Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2022 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * Author: Eric Wild <ewild@sysmocom.de> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU Affero General Public License as published by |
| 9 | * the Free Software Foundation; either version 3 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU Affero General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Affero General Public License |
| 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include "sigProcLib.h" |
| 23 | #include "signalVector.h" |
| 24 | #include <atomic> |
| 25 | #include <cassert> |
| 26 | #include <complex> |
| 27 | #include <iostream> |
| 28 | #include <future> |
| 29 | |
| 30 | #include "ms.h" |
| 31 | #include "grgsm_vitac/grgsm_vitac.h" |
| 32 | |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 33 | #include "threadpool.h" |
| 34 | |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 35 | extern "C" { |
| 36 | #include "sch.h" |
| 37 | } |
| 38 | |
| 39 | #ifdef LOG |
| 40 | #undef LOG |
| 41 | #endif |
| 42 | |
| 43 | #if !defined(SYNCTHINGONLY) //|| !defined(NODAMNLOG) |
| 44 | #define DBGLG(...) ms_trx::dummy_log() |
| 45 | #else |
| 46 | #define DBGLG(...) std::cerr |
| 47 | #endif |
| 48 | |
| 49 | #if !defined(SYNCTHINGONLY) || !defined(NODAMNLOG) |
| 50 | #define DBGLG2(...) ms_trx::dummy_log() |
| 51 | #else |
| 52 | #define DBGLG2(...) std::cerr |
| 53 | #endif |
| 54 | |
| 55 | #define PRINT_Q_OVERFLOW |
| 56 | bool ms_trx::decode_sch(float *bits, bool update_global_clock) |
| 57 | { |
| 58 | int fn; |
| 59 | struct sch_info sch; |
| 60 | ubit_t info[GSM_SCH_INFO_LEN]; |
| 61 | sbit_t data[GSM_SCH_CODED_LEN]; |
| 62 | |
| 63 | float_to_sbit(&bits[3], &data[0], 1, 39); |
| 64 | float_to_sbit(&bits[106], &data[39], 1, 39); |
| 65 | |
| 66 | if (!gsm_sch_decode(info, data)) { |
| 67 | gsm_sch_parse(info, &sch); |
| 68 | |
| 69 | if (update_global_clock) { |
| 70 | DBGLG() << "SCH : Decoded values" << std::endl; |
| 71 | DBGLG() << " BSIC: " << sch.bsic << std::endl; |
| 72 | DBGLG() << " TSC: " << (sch.bsic & 0x7) << std::endl; |
| 73 | DBGLG() << " T1 : " << sch.t1 << std::endl; |
| 74 | DBGLG() << " T2 : " << sch.t2 << std::endl; |
| 75 | DBGLG() << " T3p : " << sch.t3p << std::endl; |
| 76 | DBGLG() << " FN : " << gsm_sch_to_fn(&sch) << std::endl; |
| 77 | } |
| 78 | |
| 79 | fn = gsm_sch_to_fn(&sch); |
| 80 | if (fn < 0) { // how? wh? |
| 81 | DBGLG() << "SCH : Failed to convert FN " << std::endl; |
| 82 | return false; |
| 83 | } |
| 84 | |
| 85 | if (update_global_clock) { |
| 86 | mBSIC = sch.bsic; |
| 87 | mTSC = sch.bsic & 0x7; |
| 88 | timekeeper.set(fn, 0); |
| 89 | // global_time_keeper.FN(fn); |
| 90 | // global_time_keeper.TN(0); |
| 91 | } |
| 92 | #ifdef SYNCTHINGONLY |
| 93 | else { |
| 94 | int t3 = sch.t3p * 10 + 1; |
| 95 | if (t3 == 11) { |
| 96 | // timeslot hitter attempt @ fn 21 in mf |
| 97 | DBGLG2() << "sch @ " << t3 << std::endl; |
| 98 | auto e = GSM::Time(fn, 0); |
| 99 | e += 10; |
| 100 | ts_hitter_q.spsc_push(&e); |
| 101 | } |
| 102 | } |
| 103 | #endif |
| 104 | |
| 105 | return true; |
| 106 | } |
| 107 | return false; |
| 108 | } |
| 109 | |
| 110 | void ms_trx::maybe_update_gain(one_burst &brst) |
| 111 | { |
| 112 | static_assert((sizeof(brst.burst) / sizeof(brst.burst[0])) == ONE_TS_BURST_LEN, "wtf, buffer size mismatch?"); |
| 113 | const int avgburst_num = 8 * 20; // ~ 50*4.5ms = 90ms? |
| 114 | static_assert(avgburst_num * 577 > (50 * 1000), "can't update faster then blade wait time?"); |
| 115 | const unsigned int rx_max_cutoff = (rxFullScale * 2) / 3; |
| 116 | static int gain_check = 0; |
| 117 | static float runmean = 0; |
| 118 | float sum = 0; |
| 119 | for (auto i : brst.burst) |
| 120 | sum += abs(i.real()) + abs(i.imag()); |
| 121 | sum /= ONE_TS_BURST_LEN * 2; |
| 122 | |
| 123 | runmean = gain_check ? (runmean * (gain_check + 2) - 1 + sum) / (gain_check + 2) : sum; |
| 124 | |
| 125 | if (gain_check == avgburst_num - 1) { |
| 126 | DBGLG2() << "\x1B[32m #RXG \033[0m" << rxgain << " " << runmean << " " << sum << std::endl; |
| 127 | auto gainoffset = runmean < (rxFullScale / 4 ? 4 : 2); |
| 128 | gainoffset = runmean < (rxFullScale / 2 ? 2 : 1); |
| 129 | float newgain = runmean < rx_max_cutoff ? rxgain + gainoffset : rxgain - gainoffset; |
| 130 | // FIXME: gian cutoff |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 131 | if (newgain != rxgain && newgain <= 60) { |
| 132 | auto gain_fun = [this, newgain] { setRxGain(newgain); }; |
| 133 | worker_thread.add_task(gain_fun); |
| 134 | } |
| 135 | |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 136 | runmean = 0; |
| 137 | } |
| 138 | gain_check = (gain_check + 1) % avgburst_num; |
| 139 | } |
| 140 | |
| 141 | static char sch_demod_bits[148]; |
| 142 | |
| 143 | bool ms_trx::handle_sch_or_nb() |
| 144 | { |
| 145 | one_burst brst; |
| 146 | const auto current_gsm_time = timekeeper.gsmtime(); |
| 147 | const auto is_sch = gsm_sch_check_ts(current_gsm_time.TN(), current_gsm_time.FN()); |
| 148 | |
| 149 | //either pass burst to upper layer for demod, OR pass demodded SCH to upper layer so we don't waste time processing it twice |
| 150 | brst.gsmts = current_gsm_time; |
| 151 | |
| 152 | if (!is_sch) { |
| 153 | memcpy(brst.burst, burst_copy_buffer, sizeof(blade_sample_type) * ONE_TS_BURST_LEN); |
| 154 | } else { |
| 155 | handle_sch(false); |
| 156 | memcpy(brst.sch_bits, sch_demod_bits, sizeof(sch_demod_bits)); |
| 157 | } |
| 158 | #ifndef SYNCTHINGONLY |
| 159 | if (upper_is_ready) { // this is blocking, so only submit if there is a reader - only if upper exists! |
| 160 | #endif |
| 161 | while (!rxqueue.spsc_push(&brst)) |
| 162 | ; |
| 163 | #ifndef SYNCTHINGONLY |
| 164 | } |
| 165 | #endif |
| 166 | |
| 167 | if (do_auto_gain) |
| 168 | maybe_update_gain(brst); |
| 169 | |
| 170 | return false; |
| 171 | } |
| 172 | |
| 173 | static float sch_acq_buffer[SCH_LEN_SPS * 2]; |
| 174 | |
| 175 | bool ms_trx::handle_sch(bool is_first_sch_acq) |
| 176 | { |
| 177 | auto current_gsm_time = timekeeper.gsmtime(); |
| 178 | const auto buf_len = is_first_sch_acq ? SCH_LEN_SPS : ONE_TS_BURST_LEN; |
| 179 | const auto which_in_buffer = is_first_sch_acq ? first_sch_buf : burst_copy_buffer; |
| 180 | const auto which_out_buffer = is_first_sch_acq ? sch_acq_buffer : &sch_acq_buffer[40 * 2]; |
| 181 | const auto ss = reinterpret_cast<std::complex<float> *>(which_out_buffer); |
| 182 | std::complex<float> channel_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR]; |
| 183 | |
| 184 | int start; |
| 185 | memset((void *)&sch_acq_buffer[0], 0, sizeof(sch_acq_buffer)); |
| 186 | if (is_first_sch_acq) { |
| 187 | float max_corr = 0; |
Eric Wild | 621a49e | 2023-01-12 16:21:58 +0100 | [diff] [blame] | 188 | convert_and_scale(which_out_buffer, which_in_buffer, buf_len * 2, 1.f / float(rxFullScale)); |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 189 | start = get_sch_buffer_chan_imp_resp(ss, &channel_imp_resp[0], buf_len, &max_corr); |
| 190 | detect_burst(&ss[start], &channel_imp_resp[0], 0, sch_demod_bits); |
| 191 | } else { |
Eric Wild | 621a49e | 2023-01-12 16:21:58 +0100 | [diff] [blame] | 192 | convert_and_scale(which_out_buffer, which_in_buffer, buf_len * 2, 1.f / float(rxFullScale)); |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 193 | start = get_sch_chan_imp_resp(ss, &channel_imp_resp[0]); |
| 194 | start = start < 39 ? start : 39; |
| 195 | start = start > -39 ? start : -39; |
| 196 | detect_burst(&ss[start], &channel_imp_resp[0], 0, sch_demod_bits); |
| 197 | } |
| 198 | |
| 199 | SoftVector bitss(148); |
| 200 | for (int i = 0; i < 148; i++) { |
| 201 | bitss[i] = (sch_demod_bits[i]); |
| 202 | } |
| 203 | |
| 204 | auto sch_decode_success = decode_sch(bitss.begin(), is_first_sch_acq); |
| 205 | |
| 206 | if (sch_decode_success) { |
| 207 | const auto ts_offset_symb = 0; |
| 208 | if (is_first_sch_acq) { |
| 209 | // update ts to first sample in sch buffer, to allow delay calc for current ts |
| 210 | first_sch_ts_start = first_sch_buf_rcv_ts + start - (ts_offset_symb * 4) - 1; |
| 211 | } else if (abs(start) > 1) { |
| 212 | // continuous sch tracking, only update if off too much |
| 213 | temp_ts_corr_offset += -start; |
| 214 | std::cerr << "offs: " << start << " " << temp_ts_corr_offset << std::endl; |
| 215 | } |
| 216 | |
| 217 | return true; |
| 218 | } else { |
| 219 | DBGLG2() << "L SCH : \x1B[31m decode fail \033[0m @ toa:" << start << " " << current_gsm_time.FN() |
| 220 | << ":" << current_gsm_time.TN() << std::endl; |
| 221 | } |
| 222 | return false; |
| 223 | } |
| 224 | |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 225 | /* |
| 226 | accumulates a full big buffer consisting of 8*12 timeslots, then: |
| 227 | either |
| 228 | 1) adjusts gain if necessary and starts over |
| 229 | 2) searches and finds SCH and is done |
| 230 | */ |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 231 | SCH_STATE ms_trx::search_for_sch(dev_buf_t *rcd) |
| 232 | { |
| 233 | static unsigned int sch_pos = 0; |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 234 | auto to_copy = SCH_LEN_SPS - sch_pos; |
| 235 | |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 236 | if (sch_thread_done) |
| 237 | return SCH_STATE::FOUND; |
| 238 | |
| 239 | if (rcv_done) |
| 240 | return SCH_STATE::SEARCHING; |
| 241 | |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 242 | if (sch_pos == 0) // keep first ts for time delta calc |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 243 | first_sch_buf_rcv_ts = rcd->get_first_ts(); |
| 244 | |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 245 | if (to_copy) { |
| 246 | auto spsmax = rcd->actual_samples_per_buffer(); |
| 247 | if (to_copy > (unsigned int)spsmax) |
| 248 | sch_pos += rcd->readall(first_sch_buf + sch_pos); |
| 249 | else |
| 250 | sch_pos += rcd->read_n(first_sch_buf + sch_pos, 0, to_copy); |
| 251 | } else { // (!to_copy) |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 252 | sch_pos = 0; |
| 253 | rcv_done = true; |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 254 | auto sch_search_fun = [this] { |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 255 | auto ptr = reinterpret_cast<const int16_t *>(first_sch_buf); |
| 256 | const auto target_val = rxFullScale / 8; |
| 257 | float sum = 0; |
| 258 | for (unsigned int i = 0; i < SCH_LEN_SPS * 2; i++) |
| 259 | sum += std::abs(ptr[i]); |
| 260 | sum /= SCH_LEN_SPS * 2; |
| 261 | |
| 262 | //FIXME: arbitrary value, gain cutoff |
| 263 | if (sum > target_val || rxgain >= 60) // enough ? |
| 264 | sch_thread_done = this->handle_sch(true); |
| 265 | else { |
| 266 | std::cerr << "\x1B[32m #RXG \033[0m gain " << rxgain << " -> " << rxgain + 4 |
| 267 | << " sample avg:" << sum << " target: >=" << target_val << std::endl; |
| 268 | setRxGain(rxgain + 4); |
| 269 | } |
| 270 | |
| 271 | if (!sch_thread_done) |
| 272 | rcv_done = false; // retry! |
Eric | 3e7f4b0 | 2023-05-23 12:50:25 +0200 | [diff] [blame^] | 273 | }; |
| 274 | worker_thread.add_task(sch_search_fun); |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 275 | } |
Eric | b7253c6 | 2022-11-28 19:21:08 +0100 | [diff] [blame] | 276 | return SCH_STATE::SEARCHING; |
| 277 | } |
| 278 | |
| 279 | void ms_trx::grab_bursts(dev_buf_t *rcd) |
| 280 | { |
| 281 | // partial burst samples read from the last buffer |
| 282 | static int partial_rdofs = 0; |
| 283 | static bool first_call = true; |
| 284 | int to_skip = 0; |
| 285 | |
| 286 | // round up to next burst by calculating the time between sch detection and now |
| 287 | if (first_call) { |
| 288 | const auto next_burst_start = rcd->get_first_ts() - first_sch_ts_start; |
| 289 | const auto fullts = next_burst_start / ONE_TS_BURST_LEN; |
| 290 | const auto fracts = next_burst_start % ONE_TS_BURST_LEN; |
| 291 | to_skip = ONE_TS_BURST_LEN - fracts; |
| 292 | |
| 293 | for (unsigned int i = 0; i < fullts; i++) |
| 294 | timekeeper.inc_and_update(first_sch_ts_start + i * ONE_TS_BURST_LEN); |
| 295 | |
| 296 | if (fracts) |
| 297 | timekeeper.inc_both(); |
| 298 | // timekeeper.inc_and_update(first_sch_ts_start + 1 * ONE_TS_BURST_LEN); |
| 299 | |
| 300 | timekeeper.dec_by_one(); // oops, off by one? |
| 301 | |
| 302 | timekeeper.set(timekeeper.gsmtime(), rcd->get_first_ts() - ONE_TS_BURST_LEN + to_skip); |
| 303 | |
| 304 | DBGLG() << "this ts: " << rcd->get_first_ts() << " diff full TN: " << fullts << " frac TN: " << fracts |
| 305 | << " GSM now: " << timekeeper.gsmtime().FN() << ":" << timekeeper.gsmtime().TN() << " is sch? " |
| 306 | << gsm_sch_check_fn(timekeeper.gsmtime().FN()) << std::endl; |
| 307 | first_call = false; |
| 308 | } |
| 309 | |
| 310 | if (partial_rdofs) { |
| 311 | auto first_remaining = ONE_TS_BURST_LEN - partial_rdofs; |
| 312 | auto rd = rcd->read_n(burst_copy_buffer + partial_rdofs, 0, first_remaining); |
| 313 | if (rd != (int)first_remaining) { |
| 314 | partial_rdofs += rd; |
| 315 | return; |
| 316 | } |
| 317 | |
| 318 | timekeeper.inc_and_update_safe(rcd->get_first_ts() - partial_rdofs); |
| 319 | handle_sch_or_nb(); |
| 320 | to_skip = first_remaining; |
| 321 | } |
| 322 | |
| 323 | // apply sample rate slippage compensation |
| 324 | to_skip -= temp_ts_corr_offset; |
| 325 | |
| 326 | // FIXME: happens rarely, read_n start -1 blows up |
| 327 | // this is fine: will just be corrected one buffer later |
| 328 | if (to_skip < 0) |
| 329 | to_skip = 0; |
| 330 | else |
| 331 | temp_ts_corr_offset = 0; |
| 332 | |
| 333 | const auto left_after_burst = rcd->actual_samples_per_buffer() - to_skip; |
| 334 | |
| 335 | const int full = left_after_burst / ONE_TS_BURST_LEN; |
| 336 | const int frac = left_after_burst % ONE_TS_BURST_LEN; |
| 337 | |
| 338 | for (int i = 0; i < full; i++) { |
| 339 | rcd->read_n(burst_copy_buffer, to_skip + i * ONE_TS_BURST_LEN, ONE_TS_BURST_LEN); |
| 340 | timekeeper.inc_and_update_safe(rcd->get_first_ts() + to_skip + i * ONE_TS_BURST_LEN); |
| 341 | handle_sch_or_nb(); |
| 342 | } |
| 343 | |
| 344 | if (frac) |
| 345 | rcd->read_n(burst_copy_buffer, to_skip + full * ONE_TS_BURST_LEN, frac); |
| 346 | partial_rdofs = frac; |
| 347 | } |