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added half a second of leading noise

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This commit is contained in:
Ahmet Inan 2023-02-12 11:30:02 +01:00
commit 0c2404519d
1 changed files with 12 additions and 0 deletions
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12
encode.cc
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@ -68,6 +68,17 @@ struct Encoder
for (int i = 0; i < guard_len; ++i)
guard[i] = tdom[i];
}
void leading_noise() {
CODE::MLS seq(0b100101010001);
value factor = std::sqrt(value(symbol_len) / value(subcarrier_count));
for (int i = 0; i < symbol_len; ++i)
fdom[i] = 0;
for (int j = 0; j < 14; ++j) {
for (int i = 0; i < subcarrier_count; ++i)
fdom[first_subcarrier+i] = factor * cmplx(nrz(seq()), nrz(seq()));
symbol();
}
}
void schmidl_cox()
{
CODE::MLS seq(0b1100111);
@ -92,6 +103,7 @@ struct Encoder
}
Encoder(DSP::WritePCM<value> *pcm, const uint8_t *inp) : pcm(pcm), crc(0x8F6E37A0)
{
leading_noise();
schmidl_cox();
meta_data(1);
for (int i = 0; i < data_bits; ++i)