refactored codea little, starting to (re)port C code

git-svn-id: https://svn.code.sf.net/p/freetel/code@2095 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/octave/cohpsk.m b/codec2-dev/octave/cohpsk.m
index f7978dd50947688b38f2d5d80624ed1f1a8a4062..966af97bf5fea79da9e700e0c41ad941909586f5 100644 (file)
--- a/codec2-dev/octave/cohpsk.m
+++ b/codec2-dev/octave/cohpsk.m
@@ -95,6 +95,8 @@ function sim_in = symbol_rate_init(sim_in)
 
     sim_in.ff_phase = 1;
 
+    sim_in.ct_symb_ff_buf = zeros(Nsymbrowpilot + 2, Nc);
+
     % Init LDPC --------------------------------------------------------------------
 
     if ldpc_code
@@ -558,6 +560,60 @@ function [next_sync cohpsk] = frame_sync_fine_timing_est(cohpsk, ch_symb, sync,
 endfunction
 
 
+% fine freq correction
+
+function acohpsk = fine_freq_correct(acohpsk, sync, next_sync);
+  ct_symb_ff_buf = acohpsk.ct_symb_ff_buf;
+
+  % We can decode first frame that we achieve sync.  Need to fine freq
+  % correct all of it's symbols, including pilots.  From then on, just
+  % correct new symbols into frame.  make copy, so if we lose sync we
+  % havent fine freq corrected ct_symb_buf if next_sync == 4 correct
+  % all 8 if sync == 2 correct latest 6
+
+  if (next_sync == 4) || (sync == 4)
+
+    if next_sync == 4
+
+      % first frame, we've just gotten sync so fine freq correct all Nsymbrowpilot+2 samples
+
+      ct_symb_ff_buf = acohpsk.ct_symb_buf(acohpsk.ct+1:acohpsk.ct+acohpsk.Nsymbrowpilot+2,:);
+      for r=1:acohpsk.Nsymbrowpilot+2
+        acohpsk.ff_phase *= acohpsk.ff_rect';
+        ct_symb_ff_buf(r,:) *= acohpsk.ff_phase;
+      end
+
+    else
+      
+      % second and subsequent frames, just fine freq correct the latest Nsymbrowpilot
+
+      ct_symb_ff_buf(1:2,:) = ct_symb_ff_buf(Nsymbrowpilot+1:Nsymbrowpilot+2,:);
+      ct_symb_ff_buf(3:Nsymbrowpilot+2,:) = acohpsk.ct_symb_buf(acohpsk.ct+3:acohpsk.ct+acohpsk.Nsymbrowpilot+2,:);
+      for r=3:acohpsk.Nsymbrowpilot+2
+        afdmdv.ff_phase *= afdmdv.ff_rect';
+        ct_symb_ff_buf(r,:) *= afdmdv.ff_phase;
+      end
+
+    end
+
+    mag = abs(acohpsk.ff_phase);
+    acohpsk.ff_phase /= mag;
+
+    acohpsk.ct_symb_ff_buf = ct_symb_ff_buf;
+  end
+endfunction
+
+
+% misc sync state machine code, just wanted it in a function
+
+function sync = sync_state_machine(sync, next_sync)
+  if sync == 1
+    next_sync = 2;
+  end
+  sync = next_sync;
+endfunction
+
+
 % Rate Rs BER tests ------------------------------------------------------------------------------
 
 function sim_out = ber_test(sim_in)

diff --git a/codec2-dev/octave/tcohpsk.m b/codec2-dev/octave/tcohpsk.m
index 593dbfb120a79a8db8f76fe873927343bb366ae3..a6737ee5dffde47e1b9bc0b485721b017fc21312 100644 (file)
--- a/codec2-dev/octave/tcohpsk.m
+++ b/codec2-dev/octave/tcohpsk.m
@@ -235,52 +235,14 @@ for i=1:frames
   [next_sync acohpsk] = frame_sync_fine_timing_est(acohpsk, ch_symb, sync, next_sync);
   %acohpsk.ff_rect = exp(j*2*pi*(-1.0)/Rs);
 
-  if sync == 1
-    next_sync = 2;
-  end
-
-  %printf("i: %d sync: %d next_sync: %d\n", i, sync, next_sync);
-  sync = next_sync;
-
   if (i==1000)
     xx
   end
 
-  % We can decode first that we get sync on.  Need to fine freq correct all of it's symbols, 
-  % including pilots.  From then on, just correct new symbols into frame.
-  % make copy, so if we lose sync we havent fine freq corrected ct_symb_buf
-  % if next_sync == 4 correct all 8
-  % if sync == 2 correct latest 6
-
-  if (next_sync == 4) || (sync == 4)
-
-    if next_sync == 4
-
-      % first frame, we've just gotten sync so fine freq correct all Nsymbrowpilot+2 samples
-
-      ct_symb_ff_buf = acohpsk.ct_symb_buf(acohpsk.ct+1:acohpsk.ct+acohpsk.Nsymbrowpilot+2,:);
-      for r=1:acohpsk.Nsymbrowpilot+2
-        acohpsk.ff_phase *= acohpsk.ff_rect';
-        ct_symb_ff_buf(r,:) *= acohpsk.ff_phase;
-      end
+  acohpsk = fine_freq_correct(acohpsk, sync, next_sync);
 
-    else
-      
-      % second and subsequent frames, just fine freq correct the latest Nsymbrowpilot
-
-      ct_symb_ff_buf(1:2,:) = ct_symb_ff_buf(Nsymbrowpilot+1:Nsymbrowpilot+2,:);
-      ct_symb_ff_buf(3:Nsymbrowpilot+2,:) = acohpsk.ct_symb_buf(acohpsk.ct+3:acohpsk.ct+acohpsk.Nsymbrowpilot+2,:);
-      for r=3:acohpsk.Nsymbrowpilot+2
-        afdmdv.ff_phase *= afdmdv.ff_rect';
-        ct_symb_ff_buf(r,:) *= afdmdv.ff_phase;
-      end
-
-    end
-
-    mag = abs(acohpsk.ff_phase);
-    acohpsk.ff_phase /= mag;
-      
-    [rx_symb rx_bits amp_ phi_ EsNo_] = qpsk_symbols_to_bits(acohpsk, ct_symb_ff_buf);
+  if (sync == 4) || (next_sync == 4)  
+    [rx_symb rx_bits amp_ phi_ EsNo_] = qpsk_symbols_to_bits(acohpsk, acohpsk.ct_symb_ff_buf);
     rx_symb_log = [rx_symb_log; rx_symb];
     rx_amp_log = [rx_amp_log; amp_];
     rx_phi_log = [rx_phi_log; phi_];
@@ -296,6 +258,8 @@ for i=1:frames
     end 
   end
 
+  sync = sync_state_machine(sync, next_sync);
+
   prev_tx_bits2 = prev_tx_bits;
   prev_tx_bits = tx_bits;