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removed the extra pilot block

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This commit is contained in:
Ahmet Inan 2023-12-16 08:05:17 +01:00
commit dc1a5b2ef7
2 changed files with 12 additions and 13 deletions
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18
decode.cc
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@ -190,7 +190,6 @@ struct Decoder
static const int mls1_len = 255;
static const int mls1_off = - mls1_len / 2;
static const int mls1_poly = 0b100101011;
static const int mls2_poly = 0b100101010001;
static const int buffer_len = 4 * extended_len;
static const int search_pos = extended_len;
DSP::ReadPCM<value> *pcm;
@ -208,7 +207,7 @@ struct Decoder
int8_t genmat[255*71];
mesg_type mesg[max_bits], mess[code_len];
code_type code[code_len];
cmplx cons[cons_total], chan[cons_cols];
cmplx cons[cons_total], prev[cons_cols];
cmplx fdom[symbol_len], tdom[symbol_len];
value index[cons_cols], phase[cons_cols];
value cfo_rad, sfo_rad;
@ -225,11 +224,11 @@ struct Decoder
{
return 1 - 2 * bit;
}
static cmplx demod_or_erase(cmplx curr, cmplx chan)
static cmplx demod_or_erase(cmplx curr, cmplx prev)
{
if (!(norm(chan) > 0))
if (!(norm(prev) > 0))
return 0;
cmplx cons = curr / chan;
cmplx cons = curr / prev;
if (!(norm(cons) <= 4))
return 0;
return cons;
@ -350,16 +349,15 @@ struct Decoder
if (!okay || !oper_mode)
return;
for (int i = 0; i < symbol_pos+2*extended_len; ++i)
for (int i = 0; i < symbol_pos+extended_len; ++i)
buf = next_sample();
for (int i = 0; i < symbol_len; ++i)
tdom[i] = buf[i] * osc();
for (int i = 0; i < guard_len; ++i)
osc();
fwd(fdom, tdom);
CODE::MLS seq2(mls2_poly);
for (int i = 0; i < cons_cols; ++i)
chan[i] = nrz(seq2()) * fdom[bin(i+code_off)];
prev[i] = fdom[bin(i+code_off)];
std::cerr << "demod ";
for (int j = 0; j < cons_rows; ++j) {
for (int i = 0; i < extended_len; ++i)
@ -370,7 +368,7 @@ struct Decoder
osc();
fwd(fdom, tdom);
for (int i = 0; i < cons_cols; ++i)
cons[cons_cols*j+i] = demod_or_erase(fdom[bin(i+code_off)], chan[i]);
cons[cons_cols*j+i] = demod_or_erase(fdom[bin(i+code_off)], prev[i]);
if (1) {
for (int i = 0; i < cons_cols; ++i) {
code_type tmp[mod_bits];
@ -384,7 +382,7 @@ struct Decoder
for (int i = 0; i < cons_cols; ++i)
cons[cons_cols*j+i] *= DSP::polar<value>(1, -tse(i+code_off));
for (int i = 0; i < cons_cols; ++i)
chan[i] *= DSP::polar<value>(1, tse(i+code_off));
prev[i] *= DSP::polar<value>(1, tse(i+code_off));
}
std::cerr << ".";
}

7
encode.cc
View file

@ -54,6 +54,7 @@ struct Encoder
cmplx temp[symbol_len];
cmplx kern[symbol_len];
cmplx guard[guard_len];
cmplx prev[cons_cols];
value papr_min, papr_max;
int code_off;
int mls0_off;
@ -240,11 +241,11 @@ struct Encoder
for (int i = 0; i < 32; ++i)
mesg[i+data_bits] = nrz((crc1()>>i)&1);
polarenc(code, mesg, frozen_bits, code_order);
pilot_block();
value code_fac = std::sqrt(value(symbol_len) / value(cons_cols));
for (int i = 0; i < cons_cols; ++i)
prev[i] = fdom[bin(i+code_off)];
for (int j = 0; j < cons_rows; ++j) {
for (int i = 0; i < cons_cols; ++i)
fdom[bin(i+code_off)] = code_fac *
fdom[bin(i+code_off)] = prev[i] *
mod_map(code+mod_bits*(cons_cols*j+i));
symbol();
}