Added tetra rx ext app (#3257)

firmware/application/external/external.cmake

@@ -380,6 +380,17 @@ set(EXTCPPSRC
   #signal_hunter
   external/signal_hunter/main.cpp
   external/signal_hunter/ui_signal_hunter.cpp
+
+
+	#tetra rx
+	external/tetra_rx/main.cpp
+	external/tetra_rx/ui_tetra_rx.cpp
+	external/tetra_rx/tetra_crc.cpp
+	external/tetra_rx/tetra_descrambler.cpp
+	external/tetra_rx/tetra_interleave.cpp
+	external/tetra_rx/tetra_rcpc.cpp
+	external/tetra_rx/tetra_viterbi.cpp
+
 )
 
 set(EXTAPPLIST
@@ -473,6 +484,7 @@ set(EXTAPPLIST
 	hard_reset
 	secplustx
   signal_hunter
+	tetra_rx
 )
 
 # sdusb has type conflicts with PRALINE (HackRF Pro) - add only for non-PRALINE builds

firmware/application/external/external.ld

@@ -114,6 +114,7 @@ MEMORY
     ram_external_app_vor_rx                (rwx) : org = 0xAE090000, len = 32k
     ram_external_app_vor_tx                (rwx) : org = 0xAE0A0000, len = 32k
     ram_external_app_signal_hunter         (rwx) : org = 0xAE0B0000, len = 32k
+    ram_external_app_tetra_rx              (rwx) : org = 0xAE0C0000, len = 32k
 }
 
 SECTIONS
@@ -663,4 +664,13 @@ SECTIONS
       KEEP(*(.external_app.app_signal_hunter.application_information));
       *(*ui*external_app*signal_hunter*);
     } > ram_external_app_signal_hunter
+
+    .external_app_tetra_rx : ALIGN(4) SUBALIGN(4)
+    {
+        KEEP(*(.external_app.app_tetra_rx.application_information));
+        *(*ui*external_app*tetra_rx*);
+    } > ram_external_app_tetra_rx
+
+
+
 }

firmware/application/external/tetra_rx/main.cpp

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2026 HTotoo
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "ui_tetra_rx.hpp"
+#include "ui_navigation.hpp"
+#include "external_app.hpp"
+
+namespace ui::external_app::tetra_rx {
+void initialize_app(ui::NavigationView& nav) {
+    nav.push<TetraRxView>();
+}
+}  // namespace ui::external_app::tetra_rx
+extern "C" {
+
+__attribute__((section(".external_app.app_tetra_rx.application_information"), used)) application_information_t _application_information_tetra_rx = {
+    /*.memory_location = */ (uint8_t*)0x00000000,
+    /*.externalAppEntry = */ ui::external_app::tetra_rx::initialize_app,
+    /*.header_version = */ CURRENT_HEADER_VERSION,
+    /*.app_version = */ VERSION_MD5,
+
+    /*.app_name = */ "Tetra",
+    /*.bitmap_data = */ {
+        0xE0,
+        0x0F,
+        0x18,
+        0x38,
+        0xE4,
+        0x67,
+        0x7E,
+        0xCE,
+        0xC7,
+        0xCC,
+        0x00,
+        0x00,
+        0xFF,
+        0x4F,
+        0xBA,
+        0xB2,
+        0x9A,
+        0xEE,
+        0xBA,
+        0xB2,
+        0x00,
+        0x00,
+        0x3B,
+        0xE3,
+        0x73,
+        0x7E,
+        0xC6,
+        0x27,
+        0x1C,
+        0x18,
+        0xF0,
+        0x07,
+    },
+    /*.icon_color = */ ui::Color::orange().v,
+    /*.menu_location = */ app_location_t::RX,
+    /*.desired_menu_position = */ -1,
+
+    /*.m4_app_tag = portapack::spi_flash::image_tag_tetrarx*/ {'P', 'T', 'E', 'T'},
+    /*.m4_app_offset = */ 0x00000000,  // will be filled at compile time
+};
+}

firmware/application/external/tetra_rx/tetra_bits.hpp

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+namespace ui::external_app::tetra_rx {
+
+class BitVector {
+   public:
+    BitVector(uint8_t* p, size_t bits)
+        : data_(p),
+          bits_(bits) {
+    }
+
+    inline bool get(size_t bit) const {
+        return (data_[bit >> 3] >>
+                (7 - (bit & 7))) &
+               1;
+    }
+
+    inline void set(size_t bit, bool value) {
+        if (value)
+            data_[bit >> 3] |=
+                1 << (7 - (bit & 7));
+        else
+            data_[bit >> 3] &=
+                ~(1 << (7 - (bit & 7)));
+    }
+
+    inline void xor_bit(size_t bit, bool value) {
+        if (value)
+            data_[bit >> 3] ^=
+                1 << (7 - (bit & 7));
+    }
+
+    inline size_t size() const {
+        return bits_;
+    }
+
+   private:
+    uint8_t* data_;
+    size_t bits_;
+};
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_crc.cpp

@@ -0,0 +1,33 @@
+#include "tetra_crc.hpp"
+
+namespace ui::external_app::tetra_rx {
+
+uint16_t CRC::crc16_itut_bits(
+    const uint8_t* bits,
+    uint32_t n_bits,
+    uint16_t init) {
+    uint16_t crc = init;
+
+    for (uint32_t i = 0; i < n_bits; i++) {
+        uint8_t bit =
+            (bits[i >> 3] >>
+             (7 - (i & 7))) &
+            1;
+
+        crc ^= uint16_t(bit) << 15;
+
+        if (crc & 0x8000) {
+            crc =
+                (crc << 1) ^
+                0x1021;
+        } else {
+            crc <<= 1;
+        }
+
+        crc &= 0xffff;
+    }
+
+    return crc;
+}
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_crc.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <stdint.h>
+
+namespace ui::external_app::tetra_rx {
+
+class CRC {
+   public:
+    static constexpr uint16_t CRC_OK = 0x1d0f;
+
+    static uint16_t crc16_itut_bits(
+        const uint8_t* bits,
+        uint32_t n_bits,
+        uint16_t init = 0xffff);
+};
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_descrambler.cpp

@@ -0,0 +1,60 @@
+#include "tetra_descrambler.hpp"
+
+namespace ui::external_app::tetra_rx {
+
+static inline uint8_t lfsr_step(uint32_t& s) {
+    uint8_t b = 0;
+
+    b ^= (s >> (32 - 32)) & 1;
+    b ^= (s >> (32 - 26)) & 1;
+    b ^= (s >> (32 - 23)) & 1;
+    b ^= (s >> (32 - 22)) & 1;
+    b ^= (s >> (32 - 16)) & 1;
+    b ^= (s >> (32 - 12)) & 1;
+    b ^= (s >> (32 - 11)) & 1;
+    b ^= (s >> (32 - 10)) & 1;
+    b ^= (s >> (32 - 8)) & 1;
+    b ^= (s >> (32 - 7)) & 1;
+    b ^= (s >> (32 - 5)) & 1;
+    b ^= (s >> (32 - 4)) & 1;
+    b ^= (s >> (32 - 2)) & 1;
+    b ^= (s >> (32 - 1)) & 1;
+
+    s = (s >> 1) | (uint32_t(b) << 31);
+
+    return b;
+}
+
+void Descrambler::generate(
+    uint32_t init,
+    uint8_t* seq,
+    size_t bits) {
+    uint32_t s = init;
+
+    for (size_t i = 0; i < bits; i++)
+        seq[i] = lfsr_step(s);
+}
+
+void Descrambler::descramble(
+    BitVector& bits,
+    uint32_t init) {
+    uint32_t s = init;
+
+    for (size_t i = 0; i < bits.size(); i++)
+        bits.xor_bit(i, lfsr_step(s));
+}
+
+uint32_t Descrambler::dmo_scramb_init(
+    uint32_t mni,
+    uint32_t src) {
+    uint32_t init =
+        (src & 0xFFFFFF) |
+        ((mni & 0x3F) << 24);
+
+    init <<= 2;
+    init |= 3;
+
+    return init;
+}
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_descrambler.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <stdint.h>
+#include "tetra_bits.hpp"
+
+namespace ui::external_app::tetra_rx {
+
+class Descrambler {
+   public:
+    static constexpr uint32_t SCRAMB_INIT_BSCH = 0x00000003;
+
+    static void descramble(
+        BitVector& bits,
+        uint32_t init = SCRAMB_INIT_BSCH);
+
+    static void generate(
+        uint32_t init,
+        uint8_t* sequence,
+        size_t bits);
+
+    static uint32_t dmo_scramb_init(
+        uint32_t mni,
+        uint32_t src);
+};
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_interleave.cpp

@@ -0,0 +1,21 @@
+#include "tetra_interleave.hpp"
+
+namespace ui::external_app::tetra_rx {
+
+void Interleave::block_deinterleave(
+    BitVector& in,
+    BitVector& out,
+    uint32_t K,
+    uint32_t a) {
+    for (uint32_t i = 1; i <= K; i++) {
+        uint32_t k =
+            1 +
+            ((a * i) % K);
+
+        out.set(
+            i - 1,
+            in.get(k - 1));
+    }
+}
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_interleave.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include "tetra_bits.hpp"
+
+namespace ui::external_app::tetra_rx {
+
+class Interleave {
+   public:
+    static void block_deinterleave(
+        BitVector& in,
+        BitVector& out,
+        uint32_t K,
+        uint32_t a);
+};
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_rcpc.cpp

@@ -0,0 +1,24 @@
+#include "tetra_rcpc.hpp"
+#include <string.h>
+
+namespace ui::external_app::tetra_rx {
+
+static constexpr uint8_t P_RATE_2_3[3] = {1, 2, 5};
+
+static constexpr uint32_t T_RATE_2_3 = 3;
+static constexpr uint32_t PERIOD = 8;
+
+void RCPC::depuncture_2_3(BitVector& in, uint8_t* out, uint32_t in_bits) {
+    const uint32_t mother_bits = ((in_bits + T_RATE_2_3 - 1) / T_RATE_2_3) * PERIOD + PERIOD;
+    memset(out, ERASED, mother_bits);
+    for (uint32_t j = 1; j <= in_bits; j++) {
+        uint32_t i = j;
+        uint32_t k = PERIOD * ((i - 1) / T_RATE_2_3);
+        k += P_RATE_2_3[(i - 1) % T_RATE_2_3];
+        if (k >= 1 && k <= mother_bits) {
+            out[k - 1] = in.get(j - 1);
+        }
+    }
+}
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_rcpc.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <stdint.h>
+#include "tetra_bits.hpp"
+
+namespace ui::external_app::tetra_rx {
+
+class RCPC {
+   public:
+    static constexpr uint8_t ERASED = 0xff;
+
+    static void depuncture_2_3(
+        BitVector& in,
+        uint8_t* out,
+        uint32_t in_bits);
+};
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_viterbi.cpp

@@ -0,0 +1,73 @@
+#include "tetra_viterbi.hpp"
+#include <string.h>
+
+namespace ui::external_app::tetra_rx {
+
+int Viterbi::decode_cch(
+    const uint8_t* mother,
+    uint32_t n_info,
+    uint8_t* bits,
+    uint8_t* trace_buffer) {  // Puffer by caller
+
+    // Store these on stack, to avoid flash space usage
+    const uint8_t next_state[16][2] = {
+        {0, 1}, {2, 3}, {4, 5}, {6, 7}, {8, 9}, {10, 11}, {12, 13}, {14, 15}, {0, 1}, {2, 3}, {4, 5}, {6, 7}, {8, 9}, {10, 11}, {12, 13}, {14, 15}};
+    const uint8_t next_output[16][2] = {
+        {0, 15}, {11, 4}, {6, 9}, {13, 2}, {5, 10}, {14, 1}, {3, 12}, {8, 7}, {15, 0}, {4, 11}, {9, 6}, {2, 13}, {10, 5}, {1, 14}, {12, 3}, {7, 8}};
+
+    const uint16_t INF = 0x3fff;
+    uint16_t cost[16];
+    uint16_t new_cost[16];
+
+    // Initialization
+    for (int i = 0; i < 16; i++) cost[i] = INF;
+    cost[0] = 0;
+
+    for (uint32_t step = 0; step < n_info; step++) {
+        for (int i = 0; i < 16; i++) new_cost[i] = INF;
+        const uint8_t* rx = &mother[step * 4];
+
+        for (int prev = 0; prev < 16; prev++) {
+            if (cost[prev] >= INF) continue;
+
+            for (int bit = 0; bit < 2; bit++) {
+                const uint8_t pattern = next_output[prev][bit];
+                const uint8_t next = next_state[prev][bit];
+
+                uint16_t d = 0;
+                for (int b = 0; b < 4; b++) {
+                    if (rx[b] != 0xff && rx[b] != ((pattern >> (3 - b)) & 1)) d++;
+                }
+
+                const uint16_t total = cost[prev] + d;
+                if (total < new_cost[next]) {
+                    new_cost[next] = total;
+                    trace_buffer[step * 16 + next] = (prev << 1) | bit;
+                }
+            }
+        }
+        memcpy(cost, new_cost, sizeof(cost));
+    }
+
+    // Traceback
+    uint8_t best_state = 0;
+    for (int i = 1; i < 16; i++) {
+        if (cost[i] < cost[best_state]) best_state = i;
+    }
+
+    uint8_t state = best_state;
+    memset(bits, 0, (n_info + 7) >> 3);
+
+    for (int step = (int)n_info - 1; step >= 0; step--) {
+        uint8_t packed = trace_buffer[step * 16 + state];
+        uint8_t prev = (packed >> 1) & 0x0F;
+        uint8_t bit = packed & 0x01;
+
+        if (bit) bits[step >> 3] |= (1 << (7 - (step & 7)));
+        state = prev;
+    }
+
+    return cost[best_state];
+}
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/tetra_viterbi.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <stdint.h>
+#include <string.h>
+
+namespace ui::external_app::tetra_rx {
+
+class Viterbi {
+   public:
+    int decode_cch(
+        const uint8_t* mother,
+        uint32_t n_info,
+        uint8_t* bits,
+        uint8_t* trace_buffer);
+};
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/ui_tetra_rx.cpp

@@ -0,0 +1,354 @@
+#include "ui_tetra_rx.hpp"
+#include "rtc_time.hpp"
+#include "baseband_api.hpp"
+#include "string_format.hpp"
+#include "portapack_persistent_memory.hpp"
+#include "file_path.hpp"
+#include "tetra_crc.hpp"
+#include "tetra_descrambler.hpp"
+#include "tetra_interleave.hpp"
+#include "tetra_rcpc.hpp"
+#include "tetra_viterbi.hpp"
+#include <cstring>
+
+using namespace portapack;
+using namespace ui;
+
+namespace ui::external_app::tetra_rx {
+
+template <size_t OutBytes>
+bool TetraChannelDecoder::decode_block(
+    const std::array<uint8_t, 63>& burst,
+    size_t offset,
+    size_t len_t5,
+    size_t type1_bits,
+    size_t type2_bits,
+    size_t interleave_a,
+    std::array<uint8_t, OutBytes>& out,
+    uint16_t& crc,
+    int& cost,
+    uint32_t scramb_init) {
+    std::array<uint8_t, 64> t5{};
+    std::array<uint8_t, 64> t3{};
+    std::array<uint8_t, 1200> mother{};
+    std::array<uint8_t, 64> type2{};
+
+    out.fill(0);
+
+    for (size_t i = 0; i < len_t5; i++) {
+        set_bit(t5, i, get_bit(burst, offset + i));
+    }
+
+    BitVector t5_bits{t5.data(), len_t5};
+    Descrambler::descramble(t5_bits, scramb_init);
+
+    BitVector t3_bits{t3.data(), len_t5};
+    Interleave::block_deinterleave(t5_bits, t3_bits, len_t5, interleave_a);
+
+    RCPC::depuncture_2_3(t3_bits, mother.data(), len_t5);
+    Viterbi viterbi;
+    cost = viterbi.decode_cch(mother.data(), type2_bits, type2.data(), trace_buffer);
+    crc = CRC::crc16_itut_bits(type2.data(), type1_bits + 16);
+    for (size_t i = 0; i < type1_bits; i++) {
+        set_bit(out, i, (type2[i >> 3] >> (7 - (i & 7))) & 1);
+    }
+    return crc == CRC::CRC_OK;
+}
+
+TetraChannelDecoder::Result TetraChannelDecoder::decode_dnb(const TetraDnbMessage& message) {
+    Result result{};
+    result.inverted = message.inverted;
+
+    if (!network_synced)
+        return result;
+
+    std::array<uint8_t, 63> buffer{};
+    std::copy(message.payload.begin(), message.payload.end(), buffer.begin());
+
+    uint32_t tmo_dnb_seed = (((uint32_t)last_mcc << 20) | ((uint32_t)last_mnc << 6) | (uint32_t)last_bcc) << 2 | 3;
+    // 1. DNB Full slot (SCH/F)
+    bool ok = decode_block(buffer, 0, SCH_F_LEN_BITS, SCH_F_TYPE1_BITS, SCH_F_TYPE2_BITS,
+                           SCH_F_INTERLEAVE_A, result.payload, result.crc, result.cost, tmo_dnb_seed);
+
+    // 2. SCH/HD Block 1
+    if (!ok) {
+        ok = decode_block(buffer, 0, BLK2_LEN_BITS, SB2_TYPE1_BITS, SB2_TYPE2_BITS,
+                          SB2_INTERLEAVE_A, result.payload, result.crc, result.cost, tmo_dnb_seed);
+    }
+
+    // 3. SCH/HD Block 2
+    if (!ok) {
+        ok = decode_block(buffer, 216, BLK2_LEN_BITS, SB2_TYPE1_BITS, SB2_TYPE2_BITS,
+                          SB2_INTERLEAVE_A, result.payload, result.crc, result.cost, tmo_dnb_seed);
+    }
+
+    if (ok) {
+        result.type = Result::Type::Dnb;
+        result.is_ok = true;
+        parse_mac_pdu(result);
+    }
+
+    return result;
+}
+
+TetraChannelDecoder::Result TetraChannelDecoder::decode_burst(const TetraBurstMessage& message) {
+    Result result{};
+    result.sync_errors = message.sync_errors;
+    result.inverted = message.inverted;
+
+    // 1. SCH/S
+    bool ok = decode_block(
+        message.payload, BLK1_OFFSET_BITS, BLK1_LEN_BITS,
+        SB1_TYPE1_BITS, SB1_TYPE2_BITS, SB1_INTERLEAVE_A,
+        result.payload, result.crc, result.cost,
+        Descrambler::SCRAMB_INIT_BSCH);
+
+    if (!ok) return result;
+
+    result.type = Result::Type::Sync;
+    result.is_ok = true;
+    parse_sync_pdu(result);
+
+    uint16_t current_mcc = result.mcc;
+    uint16_t current_mnc = result.mnc;
+    uint8_t current_bcc = result.bcc;
+    uint8_t current_enc = result.encryption;
+
+    // 2. SCH/H
+    uint16_t h_crc = 0;
+    int h_cost = 0;
+
+    ok = decode_block(
+        message.payload, TMO_BLK2_OFFSET_BITS, BLK2_LEN_BITS,
+        SB2_TYPE1_BITS, SB2_TYPE2_BITS, SB2_INTERLEAVE_A,
+        result.payload, h_crc, h_cost,
+        Descrambler::SCRAMB_INIT_BSCH);
+
+    if (ok) {
+        result.type = Result::Type::SyncFull;
+        result.crc = h_crc;
+        result.cost = h_cost;
+
+        result.mcc = current_mcc;
+        result.mnc = current_mnc;
+        result.bcc = current_bcc;
+        result.encryption = current_enc;
+
+        parse_mac_pdu(result);
+    } else {
+        result.encryption = current_enc;
+    }
+
+    return result;
+}
+
+uint32_t TetraChannelDecoder::read_bits(const uint8_t* bytes, size_t bit, size_t count) const {
+    uint32_t value = 0;
+    for (size_t i = 0; i < count; i++) {
+        value <<= 1;
+        value |= (bytes[(bit + i) >> 3] >> (7 - ((bit + i) & 7))) & 1;
+    }
+    return value;
+}
+
+void TetraChannelDecoder::parse_sync_pdu(Result& result) {
+    // Sys 4 bit, then BCC
+    result.bcc = read_bits(result.payload.data(), 4, 6);
+    result.timeslot = read_bits(result.payload.data(), 10, 2);
+    result.frame_number = read_bits(result.payload.data(), 12, 5);
+    result.encryption = read_bits(result.payload.data(), 30, 1);
+    result.mcc = read_bits(result.payload.data(), 31, 10);
+    result.mnc = read_bits(result.payload.data(), 41, 14);
+
+    last_mcc = result.mcc;
+    last_mnc = result.mnc;
+    last_bcc = result.bcc;
+    network_synced = true;
+}
+
+void TetraChannelDecoder::parse_mac_pdu(Result& result) {
+    result.pdu_type = read_bits(result.payload.data(), 0, 2);
+
+    if (result.pdu_type == 0) {  // MAC-RESOURCE
+        result.encryption = read_bits(result.payload.data(), 4, 2);
+        uint8_t length_ind = read_bits(result.payload.data(), 7, 6);
+
+        if (result.encryption == 0 && length_ind > 0 && length_ind < 62) {
+            size_t offset = 13;
+            uint8_t addr_type = read_bits(result.payload.data(), offset, 3);
+            offset += 3;
+
+            if (addr_type == 1) {
+                result.calling_ssi = read_bits(result.payload.data(), offset, 24);
+                offset += 24;
+            } else if (addr_type == 2) {
+                offset += 10;
+            } else if (addr_type == 3 || addr_type == 4) {
+                result.calling_ssi = read_bits(result.payload.data(), offset, 24);
+                offset += 24;
+            } else if (addr_type == 5) {
+                offset += 34;
+            } else if (addr_type == 6) {
+                offset += 30;
+            } else if (addr_type == 7) {
+                offset += 34;
+            }
+
+            // skip optional fields
+            if (read_bits(result.payload.data(), offset++, 1)) offset += 4;  // Power control
+            if (read_bits(result.payload.data(), offset++, 1)) offset += 8;  // Slot grant
+
+            uint8_t chan_alloc = read_bits(result.payload.data(), offset++, 1);
+
+            if (chan_alloc == 0) {
+                uint8_t llc_type = read_bits(result.payload.data(), offset, 4);
+                offset += 4;
+
+                // LLC header skipped
+                if (llc_type == 0 || llc_type == 1)
+                    offset += 2;
+                else if (llc_type == 2 || llc_type == 3 || llc_type == 6 || llc_type == 7)
+                    offset += 1;
+
+                uint8_t mle_type = read_bits(result.payload.data(), offset, 3);
+                offset += 3;
+
+                // 1 = CMCE
+                if (mle_type == 1) {
+                    result.cmce_type = read_bits(result.payload.data(), offset, 5);
+                    offset += 5;
+                    result.call_id = read_bits(result.payload.data(), offset, 14);
+                }
+            }
+        }
+    } else if (result.pdu_type == 2) {  // SYSINFO/BCAST
+        uint8_t bcast_type = read_bits(result.payload.data(), 2, 2);
+        if (bcast_type == 0) {
+            result.la = read_bits(result.payload.data(), 82, 14);
+            result.encryption = read_bits(result.payload.data(), 122, 1);
+        }
+    }
+}
+
+TetraRxView::TetraRxView(NavigationView& nav)
+    : nav_{nav} {
+    baseband::run_prepared_image(portapack::memory::map::m4_code.base());
+
+    add_children({&rssi, &channel, &field_rf_amp, &field_lna, &field_vga,
+                  &field_frequency, &text_mcc, &text_la, &text_pdu,
+                  &text_mnc, &text_ts, &text_fn, &text_bcc, &text_enc, &text_debug, &console});
+
+    field_frequency.set_step(25000);
+
+    receiver_model.set_modulation(ReceiverModel::Mode::NarrowbandFMAudio);
+    receiver_model.set_sampling_rate(3072000);
+    receiver_model.set_baseband_bandwidth(1750000);
+    receiver_model.set_squelch_level(0);
+    receiver_model.enable();
+}
+
+void TetraRxView::focus() {
+    field_frequency.focus();
+}
+
+void TetraRxView::on_data_tetra(const TetraBurstMessage& message) {
+    packet_count++;
+    auto result = decoder.decode_burst(message);
+
+    if (result.type == TetraChannelDecoder::Result::Type::Sync ||
+        result.type == TetraChannelDecoder::Result::Type::SyncFull) {
+        valid_count++;
+
+        text_mcc.set("MCC: " + to_string_dec_uint(result.mcc));
+        text_mnc.set("MNC: " + to_string_dec_uint(result.mnc));
+        text_bcc.set("BCC: " + to_string_dec_uint(result.bcc));
+        text_ts.set("TS:  " + to_string_dec_uint(result.timeslot));
+        text_fn.set("FN:  " + to_string_dec_uint(result.frame_number));
+
+        std::string enc_str = (result.encryption != 0) ? "Encrypted" : "Clear";
+        text_enc.set("ENC: " + enc_str);
+
+        if (result.type == TetraChannelDecoder::Result::Type::SyncFull) {
+            h_valid_count++;
+            if (result.la != 0xffff) text_la.set("LA:  " + to_string_dec_uint(result.la));
+            text_pdu.set("PDU: " + decoder.get_pdu_name(result.pdu_type));
+        }
+    }
+    text_debug.set(
+        "Syn: " + to_string_dec_uint(packet_count) +
+        ", V: " + to_string_dec_uint(valid_count) +
+        ", H: " + to_string_dec_uint(h_valid_count) +
+        ", E:" + to_string_dec_uint(result.sync_errors));
+}
+
+void TetraRxView::on_data_dnb(const TetraDnbMessage& message) {
+    dnb_count++;
+    auto result = decoder.decode_dnb(message);
+
+    if (result.is_ok && result.type == TetraChannelDecoder::Result::Type::Dnb) {
+        if (result.la != 0xffff) text_la.set("LA:  " + to_string_dec_uint(result.la));
+        text_pdu.set("PDU: " + decoder.get_pdu_name(result.pdu_type));
+
+        std::string enc_str = (result.encryption != 0) ? "Encrypted" : "Clear";
+        text_enc.set("ENC: " + enc_str);
+
+        // if (rate_limiter++ < 2) console.writeln("DNB: " + decoder.get_pdu_name(result.pdu_type));
+        if (result.cmce_type != 0xff) {
+            std::string msg = "";
+            if (result.cmce_type == 7)
+                msg = "SETUP";
+            else if (result.cmce_type == 1)
+                msg = "CALL PROCEEDING";
+            else if (result.cmce_type == 0)
+                msg = "ALERTING";
+            else if (result.cmce_type == 2)
+                msg = "CONNECT";
+            else if (result.cmce_type == 3)
+                msg = "CONNECT ACK";
+            else if (result.cmce_type == 11)
+                msg = "TX GRANTED";
+            else if (result.cmce_type == 9)
+                msg = "TX CEASED";
+            else if (result.cmce_type == 13)
+                msg = "TX WAIT";
+            else if (result.cmce_type == 10)
+                msg = "TX CONTINUE";
+            else if (result.cmce_type == 12)
+                msg = "TX INTERRUPT";
+            else if (result.cmce_type == 4)
+                msg = "DISCONNECT";
+            else if (result.cmce_type == 6)
+                msg = "RELEASE";
+            else if (result.cmce_type == 5)
+                msg = "INFO";
+            else if (result.cmce_type == 8)
+                msg = "STATUS";
+            else if (result.cmce_type == 14)
+                msg = "SDS DATA";
+            else if (result.cmce_type == 15)
+                msg = "FACILITY";
+            else if (result.cmce_type == 16)
+                msg = "CALL RESTORE";
+            else if (result.cmce_type == 31)
+                msg = "NOT SUPPORTED";
+            else
+                msg = "CMCE:" + to_string_dec_uint(result.cmce_type);
+
+            console.writeln(msg);
+            if (result.call_id != 0xffff) {
+                console.writeln("ID:" + to_string_dec_uint(result.call_id) + " | SSI:" + to_string_dec_uint(result.calling_ssi));
+            }
+        }
+    }
+}
+
+void TetraRxView::on_timer() {
+    rate_limiter = 0;
+}
+
+TetraRxView::~TetraRxView() {
+    receiver_model.disable();
+    baseband::shutdown();
+}
+
+}  // namespace ui::external_app::tetra_rx

firmware/application/external/tetra_rx/ui_tetra_rx.hpp

@@ -0,0 +1,192 @@
+#ifndef __UI_TETRA_RX_H__
+#define __UI_TETRA_RX_H__
+
+#include "ui.hpp"
+#include "ui_language.hpp"
+#include "ui_navigation.hpp"
+#include "ui_receiver.hpp"
+#include "ui_freq_field.hpp"
+#include "app_settings.hpp"
+#include "radio_state.hpp"
+#include "log_file.hpp"
+#include "utility.hpp"
+#include "message.hpp"
+#include <array>
+#include <string>
+
+using namespace ui;
+
+namespace ui::external_app::tetra_rx {
+
+class TetraChannelDecoder {
+   public:
+    struct Result {
+        enum class Type { None,
+                          Sync,
+                          SyncFull,
+                          Dnb };
+        Type type{Type::None};
+
+        bool is_ok{false};
+        uint8_t sync_errors{0};
+        bool inverted{false};
+
+        uint16_t crc{0};
+        int cost{0};
+
+        uint8_t timeslot{0xff};
+        uint8_t frame_number{0xff};
+        uint16_t mcc{0xffff};
+        uint16_t mnc{0xffff};
+        uint8_t bcc{0xff};
+
+        uint8_t pdu_type{0xff};
+        uint16_t la{0xffff};
+        uint8_t encryption{0xff};
+
+        uint8_t cmce_type{0xff};
+        uint16_t call_id{0xffff};
+        uint32_t calling_ssi{0};
+
+        std::array<uint8_t, 34> payload{};
+    };
+
+    std::string get_pdu_name(uint8_t pdu_type) {
+        switch (pdu_type) {
+            case 0:
+                return "MAC-RESOURCE";
+            case 1:
+                return "MAC-FRAG";
+            case 2:
+                return "SYSINFO/BCAST";
+            case 3:
+                return "MAC-U-SIGNAL";
+            default:
+                return "UNK_" + std::to_string(pdu_type);
+        }
+    }
+
+    Result decode_burst(const TetraBurstMessage& message);
+    Result decode_dnb(const TetraDnbMessage& message);
+
+   private:
+    static constexpr size_t BLK1_OFFSET_BITS = 94;
+    static constexpr size_t BLK1_LEN_BITS = 120;
+    static constexpr size_t TMO_BLK2_OFFSET_BITS = 282;
+    static constexpr size_t BLK2_LEN_BITS = 216;
+    static constexpr size_t SB1_TYPE1_BITS = 60;
+    static constexpr size_t SB1_TYPE2_BITS = 80;
+    static constexpr size_t SB1_INTERLEAVE_A = 11;
+    static constexpr size_t SB2_TYPE1_BITS = 124;
+    static constexpr size_t SB2_TYPE2_BITS = 144;
+    static constexpr size_t SB2_INTERLEAVE_A = 101;
+
+    static constexpr size_t SCH_F_LEN_BITS = 432;
+    static constexpr size_t SCH_F_TYPE1_BITS = 268;
+    static constexpr size_t SCH_F_TYPE2_BITS = 288;
+    static constexpr size_t SCH_F_INTERLEAVE_A = 103;
+
+    uint16_t last_mcc{0};
+    uint16_t last_mnc{0};
+    uint8_t last_bcc{0};
+    bool network_synced{false};
+
+    // Viterbi buffer
+    uint8_t trace_buffer[9216];
+
+    template <size_t OutBytes>
+    bool decode_block(const std::array<uint8_t, 63>& burst,
+                      size_t offset,
+                      size_t len_t5,
+                      size_t type1_bits,
+                      size_t type2_bits,
+                      size_t interleave_a,
+                      std::array<uint8_t, OutBytes>& out,
+                      uint16_t& crc,
+                      int& cost,
+                      uint32_t scramb_init);
+
+    void parse_sync_pdu(Result& result);
+    void parse_mac_pdu(Result& result);
+    uint32_t read_bits(const uint8_t* bytes, size_t bit, size_t count) const;
+
+    template <size_t N>
+    uint8_t get_bit(const std::array<uint8_t, N>& arr, size_t bit_idx) const {
+        return (arr[bit_idx / 8] >> (7 - (bit_idx % 8))) & 0x01;
+    }
+
+    template <size_t N>
+    void set_bit(std::array<uint8_t, N>& arr, size_t bit_idx, uint8_t val) const {
+        if (val)
+            arr[bit_idx / 8] |= (1 << (7 - (bit_idx % 8)));
+        else
+            arr[bit_idx / 8] &= ~(1 << (7 - (bit_idx % 8)));
+    }
+};
+
+class TetraRxView : public View {
+   public:
+    TetraRxView(NavigationView& nav);
+    ~TetraRxView();
+    void focus() override;
+    std::string title() const override { return "Tetra RX"; };
+
+   private:
+    NavigationView& nav_;
+    RxRadioState radio_state_{};
+    app_settings::SettingsManager settings_{"rx_tetra", app_settings::Mode::RX};
+
+    uint32_t packet_count{0};
+    uint32_t valid_count{0};
+    uint32_t h_valid_count{0};
+    uint32_t dnb_count{0};
+
+    RxFrequencyField field_frequency{{UI_POS_X(0), UI_POS_Y(0)}, nav_};
+    RFAmpField field_rf_amp{{UI_POS_X(13), UI_POS_Y(0)}};
+    LNAGainField field_lna{{UI_POS_X(15), UI_POS_Y(0)}};
+    VGAGainField field_vga{{UI_POS_X(18), UI_POS_Y(0)}};
+    RSSI rssi{{UI_POS_X_RIGHT(9), UI_POS_Y(0), UI_POS_WIDTH(9), 4}};
+    Channel channel{{UI_POS_X_RIGHT(9), UI_POS_Y(0) + 5, UI_POS_WIDTH(9), 4}};
+
+    Text text_mcc{{UI_POS_X(0), UI_POS_Y(1), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "MCC: ---"};
+    Text text_mnc{{UI_POS_X(15), UI_POS_Y(1), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "MNC: ---"};
+    Text text_ts{{UI_POS_X(0), UI_POS_Y(2), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "TS:  -"};       // time slot
+    Text text_fn{{UI_POS_X(15), UI_POS_Y(2), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "FN:  -"};      // frame number
+    Text text_bcc{{UI_POS_X(0), UI_POS_Y(3), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "BCC: -"};      // Base Station Color Code
+    Text text_enc{{UI_POS_X(15), UI_POS_Y(3), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "ENC: -"};     // encoded or not
+    Text text_la{{UI_POS_X(0), UI_POS_Y(4), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "LA:  ----"};    // Location Area
+    Text text_pdu{{UI_POS_X(15), UI_POS_Y(4), UI_POS_WIDTH(15), UI_POS_HEIGHT(1)}, "PDU: ----"};  // pdu content type
+
+    Text text_debug{{UI_POS_X(0), UI_POS_Y(5), UI_POS_MAXWIDTH, UI_POS_HEIGHT(1)}, "Syn: 0, V: 0, H: 0, E:0"};  // sync, valid, h_valid, errors corrected in top part
+    Console console{{UI_POS_X(0), UI_POS_Y(6) + 8, UI_POS_MAXWIDTH, screen_height - (UI_POS_Y(7) + 8)}};
+
+    TetraChannelDecoder decoder{};
+
+    void on_data_tetra(const TetraBurstMessage&);
+    void on_data_dnb(const TetraDnbMessage&);
+
+    uint8_t rate_limiter{0};  // limiter, to keep the device responsive
+    void on_timer();
+
+    MessageHandlerRegistration message_handler_frame_sync{
+        Message::ID::DisplayFrameSync,
+        [this](const Message* const) {
+            this->on_timer();
+        }};
+
+    MessageHandlerRegistration message_handler_packet{
+        Message::ID::TetraBsch,
+        [this](Message* const p) {
+            this->on_data_tetra(*static_cast<const TetraBurstMessage*>(p));
+        }};
+
+    MessageHandlerRegistration message_handler_dnb{
+        Message::ID::TetraDnb,
+        [this](Message* const p) {
+            this->on_data_dnb(*static_cast<const TetraDnbMessage*>(p));
+        }};
+};
+
+}  // namespace ui::external_app::tetra_rx
+
+#endif

firmware/baseband/CMakeLists.txt

@@ -785,6 +785,15 @@ set(MODE_CPPSRC
 )
 DeclareTargets(PTSK time_sink)
 
+
+### Tetra Rx
+
+set(MODE_CPPSRC
+	proc_tetra.cpp
+)
+DeclareTargets(PTET tetra_rx)
+
+
 set(MODE_CPPSRC
 	sd_over_usb/proc_sd_over_usb.cpp
 

firmware/baseband/proc_tetra.cpp

@@ -0,0 +1,239 @@
+#include "proc_tetra.hpp"
+#include "portapack_shared_memory.hpp"
+#include "sine_table_int8.hpp"
+#include "event_m4.hpp"
+
+#include <algorithm>
+
+TetraProcessor::TetraProcessor() {
+    decim_0.configure(taps_25k0_tetra_decim_0.taps);
+    decim_1.configure(taps_25k0_tetra_decim_1.taps);
+
+    baseband_thread.start();
+    configured = true;
+}
+
+void TetraProcessor::execute(const buffer_c8_t& buffer) {
+    if (!configured) return;
+
+    const auto decim_0_out = decim_0.execute(buffer, dst_buffer_0);
+    const auto channel_out = decim_1.execute(decim_0_out, dst_buffer_1);
+
+    feed_channel_stats(channel_out);
+
+    for (size_t i = 0; i < channel_out.count; i++) {
+        complex16_t sample = channel_out.p[i];
+
+        // Carrier PLL Rotation
+        uint8_t phase_idx = (pll_phase >> 24) & 0xFF;
+        uint8_t cos_idx = (phase_idx + 64) & 0xFF;
+        int16_t rotated_real = (sample.real() * sine_table_i8[cos_idx] - sample.imag() * sine_table_i8[phase_idx]) >> 7;
+        int16_t rotated_imag = (sample.real() * sine_table_i8[phase_idx] + sample.imag() * sine_table_i8[cos_idx]) >> 7;
+        complex16_t rotated_sample = {rotated_real, rotated_imag};
+
+        uint32_t old_phase = symbol_phase;
+        symbol_phase += symbol_phase_inc;
+
+        // Half-symbol timing
+        if ((old_phase < 0x80000000) && (symbol_phase >= 0x80000000)) {
+            mid_sample = rotated_sample;
+        }
+
+        // Full-symbol timing
+        if (symbol_phase < old_phase) {
+            prev_prompt = prompt_sample;
+            prompt_sample = rotated_sample;
+
+            // Gardner Timing Error Detector
+            int32_t err_i = (mid_sample.real() * (prompt_sample.real() - prev_prompt.real()));
+            int32_t err_q = (mid_sample.imag() * (prompt_sample.imag() - prev_prompt.imag()));
+            int32_t timing_error = err_i + err_q;
+
+            const int64_t delta = (timing_error >> 16);
+            int64_t inc = static_cast<int64_t>(symbol_phase_inc) + delta;
+            // CLAMPING: Prevent the NCO from drifting into the noise!
+            if (inc < 1600000000) inc = 1600000000;
+            if (inc > 1620000000) inc = 1620000000;
+            symbol_phase_inc = static_cast<uint32_t>(inc);
+
+            process_symbol(prompt_sample);
+        }
+    }
+}
+
+void TetraProcessor::process_symbol(const complex16_t& current_sample) {
+    // Differential phase demodulation
+    int32_t dot_i = (current_sample.real() * delay_sample.real()) + (current_sample.imag() * delay_sample.imag());
+    int32_t dot_q = (current_sample.imag() * delay_sample.real()) - (current_sample.real() * delay_sample.imag());
+    delay_sample = current_sample;
+
+    // Phase error for Carrier PLL
+    int32_t phase_err = 0;
+    if (dot_i > 0 && dot_q > 0)
+        phase_err = dot_q - dot_i;
+    else if (dot_i < 0 && dot_q > 0)
+        phase_err = dot_q + dot_i;
+    else if (dot_i < 0 && dot_q < 0)
+        phase_err = -dot_q + dot_i;
+    else
+        phase_err = -dot_q - dot_i;
+
+    pll_freq += (phase_err * pll_beta) >> 8;
+
+    // CLAMPING: Prevent frequency tracking from flying away
+    if (pll_freq > 400000000) pll_freq = 400000000;
+    if (pll_freq < -400000000) pll_freq = -400000000;
+
+    pll_phase += ((phase_err * pll_alpha) >> 8) + pll_freq;
+
+    // ETSI EN 300 392-2 pi/4 DQPSK bit mapping
+    uint8_t dibit = 0;
+    if (dot_i > 0 && dot_q > 0)
+        dibit = 0b00;
+    else if (dot_i < 0 && dot_q > 0)
+        dibit = 0b01;
+    else if (dot_i < 0 && dot_q < 0)
+        dibit = 0b11;
+    else
+        dibit = 0b10;
+
+    // Insert bits into history buffer and sync register
+    for (int b = 1; b >= 0; b--) {
+        uint8_t bit_val = (dibit >> b) & 0x01;
+
+        size_t byte_idx = (history_write_idx / 8) % 128;
+        if ((history_write_idx % 8) == 0) bit_history_buffer[byte_idx] = 0;
+
+        bit_history_buffer[byte_idx] |= (bit_val << (7 - (history_write_idx % 8)));
+        history_write_idx = (history_write_idx + 1) % 1024;
+        bit_count++;
+
+        sync_register = ((sync_register << 1) | bit_val);
+
+        uint64_t sync =
+            sync_register & 0x3FFFFFFFFFULL;
+
+        uint32_t err_pos =
+            __builtin_popcountll(sync ^ Y_SYNC);
+
+        uint32_t err_neg =
+            __builtin_popcountll(
+                sync ^
+                (~Y_SYNC & 0x3FFFFFFFFFULL));
+
+        if (!pending_dsb.valid && bit_count >= Y_SYNC_BITS && (err_pos <= 4 || err_neg <= 4)) {
+            const uint64_t sync_start = bit_count - Y_SYNC_BITS;
+
+            if (sync_start >= SYNC_OFFSET) {
+                pending_dsb.valid = true;
+                pending_dsb.burst_start = sync_start - SYNC_OFFSET;
+                pending_dsb.ready_at = pending_dsb.burst_start + BURST_BITS;
+                pending_dsb.inverted = err_neg < err_pos;
+                pending_dsb.errors = std::min(err_pos, err_neg);
+            }
+        }
+
+        if (ENABLE_DNB_MESSAGES) {
+            const uint32_t train_mask = (1UL << DNB_TRAIN_BITS) - 1;
+            const uint32_t train = sync_register & train_mask;
+            const uint32_t n_err_pos = __builtin_popcount(train ^ N_SYNC);
+            const uint32_t n_err_neg = __builtin_popcount(train ^ (~N_SYNC & train_mask));
+            const uint32_t p_err_pos = __builtin_popcount(train ^ P_SYNC);
+            const uint32_t p_err_neg = __builtin_popcount(train ^ (~P_SYNC & train_mask));
+
+            if (!pending_dnb.valid && bit_count >= DNB_TRAIN_BITS && (n_err_pos <= 1 || n_err_neg <= 1 || p_err_pos <= 1 || p_err_neg <= 1)) {
+                const bool p_train = std::min(p_err_pos, p_err_neg) < std::min(n_err_pos, n_err_neg);
+                const uint32_t pos_err = p_train ? p_err_pos : n_err_pos;
+                const uint32_t neg_err = p_train ? p_err_neg : n_err_neg;
+
+                const uint64_t train_start = bit_count - DNB_TRAIN_BITS;
+                const uint64_t block1_start = train_start - 230;
+                const uint64_t block2_start = train_start + 38;
+
+                if (train_start >= 230) {
+                    pending_dnb.valid = true;
+                    pending_dnb.block1_start = block1_start;
+                    pending_dnb.block2_start = block2_start;
+                    pending_dnb.ready_at = block2_start + DNB_BLK_BITS;
+                    pending_dnb.inverted = neg_err < pos_err;
+                    pending_dnb.p_train = p_train;
+                    pending_dnb.errors = std::min(pos_err, neg_err);
+                }
+            }
+
+            if (pending_dnb.valid && bit_count >= pending_dnb.ready_at)
+                push_dnb_to_ui();
+        }
+
+        if (pending_dsb.valid && bit_count >= pending_dsb.ready_at)
+            push_burst_to_ui();
+    }
+}
+
+uint8_t TetraProcessor::history_bit(uint64_t absolute_bit) const {
+    const size_t p = absolute_bit % 1024;
+
+    return (bit_history_buffer[p >> 3] >>
+            (7 - (p & 7))) &
+           1;
+}
+
+void TetraProcessor::push_burst_to_ui() {
+    std::array<uint8_t, 63> burst{};
+
+    for (size_t i = 0; i < BURST_BITS; i++) {
+        uint8_t b = history_bit(pending_dsb.burst_start + i);
+
+        if (pending_dsb.inverted)
+            b ^= 1;
+
+        burst[i >> 3] |=
+            b << (7 - (i & 7));
+    }
+
+    shared_memory.application_queue.push(
+        TetraBurstMessage(
+            burst.data(),
+            pending_dsb.inverted,
+            pending_dsb.errors));
+
+    pending_dsb.valid = false;
+}
+
+void TetraProcessor::push_dnb_to_ui() {
+    std::array<uint8_t, 54> burst{};
+
+    for (size_t i = 0; i < DNB_BLK_BITS; i++) {
+        uint8_t b = history_bit(pending_dnb.block1_start + i);
+        if (pending_dnb.inverted)
+            b ^= 1;
+        burst[i >> 3] |= b << (7 - (i & 7));
+    }
+
+    for (size_t i = 0; i < DNB_BLK_BITS; i++) {
+        uint8_t b = history_bit(pending_dnb.block2_start + i);
+        if (pending_dnb.inverted)
+            b ^= 1;
+        const size_t out_bit = DNB_BLK_BITS + i;
+        burst[out_bit >> 3] |= b << (7 - (out_bit & 7));
+    }
+
+    shared_memory.application_queue.push(
+        TetraDnbMessage(
+            burst.data(),
+            pending_dnb.inverted,
+            pending_dnb.errors,
+            pending_dnb.p_train));
+
+    pending_dnb.valid = false;
+}
+
+void TetraProcessor::on_message(const Message* const msg) {
+    (void)msg;
+}
+
+int main() {
+    EventDispatcher event_dispatcher{std::make_unique<TetraProcessor>()};
+    event_dispatcher.run();
+    return 0;
+}

firmware/baseband/proc_tetra.hpp

@@ -0,0 +1,94 @@
+#ifndef __PROC_TETRA_H__
+#define __PROC_TETRA_H__
+
+#include "baseband_processor.hpp"
+#include "baseband_thread.hpp"
+#include "message.hpp"
+#include "dsp_decimate.hpp"
+#include "dsp_fir_taps.hpp"
+#include "rssi_thread.hpp"
+
+#include <cstdint>
+#include <array>
+#include <memory>
+
+class TetraProcessor : public BasebandProcessor {
+   public:
+    TetraProcessor();
+
+    void execute(const buffer_c8_t& buffer) override;
+    void on_message(const Message* const msg);
+
+   private:
+    static constexpr size_t baseband_fs = 3072000;
+    static constexpr size_t channel_fs = 48000;
+    static constexpr uint32_t symbol_rate = 18000;
+
+    std::array<complex16_t, 512> dst_0{};
+    const buffer_c16_t dst_buffer_0{dst_0.data(), dst_0.size()};
+
+    std::array<complex16_t, 512> dst_1{};
+    const buffer_c16_t dst_buffer_1{dst_1.data(), dst_1.size()};
+
+    dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0{};
+    dsp::decimate::FIRC16xR16x32Decim8 decim_1{};
+
+    // PLL and Timing
+    uint32_t symbol_phase{0};
+    uint32_t symbol_phase_inc{(uint32_t)((symbol_rate * 4294967296.0) / channel_fs)};
+
+    complex16_t prompt_sample{0, 0};
+    complex16_t prev_prompt{0, 0};
+    complex16_t mid_sample{0, 0};
+    complex16_t delay_sample{0, 0};
+    static constexpr uint32_t BURST_BITS = 500;
+    static constexpr uint32_t Y_SYNC_BITS = 38;
+    static constexpr uint32_t SYNC_OFFSET = 214;
+    static constexpr uint64_t Y_SYNC = 0x30673A7067ULL;
+    static constexpr uint32_t DNB_TRAIN_BITS = 22;
+    static constexpr uint32_t DNB_BLK_BITS = 216;
+    static constexpr uint32_t DNB_TRAIN_TO_BLK2 = 22;
+    static constexpr uint32_t DNB_TOTAL_T5_BITS = DNB_BLK_BITS * 2;
+    static constexpr uint32_t N_SYNC = 0x343A74UL;
+    static constexpr uint32_t P_SYNC = 0x1E90DEUL;
+    static constexpr bool ENABLE_DNB_MESSAGES = true;
+
+    uint32_t pll_phase{0};
+    int32_t pll_freq{0};
+    static constexpr int32_t pll_alpha = 150;
+    static constexpr int32_t pll_beta = 2;
+
+    uint64_t sync_register{0};
+    std::array<uint8_t, 128> bit_history_buffer{};
+    size_t history_write_idx{0};
+    uint64_t bit_count{0};
+    bool configured{false};
+
+    struct PendingDnb {
+        bool valid{false};
+        uint64_t block1_start{0};
+        uint64_t block2_start{0};
+        uint64_t ready_at{0};
+        bool inverted{false};
+        bool p_train{false};
+        uint8_t errors{0};
+    } pending_dnb{};
+
+    struct PendingDsb {
+        bool valid{false};
+        uint64_t burst_start{0};
+        uint64_t ready_at{0};
+        bool inverted{false};
+        uint8_t errors{0};
+    } pending_dsb{};
+
+    void process_symbol(const complex16_t& sample);
+    uint8_t history_bit(uint64_t absolute_bit) const;
+    void push_burst_to_ui();
+    void push_dnb_to_ui();
+
+    BasebandThread baseband_thread{baseband_fs, this, baseband::Direction::Receive, false};
+    RSSIThread rssi_thread{};
+};
+
+#endif  // __PROC_TETRA_H__

firmware/common/dsp_fir_taps.hpp

@@ -2070,4 +2070,20 @@ static constexpr fir_taps_complex<63> taps_1k5_LSB_channel = {
     }},
 };
 
+// TETRA 25kHz filters
+// IFIR wideband pre-filter: fs=3072000, pass=90000, decim=8, fout=384000
+constexpr fir_taps_real<24> taps_25k0_tetra_decim_0 = {
+    .low_frequency_normalized = -90000.0f / 3072000.0f,
+    .high_frequency_normalized = 90000.0f / 3072000.0f,
+    .transition_normalized = 160000.0f / 3072000.0f,
+    .taps = {{55, 122, 244, 424, 666, 965, 1308, 1669, 2019, 2321, 2544, 2663, 2663, 2544, 2321, 2019, 1669, 1308, 965, 666, 424, 244, 122, 55}},
+};
+// IFIR channel filter: fs=384000, pass=15000, decim=8, fout=48000
+constexpr fir_taps_real<32> taps_25k0_tetra_decim_1 = {
+    .low_frequency_normalized = -15000.0f / 384000.0f,
+    .high_frequency_normalized = 15000.0f / 384000.0f,
+    .transition_normalized = 25000.0f / 384000.0f,
+    .taps = {{2, -18, -60, -124, -198, -259, -267, -177, 53, 448, 1003, 1677, 2398, 3068, 3585, 3868, 3868, 3585, 3068, 2398, 1677, 1003, 448, 53, -177, -267, -259, -198, -124, -60, -18, 2}},
+};
+
 #endif /*__DSP_FIR_TAPS_H__*/

firmware/common/message.hpp

@@ -168,6 +168,8 @@ class Message {
         HunterConfig = 110,
         HunterTrigger = 111,
         HunterStop = 112,
+        TetraBsch = 113,
+        TetraDnb = 114,
         MAX
     };
 
@@ -2009,4 +2011,46 @@ class HunterStopMessage : public Message {
         : Message{ID::HunterStop} {}
 };
 
+struct TetraBurstMessage : public Message {
+    constexpr TetraBurstMessage(
+        const uint8_t* bits,
+        bool inv,
+        uint8_t err)
+        : Message(Message::ID::TetraBsch),
+          inverted(inv),
+          sync_errors(err),
+          payload{} {
+        for (size_t i = 0; i < 63; i++)
+            payload[i] = bits[i];
+    }
+
+    bool inverted;
+    uint8_t sync_errors;
+
+    // 500 bit
+    std::array<uint8_t, 63> payload;
+};
+
+struct TetraDnbMessage : public Message {
+    constexpr TetraDnbMessage(
+        const uint8_t* bits,
+        bool inv,
+        uint8_t err,
+        bool p_train)
+        : Message(Message::ID::TetraDnb),
+          inverted(inv),
+          train_errors(err),
+          is_p_train(p_train),
+          payload{} {
+        for (size_t i = 0; i < 54; i++)
+            payload[i] = bits[i];
+    }
+
+    bool inverted;
+    uint8_t train_errors;
+    bool is_p_train;
+
+    // 432 TCH type-5 bits: 216 bits before the training sequence + 216 bits after.
+    std::array<uint8_t, 54> payload;
+};
 #endif /*__MESSAGE_H__*/

firmware/common/spi_image.hpp

@@ -134,6 +134,7 @@ constexpr image_tag_t image_tag_vor_rx{'P', 'V', 'R', 'X'};
 constexpr image_tag_t image_tag_rttyrx{'P', 'R', 'T', 'R'};
 constexpr image_tag_t image_tag_rttytx{'P', 'R', 'T', 'T'};
 constexpr image_tag_t image_tag_tonedetect{'P', 'T', 'N', 'E'};
+constexpr image_tag_t image_tag_tetrarx{'P', 'T', 'E', 'T'};
 
 constexpr image_tag_t image_tag_noop{'P', 'N', 'O', 'P'};