Mirror/aicodix___modem
1
0
Fork 0
mirror of https://github.com/aicodix/modem.git synced 2026-04-27 22:35:41 +00:00
Code Issues Projects Releases Packages Wiki Activity

added nrz() helper function

Browse source
This commit is contained in:
Ahmet Inan 2021-06-13 14:19:46 +02:00
commit c87bfc6e78
2 changed files with 19 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

12
decode.cc
View file

@ -204,13 +204,17 @@ struct Decoder
{
return (carrier + symbol_len) % symbol_len;
}
static int nrz(bool bit)
{
return 1 - 2 * bit;
}
const cmplx *mls0_seq()
{
CODE::MLS seq0(mls0_poly);
for (int i = 0; i < symbol_len/2; ++i)
fdom[i] = 0;
for (int i = 0; i < mls0_len; ++i)
fdom[(i+mls0_off/2+symbol_len/2)%(symbol_len/2)] = 1 - 2 * seq0();
fdom[(i+mls0_off/2+symbol_len/2)%(symbol_len/2)] = nrz(seq0());
return fdom;
}
int displacement(const cmplx *sym0, const cmplx *sym1)
@ -298,7 +302,7 @@ struct Decoder
fwd(fdom, tdom);
CODE::MLS seq1(mls1_poly);
for (int i = 0; i < mls1_len; ++i)
fdom[bin(i+mls1_off)] *= (1 - 2 * seq1());
fdom[bin(i+mls1_off)] *= nrz(seq1());
int8_t soft[mls1_len];
uint8_t data[(mls1_len+7)/8];
for (int i = 0; i < mls1_len; ++i)
@ -362,7 +366,7 @@ struct Decoder
fwd(fdom, cur += symbol_len+guard_len);
for (int i = 0; i < code_cols; ++i) {
cmplx con = fdom[bin(i+code_off)] / head[bin(i+code_off)];
cons[code_cols*j+i] = cmplx(con.real() * (1 - 2 * seq3()), con.imag() * (1 - 2 * seq4()));
cons[code_cols*j+i] = cmplx(con.real() * nrz(seq3()), con.imag() * nrz(seq4()));
}
}
value precision = 16;
@ -395,7 +399,7 @@ struct Decoder
for (int i = 0; i < cons_cnt; ++i) {
int8_t tmp[Mod::BITS];
for (int k = 0; k < Mod::BITS; ++k)
tmp[k] = 1 - 2 * (bint[Mod::BITS*i+k] < 0);
tmp[k] = nrz(bint[Mod::BITS*i+k] < 0);
cmplx hard = Mod::map(tmp);
cmplx error = cons[i] - hard;
sp += norm(hard);