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https://github.com/aicodix/modem.git
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added helper arrays
This commit is contained in:
Ahmet Inan
parent
8bcfd30426
commit
d5c4bb25f5
2 changed files with 43 additions and 48 deletions
51
decode.cc
51
decode.cc
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@ -52,13 +52,17 @@ struct Decoder
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static const int cols_max = 256 + 32;
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static const int rows_max = 32;
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static const int cons_max = cols_max * rows_max;
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static const int mls0_len = 320;
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static const int mls0_poly = 0b1100110001;
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static const int mls0_seed = 214;
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static const int mls0_off = - mls0_len / 2;
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static const int mls1_poly = 0b100101011;
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static const int buffer_len = 5 * extended_len;
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static const int search_pos = extended_len;
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static const int comb_cols = 32;
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static const int code_cols = 256;
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static const int comb_dist = 9;
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static const int comb_off = 4;
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static const int cons_cols = code_cols + comb_cols;
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static const int cons_off = - cons_cols / 2;
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DSP::ReadPCM<value> *pcm;
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DSP::FastFourierTransform<symbol_len, cmplx, -1> fwd;
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DSP::BlockDC<value, value> blockdc;
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@ -74,7 +78,7 @@ struct Decoder
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mesg_type mesg[bits_max];
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code_type code[bits_max], perm[bits_max];
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int8_t mode[32];
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cmplx cons[cons_max], chan[cols_max];
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cmplx cons[cons_max], chan[cols_max], scar[cols_max];
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cmplx fdom[symbol_len], tdom[symbol_len];
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value index[cols_max], phase[cols_max];
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value cfo_rad, sfo_rad;
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@ -82,7 +86,6 @@ struct Decoder
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int mod_bits;
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int code_order;
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int symbol_pos;
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int oper_mode;
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int crc_bits;
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int data_bits;
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int data_bytes;
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@ -108,11 +111,9 @@ struct Decoder
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const cmplx *mls0_seq()
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{
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CODE::MLS seq0(mls0_poly, mls0_seed);
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for (int i = 0; i < symbol_len; ++i)
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fdom[i] = 0;
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value cur = 0, prv = 0;
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for (int i = 0; i < mls0_len; ++i, prv = cur)
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fdom[bin(i+mls0_off)] = prv * (cur = nrz(seq0()));
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for (int i = 0; i < cons_cols; ++i, prv = cur)
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fdom[bin(i+cons_off)] = prv * (cur = nrz(seq0()));
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return fdom;
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}
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cmplx mod_map(code_type *b)
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@ -261,12 +262,6 @@ struct Decoder
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DSP::Phasor<cmplx> osc;
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const cmplx *buf;
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int output_index = 0;
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int comb_cols = 32;
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int code_cols = 256;
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int comb_dist = 9;
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int comb_off = 4;
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int cons_cols = code_cols + comb_cols;
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int code_off = - cons_cols / 2;
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while (output_index < output_count) {
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do {
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if (!pcm->good())
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@ -285,21 +280,23 @@ struct Decoder
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for (int i = 0; i < guard_len; ++i)
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osc();
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fwd(fdom, tdom);
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CODE::MLS seq0(mls0_poly, mls0_seed);
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for (int i = 0; i < mls0_len; ++i)
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fdom[bin(i+mls0_off)] *= nrz(seq0());
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for (int i = 0; i < cons_cols; ++i)
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chan[i] = fdom[bin(i+code_off)];
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scar[i] = fdom[bin(i+cons_off)];
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CODE::MLS seq0(mls0_poly, mls0_seed);
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for (int i = 0; i < cons_cols; ++i)
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chan[i] = nrz(seq0()) * scar[i];
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for (int i = 0; i < symbol_len; ++i)
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tdom[i] = buf[i+symbol_pos+symbol_len+extended_len] * osc();
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for (int i = 0; i < guard_len; ++i)
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osc();
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fwd(fdom, tdom);
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for (int i = 0; i < cons_cols; ++i)
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scar[i] = fdom[bin(i+cons_off)];
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CODE::MLS seq1(mls1_poly);
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auto clamp = [](int v){ return v < -127 ? -127 : v > 127 ? 127 : v; };
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for (int i = 0; i < comb_cols; ++i)
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mode[i] = clamp(std::nearbyint(127 * demod_or_erase(fdom[bin(i*comb_dist+comb_off+code_off)], chan[i]).real() * nrz(seq1())));
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oper_mode = hadamarddec(mode);
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mode[i] = clamp(std::nearbyint(127 * demod_or_erase(scar[i*comb_dist+comb_off], chan[i*comb_dist+comb_off]).real() * nrz(seq1())));
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int oper_mode = hadamarddec(mode);
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if (oper_mode < 0 || oper_mode > 8) {
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std::cerr << "operation mode " << oper_mode << " unsupported." << std::endl;
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continue;
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@ -318,6 +315,8 @@ struct Decoder
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for (int i = 0; i < guard_len; ++i)
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osc();
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fwd(fdom, tdom);
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for (int i = 0; i < cons_cols; ++i)
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scar[i] = fdom[bin(i+cons_off)];
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} else {
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for (int i = 0; i < symbol_pos+symbol_len+extended_len; ++i)
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correlator(buf = next_sample());
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@ -325,23 +324,23 @@ struct Decoder
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hadamardenc(mode, oper_mode);
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}
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for (int i = 0; i < comb_cols; ++i)
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fdom[bin(comb_dist*i+comb_off+code_off)] *= nrz(seq1()) * mode[i];
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scar[comb_dist*i+comb_off] *= nrz(seq1()) * mode[i];
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for (int i = 0; i < cons_cols; ++i)
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cons[cons_cols*j+i] = demod_or_erase(fdom[bin(i+code_off)], chan[i]);
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cons[cons_cols*j+i] = demod_or_erase(scar[i], chan[i]);
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for (int i = 0; i < comb_cols; ++i) {
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index[i] = code_off + comb_dist * i + comb_off;
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index[i] = cons_off + comb_dist * i + comb_off;
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phase[i] = arg(cons[cons_cols*j+comb_dist*i+comb_off]);
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}
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tse.compute(index, phase, comb_cols);
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//std::cerr << "Theil-Sen slope = " << tse.slope() << std::endl;
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//std::cerr << "Theil-Sen yint = " << tse.yint() << std::endl;
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for (int i = 0; i < cons_cols; ++i)
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cons[cons_cols*j+i] *= DSP::polar<value>(1, -tse(i+code_off));
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cons[cons_cols*j+i] *= DSP::polar<value>(1, -tse(i+cons_off));
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for (int i = 0; i < cons_cols; ++i)
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if (i % comb_dist == comb_off)
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chan[i] = fdom[bin(i+code_off)];
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chan[i] = scar[i];
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else
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chan[i] *= DSP::polar<value>(1, tse(i+code_off));
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chan[i] *= DSP::polar<value>(1, tse(i+cons_off));
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std::cerr << ".";
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}
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std::cerr << " done" << std::endl;
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42
encode.cc
42
encode.cc
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@ -32,7 +32,6 @@ struct Encoder
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static const int bits_max = 65536;
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static const int data_max = 1024;
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static const int cols_max = 256 + 32;
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static const int mls0_len = 320;
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static const int mls0_poly = 0b1100110001;
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static const int mls0_seed = 214;
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static const int mls1_poly = 0b100101011;
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@ -57,15 +56,15 @@ struct Encoder
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cmplx temp[symbol_len];
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cmplx kern[symbol_len];
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cmplx guard[guard_len];
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cmplx cons[cons_cols];
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value weight[guard_len];
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value papr_min, papr_max;
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const uint32_t *frozen_bits;
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int mod_bits;
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int oper_mode;
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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 code_off;
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int cons_off;
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int cons_rows;
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int mls0_off;
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@ -117,6 +116,8 @@ struct Encoder
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}
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void symbol(bool papr_reduction = true, bool guard_interval = true)
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{
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for (int i = 0; i < cons_cols; ++i)
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fdom[bin(i+cons_off)] = cons[i];
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bwd(tdom, fdom);
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value scale = 2 / std::sqrt(value(symbol_len) / value(cons_cols));
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for (int i = 0; i < symbol_len; ++i)
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@ -150,19 +151,15 @@ struct Encoder
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void pilot_block()
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{
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CODE::MLS seq2(mls2_poly);
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for (int i = 0; i < symbol_len; ++i)
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fdom[i] = 0;
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for (int i = code_off; i < code_off + cons_cols; ++i)
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fdom[bin(i)] = nrz(seq2());
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for (int i = 0; i < cons_cols; ++i)
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cons[i] = nrz(seq2());
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symbol();
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}
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void schmidl_cox()
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{
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CODE::MLS seq0(mls0_poly, mls0_seed);
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for (int i = 0; i < symbol_len; ++i)
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fdom[i] = 0;
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for (int i = 0; i < mls0_len; ++i)
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fdom[bin(i+mls0_off)] = nrz(seq0());
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for (int i = 0; i < cons_cols; ++i)
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cons[i] = nrz(seq0());
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symbol(false);
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symbol(false, false);
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}
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@ -291,18 +288,17 @@ struct Encoder
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}
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data_bytes = data_bits / 8;
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int offset = (freq_off * symbol_len) / rate;
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mls0_off = offset - mls0_len / 2;
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code_off = offset - cons_cols / 2;
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cons_off = offset - cons_cols / 2;
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}
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void tone_reservation_kernels()
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{
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value mag = 1 / value(10 * reserved_tones);
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for (int i = 0, j = code_off - reserved_tones / 2; i < reserved_tones; ++i, ++j) {
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if (j == code_off)
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for (int i = 0, j = cons_off - reserved_tones / 2; i < reserved_tones; ++i, ++j) {
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if (j == cons_off)
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j += cons_cols;
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fdom[bin(j)] = mag;
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temp[bin(j)] = mag;
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}
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bwd(kern, fdom);
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bwd(kern, temp);
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for (int i = 0; i < guard_len / 4; ++i)
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weight[i] = 0;
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for (int i = guard_len / 4; i < guard_len / 4 + guard_len / 2; ++i) {
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@ -325,9 +321,9 @@ struct Encoder
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CODE::MLS seq1(mls1_poly);
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for (int i = 0, m = 0; i < cons_cols; ++i) {
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if (i % comb_dist == comb_off) {
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fdom[bin(i+code_off)] = nrz(seq1()) * mode[m++];
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cons[i] = nrz(seq1()) * mode[m++];
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} else {
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fdom[bin(i+code_off)] = 0;
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cons[i] = 0;
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}
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}
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symbol(false);
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@ -360,17 +356,17 @@ struct Encoder
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for (int j = 0, k = 0; j < cons_rows; ++j) {
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for (int i = 0, m = 0; i < cons_cols; ++i) {
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if (i % comb_dist == comb_off) {
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fdom[bin(i+code_off)] = nrz(seq1()) * mode[m++];
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cons[i] = nrz(seq1()) * mode[m++];
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} else {
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fdom[bin(i+code_off)] = mod_map(perm+k);
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cons[i] = mod_map(perm+k);
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k += mod_bits;
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}
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}
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symbol();
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}
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}
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for (int i = 0; i < symbol_len; ++i)
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fdom[i] = 0;
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for (int i = 0; i < cons_cols; ++i)
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cons[i] = 0;
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symbol();
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std::cerr << "PAPR: " << DSP::decibel(papr_min) << " .. " << DSP::decibel(papr_max) << " dB" << std::endl;
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}
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