From a6c75950e619982e47d69baa66a099e9a74aaeab Mon Sep 17 00:00:00 2001
From: Wojciech Kaczmarski <w.kaczmarski@teletra.pl>
Date: Tue, 9 Jan 2024 11:05:06 +0100
Subject: [PATCH] added new functions

- soft_bit_NOT()
- reorder_soft_bits()
---
 SP5WWP/include/m17/m17.h             |  2 ++
 SP5WWP/lib/math/math.c               | 11 +++++++++++
 SP5WWP/lib/phy/interleave.c          | 14 +++++++++++++-
 SP5WWP/m17-decoder/m17-decoder-sym.c |  9 +++------
 4 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/SP5WWP/include/m17/m17.h b/SP5WWP/include/m17/m17.h
index 1988c1b..559064e 100644
--- a/SP5WWP/include/m17/m17.h
+++ b/SP5WWP/include/m17/m17.h
@@ -84,6 +84,7 @@ void encode_LICH(uint8_t outp[12], const uint8_t inp[6]);
 extern const uint16_t intrl_seq[SYM_PER_PLD*2];
 
 void reorder_bits(uint8_t outp[SYM_PER_PLD*2], const uint8_t inp[SYM_PER_PLD*2]);
+void reorder_soft_bits(uint16_t outp[SYM_PER_PLD*2], const uint16_t inp[SYM_PER_PLD*2]);
 
 // M17 C library - lib/math/math.c
 uint16_t q_abs_diff(const uint16_t v1, const uint16_t v2);
@@ -93,6 +94,7 @@ uint16_t soft_to_int(const uint16_t* in, const uint8_t len);
 uint16_t div16(const uint16_t a, const uint16_t b);
 uint16_t mul16(const uint16_t a, const uint16_t b);
 uint16_t soft_bit_XOR(const uint16_t a, const uint16_t b);
+uint16_t soft_bit_NOT(const uint16_t a);
 void soft_XOR(uint16_t* out, const uint16_t* a, const uint16_t* b, const uint8_t len);
 
 // M17 C library - lib/phy/randomize.c
diff --git a/SP5WWP/lib/math/math.c b/SP5WWP/lib/math/math.c
index b78db64..2e868ef 100644
--- a/SP5WWP/lib/math/math.c
+++ b/SP5WWP/lib/math/math.c
@@ -153,6 +153,17 @@ uint16_t soft_bit_XOR(const uint16_t a, const uint16_t b)
 	return add16(mul16(a, sub16(0xFFFF, b)), mul16(b, sub16(0xFFFF, a)));
 }
 
+/**
+ * @brief Soft logic NOT.
+ * 
+ * @param a Input A.
+ * @return uint16_t Output = not A.
+ */
+uint16_t soft_bit_NOT(const uint16_t a)
+{
+	return 0xFFFFU-a;
+}
+
 /**
  * @brief XOR for vectors of soft-valued logic.
  * Max length is 255.
diff --git a/SP5WWP/lib/phy/interleave.c b/SP5WWP/lib/phy/interleave.c
index f0a8e26..14743cd 100644
--- a/SP5WWP/lib/phy/interleave.c
+++ b/SP5WWP/lib/phy/interleave.c
@@ -36,7 +36,7 @@ const uint16_t intrl_seq[SYM_PER_PLD*2]=
 };
 
 /**
- * @brief Reorder (interleave) unpacked payload bits.
+ * @brief Reorder (interleave) 368 unpacked payload bits.
  * 
  * @param outp Reordered, unpacked type-4 bits.
  * @param inp Input unpacked type-2/3 bits.
@@ -46,3 +46,15 @@ void reorder_bits(uint8_t outp[SYM_PER_PLD*2], const uint8_t inp[SYM_PER_PLD*2])
 	for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
         outp[i]=inp[intrl_seq[i]];
 }
+
+/**
+ * @brief Reorder (interleave) 368 soft bits.
+ * 
+ * @param outp Reordered soft bits.
+ * @param inp Input soft bits.
+ */
+void reorder_soft_bits(uint16_t outp[SYM_PER_PLD*2], const uint16_t inp[SYM_PER_PLD*2])
+{
+	for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
+        outp[i]=inp[intrl_seq[i]];
+}
diff --git a/SP5WWP/m17-decoder/m17-decoder-sym.c b/SP5WWP/m17-decoder/m17-decoder-sym.c
index e021834..09dc513 100644
--- a/SP5WWP/m17-decoder/m17-decoder-sym.c
+++ b/SP5WWP/m17-decoder/m17-decoder-sym.c
@@ -121,15 +121,12 @@ int main(void)
                 //derandomize
                 for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
                 {
-                    if((rand_seq[i/8]>>(7-(i%8)))&1) //soft XOR. flip soft bit if "1"
-                        soft_bit[i]=0xFFFF-soft_bit[i];
+                    if((rand_seq[i/8]>>(7-(i%8)))&1) //soft NOT. flip soft bit if "1"
+                        soft_bit[i]=soft_bit_NOT(soft_bit[i]);
                 }
 
                 //deinterleave
-                for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
-                {
-                    d_soft_bit[i]=soft_bit[intrl_seq[i]];
-                }
+                reorder_soft_bits(d_soft_bit, soft_bit);
 
                 //if it is a frame
                 if(!fl)