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improve CFO estimation using hard decision

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Ahmet Inan 2021-07-21 00:12:59 +02:00
commit 6f99db1444
1 changed files with 14 additions and 0 deletions
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14
decode.cc
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@ -416,6 +416,20 @@ struct Decoder
for (int i = 0; i < code_cols; ++i)
cons[code_cols*j+i] = fdom[bin(i+code_off)] / head[bin(i+code_off)];
}
if (1) {
value sum = 0;
for (int i = 0; i < cons_cnt; ++i) {
int8_t tmp[mod_max];
mod_hard(tmp, cons[i]);
sum += arg(cons[i] * conj(mod_map(tmp)));
}
value avg = sum / cons_cnt;
cfo_rad += avg / (symbol_len+guard_len);
std::cerr << "finer cfo: " << cfo_rad * (rate / Const::TwoPi()) << " Hz " << std::endl;
cmplx comp = DSP::polar<value>(1, -avg);
for (int i = 0; i < cons_cnt; ++i)
cons[i] *= comp;
}
value precision = 16;
if (1) {
value sp = 0, np = 0;