diff --git a/grc/ieee802_11_ofdm_equalize_symbols.xml b/grc/ieee802_11_ofdm_equalize_symbols.xml
index 479f3a3..5056085 100644
--- a/grc/ieee802_11_ofdm_equalize_symbols.xml
+++ b/grc/ieee802_11_ofdm_equalize_symbols.xml
@@ -5,7 +5,24 @@
ieee802_11_ofdm_equalize_symbols
IEEE802.11
import ieee802_11
- ieee802_11.ofdm_equalize_symbols($debug)
+ ieee802_11.ofdm_equalize_symbols($algo, $debug)
+ set_algorithm($algo)
+
+
+ Algorithm
+ algo
+ ieee802_11.LINEAR_COMB
+ int
+
+
+
+
Debug
diff --git a/include/ieee802-11/ofdm_equalize_symbols.h b/include/ieee802-11/ofdm_equalize_symbols.h
index 143b265..d9a1cc4 100644
--- a/include/ieee802-11/ofdm_equalize_symbols.h
+++ b/include/ieee802-11/ofdm_equalize_symbols.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2013 Bastian Bloessl
+ * Copyright (C) 2013, 2015 Bastian Bloessl
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -20,6 +20,11 @@
#include
#include
+enum Equalizer {
+ LMS = 0,
+ LINEAR_COMB = 1,
+};
+
namespace gr {
namespace ieee802_11 {
@@ -28,7 +33,8 @@ class IEEE802_11_API ofdm_equalize_symbols : virtual public block
public:
typedef boost::shared_ptr sptr;
- static sptr make(bool debug = false);
+ static sptr make(Equalizer algo, bool debug = false);
+ virtual void set_algorithm(Equalizer algo) = 0;
};
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index b615b10..10c06f0 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -94,6 +94,8 @@ add_dependencies(ieee802_11_generated_sources ieee802_11_generated_includes)
########################################################################
list(APPEND gr_ieee802_11_sources
${generated_sources}
+ equalizer/linear_comb.cc
+ equalizer/lms.cc
chunks_to_symbols_impl.cc
ether_encap_impl.cc
ofdm_decode_mac.cc
diff --git a/lib/equalizer/base.h b/lib/equalizer/base.h
new file mode 100644
index 0000000..1e8ffb5
--- /dev/null
+++ b/lib/equalizer/base.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2015 Bastian Bloessl
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#ifndef INCLUDED_IEEE802_11_EQUALIZER_BASE_H
+#define INCLUDED_IEEE802_11_EQUALIZER_BASE_H
+
+#include
+
+namespace gr {
+namespace ieee802_11 {
+namespace equalizer {
+
+class base {
+public:
+ virtual ~base() {};
+ virtual void equalize(const gr_complex *in, gr_complex *out, int n) = 0;
+};
+
+} /* namespace channel_estimation */
+} /* namespace ieee802_11 */
+} /* namespace gr */
+
+#endif /* INCLUDED_IEEE802_11_EQUALIZER_BASE_H */
diff --git a/lib/equalizer/linear_comb.cc b/lib/equalizer/linear_comb.cc
new file mode 100644
index 0000000..455deaa
--- /dev/null
+++ b/lib/equalizer/linear_comb.cc
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2015 Bastian Bloessl
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include "linear_comb.h"
+
+using namespace gr::ieee802_11::equalizer;
+
+void linear_comb::equalize(const gr_complex *in, gr_complex *out, int n) {
+ if(n < 2)
+ return;
+
+ double avg_mag = (abs(in[11]) + abs(in[25]) + abs(in[39]) + abs(in[53])) / 4;
+
+ gr_complex p = POLARITY[(n - 2) % 127 ];
+
+ double p1 = arg( p * in[11]);
+ double p2 = arg( p * in[25] * conj(p * in[11])) + p1;
+ double p3 = arg( p * in[39] * conj(p * in[25])) + p2;
+ double p4 = arg(-p * in[53] * conj(p * in[39])) + p3;
+
+ double my = (p1 + p2 + p3 + p4) / 4;
+ double mx = (11.0 + 25 + 39 + 53) / 4;
+
+ double var = (((11.0 * 11.0) + (25.0 * 25.0) + (39.0 * 39.0) + (53.0 * 53.0)) / 4) - (mx * mx);
+ double cov = (( (p1 * 11) + (p2 * 25) + (p3 * 39) + (p4 * 53) ) / 4) - (mx * my);
+ double beta = cov / var;
+ double alpha = my - beta * mx;
+
+ int c = 0;
+ for(int n = 0; n < 64; n++) {
+ if( (n == 11) || (n == 25) || (n == 32) || (n == 39) || (n == 53) || (n < 6) || ( n > 58)) {
+ continue;
+ } else {
+ out[c] = in[n] * exp(gr_complex(0, -n * beta - alpha)) * gr_complex(1 / avg_mag, 0);
+ c++;
+ }
+ }
+
+}
+
+const gr_complex linear_comb::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 };
diff --git a/lib/equalizer/linear_comb.h b/lib/equalizer/linear_comb.h
new file mode 100644
index 0000000..dc598cc
--- /dev/null
+++ b/lib/equalizer/linear_comb.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2015 Bastian Bloessl
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#ifndef INCLUDED_IEEE802_11_EQUALIZER_LINEAR_COMB_H
+#define INCLUDED_IEEE802_11_EQUALIZER_LINEAR_COMB_H
+
+#include "base.h"
+
+namespace gr {
+namespace ieee802_11 {
+namespace equalizer {
+
+class linear_comb: public base {
+public:
+ virtual void equalize(const gr_complex *in, gr_complex *out, int n);
+private:
+ static const gr_complex POLARITY[127];
+};
+
+} /* namespace channel_estimation */
+} /* namespace ieee802_11 */
+} /* namespace gr */
+
+#endif /* INCLUDED_IEEE802_11_EQUALIZER_LINEAR_COMB_H */
+
diff --git a/lib/equalizer/lms.cc b/lib/equalizer/lms.cc
new file mode 100644
index 0000000..65dddf3
--- /dev/null
+++ b/lib/equalizer/lms.cc
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2015 Bastian Bloessl
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include "lms.h"
+#include
+#include
+
+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;
+
+ if(n == 0) {
+ std::memcpy(carrier, 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;
+ for(int i = 0; i < 64; i++) {
+ carrier[i] += in[i];
+ carrier[i] *= ref[i] * gr_complex(0.5, 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));
+ 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 };
diff --git a/lib/equalizer/lms.h b/lib/equalizer/lms.h
new file mode 100644
index 0000000..c6d1d2f
--- /dev/null
+++ b/lib/equalizer/lms.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2015 Bastian Bloessl
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#ifndef INCLUDED_IEEE802_11_EQUALIZER_LMS_H
+#define INCLUDED_IEEE802_11_EQUALIZER_LMS_H
+
+#include "base.h"
+#include
+
+namespace gr {
+namespace ieee802_11 {
+namespace equalizer {
+
+class lms: public base {
+public:
+ virtual void equalize(const gr_complex *in, gr_complex *out, int n);
+private:
+ gr_complex carrier[64];
+ static const gr_complex ref[64];
+ static const gr_complex POLARITY[127];
+};
+
+} /* namespace channel_estimation */
+} /* namespace ieee802_11 */
+} /* namespace gr */
+
+#endif /* INCLUDED_IEEE802_11_EQUALIZER_LMS_H */
+
diff --git a/lib/ofdm_equalize_symbols.cc b/lib/ofdm_equalize_symbols.cc
index a755d86..22f77be 100644
--- a/lib/ofdm_equalize_symbols.cc
+++ b/lib/ofdm_equalize_symbols.cc
@@ -17,6 +17,9 @@
#include
#include "utils.h"
+#include "equalizer/base.h"
+#include "equalizer/linear_comb.h"
+#include "equalizer/lms.h"
#include
using namespace gr::ieee802_11;
@@ -25,12 +28,14 @@ using namespace gr::ieee802_11;
class ofdm_equalize_symbols_impl : public ofdm_equalize_symbols {
public:
-ofdm_equalize_symbols_impl(bool debug) : block("ofdm_equalize_symbols",
+ofdm_equalize_symbols_impl(Equalizer algo, bool debug) : block("ofdm_equalize_symbols",
gr::io_signature::make(1, 1, 64 * sizeof(gr_complex)),
gr::io_signature::make(1, 1, 48 * sizeof(gr_complex))),
- d_debug(debug) {
+ d_debug(debug), d_equalizer(NULL) {
set_relative_rate(1);
+ set_tag_propagation_policy(block::TPP_DONT);
+ set_algorithm(algo);
}
~ofdm_equalize_symbols_impl(){
@@ -40,87 +45,76 @@ int general_work (int noutput_items, gr_vector_int& ninput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items) {
+ gr::thread::scoped_lock lock(d_mutex);
+
const gr_complex *in = (const gr_complex*)input_items[0];
gr_complex *out = (gr_complex*)output_items[0];
- int noutput = noutput_items;
int i = 0;
-
- std::vector tags;
- const uint64_t nread = nitems_read(0);
+ int o = 0;
dout << "SYMBOLS: input " << ninput_items[0] << " output " << noutput_items << std::endl;
- while((i < ninput_items[0]) && (i < noutput)) {
+ while((i < ninput_items[0]) && (o < noutput_items)) {
- get_tags_in_range(tags, 0, nread + i, nread + i + 1,
- pmt::string_to_symbol("ofdm_start"));
+ get_tags_in_window(tags, 0, i, i + 1, pmt::string_to_symbol("ofdm_start"));
+ // new WiFi frame
if(tags.size()) {
- index = 0;
+ d_nsym = 0;
}
- gr_complex p = POLARITY[index];
- index++;
- index %= 127;
-
- // FIXME: think about this... average over amplitude or power
- double avg_mag = (abs(in[11]) + abs(in[25]) + abs(in[39]) + abs(in[53])) / 4;
-
-
- double p1 = arg( p * in[11]);
- double p2 = arg( p * in[25] * conj(p * in[11])) + p1;
- double p3 = arg( p * in[39] * conj(p * in[25])) + p2;
- double p4 = arg(-p * in[53] * conj(p * in[39])) + p3;
-
- double my = (p1 + p2 + p3 + p4) / 4;
- double mx = (11.0 + 25 + 39 + 53) / 4;
-
- double var = (((11.0 * 11.0) + (25.0 * 25.0) + (39.0 * 39.0) + (53.0 * 53.0)) / 4) - (mx * mx);
- double cov = (( (p1 * 11) + (p2 * 25) + (p3 * 39) + (p4 * 53) ) / 4) - (mx * my);
- double beta = cov / var;
- double alpha = my - beta * mx;
-
- int o = 0;
- for(int n = 0; n < 64; n++) {
- if( (n == 11) || (n == 25) || (n == 32) || (n == 39) || (n == 53) || (n < 6) || ( n > 58)) {
- continue;
- } else {
- // FIXME: think about this... square or not
- out[o] = in[n] * exp(gr_complex(0, -n * beta - alpha)) * gr_complex(1 / avg_mag, 0);
- o++;
- }
+ // first data symbol (= signal field)
+ if(d_nsym == 2) {
+ add_item_tag(0, nitems_written(0) + o,
+ pmt::string_to_symbol("ofdm_start"),
+ pmt::PMT_T,
+ pmt::string_to_symbol(name()));
}
+ d_equalizer->equalize(in + (i * 64), out + (o * 48), d_nsym);
+
+ if(d_nsym > 1) {
+ o++;
+ }
i++;
- in += 64;
- out += 48;
+ d_nsym++;
}
- dout << "SYMBOLS: produced / consumed " << i << std::endl;
+ dout << "SYMBOLS: consumed " << i << " produced " << o << std::endl;
consume(0, i);
- return i;
+ return o;
+}
+
+void set_algorithm(Equalizer algo) {
+ gr::thread::scoped_lock lock(d_mutex);
+ delete d_equalizer;
+
+ switch(algo) {
+ case LMS:
+ dout << "LMS" << std::endl;
+ d_equalizer = new equalizer::lms();
+ break;
+
+ case LINEAR_COMB:
+ dout << "Linear Comb" << std::endl;
+ d_equalizer = new equalizer::linear_comb();
+ break;
+ }
}
private:
- int index;
+ int d_nsym;
const bool d_debug;
- static const gr_complex POLARITY[127];
+ equalizer::base *d_equalizer;
+ std::vector tags;
+ gr::thread::mutex d_mutex;
};
-const gr_complex ofdm_equalize_symbols_impl::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 };
ofdm_equalize_symbols::sptr
-ofdm_equalize_symbols::make(bool debug) {
- return gnuradio::get_initial_sptr(new ofdm_equalize_symbols_impl(debug));
+ofdm_equalize_symbols::make(Equalizer algo, bool debug) {
+ return gnuradio::get_initial_sptr(new ofdm_equalize_symbols_impl(algo, debug));
}