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do pts on even and odd subcarrier sets

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This commit is contained in:
Ahmet Inan 2025-08-07 00:50:10 +02:00
commit 64f01501cc
2 changed files with 50 additions and 26 deletions
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decode.cc
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@ -296,18 +296,31 @@ struct Decoder : Common
tone[i] *= nrz(seq1());
for (int i = 0; i < tone_count; ++i)
demod[i] = demod_or_erase(tone[i], chan[i]);
value pilot_sum = 0;
for (int i = 0; i < pilot_tones; ++i)
pilot_sum += demod[i*block_length+pilot_off].real();
int pilot_phase = DSP::signum(pilot_sum);
if (std::abs(pilot_sum) < pilot_tones / 4) {
value ptsa_sum = 0;
for (int i = 0; i < pilot_tones; i += 2)
ptsa_sum += demod[i*block_length+pilot_off].real();
int ptsa_phase = DSP::signum(ptsa_sum);
if (std::abs(ptsa_sum) < pilot_tones / 4) {
std::cerr << "pilot phase damaged" << std::endl;
oper_mode = -1;
break;
}
for (int i = 0; i < tone_count; ++i) {
tone[i] *= pilot_phase;
demod[i] *= pilot_phase;
for (int i = 0; i < tone_count; i += 2) {
tone[i] *= ptsa_phase;
demod[i] *= ptsa_phase;
}
value ptsb_sum = 0;
for (int i = 1; i < pilot_tones; i += 2)
ptsb_sum += demod[i*block_length+pilot_off].real();
int ptsb_phase = DSP::signum(ptsb_sum);
if (std::abs(ptsb_sum) < pilot_tones / 4) {
std::cerr << "pilot phase damaged" << std::endl;
oper_mode = -1;
break;
}
for (int i = 1; i < tone_count; i += 2) {
tone[i] *= ptsb_phase;
demod[i] *= ptsb_phase;
}
for (int i = 0; i < pilot_tones; ++i) {
index[i] = tone_off + block_length * i + pilot_off;