From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Fri, 20 Apr 2012 01:48:54 +0000 (+0000)
Subject: typos and minor tweaks
X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=0c7de118acc259df25199386eacd07fcc44f9af7;p=freetel-svn-tracking.git

typos and minor tweaks

git-svn-id: https://svn.code.sf.net/p/freetel/code@372 01035d8c-6547-0410-b346-abe4f91aad63
---

diff --git a/codec2-dev/octave/fdmdv.m b/codec2-dev/octave/fdmdv.m
index c295d7db..afa5d186 100644
--- a/codec2-dev/octave/fdmdv.m
+++ b/codec2-dev/octave/fdmdv.m
@@ -251,8 +251,11 @@ function foff = rx_est_freq_offset(rx_fdm, pilot, pilot_prev, nin)
   global pilot_lpf1;
   global pilot_lpf2;
 
-  % down convert latest M samples of pilot by multiplying by
-  % ideal BPSK pilot signal we have generated locally
+  % down convert latest nin samples of pilot by multiplying by
+  % ideal BPSK pilot signal we have generated locally.  This
+  % peak of the resulting signal is sensitive to the time shift between 
+  % the received and local version of the pilot, so we do it twice at
+  % different time shifts and choose the maximum.
  
   pilot_baseband1(1:Npilotbaseband-nin) = pilot_baseband1(nin+1:Npilotbaseband);
   pilot_baseband2(1:Npilotbaseband-nin) = pilot_baseband2(nin+1:Npilotbaseband);
@@ -535,7 +538,7 @@ endfunction
 
 % Generate a 4M sample vector of DBPSK pilot signal.  As the pilot signal
 % is periodic in 4M samples we can then use this vector as a look up table
-% for pilot signsl generation at the demod.
+% for pilot signal generation in the demod.
 
 function pilot_lut = generate_pilot_lut()
   global Nc;
@@ -550,7 +553,7 @@ function pilot_lut = generate_pilot_lut()
   pilot_freq = freq(Nc+1);
   pilot_phase = 1;
   pilot_filter_mem = zeros(1, Nfilter);
-  prev_pilot = zeros(M,1);
+  %prev_pilot = zeros(M,1);
 
   pilot_lut = [];
 
@@ -558,7 +561,7 @@ function pilot_lut = generate_pilot_lut()
 
   for f=1:F
     [pilot pilot_rx_bit pilot_symbol pilot_filter_mem pilot_phase] = generate_pilot_fdm(pilot_rx_bit, pilot_symbol, pilot_filter_mem, pilot_phase, pilot_freq);
-    prev_pilot = pilot;
+    %prev_pilot = pilot;
     pilot_lut = [pilot_lut pilot];
   end
 
@@ -742,6 +745,23 @@ function rn_file(filename)
 endfunction
 
 
+% Saves 200Hz LPF filter coeffs to a text file in the form of a C array
+
+function pilot_coeff_file(filename)
+  global pilot_coeff;
+  global Nfilter;
+
+  f=fopen(filename,"wt");
+  fprintf(f,"/* Generated by pilot_coeff_file() Octave function */\n\n");
+  fprintf(f,"const float pilot_coeff[]={\n");
+  for m=1:Npilotcoeff-1
+    fprintf(f,"  %g,\n", pilot_coeff(m));
+  endfor
+  fprintf(f,"  %g\n};\n", pilot_coeff(Npilotcoeff));
+  fclose(f);
+endfunction
+
+
 % Initialise ----------------------------------------------------
 
 global pilot_bit;
@@ -757,11 +777,11 @@ rx_filter_memory = zeros(Nc+1, Nfilter);
 global freq;
 freq = zeros(Nc+1,1);
 for c=1:Nc/2
-  carrier_freq = (-Nc/2 - 1 + c)*Fsep + Fcentre
+  carrier_freq = (-Nc/2 - 1 + c)*Fsep + Fcentre;
   freq(c) = exp(j*2*pi*carrier_freq/Fs);
 end
 for c=Nc/2+1:Nc
-  carrier_freq = (-Nc/2 + c)*Fsep + Fcentre
+  carrier_freq = (-Nc/2 + c)*Fsep + Fcentre;
   freq(c) = exp(j*2*pi*carrier_freq/Fs);
 end
 
diff --git a/codec2-dev/octave/tfdmdv.m b/codec2-dev/octave/tfdmdv.m
index 2d63d147..ad606d2a 100644
--- a/codec2-dev/octave/tfdmdv.m
+++ b/codec2-dev/octave/tfdmdv.m
@@ -1,6 +1,8 @@
 % tfdmdv.m
 %
-% Octave script that evaluates the output of tfdmdv.c Unit Test program for FDMDV modem.
+% Octave script that tests the C port of the FDMDV modem.  This script loads
+% the output of unittest/tfdmdv.c and compares it to the output of the
+% reference versions of the same functions written in Octave.
 %
 % Copyright David Rowe 2012
 % This program is distributed under the terms of the GNU General Public License 
@@ -84,6 +86,21 @@ plot(imag(tx_fdm_log - tx_fdm_log_c),'g');
 hold off;
 title('tx fdm imag')
 
+figure(4)
+clf
+subplot(211)
+plot(real(pilot_lut_c));
+hold on;
+plot(real(pilot_lut - pilot_lut_c),'g');
+hold off;
+title('pilot lut real')
+subplot(212)
+plot(imag(pilot_lut_c));
+hold on;
+plot(imag(pilot_lut - pilot_lut_c),'g');
+hold off;
+title('pilot lut imag')
+
 if sum(tx_bits_log - tx_bits_log_c) == 0
   printf("fdmdv_get_test_bits..: OK\n");
   passes++;
@@ -108,4 +125,20 @@ else;
   fails++;
 end
 
+if sum(tx_fdm_log - tx_fdm_log_c) < 1E-3
+  printf("tx_fdm...............: OK\n");
+  passes++;
+else;
+  printf("tx_fdm...............: FAIL\n");
+  fails++;
+end
+
+if sum(pilot_lut - pilot_lut_c) < 1E-3
+  printf("pilot_lut............: OK\n");
+  passes++;
+else;
+  printf("pilot_lut............: FAIL\n");
+  fails++;
+end
+
 printf("\npasses: %d fails: %d\n", passes, fails);