty(fac_c))
 				fac_i = fac_c - ofdm_spec_occ.kmin + 1;
 				hold on;
@@ -313,16 +326,17 @@ for k=start:length(Z_)
 				grid; title('FAC'); axis([-1 1 -1 1]);
 				hold off;
 			end
-        end
+		end
+		end
     end
     kk = kk + 1;
-    win_count = mod(win_count+1, frames_per_window);
-    symbol_counter = mod(symbol_counter + 1, symbols_per_frame);
+    m = mod(m+1, frames_per_window);
+    s = mod(s + 1, symbols_per_frame);
 
 end
 
 figure;
-plot(df_track_); grid; title('df_{track}');
+plot(dw_track_); grid; title('dw_{track}');
 
 function Y = spec_order(N, X)
     Y = [X(N/2+1:N)' X(1:N/2)']';