Improve_RF_sensitivity_NOAA_signal (#2654)

firmware/application/apps/analog_audio_app.hpp

@@ -143,7 +143,7 @@ class WFMAMAptOptionsView : public View {
     };
     OptionsField options_config{
         {3 * 8, 0 * 16},
-        15,  // Max option char length "FM+AM(NOAA Apt)"
+        16,  // Max option char length "80khz (NOAA Apt)" example.
         {
             // Using common messages from freqman_ui.cpp
         }};

firmware/application/freqman_db.cpp

@@ -108,7 +108,8 @@ options_t freqman_bandwidths[6] = {
     },
     {
         // WFMAM for NOAA satellites,  137 Mhz band
-        {"FM+AM(NOAA Apt)", 1},  // Fixed RX demod- WFM config Index 1 : FM+AM  for Audio NOAA APT ones.
+        {"80kHz (NOAA Apt)", 0},  // Fixed RX demod- WFM config Index 1 : FM+AM  for Audio NOAA APT ones.
+        {"38kHz (NOAA Apt)", 1},
     },
 };
 

firmware/application/receiver_model.cpp

@@ -69,8 +69,9 @@ static constexpr std::array<baseband::WFMConfig, 3> wfm_configs{{
     {taps_40k_wfm_decim_0, taps_40k_wfm_decim_1},
 }};
 
-static constexpr std::array<baseband::WFMAMConfig, 1> wfmam_configs{{
+static constexpr std::array<baseband::WFMAMConfig, 2> wfmam_configs{{
-    {taps_16k0_decim_0, taps_84k_wfmam_decim_1},
+    {taps_16k0_decim_0, taps_80k_wfmam_decim_1},
+    {taps_16k0_decim_0, taps_38k_wfmam_decim_1},
 }};
 
 } /* namespace */

firmware/baseband/proc_noaaapt_rx.cpp

@@ -146,16 +146,16 @@ void NoaaAptRx::configure(const NoaaAptRxConfigureMessage& message) {
     // Temptatively , I splitted, in two WidebandFMAudio::configure_wfm / WidebandFMAudio::configure_wfmam  and dynamically /2, /8 . (here /8)
     // decim_1.set<dsp::decimate::FIRC16xR16x16Decim2>().configure(message.decim_1_filter.taps);  // for wfm
     // decim_1.set<dsp::decimate::FIRC16xR16x32Decim8>().configure(message.decim_1_filter.taps);    // for wfmam
-    decim_1.configure(taps_84k_wfmam_decim_1.taps);                           // for wfmam
+    decim_1.configure(taps_38k_wfmam_decim_1.taps);                           // for wfmam
     size_t decim_1_output_fs = decim_1_input_fs / decim_1.decimation_factor;  // wfmam,  decim_1.decimation_factor() = /8 ,if applied after the line, decim_1.set<dsp::decimate::FIRC16xR16x16Decim2>().configure(message.decim_1_filter.taps);
     size_t demod_input_fs = decim_1_output_fs;
 
     // spectrum_interval_samples = decim_1_output_fs / spectrum_rate_hz;
     // spectrum_samples = 0;
 
-    channel_filter_low_f = taps_84k_wfmam_decim_1.low_frequency_normalized * decim_1_input_fs;
+    channel_filter_low_f = taps_38k_wfmam_decim_1.low_frequency_normalized * decim_1_input_fs;
-    channel_filter_high_f = taps_84k_wfmam_decim_1.high_frequency_normalized * decim_1_input_fs;
+    channel_filter_high_f = taps_38k_wfmam_decim_1.high_frequency_normalized * decim_1_input_fs;
-    channel_filter_transition = taps_84k_wfmam_decim_1.transition_normalized * decim_1_input_fs;
+    channel_filter_transition = taps_38k_wfmam_decim_1.transition_normalized * decim_1_input_fs;
     demod.configure(demod_input_fs, 17000);
     audio_filter.configure(taps_64_lp_1875_2166.taps);
     audio_output.configure(apt_audio_12k_notch_2k4_config, apt_audio_12k_lpf_2000hz_config);

firmware/common/dsp_fir_taps.hpp

@@ -1327,44 +1327,88 @@ constexpr fir_taps_real<16> taps_40k_wfm_decim_1 = {
 
 // WFMAM decimation filters  ////////////////////////////////////////////////
 // Used for NOAA 137 Mhz APT sat demod.
-// IFIR prototype filter: fs=768000, pass=42000, stop=95000, decim=8, fout=96000
+// IFIR prototype filter: fs=768000, pass=40000, stop=95000, decim=8, fout=96000
-constexpr fir_taps_real<32> taps_84k_wfmam_decim_1 = {
+constexpr fir_taps_real<32> taps_80k_wfmam_decim_1 = {
-    .low_frequency_normalized = -42000.0f / 768000.0f,
+    .low_frequency_normalized = -40000.0f / 768000.0f,
-    .high_frequency_normalized = 42000.0f / 768000.0f,
+    .high_frequency_normalized = 40000.0f / 768000.0f,
     .transition_normalized = 53000.0f / 768000.0f,
     .taps = {{
-        13,
+        5,
-        -6,
+        -37,
-        -47,
+        -120,
-        -116,
+        -248,
-        -207,
+        -397,
-        -294,
+        -519,
-        -332,
+        -535,
-        -266,
+        -354,
-        -39,
+        106,
-        386,
+        896,
-        1012,
+        2006,
-        1795,
+        3355,
-        2648,
+        4797,
-        3452,
+        6136,
-        4079,
+        7171,
-        4423,
+        7736,
-        4423,
+        7736,
-        4079,
+        7171,
-        3452,
+        6136,
-        2648,
+        4797,
-        1795,
+        3355,
-        1012,
+        2006,
-        386,
+        896,
-        -39,
+        106,
-        -266,
+        -354,
-        -332,
+        -535,
-        -294,
+        -519,
-        -207,
+        -397,
-        -116,
+        -248,
-        -47,
+        -120,
-        -6,
+        -37,
-        13,
+        5,
+
+    }},
+};
+
+// WFMAM decimation filters  ////////////////////////////////////////////////
+// Used for NOAA 137 Mhz APT sat demod.
+// IFIR prototype filter: fs=768000, pass=19000, stop=68000, decim=8, fout=96000
+constexpr fir_taps_real<32> taps_38k_wfmam_decim_1 = {
+    .low_frequency_normalized = -19000.0f / 768000.0f,
+    .high_frequency_normalized = 19000.0f / 768000.0f,
+    .transition_normalized = 49000.0f / 768000.0f,
+    .taps = {{
+        49,
+        91,
+        175,
+        303,
+        483,
+        724,
+        1028,
+        1391,
+        1805,
+        2253,
+        2712,
+        3158,
+        3560,
+        3891,
+        4127,
+        4250,
+        4250,
+        4127,
+        3891,
+        3560,
+        3158,
+        2712,
+        2253,
+        1805,
+        1391,
+        1028,
+        724,
+        483,
+        303,
+        175,
+        91,
+        49,
     }},
 };