From cf14cd5c7c4262c74399f4816c7013f1ef5c8561 Mon Sep 17 00:00:00 2001
From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Tue, 31 Dec 2013 03:05:19 +0000
Subject: [PATCH] separate enc/mod/dec

git-svn-id: https://svn.code.sf.net/p/freetel/code@1351 01035d8c-6547-0410-b346-abe4f91aad63
---
 codec2-dev/octave/ldpcenc.m | 62 +++++++++++++++++++++++++------------
 1 file changed, 43 insertions(+), 19 deletions(-)

diff --git a/codec2-dev/octave/ldpcenc.m b/codec2-dev/octave/ldpcenc.m
index d32cc7da..4a1e28f4 100644
--- a/codec2-dev/octave/ldpcenc.m
+++ b/codec2-dev/octave/ldpcenc.m
@@ -30,22 +30,23 @@ demod_type = 0;
 decoder_type = 0;
 max_iterations = 100;
 EsNo = 10;
-Eprob = 0.18;
+Eprob = 0.15;
 
 vocoderframesize = 52;
 nvocoderframes = 8;
+nbitspermodemframe = 72;
 
 code_param = ldpc_init(rate, framesize, modulation, mod_order, mapping);
 
 data = [];
 r = []; 
 
-% Encode a bunch of frames
+% Encoder: Generate simulated vocoder data, insert UW, and LPDC encode ---------------
 
 Nframes = 100;
 uw = [1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0];
 
-% repeat same codeword frame for now to ease testing
+% repeat same simulated vocoder data to ease testing
 
 vd = round( rand( 1, vocoderframesize*nvocoderframes) );
 d  = insert_uw(vd, uw);
@@ -65,32 +66,56 @@ fclose(fc);
 %printf("framesize: %d data_bits_per_frame: %d code_bits_per_frame: %d\n", ...
 %        framesize, code_param.data_bits_per_frame,  code_param.code_bits_per_frame);
 
-% rx simulation (separate later)
+printf("Encoded %d LDPC frames\n", Nframes);
 
-mod_uw = build_mod_uw(uw, 2*length(vd)/length(uw));
+% Modulator: Modulate to QPSK symbols ------------------------------------------
 
 lpackedcodeword=length(packedcodeword);
 fc=fopen("codeword.bin","rb");
-lpackedmodem = 72/8;
-mod_codeword = zeros(1, code_param.code_bits_per_frame/2);
-lmod_codeword = code_param.code_bits_per_frame/2;
-
-Terrs = 0; Ferrs = 0; Tbits = 0; Tframes = 0; nerr = [];
-corr = []; n = 0;
-sync_state = 0; sync_count = 0;
+fm=fopen("modcodeword.bin","wb");
+lpackedmodem = nbitspermodemframe/8;
+n = 0;
 
 [packedmodem, count] = fread(fc,lpackedmodem,"uchar");
 while (count == lpackedmodem)
     n++;
     unpackedmodem = unpackmsb(packedmodem);
 
-    j = 1;
+    ii = 1;
     for i=1:2:length(unpackedmodem)
-        mod_unpackedmodem(j) = qpsk_mod(unpackedmodem(i:i+1));
-        j += 1;
+        mod_unpackedmodem(ii) = qpsk_mod(unpackedmodem(i:i+1));
+        mod_unpackedmodem_float32(i) = real(mod_unpackedmodem(ii));
+        mod_unpackedmodem_float32(i+1) = imag(mod_unpackedmodem(ii));
+        ii += 1;
     end
 
-    erasures = rand(1,length(mod_unpackedmodem))<Eprob; 
+    fwrite(fm, mod_unpackedmodem_float32, "float32");
+    [packedmodem, count] = fread(fc,lpackedmodem,"uchar");
+end
+fclose(fc);
+fclose(fm);
+printf("Modulated %d modem frames\n", n);
+
+
+% Decoder: Sync with LDPC frames, LDPC decode, strip off UW, measure BER -------
+
+fm=fopen("modcodeword.bin","rb");
+
+mod_uw = build_mod_uw(uw, 2*length(vd)/length(uw));
+
+mod_codeword = zeros(1, code_param.code_bits_per_frame/2);
+lmod_codeword = code_param.code_bits_per_frame/2;
+
+Terrs = 0; Ferrs = 0; Tbits = 0; Tframes = 0; nerr = [];
+corr = []; n = 0;
+sync_state = 0; sync_count = 0;
+
+[mod_unpackedmodem_float32, count] = fread(fm,nbitspermodemframe, "float32");
+while (count == nbitspermodemframe)
+    n++;
+
+    mod_unpackedmodem = mod_unpackedmodem_float32(1:2:nbitspermodemframe) + j*mod_unpackedmodem_float32(2:2:nbitspermodemframe);
+    erasures = rand(1,length(mod_unpackedmodem)) < Eprob; 
     mod_unpackedmodem(erasures) = 0;
 
     % keep buffer of one entire codeword
@@ -135,11 +160,10 @@ while (count == lpackedmodem)
         end
     end
 
-    % read in one modem frame at a time
+    % read in one modulated modem frame at a time
 
-    [packedmodem, count] = fread(fc, lpackedmodem, "uchar");
+    [mod_unpackedmodem_float32, count] = fread(fm, nbitspermodemframe, "float32");
 end
-fclose(fc);
 
 fprintf(1,"\nFrames: %d bits: %d errors: %d BER = %f FER = %f\n", Tframes, Tbits, Terrs, Terrs/Tbits, Ferrs/Tframes);
 subplot(211)
-- 
2.25.1