From 3fc175c5997d61184934b1ac4b1c7b9d4c26577a Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Sat, 2 May 2015 18:05:57 +0000
Subject: [PATCH] - cleaned up

git-svn-id: http://moon:8086/svn/matlab/trunk@59 801c6759-fa7c-4059-a304-17956f83a07c
---
 ofdm/ofdm_rx.m | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/ofdm/ofdm_rx.m b/ofdm/ofdm_rx.m
index 3f2ae86..e93d745 100644
--- a/ofdm/ofdm_rx.m
+++ b/ofdm/ofdm_rx.m
@@ -225,7 +225,6 @@ symbols_per_frame = ofdm_drm_params.nspf;
 symbols_to_delay = ofdm_drm_params.y;
 frames_per_window = 2*ofdm_drm_params.y;
 H_gain_cell = cell (frames_per_window, 1);
-H_gain_carriers_cell = cell (frames_per_window, 1);
 H_raw = zeros(length(ofdm_spec_occ.kmin:ofdm_spec_occ.kmax),1);
 carriers = ofdm_spec_occ.kmin:ofdm_spec_occ.kmax;
 carrier_indexes = c2i(N, carriers);
@@ -269,17 +268,24 @@ for k=start:length(Z_)
 
     H_raw(carrier_gain_bins) = (H_);
     H_gain_cell{m+1} = (H_);
-    H_gain_carriers_cell{m+1} = carrier_gain;
     
     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};
-		ZZ = Z_(carrier_indexes, k-symbols_to_delay).';
-		hhh = H_gain_cell{mod(m-1, frames_per_window)+1};
-		df_track = 12000/(2*pi*N)*angle( (H_pilots) * hhh' + MIN_ABS_H);
+		
+		% Get the correctly delayed symbols
+		sym = Z_(carrier_indexes, k-symbols_to_delay).';
+		
+		% Get the correctly delayed raw channel estimate
+		Hr = H_gain_cell{mod(m-1, frames_per_window)+1};
+		
+		% get frequency error
+		% correlate wiener filtered channel with raw estimate
+		df_track = 12000/(2*pi*N)*angle(H_pilots * Hr' + MIN_ABS_H);
 		df_track_ = [df_track_ df_track];
 		
 		% check for too small values
@@ -288,13 +294,14 @@ for k=start:length(Z_)
 		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;
+		% equalize symbol
+		sym_eq = sym ./ 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; 
+			plot(1:length(Hr), abs(Hr), '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; 
+			plot(1:length(Hr), angle(Hr), 'b-', 1:length(H_pilots), angle(H_pilots), 'r-'); grid; 
 			title(str);
 			pause(0.01);
 		end