diff options
| -rw-r--r-- | src/lib/gsm_receiver_cf.cc | 86 |
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)); +}
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