diff options
Diffstat (limited to 'src/lib')
| -rw-r--r-- | src/lib/gsm_constants.h | 2 | ||||
| -rw-r--r-- | src/lib/gsm_receiver_cf.cc | 16 | ||||
| -rw-r--r-- | src/lib/gsm_receiver_cf.h | 2 |
3 files changed, 15 insertions, 5 deletions
diff --git a/src/lib/gsm_constants.h b/src/lib/gsm_constants.h index 3f7ef04..1ebce1c 100644 --- a/src/lib/gsm_constants.h +++ b/src/lib/gsm_constants.h @@ -33,6 +33,8 @@ #define CHAN_IMP_RESP_LENGTH 5 +#define MAX_SCH_ERRORS 2 //maximum number of subsequent sch errors after which gsm receiver goes to find_next_fcch state + typedef enum {empty, fcch_burst, sch_burst, normal_burst, rach_burst, dummy} burst_type; typedef enum {unknown, multiframe_26, multiframe_51} multiframe_type; diff --git a/src/lib/gsm_receiver_cf.cc b/src/lib/gsm_receiver_cf.cc index 7f91fa8..0fde642 100644 --- a/src/lib/gsm_receiver_cf.cc +++ b/src/lib/gsm_receiver_cf.cc @@ -55,10 +55,10 @@ void gsm_receiver_cf::process_normal_burst(burst_counter burst_nr, const unsigne void gsm_receiver_cf::configure_receiver() { d_channel_conf.set_multiframe_type(TSC0, multiframe_51); - + d_channel_conf.set_burst_types(TSC0, TEST_CCH_FRAMES, sizeof(TEST_CCH_FRAMES) / sizeof(unsigned), normal_burst); d_channel_conf.set_burst_types(TSC0, FCCH_FRAMES, sizeof(FCCH_FRAMES) / sizeof(unsigned), fcch_burst); - + // d_channel_conf.set_multiframe_type(TIMESLOT6, multiframe_26); // d_channel_conf.set_burst_types(TIMESLOT6, TRAFFIC_CHANNEL_F, sizeof(TRAFFIC_CHANNEL_F) / sizeof(unsigned), normal_burst); } @@ -94,7 +94,8 @@ gsm_receiver_cf::gsm_receiver_cf(gr_feval_dd *tuner, int osr) d_fcch_start_pos(0), d_freq_offset(0), d_state(first_fcch_search), - d_burst_nr(osr) + d_burst_nr(osr), + d_failed_sch(0) { int i; gmsk_mapper(SYNC_BITS, N_SYNC_BITS, d_sch_training_seq, gr_complex(0.0, -1.0)); @@ -102,7 +103,7 @@ gsm_receiver_cf::gsm_receiver_cf(gr_feval_dd *tuner, int osr) for (i = 0; i < TRAIN_SEQ_NUM; i++) { gmsk_mapper(train_seq[i], N_TRAIN_BITS, d_norm_training_seq[i], gr_complex(1.0, 0.0)); } - + /* Initialize GSM Stack */ GS_new(&d_gs_ctx); //TODO: remove it! it'a not right place for a decoder } @@ -218,10 +219,16 @@ gsm_receiver_cf::general_work(int noutput_items, detect_burst(input, &channel_imp_resp[0], burst_start, output_binary); //MLSE detection of bits if (decode_sch(&output_binary[3], &t1, &t2, &t3, &d_ncc, &d_bcc) == 0) { //and decode SCH data // d_burst_nr.set(t1, t2, t3, 0); //but only to check if burst_start value is correct + d_failed_sch = 0; DCOUT("bcc: " << d_bcc << " ncc: " << d_ncc << " t1: " << t1 << " t2: " << t2 << " t3: " << t3); offset = burst_start - floor((GUARD_PERIOD) * d_OSR); //compute offset from burst_start - burst should start after a guard period DCOUT(offset); to_consume += offset; //adjust with offset number of samples to be consumed + } else { + d_failed_sch++; + if(d_failed_sch >= MAX_SCH_ERRORS){ + d_state = next_fcch_search; + } } } break; @@ -680,6 +687,5 @@ int gsm_receiver_cf::get_norm_chan_imp_resp(const gr_complex *input, gr_complex //std::cout << " burst_start: " << burst_start << " center: " << ((float)(search_start_pos + strongest_window_nr + chan_imp_resp_center)) / d_OSR << " stronegest window nr: " << strongest_window_nr << "\n"; return burst_start; - } diff --git a/src/lib/gsm_receiver_cf.h b/src/lib/gsm_receiver_cf.h index af13618..c37813a 100644 --- a/src/lib/gsm_receiver_cf.h +++ b/src/lib/gsm_receiver_cf.h @@ -96,6 +96,8 @@ class gsm_receiver_cf : public gr_block channel_configuration d_channel_conf; ///< mapping of burst_counter to burst_type //@} + unsigned d_failed_sch; ///< number of subsequent erroneous SCH bursts + // GSM Stack GS_CTX d_gs_ctx;//TODO: remove it! it'a not right place for a decoder |