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add equalizers

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This commit is contained in:
Bastian Bloessl
2016-05-31 15:36:05 +02:00
parent 5a9846fa67
commit 052d5022b0
12 changed files with 413 additions and 140 deletions
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lib/equalizer/lms.cc
+24 -64
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@@ -21,84 +21,44 @@
using namespace gr::ieee802_11::equalizer;
void lms::equalize(const gr_complex *in, gr_complex *out, int n) {
static float freq_offset = 0;
static float freq_sum = 0;
static float alpha = 0.9;
void lms::equalize(gr_complex *in, int n, gr_complex *symbols, uint8_t *bits, boost::shared_ptr<gr::digital::constellation> mod) {
if(n == 0) {
std::memcpy(carrier, in, 64 * sizeof(gr_complex));
std::memcpy(d_H, in, 64 * sizeof(gr_complex));
} else if(n == 1) {
gr_complex sum =
(carrier[11] * conj(in[11])) +
(carrier[25] * conj(in[25])) +
(carrier[39] * conj(in[39])) +
(carrier[53] * conj(in[53]));
freq_offset = arg(sum);
freq_sum = 0;
double signal = 0;
double noise = 0;
for(int i = 0; i < 64; i++) {
carrier[i] += in[i];
carrier[i] *= ref[i] * gr_complex(0.5, 0);
noise += std::pow(std::abs(d_H[i] - in[i]), 2);
signal += std::pow(std::abs(d_H[i] + in[i]), 2);
}
d_snr = 10 * std::log10(signal / noise / 2);
for(int i = 0; i < 64; i++) {
d_H[i] += in[i];
d_H[i] /= LONG[i] * gr_complex(2, 0);
}
} else {
gr_complex p = POLARITY[(n - 2) % 127];
gr_complex sum =
(carrier[11] * conj(in[11]) * p) +
(carrier[25] * conj(in[25]) * p) +
(carrier[39] * conj(in[39]) * p) +
(carrier[53] * conj(in[53]) * -p);
freq_offset = (1 - alpha) * freq_offset + alpha * arg(sum);
freq_sum += freq_offset;
//std::cout << "lms: symbol " << n
// << " p1 " << abs(carrier[11] * conj(in[11]) * p)
// << " p2 " << abs(carrier[25] * conj(in[25]) * p)
// << " p3 " << abs(carrier[39] * conj(in[39]) * p)
// << " p4 " << abs(carrier[53] * conj(in[53]) * -p)
// << std::endl;
//std::cout << "lms: symbol " << n
// << " p1 " << arg(carrier[11] * conj(in[11]) * p)
// << " p2 " << arg(carrier[25] * conj(in[25]) * p)
// << " p3 " << arg(carrier[39] * conj(in[39]) * p)
// << " p4 " << arg(carrier[53] * conj(in[53]) * -p)
// << std::endl;
carrier[11] = in[11] * p;
carrier[25] = in[25] * p;
carrier[39] = in[39] * p;
carrier[53] = in[53] * -p;
int c = 0;
for(int i = 0; i < 64; i++) {
if( (i == 11) || (i == 25) || (i == 32) || (i == 39) || (i == 53) || (i < 6) || ( i > 58)) {
continue;
} else {
out[c] = in[i] / carrier[i] * exp(gr_complex(0, freq_sum));
symbols[c] = in[i] / d_H[i];
bits[c] = mod->decision_maker(&symbols[c]);
gr_complex point;
mod->map_to_points(bits[c], &point);
d_H[i] = gr_complex(1-alpha,0) * d_H[i] + gr_complex(alpha,0) * in[i] / point;
c++;
}
}
}
}
const gr_complex lms::ref[] = {
0, 0, 0, 0, 0, 0, 1, 1, -1, -1,
1, 1, -1, 1, -1, 1, 1, 1, 1, 1,
1, -1, -1, 1, 1, -1, 1, -1, 1, 1,
1, 1, 0, 1, -1, -1, 1, 1, -1, 1,
-1, 1, -1, -1, -1, -1, -1, 1, 1, -1,
-1, 1, -1, 1, -1, 1, 1, 1, 1, 0,
0, 0, 0, 0
};
const gr_complex lms::POLARITY[127] = {
1, 1, 1, 1,-1,-1,-1, 1,-1,-1,-1,-1, 1, 1,-1, 1,
-1,-1, 1, 1,-1, 1, 1,-1, 1, 1, 1, 1, 1, 1,-1, 1,
1, 1,-1, 1, 1,-1,-1, 1, 1, 1,-1, 1,-1,-1,-1, 1,
-1, 1,-1,-1, 1,-1,-1, 1, 1, 1, 1, 1,-1,-1, 1, 1,
-1,-1, 1,-1, 1,-1, 1, 1,-1,-1,-1, 1, 1,-1,-1,-1,
-1, 1,-1,-1, 1,-1, 1, 1, 1, 1,-1, 1,-1, 1,-1, 1,
-1,-1,-1,-1,-1, 1,-1, 1, 1,-1, 1,-1, 1, 1, 1,-1,
-1, 1,-1,-1,-1, 1, 1, 1,-1,-1,-1,-1,-1,-1,-1 };
double
lms::get_snr() {
return d_snr;
}