From 0cbdafcc4b125531df4dab65b586b752161914c3 Mon Sep 17 00:00:00 2001
From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Tue, 12 Jun 2012 06:12:18 +0000
Subject: [PATCH] reduced sizeof tx_filter_mem, saving 100k out of 400k for
 FDMDV states

git-svn-id: https://svn.code.sf.net/p/freetel/code@545 01035d8c-6547-0410-b346-abe4f91aad63
---
 codec2-dev/octave/tfdmdv.m      |  2 +-
 codec2-dev/src/fdmdv.c          | 31 +++++++++++++++++++------------
 codec2-dev/src/fdmdv_internal.h |  4 ++--
 codec2-dev/unittest/tfdmdv.c    |  2 ++
 4 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/codec2-dev/octave/tfdmdv.m b/codec2-dev/octave/tfdmdv.m
index 787913cf..41e68c88 100644
--- a/codec2-dev/octave/tfdmdv.m
+++ b/codec2-dev/octave/tfdmdv.m
@@ -196,7 +196,7 @@ stem_sig_and_error(1, 212, real(tx_symbols_log_c(1:n/2)), real(tx_symbols_log(1:
 % tx_filter()
 
 diff = tx_baseband_log - tx_baseband_log_c;
-c=3;
+c=15;
 plot_sig_and_error(2, 211, real(tx_baseband_log_c(c,:)), real(sum(diff)), 'tx baseband real')
 plot_sig_and_error(2, 212, imag(tx_baseband_log_c(c,:)), imag(sum(diff)), 'tx baseband imag')
 
diff --git a/codec2-dev/src/fdmdv.c b/codec2-dev/src/fdmdv.c
index 3526e780..1ded60f1 100644
--- a/codec2-dev/src/fdmdv.c
+++ b/codec2-dev/src/fdmdv.c
@@ -145,9 +145,12 @@ struct FDMDV * CODEC2_WIN32SUPPORT fdmdv_create(void)
 	f->prev_rx_symbols[c].real = 1.0;
 	f->prev_rx_symbols[c].imag = 0.0;
 
-	for(k=0; k<NFILTER; k++) {
+	for(k=0; k<NSYM; k++) {
 	    f->tx_filter_memory[c][k].real = 0.0;
 	    f->tx_filter_memory[c][k].imag = 0.0;
+	}
+
+	for(k=0; k<NFILTER; k++) {
 	    f->rx_filter_memory[c][k].real = 0.0;
 	    f->rx_filter_memory[c][k].imag = 0.0;
 	}
@@ -332,7 +335,7 @@ void bits_to_dqpsk_symbols(COMP tx_symbols[], COMP prev_tx_symbols[], int tx_bit
 
 \*---------------------------------------------------------------------------*/
 
-void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memory[NC+1][NFILTER])
+void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memory[NC+1][NSYM])
 {
     int     c;
     int     i,j,k;
@@ -341,9 +344,14 @@ void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memo
 
     gain.real = sqrt(2.0)/2.0;
     gain.imag = 0.0;
-
+    
+    /*
     for(c=0; c<NC+1; c++)
 	tx_filter_memory[c][NFILTER-1] = cmult(tx_symbols[c], gain);
+    */
+    for(c=0; c<NC+1; c++)
+	tx_filter_memory[c][NSYM-1] = cmult(tx_symbols[c], gain);
+    
 
     /* 
        tx filter each symbol, generate M filtered output samples for each symbol.
@@ -356,14 +364,14 @@ void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memo
 	    /* filter real sample of symbol for carrier c */
 
 	    acc = 0.0;
-	    for(j=M-1,k=M-i-1; j<NFILTER; j+=M,k+=M)
+	    for(j=0,k=M-i-1; j<NSYM; j++,k+=M)
 		acc += M * tx_filter_memory[c][j].real * gt_alpha5_root[k];
 	    tx_baseband[c][i].real = acc;	
 
 	    /* filter imag sample of symbol for carrier c */
 
 	    acc = 0.0;
-	    for(j=M-1,k=M-i-1; j<NFILTER; j+=M,k+=M)
+	    for(j=0,k=M-i-1; j<NSYM; j++,k+=M)
 		acc += M * tx_filter_memory[c][j].imag * gt_alpha5_root[k];
 	    tx_baseband[c][i].imag = acc;
 
@@ -372,15 +380,14 @@ void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memo
 
     /* shift memory, inserting zeros at end */
 
-    for(i=0; i<NFILTER-M; i++)
+    for(i=0; i<NSYM-1; i++)
 	for(c=0; c<NC+1; c++)
-	    tx_filter_memory[c][i] = tx_filter_memory[c][i+M];
+	    tx_filter_memory[c][i] = tx_filter_memory[c][i+1];
 
-    for(i=NFILTER-M; i<NFILTER; i++)
-	for(c=0; c<NC+1; c++) {
-	    tx_filter_memory[c][i].real = 0.0;
-	    tx_filter_memory[c][i].imag = 0.0;
-	}
+    for(c=0; c<NC+1; c++) {
+	tx_filter_memory[c][NSYM-1].real = 0.0;
+	tx_filter_memory[c][NSYM-1].imag = 0.0;
+    }
 }
 
 /*---------------------------------------------------------------------------*\
diff --git a/codec2-dev/src/fdmdv_internal.h b/codec2-dev/src/fdmdv_internal.h
index 8c5ead60..b51036e2 100644
--- a/codec2-dev/src/fdmdv_internal.h
+++ b/codec2-dev/src/fdmdv_internal.h
@@ -89,7 +89,7 @@ struct FDMDV {
 
     int  tx_pilot_bit;
     COMP prev_tx_symbols[NC+1];
-    COMP tx_filter_memory[NC+1][NFILTER];
+    COMP tx_filter_memory[NC+1][NSYM];
     COMP phase_tx[NC+1];
     COMP freq[NC+1];
  
@@ -148,7 +148,7 @@ struct FDMDV {
 \*---------------------------------------------------------------------------*/
 
 void bits_to_dqpsk_symbols(COMP tx_symbols[], COMP prev_tx_symbols[], int tx_bits[], int *pilot_bit);
-void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memory[NC+1][NFILTER]);
+void tx_filter(COMP tx_baseband[NC+1][M], COMP tx_symbols[], COMP tx_filter_memory[NC+1][NSYM]);
 void fdm_upconvert(COMP tx_fdm[], COMP tx_baseband[NC+1][M], COMP phase_tx[], COMP freq_tx[]);
 void generate_pilot_fdm(COMP *pilot_fdm, int *bit, float *symbol, float *filter_mem, COMP *phase, COMP *freq);
 void generate_pilot_lut(COMP pilot_lut[], COMP *pilot_freq);
diff --git a/codec2-dev/unittest/tfdmdv.c b/codec2-dev/unittest/tfdmdv.c
index b33a6342..50848e46 100644
--- a/codec2-dev/unittest/tfdmdv.c
+++ b/codec2-dev/unittest/tfdmdv.c
@@ -102,6 +102,8 @@ int main(int argc, char *argv[])
     rx_baseband_log_col_index = 0;
     rx_filt_log_col_index = 0;
 
+    printf("sizeof FDMDV states: %d bytes\n", sizeof(struct FDMDV));
+
     for(f=0; f<FRAMES; f++) {
 
 	/* --------------------------------------------------------*\
-- 
2.25.1