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128 lines
2.7 KiB
C++
128 lines
2.7 KiB
C++
/*
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OFDM modem common bits
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Copyright 2025 Ahmet Inan <inan@aicodix.de>
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*/
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#pragma once
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#include "crc.hh"
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#include "polar_tables.hh"
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#include "hadamard_encoder.hh"
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struct Common
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{
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static const int mod_max = 8;
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static const int code_max = 15;
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static const int bits_max = 1 << code_max;
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static const int data_max = 2048;
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static const int symbols_max = 22;
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static const int mls0_poly = 0x331;
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static const int mls0_seed = 214;
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static const int mls1_poly = 0x43;
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static const int mls2_poly = 0x163;
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static const int data_tones = 256;
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static const int head_tones = 32;
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static const int tail_tones = 32;
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static const int tone_count = data_tones + head_tones + tail_tones;
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static const int block_length = 10;
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static const int block_skew = 3;
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static const int first_head = 4;
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static const int first_tail = 9;
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static constexpr int slm_poly[16] = {
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0x11d, 0x12b, 0x12d, 0x14d, 0x15f, 0x163, 0x165, 0x169,
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0x171, 0x187, 0x18d, 0x1a9, 0x1c3, 0x1cf, 0x1e7, 0x1f5 };
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CODE::CRC<uint32_t> crc0;
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CODE::HadamardEncoder<6> hadamard_encoder;
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int8_t head[32];
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int8_t tail[32];
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uint8_t data[data_max];
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const uint32_t *frozen_bits;
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int mod_bits;
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int data_bits;
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int data_bytes;
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int code_order;
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int oper_mode;
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int tone_off;
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int head_off;
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int tail_off;
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int symbol_count;
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bool differential;
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Common() : crc0(0x8F6E37A0) {}
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void setup(int mode)
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{
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switch (mode) {
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case 0:
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mod_bits = 1;
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symbol_count = 16;
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differential = true;
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code_order = 12;
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data_bits = 2048;
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frozen_bits = frozen_4096_2080;
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break;
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case 1:
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mod_bits = 2;
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symbol_count = 16;
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differential = true;
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code_order = 13;
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data_bits = 4096;
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frozen_bits = frozen_8192_4128;
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break;
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case 2:
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mod_bits = 3;
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symbol_count = 22;
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differential = true;
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code_order = 14;
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data_bits = 8192;
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frozen_bits = frozen_16384_8224;
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break;
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case 3:
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mod_bits = 1;
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symbol_count = 16;
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differential = false;
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code_order = 12;
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data_bits = 2048;
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frozen_bits = frozen_4096_2080;
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break;
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case 4:
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mod_bits = 2;
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symbol_count = 16;
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differential = false;
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code_order = 13;
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data_bits = 4096;
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frozen_bits = frozen_8192_4128;
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break;
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case 5:
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mod_bits = 4;
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symbol_count = 4;
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differential = false;
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code_order = 12;
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data_bits = 2048;
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frozen_bits = frozen_4096_2080;
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break;
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case 6:
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mod_bits = 4;
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symbol_count = 16;
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differential = false;
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code_order = 14;
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data_bits = 8192;
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frozen_bits = frozen_16384_8224;
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break;
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case 7:
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mod_bits = 6;
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symbol_count = 22;
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differential = false;
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code_order = 15;
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data_bits = 16384;
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frozen_bits = frozen_32768_16416;
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break;
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default:
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return;
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}
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oper_mode = mode;
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data_bytes = data_bits / 8;
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}
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};
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