From cf527a13f27e6f9dc5e48ce8936b2b5fd203a109 Mon Sep 17 00:00:00 2001
From: Albin Chaboissier <chalbin73@gmail.com>
Date: Thu, 2 Oct 2025 22:26:54 +0200
Subject: [PATCH] Radio test

---
 src/main.rs | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index e06bbc4..32b681b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -58,7 +58,7 @@ where
 {
     ((input - in_min.clone()) / (in_max - in_min)) * (out_max - out_min.clone()) + out_min
 }
-const BAUD_RATE: u32 = 1200;
+const BAUD_RATE: u32 = 1000;
 
 fn main() {
     modulate();
@@ -78,15 +78,15 @@ fn main() {
         .with_sample_rate(SampleRate(48000));
 
     // Channel to move samples from callback to main thread
-    let (tx, rx) = sync_channel::<f32>(1024);
+    let (tx, rx) = sync_channel::<f32>(4096);
 
     // Build input stream
     let stream = device
         .build_input_stream(
             &config.into(),
-            move |data: &[i16], _| {
+            move |data: &[f32], _| {
                 for x in data.iter() {
-                    let _ = tx.send(*x as f32 / i16::MAX as f32); // non-blocking send
+                    let _ = tx.send(*x * 10.); // non-blocking send
                 }
             },
             move |err| eprintln!("Stream error: {}", err),
@@ -115,7 +115,7 @@ fn main() {
         let samples = reader.samples::<i16>();
         for x in samples {
             let noise = rand.random::<f32>() * 2. - 1.;
-            let sample = x.unwrap() as f32 / i16::MAX as f32 + noise * 1.;
+            let sample = x.unwrap() as f32 / i16::MAX as f32 + noise * 0.9;
             let _ = tx.send(sample);
             writer
                 .write_sample((sample * i16::MAX as f32) as i16)
@@ -156,16 +156,19 @@ fn demodulator(
     // Corellators
     let mut nco_pos = Nco::new(hz_to_rad_per_sample(deviation, sample_rate as f32));
     let mut nco_neg = Nco::new(hz_to_rad_per_sample(-deviation, sample_rate as f32));
-    let corellator_pos = (0..sample_per_symbol)
-        .map(|_| {
+    let corellator_length = (sample_per_symbol as f32 * 1.5) as usize;
+    let corellator_pos = (0..corellator_length)
+        .map(|i| {
             nco_pos.step();
-            nco_pos.cexp()
+            nco_pos.cexp() * windows::blackmann(i as f32 / (corellator_length as f32))
+            //nco_pos.cexp()
         })
         .collect::<Vec<_>>();
-    let corellator_neg = (0..sample_per_symbol)
-        .map(|_| {
+    let corellator_neg = (0..corellator_length)
+        .map(|i| {
             nco_neg.step();
-            nco_neg.cexp()
+            nco_neg.cexp() * windows::blackmann(i as f32 / (corellator_length as f32))
+            //nco_neg.cexp()
         })
         .collect::<Vec<_>>();
     let mut matched_filter_pos = FIRFilter::new(&corellator_pos);
@@ -173,11 +176,11 @@ fn demodulator(
 
     let mut elg_buffer = VecDeque::new();
     let mut sps = sample_per_symbol as f32;
-    let delta = 0.3;
-    let loop_p = 0.1;
-    let loop_i = 0.3;
-    let mut loop_filter = FIRFilter::new(&[Complex32::new(1., 0.); 40]);
-    let mut matched_filter = FIRFilter::new(&[Complex32::new(1., 0.); 70]);
+    let delta = 0.5;
+    let loop_p = 0.8;
+    let loop_i = 0.2;
+    let mut loop_filter = FIRFilter::new(&[Complex32::new(1., 0.); 30]);
+    let mut matched_filter = FIRFilter::new(&[Complex32::new(1., 0.); 20]);
     let mut current_position = 0.;
     let mut next_sample = (sps as f32) / 2.;