diff --git a/grc/ieee802_11_ofdm_sync_short.xml b/grc/ieee802_11_ofdm_sync_short.xml
index 5ee8da9..0913174 100644
--- a/grc/ieee802_11_ofdm_sync_short.xml
+++ b/grc/ieee802_11_ofdm_sync_short.xml
@@ -5,7 +5,7 @@
ieee802_11_ofdm_sync_short
IEEE802.11
import ieee802_11
- ieee802_11.ofdm_sync_short($threshold, $max_samples, $min_plateau, $log, $debug)
+ ieee802_11.ofdm_sync_short($threshold, $min_plateau, $log, $debug)
Log
@@ -46,13 +46,6 @@
real
-
- Max Samples
- max_samples
- 5200
- int
-
-
Min Plateau
min_plateau
@@ -61,7 +54,6 @@
$threshold > 0
- $max_samples > 400
$min_plateau > 0
@@ -70,6 +62,12 @@
1
+
+ abs
+ complex
+ 1
+
+
cor
float
diff --git a/include/ieee802-11/ofdm_sync_short.h b/include/ieee802-11/ofdm_sync_short.h
index 2bfbca2..94d56e8 100644
--- a/include/ieee802-11/ofdm_sync_short.h
+++ b/include/ieee802-11/ofdm_sync_short.h
@@ -28,8 +28,7 @@ class IEEE802_11_API ofdm_sync_short : virtual public block
public:
typedef boost::shared_ptr sptr;
- static sptr make(double threshold, unsigned int max_samples,
- unsigned int min_plateau, bool log = false, bool debug = false);
+ static sptr make(double threshold, unsigned int min_plateau, bool log = false, bool debug = false);
};
diff --git a/lib/ofdm_sync_short.cc b/lib/ofdm_sync_short.cc
index 11990fd..5c715a3 100644
--- a/lib/ofdm_sync_short.cc
+++ b/lib/ofdm_sync_short.cc
@@ -23,38 +23,38 @@
using namespace gr::ieee802_11;
static const int MIN_GAP = 480;
+static const int MAX_SAMPLES = 540 * 80;
class ofdm_sync_short_impl : public ofdm_sync_short {
public:
-ofdm_sync_short_impl(double threshold, unsigned int max_samples,
- unsigned int min_plateau, bool log, bool debug) : block("ofdm_sync_short",
- gr::io_signature::make2(2, 2, sizeof(gr_complex), sizeof(float)),
+ofdm_sync_short_impl(double threshold, unsigned int min_plateau, bool log, bool debug) :
+ block("ofdm_sync_short",
+ gr::io_signature::make3(3, 3, sizeof(gr_complex), sizeof(gr_complex), sizeof(float)),
gr::io_signature::make(1, 1, sizeof(gr_complex))),
- d_log(log),
- d_debug(debug),
- d_state(SEARCH),
- d_plateau(0),
- MAX_SAMPLES(max_samples),
- MIN_PLATEAU(min_plateau),
- d_threshold(threshold) {
+ d_log(log),
+ d_debug(debug),
+ d_state(SEARCH),
+ d_plateau(0),
+ d_freq_offset(0),
+ d_copied(0),
+ MIN_PLATEAU(min_plateau),
+ d_threshold(threshold) {
set_tag_propagation_policy(block::TPP_DONT);
}
-~ofdm_sync_short_impl(){
-}
-
int general_work (int noutput_items, gr_vector_int& ninput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items) {
const gr_complex *in = (const gr_complex*)input_items[0];
- const float *in2 = (const float*)input_items[1];
+ const gr_complex *in_abs = (const gr_complex*)input_items[1];
+ const float *in_cor = (const float*)input_items[2];
gr_complex *out = (gr_complex*)output_items[0];
int noutput = noutput_items;
- int ninput = std::min(ninput_items[0], ninput_items[1]);
+ int ninput = std::min(std::min(ninput_items[0], ninput_items[1]), ninput_items[2]);
// dout << "SHORT noutput : " << noutput << " ninput: " << ninput_items[0] << std::endl;
@@ -64,13 +64,14 @@ int general_work (int noutput_items, gr_vector_int& ninput_items,
int i;
for(i = 0; i < ninput; i++) {
- if(in2[i] > d_threshold) {
+ if(in_cor[i] > d_threshold) {
if(d_plateau < MIN_PLATEAU) {
d_plateau++;
} else {
d_state = COPY;
- d_copy_left = MAX_SAMPLES;
+ d_copied = 0;
+ d_freq_offset = arg(in_abs[i]) / 16;
d_plateau = 0;
insert_tag(nitems_written(0));
dout << "SHORT Frame!" << std::endl;
@@ -81,23 +82,23 @@ int general_work (int noutput_items, gr_vector_int& ninput_items,
}
}
- consume(0, i);
- consume(1, i);
+ consume_each(i);
return 0;
}
case COPY: {
int o = 0;
- while( (o < ninput) && (o < noutput) && d_copy_left) {
- if(in2[o] > d_threshold) {
+ while( o < ninput && o < noutput && d_copied < MAX_SAMPLES) {
+ if(in_cor[o] > d_threshold) {
if(d_plateau < MIN_PLATEAU) {
d_plateau++;
// there's another frame
- } else if((MAX_SAMPLES - d_copy_left) > MIN_GAP) {
- d_copy_left = MAX_SAMPLES;
+ } else if(d_copied > MIN_GAP) {
+ d_copied = 0;
d_plateau = 0;
+ d_freq_offset = arg(in_abs[o]) / 16;
insert_tag(nitems_written(0) + o);
dout << "SHORT Frame!" << std::endl;
break;
@@ -107,19 +108,18 @@ int general_work (int noutput_items, gr_vector_int& ninput_items,
d_plateau = 0;
}
- out[o] = in[o];
+ out[o] = in[o] * exp(gr_complex(0, -d_freq_offset * d_copied));
o++;
- d_copy_left--;
+ d_copied++;
}
- if(!d_copy_left) {
+ if(d_copied == MAX_SAMPLES) {
d_state = SEARCH;
}
dout << "SHORT copied " << o << std::endl;
- consume(0, o);
- consume(1, o);
+ consume_each(o);
return o;
}
}
@@ -139,18 +139,16 @@ void insert_tag(uint64_t item) {
private:
enum {SEARCH, COPY} d_state;
- int d_copy_left;
+ int d_copied;
int d_plateau;
+ float d_freq_offset;
const double d_threshold;
const bool d_log;
const bool d_debug;
- const unsigned int MAX_SAMPLES;
const unsigned int MIN_PLATEAU;
};
ofdm_sync_short::sptr
-ofdm_sync_short::make(double threshold, unsigned int max_samples,
- unsigned int min_plateau, bool log, bool debug) {
- return gnuradio::get_initial_sptr(new ofdm_sync_short_impl(threshold,
- max_samples, min_plateau, log, debug));
+ofdm_sync_short::make(double threshold, unsigned int min_plateau, bool log, bool debug) {
+ return gnuradio::get_initial_sptr(new ofdm_sync_short_impl(threshold, min_plateau, log, debug));
}