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use the tone reservation technique to improve PAPR

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This commit is contained in:
Ahmet Inan 2023-12-14 10:51:43 +01:00
commit d3a37c9e83
1 changed files with 25 additions and 2 deletions
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27
encode.cc
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@ -51,6 +51,7 @@ struct Encoder
cmplx fdom[symbol_len];
cmplx tdom[symbol_len];
cmplx temp[symbol_len];
cmplx kern[symbol_len];
cmplx guard[guard_len];
value papr_min, papr_max;
int code_off;
@ -80,13 +81,29 @@ struct Encoder
temp[i] = 0;
bwd(tdom, temp);
}
void tone_reservation()
{
for (int n = 0; n < 10; ++n) {
int peak = 0;
for (int i = 1; i < symbol_len; ++i)
if (norm(tdom[peak]) < norm(tdom[i]))
peak = i;
cmplx orig = tdom[peak];
for (int i = 0; i < peak; ++i)
tdom[i] -= orig * kern[symbol_len-peak+i];
for (int i = peak; i < symbol_len; ++i)
tdom[i] -= orig * kern[i-peak];
}
}
void symbol(bool papr_reduction = true)
{
bwd(tdom, fdom);
for (int i = 0; i < symbol_len; ++i)
tdom[i] /= std::sqrt(value(8*symbol_len));
if (papr_reduction)
clipping_and_filtering();
if (papr_reduction) {
// clipping_and_filtering();
tone_reservation();
}
for (int i = 0; i < guard_len; ++i) {
value x = value(i) / value(guard_len - 1);
value ratio(0.5);
@ -176,6 +193,12 @@ struct Encoder
code_off = offset - cons_cols / 2;
mls0_off = offset - mls0_len + 1;
mls1_off = offset - mls1_len / 2;
value kern_fac = 1 / value(10 * 32);
for (int i = 0; i < 16; ++i) {
fdom[bin(code_off-1-i)] = kern_fac;
fdom[bin(code_off+cons_cols+i)] = kern_fac;
}
bwd(kern, fdom);
papr_min = 1000, papr_max = -1000;
pilot_block();
schmidl_cox();