mirror of
https://github.com/aicodix/modem.git
synced 2026-04-27 14:30:34 +00:00
integrated new preamble
This commit is contained in:
Ahmet Inan
parent
b8fb5e7dd6
commit
bca52ea9e8
3 changed files with 80 additions and 47 deletions
|
|
@ -16,7 +16,7 @@ struct Common
|
|||
static const int code_max = 15;
|
||||
static const int bits_max = 1 << code_max;
|
||||
static const int data_max = 2048;
|
||||
static const int symbols_max = 22;
|
||||
static const int symbols_max = 23;
|
||||
static const int mls0_poly = 0x331;
|
||||
static const int mls0_seed = 214;
|
||||
static const int mls1_poly = 0x43;
|
||||
|
|
|
|||
100
decode.cc
100
decode.cc
|
|
@ -177,6 +177,27 @@ struct Decoder : Common
|
|||
tmp = hilbert(blockdc(tmp.real()));
|
||||
return input_hist(tmp);
|
||||
}
|
||||
int64_t meta_data()
|
||||
{
|
||||
shuffle(code, perm, 8);
|
||||
polar_decoder(nullptr, mesg, code, frozen_256_71, 8);
|
||||
int best = -1;
|
||||
for (int k = 0; k < mesg_type::SIZE; ++k) {
|
||||
crc0.reset();
|
||||
for (int i = 0; i < 71; ++i)
|
||||
crc0(mesg[i].v[k] < 0);
|
||||
if (crc0() == 0) {
|
||||
best = k;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (best < 0)
|
||||
return -1;
|
||||
uint64_t md = 0;
|
||||
for (int i = 0; i < 55; ++i)
|
||||
md |= uint64_t(mesg[i].v[best] < 0) << i;
|
||||
return md;
|
||||
}
|
||||
Decoder(DSP::ReadPCM<value> *pcm, const char *const *output_names, int output_count) : pcm(pcm), correlator(mls0_seq())
|
||||
{
|
||||
blockdc.samples(filter_len);
|
||||
|
|
@ -210,12 +231,6 @@ struct Decoder : Common
|
|||
fwd(fdom, tdom);
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] = fdom[bin(i+tone_off)];
|
||||
CODE::MLS seq0(mls0_poly, mls0_seed);
|
||||
for (int i = 0; i < tone_count; ++i) {
|
||||
value sign = nrz(seq0());
|
||||
tone[i] *= sign;
|
||||
chan[i] *= sign;
|
||||
}
|
||||
for (int i = 0; i < tone_count; ++i) {
|
||||
index[i] = tone_off + i;
|
||||
phase[i] = arg(demod_or_erase(chan[i], tone[i]));
|
||||
|
|
@ -223,6 +238,13 @@ struct Decoder : Common
|
|||
tse.compute(index, phase, tone_count);
|
||||
std::cerr << "coarse sfo: " << -1000000 * tse.slope() / Const::TwoPi() << " ppm" << std::endl;
|
||||
std::cerr << "residual cfo: " << 1000 * tse.yint() * rate / (Const::TwoPi() * symbol_len) << " mHz" << std::endl;
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
tone[i] *= DSP::polar<value>(1, tse(i+tone_off));
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] = DSP::lerp(chan[i], tone[i], value(0.5));
|
||||
CODE::MLS seq0(mls0_poly, mls0_seed);
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] *= nrz(seq0());
|
||||
for (int i = 0; i < symbol_len; ++i)
|
||||
tdom[i] = buf[i+symbol_pos+symbol_len+extended_len] * osc();
|
||||
for (int i = 0; i < guard_len; ++i)
|
||||
|
|
@ -230,24 +252,10 @@ struct Decoder : Common
|
|||
fwd(fdom, tdom);
|
||||
CODE::MLS seq1(mls1_poly);
|
||||
auto clamp = [](int v){ return v < -127 ? -127 : v > 127 ? 127 : v; };
|
||||
for (int i = 0; i < head_tones; ++i) {
|
||||
head[i] = clamp(std::nearbyint(127 * demod_or_erase(fdom[bin(i*block_length+first_head+tone_off)], chan[i*block_length+first_head]).real() * nrz(seq1())));
|
||||
seq1();
|
||||
}
|
||||
int head_data = hadamard_decoder(head);
|
||||
if (head_data < 0) {
|
||||
std::cerr << "head data damaged" << std::endl;
|
||||
continue;
|
||||
}
|
||||
setup(head_data >> 3);
|
||||
std::cerr << "oper mode: " << oper_mode << std::endl;
|
||||
if (oper_mode >= 3) {
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
tone[i] *= DSP::polar<value>(1, tse(i+tone_off));
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] = DSP::lerp(chan[i], tone[i], value(0.5));
|
||||
}
|
||||
for (int j = 0, k = 0; j < symbol_count; ++j) {
|
||||
mod_bits = 1;
|
||||
oper_mode = -1;
|
||||
symbol_count = 0;
|
||||
for (int j = 0, k = 0; j < symbol_count + 1; ++j) {
|
||||
head_off = (block_skew * j + first_head) % block_length;
|
||||
tail_off = (block_skew * j + first_tail) % block_length;
|
||||
if (j) {
|
||||
|
|
@ -258,12 +266,6 @@ struct Decoder : Common
|
|||
for (int i = 0; i < guard_len; ++i)
|
||||
osc();
|
||||
fwd(fdom, tdom);
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
tone[i] = fdom[bin(i+tone_off)];
|
||||
} else {
|
||||
for (int i = 0; i < symbol_pos+symbol_len+extended_len; ++i)
|
||||
correlator(buf = next_sample());
|
||||
seq1.reset();
|
||||
}
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
tone[i] = fdom[bin(i+tone_off)];
|
||||
|
|
@ -311,17 +313,8 @@ struct Decoder : Common
|
|||
demod[i] *= DSP::polar<value>(1, -tse(i+tone_off));
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] *= DSP::polar<value>(1, tse(i+tone_off));
|
||||
if (differential) {
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] = fdom[bin(i+tone_off)];
|
||||
} else {
|
||||
for (int i = head_off; i < tone_count; i += block_length)
|
||||
chan[i] = DSP::lerp(chan[i], tone[i], value(0.5));
|
||||
for (int i = tail_off; i < tone_count; i += block_length)
|
||||
chan[i] = DSP::lerp(chan[i], tone[i], value(0.5));
|
||||
}
|
||||
CODE::XorShiftMask<int, 14, 1, 5, 10, 1> combination;
|
||||
int trial = j ? (head_data << 6) | tail_data : (head_data & 7) << 6 | tail_data;
|
||||
int trial = (head_data << 6) | tail_data;
|
||||
int comb = 0;
|
||||
for (int i = 0; i <= trial; ++i)
|
||||
comb = combination();
|
||||
|
|
@ -364,7 +357,34 @@ struct Decoder : Common
|
|||
k += bits;
|
||||
}
|
||||
}
|
||||
if (!j) {
|
||||
int64_t meta_info = meta_data();
|
||||
if (meta_info < 0) {
|
||||
std::cerr << "preamble decoding error." << std::endl;
|
||||
break;
|
||||
}
|
||||
if (meta_info > 7) {
|
||||
std::cerr << "unsupported operation mode: " << meta_info << std::endl;
|
||||
break;
|
||||
}
|
||||
k = 0;
|
||||
setup(meta_info);
|
||||
for (int i = 0; i < symbol_pos+symbol_len+extended_len; ++i)
|
||||
correlator(buf = next_sample());
|
||||
std::cerr << "oper mode: " << oper_mode << std::endl;
|
||||
}
|
||||
if (differential) {
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
chan[i] = fdom[bin(i+tone_off)];
|
||||
} else {
|
||||
for (int i = head_off; i < tone_count; i += block_length)
|
||||
chan[i] = DSP::lerp(chan[i], tone[i], value(0.5));
|
||||
for (int i = tail_off; i < tone_count; i += block_length)
|
||||
chan[i] = DSP::lerp(chan[i], tone[i], value(0.5));
|
||||
}
|
||||
}
|
||||
if (oper_mode < 1)
|
||||
continue;
|
||||
DSP::quick_sort(snr, symbol_count);
|
||||
std::cerr << "Es/N0 (dB): " << DSP::decibel(snr[0]) << " .. " << DSP::decibel(snr[symbol_count/2]) << " .. " << DSP::decibel(snr[symbol_count-1]) << std::endl;
|
||||
crc_bits = data_bits + 32;
|
||||
|
|
|
|||
25
encode.cc
25
encode.cc
|
|
@ -34,7 +34,7 @@ struct Encoder : public Common
|
|||
DSP::FastFourierTransform<symbol_len, cmplx, -1> fwd;
|
||||
DSP::FastFourierTransform<symbol_len, cmplx, 1> bwd;
|
||||
CODE::PolarEncoder<code_type> polar_encoder;
|
||||
code_type code[bits_max], perm[bits_max], mesg[bits_max];
|
||||
code_type code[bits_max], perm[bits_max], mesg[bits_max], meta[256];
|
||||
cmplx fdom[symbol_len];
|
||||
cmplx tdom[symbol_len];
|
||||
cmplx best[symbol_len];
|
||||
|
|
@ -82,14 +82,13 @@ struct Encoder : public Common
|
|||
for (int i = 0; differential && symbol_number > 0 && i < tone_count; ++i)
|
||||
tone[i] *= prev[i];
|
||||
value best_papr = 1000;
|
||||
int trials = symbol_number ? 4096 : 512;
|
||||
CODE::XorShiftMask<int, 14, 1, 5, 10, 1> combination;
|
||||
for (int trial = 0; trial < trials; ++trial) {
|
||||
for (int trial = 0; trial < 4096; ++trial) {
|
||||
for (int i = 0; i < tone_count; ++i)
|
||||
temp[i] = tone[i];
|
||||
if (symbol_number >= 0) {
|
||||
int comb = combination();
|
||||
int head_data = symbol_number ? trial >> 6 : (oper_mode << 3) | (trial >> 6);
|
||||
int head_data = trial >> 6;
|
||||
hadamard_encoder(head, head_data);
|
||||
int tail_data = trial & 63;
|
||||
hadamard_encoder(tail, tail_data);
|
||||
|
|
@ -173,6 +172,17 @@ struct Encoder : public Common
|
|||
symbol(-2);
|
||||
symbol(-1);
|
||||
}
|
||||
void meta_data(uint64_t md)
|
||||
{
|
||||
for (int i = 0; i < 55; ++i)
|
||||
mesg[i] = nrz((md >> i) & 1);
|
||||
crc0.reset();
|
||||
crc0(md << 9);
|
||||
for (int i = 0; i < 16; ++i)
|
||||
mesg[i+55] = nrz((crc0() >> i) & 1);
|
||||
polar_encoder(code, mesg, frozen_256_71, 8);
|
||||
shuffle(meta, code, 8);
|
||||
}
|
||||
cmplx map_bits(code_type *b, int bits)
|
||||
{
|
||||
switch (bits) {
|
||||
|
|
@ -255,6 +265,7 @@ struct Encoder : public Common
|
|||
int offset = (freq_off * symbol_len) / rate;
|
||||
tone_off = offset - tone_count / 2;
|
||||
guard_interval_weights();
|
||||
meta_data(oper_mode);
|
||||
leading_noise();
|
||||
for (int input_index = 0; input_index < input_count; ++input_index) {
|
||||
const char *input_name = input_names[input_index];
|
||||
|
|
@ -281,13 +292,13 @@ struct Encoder : public Common
|
|||
polar_encoder(code, mesg, frozen_bits, code_order);
|
||||
shuffle(perm, code, code_order);
|
||||
CODE::MLS seq1(mls1_poly);
|
||||
for (int j = 0, k = 0; j < symbol_count; ++j) {
|
||||
for (int j = 0, k = 0, m = 0; j < symbol_count + 1; ++j) {
|
||||
head_off = (block_skew * j + first_head) % block_length;
|
||||
tail_off = (block_skew * j + first_tail) % block_length;
|
||||
for (int i = 0; i < tone_count; ++i) {
|
||||
if (i % block_length == head_off || i % block_length == tail_off) {
|
||||
tone[i] = nrz(seq1());
|
||||
} else {
|
||||
} else if (j) {
|
||||
int bits = mod_bits;
|
||||
if (oper_mode == 2 && k % 32 == 30)
|
||||
bits = 2;
|
||||
|
|
@ -295,6 +306,8 @@ struct Encoder : public Common
|
|||
bits = 4;
|
||||
tone[i] = map_bits(perm+k, bits);
|
||||
k += bits;
|
||||
} else {
|
||||
tone[i] = map_bits(meta+m++, 1);
|
||||
}
|
||||
}
|
||||
symbol(j);
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue