piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 1 | /* -*- c++ -*- */ |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 2 | /* |
| 3 | * @file |
Piotr Krysik | a6268a5 | 2017-08-23 16:02:19 +0200 | [diff] [blame] | 4 | * @author (C) 2009-2017 by Piotr Krysik <ptrkrysik@gmail.com> |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 5 | * @section LICENSE |
| 6 | * |
| 7 | * Gr-gsm is free software; you can redistribute it and/or modify |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 3, or (at your option) |
| 10 | * any later version. |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 11 | * |
| 12 | * Gr-gsm is distributed in the hope that it will be useful, |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 16 | * |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 17 | * You should have received a copy of the GNU General Public License |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 18 | * along with gr-gsm; see the file COPYING. If not, write to |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 19 | * the Free Software Foundation, Inc., 51 Franklin Street, |
| 20 | * Boston, MA 02110-1301, USA. |
| 21 | */ |
| 22 | |
| 23 | #ifndef INCLUDED_GSM_RECEIVER_IMPL_H |
| 24 | #define INCLUDED_GSM_RECEIVER_IMPL_H |
| 25 | |
ptrkrysik | 3be74a7 | 2014-12-13 10:11:00 +0100 | [diff] [blame] | 26 | #include <grgsm/receiver/receiver.h> |
| 27 | #include <grgsm/gsmtap.h> |
Piotr Krysik | d7efc05 | 2017-11-07 19:33:22 +0100 | [diff] [blame] | 28 | #include <grgsm/gsm_constants.h> |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 29 | #include <receiver_config.h> |
ptrkrysik | 42411c6 | 2015-07-08 10:50:41 +0200 | [diff] [blame] | 30 | #include <vector> |
Piotr Krysik | df97869 | 2017-09-27 21:58:24 +0200 | [diff] [blame] | 31 | #include "time_sample_ref.h" |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 32 | |
| 33 | namespace gr { |
| 34 | namespace gsm { |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 35 | class receiver_impl : public receiver |
| 36 | { |
| 37 | private: |
Piotr Krysik | 96f2ea7 | 2017-10-16 15:47:08 +0200 | [diff] [blame] | 38 | unsigned int d_samples_consumed; |
Piotr Krysik | df97869 | 2017-09-27 21:58:24 +0200 | [diff] [blame] | 39 | bool d_rx_time_received; |
| 40 | time_sample_ref d_time_samp_ref; |
Piotr Krysik | bfb47dc | 2017-11-11 11:12:02 +0100 | [diff] [blame] | 41 | int d_c0_burst_start; |
ptrkrysik | 5821379 | 2014-10-30 09:05:15 +0100 | [diff] [blame] | 42 | float d_c0_signal_dbm; |
Piotr Krysik | d61f85b | 2016-08-29 07:38:25 +0200 | [diff] [blame] | 43 | |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 44 | /**@name Configuration of the receiver */ |
| 45 | //@{ |
| 46 | const int d_OSR; ///< oversampling ratio |
ptrkrysik | 380dea8 | 2015-08-06 10:11:58 +0200 | [diff] [blame] | 47 | bool d_process_uplink; |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 48 | const int d_chan_imp_length; ///< channel impulse length |
ptrkrysik | 5821379 | 2014-10-30 09:05:15 +0100 | [diff] [blame] | 49 | float d_signal_dbm; |
ptrkrysik | e518bbf | 2014-11-06 14:50:59 +0100 | [diff] [blame] | 50 | std::vector<int> d_tseq_nums; ///< stores training sequence numbers for channels different than C0 |
ptrkrysik | 7a7b9b0 | 2014-11-19 11:27:34 +0100 | [diff] [blame] | 51 | std::vector<int> d_cell_allocation; ///< stores cell allocation - absolute rf channel numbers (ARFCNs) assigned to the given cell. The variable should at least contain C0 channel number. |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 52 | //@} |
| 53 | |
| 54 | gr_complex d_sch_training_seq[N_SYNC_BITS]; ///<encoded training sequence of a SCH burst |
ptrkrysik | 5821379 | 2014-10-30 09:05:15 +0100 | [diff] [blame] | 55 | gr_complex d_norm_training_seq[TRAIN_SEQ_NUM][N_TRAIN_BITS]; ///<encoded training sequences of a normal and dummy burst |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 56 | |
ptrkrysik | 32c2116 | 2015-04-04 14:01:52 +0200 | [diff] [blame] | 57 | float d_last_time; |
| 58 | |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 59 | /** Counts samples consumed by the receiver |
| 60 | * |
| 61 | * It is used in beetween find_fcch_burst and reach_sch_burst calls. |
| 62 | * My intention was to synchronize this counter with some internal sample |
| 63 | * counter of the USRP. Simple access to such USRP's counter isn't possible |
| 64 | * so this variable isn't used in the "synchronized" state of the receiver yet. |
| 65 | */ |
| 66 | unsigned d_counter; |
| 67 | |
| 68 | /**@name Variables used to store result of the find_fcch_burst fuction */ |
| 69 | //@{ |
Vadim Yanitskiy | cc82cf0 | 2017-07-24 19:21:02 +0700 | [diff] [blame] | 70 | bool d_freq_offset_tag_in_fcch; ///< frequency offset tag presence |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 71 | unsigned d_fcch_start_pos; ///< position of the first sample of the fcch burst |
piotr | 4089c1a | 2014-08-06 14:10:56 +0200 | [diff] [blame] | 72 | float d_freq_offset_setting; ///< frequency offset set in frequency shifter located upstream |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 73 | //@} |
| 74 | std::list<double> d_freq_offset_vals; |
| 75 | |
| 76 | /**@name Identifiers of the BTS extracted from the SCH burst */ |
| 77 | //@{ |
| 78 | int d_ncc; ///< network color code |
| 79 | int d_bcc; ///< base station color code |
| 80 | //@} |
| 81 | |
| 82 | /**@name Internal state of the gsm receiver */ |
| 83 | //@{ |
| 84 | enum states { |
piotr | d6d6687 | 2014-08-06 15:20:33 +0200 | [diff] [blame] | 85 | fcch_search, sch_search, // synchronization search part |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 86 | synchronized // receiver is synchronized in this state |
| 87 | } d_state; |
| 88 | //@} |
| 89 | |
| 90 | /**@name Variables which make internal state in the "synchronized" state */ |
| 91 | //@{ |
| 92 | burst_counter d_burst_nr; ///< frame number and timeslot number |
| 93 | channel_configuration d_channel_conf; ///< mapping of burst_counter to burst_type |
| 94 | //@} |
ptrkrysik | e518bbf | 2014-11-06 14:50:59 +0100 | [diff] [blame] | 95 | |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 96 | unsigned d_failed_sch; ///< number of subsequent erroneous SCH bursts |
| 97 | |
| 98 | /** Function whis is used to search a FCCH burst and to compute frequency offset before |
| 99 | * "synchronized" state of the receiver |
| 100 | * |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 101 | * @param input vector with input signal |
| 102 | * @param nitems number of samples in the input vector |
| 103 | * @return |
| 104 | */ |
piotr | 4089c1a | 2014-08-06 14:10:56 +0200 | [diff] [blame] | 105 | bool find_fcch_burst(const gr_complex *input, const int nitems, double & computed_freq_offset); |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 106 | |
| 107 | /** Computes frequency offset from FCCH burst samples |
| 108 | * |
piotr | 4089c1a | 2014-08-06 14:10:56 +0200 | [diff] [blame] | 109 | * @param[in] input vector with input samples |
| 110 | * @param[in] first_sample number of the first sample of the FCCH busrt |
| 111 | * @param[in] last_sample number of the last sample of the FCCH busrt |
| 112 | * @param[out] computed_freq_offset contains frequency offset estimate if FCCH burst was located |
| 113 | * @return true if frequency offset was faound |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 114 | */ |
| 115 | double compute_freq_offset(const gr_complex * input, unsigned first_sample, unsigned last_sample); |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 116 | /** Computes angle between two complex numbers |
| 117 | * |
| 118 | * @param val1 first complex number |
| 119 | * @param val2 second complex number |
| 120 | * @return |
| 121 | */ |
| 122 | inline float compute_phase_diff(gr_complex val1, gr_complex val2); |
| 123 | |
| 124 | /** Function whis is used to get near to SCH burst |
| 125 | * |
| 126 | * @param nitems number of samples in the gsm_receiver's buffer |
| 127 | * @return true if SCH burst is near, false otherwise |
| 128 | */ |
| 129 | bool reach_sch_burst(const int nitems); |
| 130 | |
| 131 | /** Extracts channel impulse response from a SCH burst and computes first sample number of this burst |
| 132 | * |
| 133 | * @param input vector with input samples |
| 134 | * @param chan_imp_resp complex vector where channel impulse response will be stored |
| 135 | * @return number of first sample of the burst |
| 136 | */ |
| 137 | int get_sch_chan_imp_resp(const gr_complex *input, gr_complex * chan_imp_resp); |
| 138 | |
| 139 | /** MLSE detection of a burst bits |
| 140 | * |
| 141 | * Detects bits of burst using viterbi algorithm. |
| 142 | * @param input vector with input samples |
| 143 | * @param chan_imp_resp vector with the channel impulse response |
| 144 | * @param burst_start number of the first sample of the burst |
| 145 | * @param output_binary vector with output bits |
| 146 | */ |
| 147 | void detect_burst(const gr_complex * input, gr_complex * chan_imp_resp, int burst_start, unsigned char * output_binary); |
| 148 | |
| 149 | /** Encodes differentially input bits and maps them into MSK states |
| 150 | * |
| 151 | * @param input vector with input bits |
| 152 | * @param nitems number of samples in the "input" vector |
| 153 | * @param gmsk_output bits mapped into MSK states |
| 154 | * @param start_point first state |
| 155 | */ |
| 156 | void gmsk_mapper(const unsigned char * input, int nitems, gr_complex * gmsk_output, gr_complex start_point); |
| 157 | |
| 158 | /** Correlates MSK mapped sequence with input signal |
| 159 | * |
| 160 | * @param sequence MKS mapped sequence |
| 161 | * @param length length of the sequence |
| 162 | * @param input_signal vector with input samples |
| 163 | * @return correlation value |
| 164 | */ |
| 165 | gr_complex correlate_sequence(const gr_complex * sequence, int length, const gr_complex * input); |
| 166 | |
| 167 | /** Computes autocorrelation of input vector for positive arguments |
| 168 | * |
| 169 | * @param input vector with input samples |
| 170 | * @param out output vector |
| 171 | * @param nitems length of the input vector |
| 172 | */ |
| 173 | inline void autocorrelation(const gr_complex * input, gr_complex * out, int nitems); |
| 174 | |
| 175 | /** Filters input signal through channel impulse response |
| 176 | * |
| 177 | * @param input vector with input samples |
| 178 | * @param nitems number of samples to pass through filter |
| 179 | * @param filter filter taps - channel impulse response |
| 180 | * @param filter_length nember of filter taps |
| 181 | * @param output vector with filtered samples |
| 182 | */ |
| 183 | inline void mafi(const gr_complex * input, int nitems, gr_complex * filter, int filter_length, gr_complex * output); |
| 184 | |
| 185 | /** Extracts channel impulse response from a normal burst and computes first sample number of this burst |
| 186 | * |
| 187 | * @param input vector with input samples |
| 188 | * @param chan_imp_resp complex vector where channel impulse response will be stored |
| 189 | * @param search_range possible absolute offset of a channel impulse response start |
| 190 | * @param bcc base station color code - number of a training sequence |
| 191 | * @return first sample number of normal burst |
| 192 | */ |
piotr | 7e3b0db | 2014-02-05 22:44:30 +0100 | [diff] [blame] | 193 | int get_norm_chan_imp_resp(const gr_complex *input, gr_complex * chan_imp_resp, float *corr_max, int bcc); |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 194 | |
| 195 | /** |
ptrkrysik | e518bbf | 2014-11-06 14:50:59 +0100 | [diff] [blame] | 196 | * Sends burst through a C0 (for burst from C0 channel) or Cx (for other bursts) message port |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 197 | * |
ptrkrysik | e518bbf | 2014-11-06 14:50:59 +0100 | [diff] [blame] | 198 | * @param burst_nr - frame number of the burst |
| 199 | * @param burst_binary - content of the burst |
| 200 | * @b_type - type of the burst |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 201 | */ |
Piotr Krysik | 8a8d41a | 2018-04-16 22:21:29 +0200 | [diff] [blame] | 202 | void send_burst(burst_counter burst_nr, const unsigned char * burst_binary, uint8_t burst_type, size_t input_nr, unsigned int burst_start=-1); |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 203 | |
| 204 | /** |
ptrkrysik | e518bbf | 2014-11-06 14:50:59 +0100 | [diff] [blame] | 205 | * Configures burst types in different channels |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 206 | */ |
| 207 | void configure_receiver(); |
piotr | f2b6a1b | 2014-08-04 11:28:59 +0200 | [diff] [blame] | 208 | |
Vadim Yanitskiy | cc82cf0 | 2017-07-24 19:21:02 +0700 | [diff] [blame] | 209 | /* State machine handlers */ |
| 210 | void fcch_search_handler(gr_complex *input, int noutput_items); |
| 211 | void sch_search_handler(gr_complex *input, int noutput_items); |
| 212 | void synchronized_handler(gr_complex *input, |
| 213 | gr_vector_const_void_star &input_items, int noutput_items); |
| 214 | |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 215 | public: |
Piotr Krysik | 8a8d41a | 2018-04-16 22:21:29 +0200 | [diff] [blame] | 216 | receiver_impl(int osr, const std::vector<int> &cell_allocation, const std::vector<int> &tseq_nums, bool process_uplink); |
Piotr Krysik | df97869 | 2017-09-27 21:58:24 +0200 | [diff] [blame] | 217 | ~receiver_impl(); |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 218 | |
Piotr Krysik | df97869 | 2017-09-27 21:58:24 +0200 | [diff] [blame] | 219 | int work(int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items); |
| 220 | virtual void set_cell_allocation(const std::vector<int> &cell_allocation); |
| 221 | virtual void set_tseq_nums(const std::vector<int> & tseq_nums); |
| 222 | virtual void reset(); |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 223 | }; |
| 224 | } // namespace gsm |
| 225 | } // namespace gr |
| 226 | |
| 227 | #endif /* INCLUDED_GSM_RECEIVER_IMPL_H */ |
| 228 | |