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-rw-r--r--src/lib/gsm_receiver_cf.cc86
1 files changed, 62 insertions, 24 deletions
diff --git a/src/lib/gsm_receiver_cf.cc b/src/lib/gsm_receiver_cf.cc
index 474a9d1..5f730dc 100644
--- a/src/lib/gsm_receiver_cf.cc
+++ b/src/lib/gsm_receiver_cf.cc
@@ -75,7 +75,7 @@ gsm_receiver_cf::~gsm_receiver_cf()
void gsm_receiver_cf::forecast(int noutput_items, gr_vector_int &ninput_items_required)
{
- ninput_items_required[0] = noutput_items * TS_BITS; //TODO include oversampling ratio here
+ ninput_items_required[0] = noutput_items * (TS_BITS + SAFETY_MARGIN) * d_OSR;
}
int
@@ -294,46 +294,73 @@ void gsm_receiver_cf::set_frequency(double freq_offset)
bool gsm_receiver_cf::find_sch_burst(const gr_complex *in, const int nitems , float *out)
{
- int sample_number = 0;
+// int sample_number = 0;
int to_consume = 0;
bool end = false;
bool result = false;
- int sch_start = d_fcch_start_pos + FRAME_BITS * d_OSR;
+ int sample_nr_near_sch_start = d_fcch_start_pos + (FRAME_BITS - SAFETY_MARGIN) * d_OSR;
+
enum states {
- init, search, sch_found, search_fail
+ start, reach_sch, find_sch_start, search_not_finished, sch_found
} sch_search_state;
+
+ sch_search_state = start;
+
while (!end) {
switch (sch_search_state) {
-
- case init:
- sch_search_state = search_fail;
+ case start:
+ if(d_counter < sample_nr_near_sch_start){
+ sch_search_state = reach_sch;
+ } else {
+ sch_search_state = find_sch_start;
+ }
break;
- case search:
+ case reach_sch:
- if ((sch_start >= d_counter) && (sch_start <= d_counter + nitems)) {
- DCOUT("sch_start-d_counter: " << sch_start - d_counter);
- /* for (int i = 0; i < nitems - N_SYNC_BITS; i++) {
- gr_complex result = correlation(&d_sch_training_seq[5], in + i, N_SYNC_BITS-10);
- //std::cout << "(" << real(in[i]) << "," << imag(in[i]) << ")\n";
- std::cout << "(" << real(result) << "," << imag(result) << ")\n";
- }
- std::cout << std::endl;
- */
+ if(d_counter + nitems >= sample_nr_near_sch_start){
+ to_consume = sample_nr_near_sch_start - d_counter;
+ DCOUT("reach_sch consumes: " << to_consume << "bits");
+ } else {
+ to_consume = nitems;
}
+
+
- to_consume = nitems - N_SYNC_BITS;
+ sch_search_state = search_not_finished;
+ break;
- sch_search_state = search_fail;
+ case find_sch_start:
+ DCOUT("find_sch_start nitems" << nitems);
+// if ((sch_start >= d_counter) && (sch_start <= d_counter + nitems)) {
+// for (int i = 0; i < ninput_items[0] - N_SYNC_BITS; i++) {
+// gr_complex result;
+// d_counter++;
+// result = correlation(&d_sch_training_seq[5], in + i, N_SYNC_BITS - 10);
+//
+// if (abs(result) > 60000) {
+// DCOUT("znaleziono środek sch na pozycji: " << d_counter);
+// }
+//
+// // std::cout << "(" << real(in[i]) << "," << imag(in[i]) << ")\n";
+// // std::cout << "(" << real(result) << "," << imag(result) << ")\n";
+//
+// int ninput = N_SYNC_BITS - 10;
+// const gr_complex * input_signal = in + i;
+// gr_complex * sequence = &d_sch_training_seq[5];
+// }
+// }
+ to_consume = nitems;
+ sch_search_state = sch_found;
break;
- case sch_found:
+ case search_not_finished:
end = true;
break;
- case search_fail:
+ case sch_found:
end = true;
break;
}
@@ -341,7 +368,7 @@ bool gsm_receiver_cf::find_sch_burst(const gr_complex *in, const int nitems , fl
d_counter += to_consume;
-// consume_each(to_consume);
+ consume_each(to_consume);
return result;
}
@@ -369,10 +396,21 @@ void gsm_receiver_cf::gmsk_mapper(const int * input, gr_complex * output, int ni
gr_complex gsm_receiver_cf::correlation(const gr_complex * sequence, const gr_complex * input_signal, int ninput)
{
gr_complex result(0.0, 0.0);
+ int sample_number = 0;
- for (int ii = 1; (ii * d_OSR) <= ninput; ii++) {
- result += sequence[ii-1] * conj(input_signal[(ii * d_OSR)]);
+ for (int ii = 0; ii < ninput; ii++) {
+ sample_number = (ii * d_OSR) ;
+ result += sequence[ii] * conj(input_signal[sample_number]);
}
return result;
}
+
+// gr_complex gsm_receiver_cf::calc_energy(int window_len){
+//
+// }
+inline float gsm_receiver_cf::compute_phase_diff(gr_complex val1, gr_complex val2)
+{
+ gr_complex conjprod = val1 * conj(val2);
+ return gr_fast_atan2f(imag(conjprod), real(conjprod));
+} \ No newline at end of file
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