Mirror/aicodix___modem
1
0
Fork 0
mirror of https://github.com/aicodix/modem.git synced 2026-04-27 14:30:34 +00:00
Code Issues Projects Releases Packages Wiki Activity

give symbol() the symbol number

Browse source
This commit is contained in:
Ahmet Inan 2025-07-10 08:52:50 +02:00
commit 06f3d5703b
1 changed files with 21 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

34
encode.cc
View file

@ -92,10 +92,10 @@ struct Encoder : public Common
tdom[i] -= orig * kern[bin(i-peak)];
}
}
void symbol(bool papr_reduction = true, bool guard_interval = true)
void symbol(int symbol_number)
{
for (int i = 0; differential && i < tone_count; ++i)
if (!papr_reduction)
if (symbol_number < 0)
prev[i] = 1;
else if (i % block_length != reserved_off)
prev[i] = tone[i] *= prev[i];
@ -107,6 +107,7 @@ struct Encoder : public Common
value scale = value(0.5) / std::sqrt(value(tone_count));
for (int i = 0; i < symbol_len; ++i)
tdom[i] *= scale;
bool papr_reduction = symbol_number >= 0;
if (papr_reduction) {
clipping_and_filtering(scale, true);
tone_reservation();
@ -114,8 +115,6 @@ struct Encoder : public Common
auto clamp = [](value v){ return v < value(-1) ? value(-1) : v > value(1) ? value(1) : v; };
for (int i = 0; i < symbol_len; ++i)
tdom[i] = cmplx(clamp(tdom[i].real()), clamp(tdom[i].imag()));
for (int i = 0; i < guard_len; ++i)
guard[i] = DSP::lerp(guard[i], tdom[i+symbol_len-guard_len], weight[i]);
if (papr_reduction) {
value peak = 0, mean = 0;
for (int i = 0; i < symbol_len; ++i) {
@ -130,11 +129,22 @@ struct Encoder : public Common
papr_max = std::max(papr_max, papr);
}
}
if (guard_interval)
if (symbol_number != -1) {
for (int i = 0; i < guard_len; ++i)
guard[i] = DSP::lerp(guard[i], tdom[i+symbol_len-guard_len], weight[i]);
pcm->write(reinterpret_cast<value *>(guard), guard_len, 2);
pcm->write(reinterpret_cast<value *>(tdom), symbol_len, 2);
}
for (int i = 0; i < guard_len; ++i)
guard[i] = tdom[i];
pcm->write(reinterpret_cast<value *>(tdom), symbol_len, 2);
}
void finish()
{
for (int i = 0; i < guard_len; ++i)
guard[i] *= 1 - weight[i];
pcm->write(reinterpret_cast<value *>(guard), guard_len, 2);
for (int i = 0; i < guard_len; ++i)
guard[i] = 0;
}
void leading_noise(int num = 1)
{
@ -142,7 +152,7 @@ struct Encoder : public Common
for (int j = 0; j < num; ++j) {
for (int i = 0; i < tone_count; ++i)
tone[i] = nrz(noise());
symbol(false);
symbol(-3);
}
}
void schmidl_cox()
@ -150,8 +160,8 @@ struct Encoder : public Common
CODE::MLS seq0(mls0_poly, mls0_seed);
for (int i = 0; i < tone_count; ++i)
tone[i] = nrz(seq0());
symbol(false);
symbol(false, false);
symbol(-2);
symbol(-1);
}
cmplx map_bits(code_type *b, int bits)
{
@ -296,12 +306,10 @@ struct Encoder : public Common
}
}
tone_reservation_kernel();
symbol();
symbol(j);
}
}
for (int i = 0; i < tone_count; ++i)
tone[i] = 0;
symbol(false);
finish();
std::cerr << "PAPR: " << DSP::decibel(papr_min) << " .. " << DSP::decibel(papr_max) << " dB" << std::endl;
}
};