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

scramble I and Q using two independent sequences

Browse source
This commit is contained in:
Ahmet Inan 2021-06-11 22:52:01 +02:00
commit a07fe52134
2 changed files with 27 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

10
encode.cc
View file

@ -37,6 +37,8 @@ struct Encoder
static const int mls1_len = 255;
static const int mls1_poly = 0b100101011;
static const int mls2_poly = 0b100101010001;
static const int mls3_poly = 0b10001000000001011;
static const int mls4_poly = 0b10111010010000001;
DSP::WritePCM<value> *pcm;
DSP::FastFourierTransform<symbol_len, cmplx, 1> bwd;
CODE::CRC<uint16_t> crc0;
@ -166,9 +168,13 @@ struct Encoder
for (int i = 0; i < data_bits+32+12*16; ++i)
code[i] = 1 - 2 * CODE::get_le_bit(inp, i);
ldpcenc(code, code+data_bits+32+12*16);
CODE::MLS seq3(mls3_poly), seq4(mls4_poly);
for (int j = 0; j < code_rows; ++j) {
for (int i = 0; i < code_cols; ++i)
fdom[bin(i+code_off)] *= Mod::map(code+Mod::BITS*(code_cols*j+i));
for (int i = 0; i < code_cols; ++i) {
cmplx con = Mod::map(code+Mod::BITS*(code_cols*j+i));
con = cmplx(con.real() * (1 - 2 * seq3()), con.imag() * (1 - 2 * seq4()));
fdom[bin(i+code_off)] *= con;
}
symbol();
}
schmidl_cox();