From b71926062d4c3fe8847f92add98242f79445ac01 Mon Sep 17 00:00:00 2001
From: Ahmet Inan <xdsopl@gmail.com>
Date: Tue, 1 Jul 2025 22:53:14 +0200
Subject: [PATCH] use 16 bit LLRs

---
 decode.cc | 11 ++---------
 psk.hh    |  6 ++++++
 qam.hh    |  8 ++++++++
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/decode.cc b/decode.cc
index f9b5e9b..18989dc 100644
--- a/decode.cc
+++ b/decode.cc
@@ -34,12 +34,8 @@ namespace DSP { using std::abs; using std::min; using std::cos; using std::sin;
 template <typename value, typename cmplx, int rate>
 struct Decoder
 {
-	typedef int8_t code_type;
-#ifdef __AVX2__
-	typedef SIMD<code_type, 32 / sizeof(code_type)> mesg_type;
-#else
-	typedef SIMD<code_type, 16 / sizeof(code_type)> mesg_type;
-#endif
+	typedef int16_t code_type;
+	typedef SIMD<code_type, 16> mesg_type;
 	typedef DSP::Const<value> Const;
 	static const int guard_len = rate / 100;
 	static const int symbol_len = guard_len * 16;
@@ -387,11 +383,8 @@ struct Decoder
 					np += norm(error);
 				}
 				value precision = sp / np;
-				// precision = 8;
 				value snr = DSP::decibel(precision);
 				std::cerr << " " << snr;
-				if (std::is_same<code_type, int8_t>::value && precision > 32)
-					precision = 32;
 				for (int i = 0; i < tone_count; ++i) {
 					if (i % block_length == poff)
 						continue;
diff --git a/psk.hh b/psk.hh
index f20e3bc..efaabbc 100644
--- a/psk.hh
+++ b/psk.hh
@@ -27,6 +27,8 @@ struct PhaseShiftKeying<2, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}
 
@@ -66,6 +68,8 @@ struct PhaseShiftKeying<4, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}
 
@@ -112,6 +116,8 @@ struct PhaseShiftKeying<8, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}
 
diff --git a/qam.hh b/qam.hh
index 7715e3e..4efbf9c 100644
--- a/qam.hh
+++ b/qam.hh
@@ -36,6 +36,8 @@ struct QuadratureAmplitudeModulation<16, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}
 
@@ -90,6 +92,8 @@ struct QuadratureAmplitudeModulation<64, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}
 
@@ -148,6 +152,8 @@ struct QuadratureAmplitudeModulation<256, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}
 
@@ -210,6 +216,8 @@ struct QuadratureAmplitudeModulation<1024, TYPE, CODE>
 			value = std::nearbyint(value);
 		if (std::is_same<code_type, int8_t>::value)
 			value = std::min<value_type>(std::max<value_type>(value, -127), 127);
+		if (std::is_same<code_type, int16_t>::value)
+			value = std::min<value_type>(std::max<value_type>(value, -32767), 32767);
 		return value;
 	}