diff options
| author | Piotr Krysik <perper@o2.pl> | 2009-06-14 19:16:20 +0200 |
|---|---|---|
| committer | Piotr Krysik <perper@o2.pl> | 2009-06-14 19:16:20 +0200 |
| commit | 48dc955afd9c020c9e5627111db222717ce0664f (patch) | |
| tree | c84006510e47402e7f68d37e03eca8c252875fa1 | |
| parent | 5a3a299da271e6e81c6bf90cec0c235e0b73ddb2 (diff) | |
little changes to decrease number of errors in output bits
| -rw-r--r-- | src/lib/gsm_constants.h | 2 | ||||
| -rw-r--r-- | src/lib/gsm_receiver_cf.cc | 15 |
2 files changed, 11 insertions, 6 deletions
diff --git a/src/lib/gsm_constants.h b/src/lib/gsm_constants.h index 1ebce1c..e4e2461 100644 --- a/src/lib/gsm_constants.h +++ b/src/lib/gsm_constants.h @@ -33,7 +33,7 @@ #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 +#define MAX_SCH_ERRORS 5 //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 0fde642..ceea6a1 100644 --- a/src/lib/gsm_receiver_cf.cc +++ b/src/lib/gsm_receiver_cf.cc @@ -613,6 +613,9 @@ inline void gsm_receiver_cf::mafi(const gr_complex * input, int nitems, gr_compl } } +//TODO: get_norm_chan_imp_resp is similar to get_sch_chan_imp_resp - consider joining this two functions +//TODO: this is place where most errors are introduced and can be corrected by improvements to this fuction +//especially computations of strongest_window_nr int gsm_receiver_cf::get_norm_chan_imp_resp(const gr_complex *input, gr_complex * chan_imp_resp, unsigned search_range, int bcc) { vector_complex correlation_buffer; @@ -626,7 +629,8 @@ int gsm_receiver_cf::get_norm_chan_imp_resp(const gr_complex *input, gr_complex float energy = 0; int search_center = (int)((TRAIN_POS + GUARD_PERIOD) * d_OSR); - int search_start_pos = search_center + 1; +// int search_start_pos = search_center + 1; + int search_start_pos = search_center - d_chan_imp_length * d_OSR; int search_stop_pos = search_center + d_chan_imp_length * d_OSR + 2 * d_OSR; for (int ii = search_start_pos; ii < search_stop_pos; ii++) { @@ -643,7 +647,8 @@ int gsm_receiver_cf::get_norm_chan_imp_resp(const gr_complex *input, gr_complex vector_float::iterator iter_ii = iter; energy = 0; - for (int ii = 0; ii < (d_chan_imp_length)*d_OSR; ii++, iter_ii++) { + for (int ii = 0; ii < (d_chan_imp_length-2)*d_OSR; ii++, iter_ii++) { +// for (int ii = 0; ii < (d_chan_imp_length)*d_OSR; ii++, iter_ii++) { if (iter_ii == power_buffer.end()) { loop_end = true; break; @@ -657,9 +662,9 @@ int gsm_receiver_cf::get_norm_chan_imp_resp(const gr_complex *input, gr_complex window_energy_buffer.push_back(energy); } - - strongest_window_nr = max_element(window_energy_buffer.begin(), window_energy_buffer.end()) - window_energy_buffer.begin(); -// d_channel_imp_resp.clear(); + //!why doesn't this work + strongest_window_nr = max_element(window_energy_buffer.begin(), window_energy_buffer.end()) - window_energy_buffer.begin(); + //strongest_window_nr = 3; //! so I have to override it here max_correlation = 0; for (int ii = 0; ii < (d_chan_imp_length)*d_OSR; ii++) { |