| /* |
| * (C) 2022 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * Author: Eric Wild <ewild@sysmocom.de> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include "sigProcLib.h" |
| #include "signalVector.h" |
| #include <atomic> |
| #include <cassert> |
| #include <complex> |
| #include <iostream> |
| #include <future> |
| |
| #include "ms.h" |
| #include "grgsm_vitac/grgsm_vitac.h" |
| |
| #include "threadpool.h" |
| |
| extern "C" { |
| #include "sch.h" |
| } |
| |
| #ifdef LOG |
| #undef LOG |
| #endif |
| |
| #if !defined(NODAMNLOG) |
| #define DBGLG(...) ms_trx::dummy_log() |
| #else |
| #define DBGLG(...) std::cerr |
| #endif |
| |
| #if !defined(NODAMNLOG) |
| #define DBGLG2(...) ms_trx::dummy_log() |
| #else |
| #define DBGLG2(...) std::cerr |
| #endif |
| |
| #define PRINT_Q_OVERFLOW |
| |
| extern std::atomic<bool> g_exit_flag; |
| |
| bool ms_trx::decode_sch(char *bits, bool update_global_clock) |
| { |
| int fn; |
| struct sch_info sch; |
| ubit_t info[GSM_SCH_INFO_LEN]; |
| sbit_t data[GSM_SCH_CODED_LEN]; |
| |
| memcpy(&data[0], &bits[3], 39); |
| memcpy(&data[39], &bits[106], 39); |
| |
| if (!gsm_sch_decode(info, data)) { |
| gsm_sch_parse(info, &sch); |
| |
| if (update_global_clock) { |
| DBGLG() << "SCH : Decoded values" << std::endl; |
| DBGLG() << " BSIC: " << sch.bsic << std::endl; |
| DBGLG() << " TSC: " << (sch.bsic & 0x7) << std::endl; |
| DBGLG() << " T1 : " << sch.t1 << std::endl; |
| DBGLG() << " T2 : " << sch.t2 << std::endl; |
| DBGLG() << " T3p : " << sch.t3p << std::endl; |
| DBGLG() << " FN : " << gsm_sch_to_fn(&sch) << std::endl; |
| } |
| |
| fn = gsm_sch_to_fn(&sch); |
| if (fn < 0) { // how? wh? |
| DBGLG() << "SCH : Failed to convert FN " << std::endl; |
| return false; |
| } |
| |
| if (update_global_clock) { |
| mBSIC = sch.bsic; |
| mTSC = sch.bsic & 0x7; |
| timekeeper.set(fn, 0); |
| } |
| |
| return true; |
| } |
| return false; |
| } |
| |
| void ms_trx::maybe_update_gain(one_burst &brst) |
| { |
| static_assert((sizeof(brst.burst) / sizeof(brst.burst[0])) == ONE_TS_BURST_LEN, "wtf, buffer size mismatch?"); |
| const int avgburst_num = 8 * 20; // ~ 50*4.5ms = 90ms? |
| static_assert(avgburst_num * 577 > (50 * 1000), "can't update faster then blade wait time?"); |
| const unsigned int rx_max_cutoff = (rxFullScale * 2) / 3; |
| static int gain_check = 0; |
| static float runmean = 0; |
| float sum = normed_abs_sum(&brst.burst[0], ONE_TS_BURST_LEN); |
| runmean = gain_check ? (runmean * (gain_check + 2) - 1 + sum) / (gain_check + 2) : sum; |
| |
| if (gain_check == avgburst_num - 1) { |
| DBGLG2() << "\x1B[32m #RXG \033[0m" << cfg.rxgain << " " << runmean << " " << sum << std::endl; |
| auto gainoffset = runmean < (rxFullScale / 4 ? 4 : 2); |
| gainoffset = runmean < (rxFullScale / 2 ? 2 : 1); |
| float newgain = runmean < rx_max_cutoff ? cfg.rxgain + gainoffset : cfg.rxgain - gainoffset; |
| // FIXME: gian cutoff |
| if (newgain != cfg.rxgain && newgain <= 60) { |
| auto gain_fun = [this, newgain] { setRxGain(newgain); }; |
| worker_thread.add_task(gain_fun); |
| } |
| |
| runmean = 0; |
| } |
| gain_check = (gain_check + 1) % avgburst_num; |
| } |
| |
| static char sch_demod_bits[148]; |
| |
| bool ms_trx::handle_sch_or_nb() |
| { |
| one_burst brst; |
| const auto current_gsm_time = timekeeper.gsmtime(); |
| const auto is_sch = gsm_sch_check_ts(current_gsm_time.TN(), current_gsm_time.FN()); |
| |
| //either pass burst to upper layer for demod, OR pass demodded SCH to upper layer so we don't waste time processing it twice |
| brst.gsmts = current_gsm_time; |
| |
| if (!is_sch) { |
| memcpy(brst.burst, burst_copy_buffer, sizeof(blade_sample_type) * ONE_TS_BURST_LEN); |
| } else { |
| handle_sch(false); |
| memcpy(brst.sch_bits, sch_demod_bits, sizeof(sch_demod_bits)); |
| } |
| |
| while (!g_exit_flag && upper_is_ready && !rxqueue.spsc_push(&brst)) |
| ; |
| |
| if (!use_agc) |
| maybe_update_gain(brst); |
| |
| return false; |
| } |
| |
| static float sch_acq_buffer[SCH_LEN_SPS * 2]; |
| |
| bool ms_trx::handle_sch(bool is_first_sch_acq) |
| { |
| auto current_gsm_time = timekeeper.gsmtime(); |
| const auto buf_len = is_first_sch_acq ? SCH_LEN_SPS : ONE_TS_BURST_LEN; |
| const auto which_in_buffer = is_first_sch_acq ? first_sch_buf : burst_copy_buffer; |
| memset((void *)&sch_acq_buffer[0], 0, sizeof(sch_acq_buffer)); |
| if (use_va) { |
| const auto which_out_buffer = is_first_sch_acq ? sch_acq_buffer : &sch_acq_buffer[40 * 2]; |
| const auto ss = reinterpret_cast<std::complex<float> *>(which_out_buffer); |
| std::complex<float> channel_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR]; |
| int start; |
| convert_and_scale(which_out_buffer, which_in_buffer, buf_len * 2, 1.f / float(rxFullScale)); |
| if (is_first_sch_acq) { |
| float max_corr = 0; |
| start = get_sch_buffer_chan_imp_resp(ss, &channel_imp_resp[0], buf_len, &max_corr); |
| } else { |
| start = get_sch_chan_imp_resp(ss, &channel_imp_resp[0]); |
| start = start < 39 ? start : 39; |
| start = start > -39 ? start : -39; |
| } |
| detect_burst_nb(&ss[start], &channel_imp_resp[0], 0, sch_demod_bits); |
| |
| auto sch_decode_success = decode_sch(sch_demod_bits, is_first_sch_acq); |
| #if 0 // useful to debug offset shifts |
| auto burst = new signalVector(buf_len, 50); |
| const auto corr_type = is_first_sch_acq ? sch_detect_type::SCH_DETECT_BUFFER : sch_detect_type::SCH_DETECT_FULL; |
| struct estim_burst_params ebp; |
| |
| // scale like uhd, +-2k -> +-32k |
| convert_and_scale(burst->begin(), which_in_buffer, buf_len * 2, SAMPLE_SCALE_FACTOR); |
| |
| auto rv = detectSCHBurst(*burst, 4, 4, corr_type, &ebp); |
| |
| int howmuchdelay = ebp.toa * 4; |
| std::cerr << "ooffs: " << howmuchdelay << " " << std::endl; |
| std::cerr << "voffs: " << start << " " << sch_decode_success << std::endl; |
| #endif |
| if (sch_decode_success) { |
| const auto ts_offset_symb = 4; |
| if (is_first_sch_acq) { |
| // update ts to first sample in sch buffer, to allow delay calc for current ts |
| first_sch_ts_start = first_sch_buf_rcv_ts + start - (ts_offset_symb * 4) - 1; |
| } else if (abs(start) > 1) { |
| // continuous sch tracking, only update if off too much |
| temp_ts_corr_offset += -start; |
| std::cerr << "offs: " << start << " " << temp_ts_corr_offset << std::endl; |
| } |
| |
| return true; |
| } else { |
| DBGLG2() << "L SCH : \x1B[31m decode fail \033[0m @ toa:" << start << " " |
| << current_gsm_time.FN() << ":" << current_gsm_time.TN() << std::endl; |
| } |
| } else { |
| const auto ts_offset_symb = 4; |
| auto burst = new signalVector(buf_len, 50); |
| const auto corr_type = |
| is_first_sch_acq ? sch_detect_type::SCH_DETECT_BUFFER : sch_detect_type::SCH_DETECT_FULL; |
| struct estim_burst_params ebp; |
| |
| // scale like uhd, +-2k -> +-32k |
| convert_and_scale(burst->begin(), which_in_buffer, buf_len * 2, SAMPLE_SCALE_FACTOR); |
| |
| auto rv = detectSCHBurst(*burst, 4, 4, corr_type, &ebp); |
| |
| int howmuchdelay = ebp.toa * 4; |
| |
| if (!rv) { |
| delete burst; |
| DBGLG() << "SCH : \x1B[31m detect fail \033[0m NOOOOOOOOOOOOOOOOOO toa:" << ebp.toa << " " |
| << current_gsm_time.FN() << ":" << current_gsm_time.TN() << std::endl; |
| return false; |
| } |
| |
| SoftVector *bits; |
| if (is_first_sch_acq) { |
| // can't be legit with a buf size spanning _at least_ one SCH but delay that implies partial sch burst |
| if (howmuchdelay < 0 || (buf_len - howmuchdelay) < ONE_TS_BURST_LEN) { |
| delete burst; |
| return false; |
| } |
| |
| struct estim_burst_params ebp2; |
| // auto sch_chunk = new signalVector(ONE_TS_BURST_LEN, 50); |
| // auto sch_chunk_start = sch_chunk->begin(); |
| // memcpy(sch_chunk_start, sch_buf_f.data() + howmuchdelay, sizeof(std::complex<float>) * ONE_TS_BURST_LEN); |
| |
| auto delay = delayVector(burst, NULL, -howmuchdelay); |
| |
| scaleVector(*delay, (complex)1.0 / ebp.amp); |
| |
| auto rv2 = detectSCHBurst(*delay, 4, 4, sch_detect_type::SCH_DETECT_FULL, &ebp2); |
| DBGLG() << "FIRST SCH : " << (rv2 ? "yes " : " ") << "Timing offset " << ebp2.toa |
| << " symbols" << std::endl; |
| |
| bits = demodAnyBurst(*delay, SCH, 4, &ebp2); |
| delete delay; |
| } else { |
| bits = demodAnyBurst(*burst, SCH, 4, &ebp); |
| } |
| |
| delete burst; |
| |
| // clamp to +-1.5 because +-127 softbits scaled by 64 after -0.5 can be at most +-1.5 |
| clamp_array(bits->begin(), 148, 1.5f); |
| |
| float_to_sbit(&bits->begin()[0], (signed char *)&sch_demod_bits[0], 62, 148); |
| |
| if (decode_sch((char *)sch_demod_bits, is_first_sch_acq)) { |
| auto current_gsm_time_updated = timekeeper.gsmtime(); |
| if (is_first_sch_acq) { |
| // update ts to first sample in sch buffer, to allow delay calc for current ts |
| first_sch_ts_start = first_sch_buf_rcv_ts + howmuchdelay - (ts_offset_symb * 4); |
| } else { |
| // continuous sch tracking, only update if off too much |
| auto diff = [](float x, float y) { return x > y ? x - y : y - x; }; |
| |
| auto d = diff(ebp.toa, ts_offset_symb); |
| if (abs(d) > 0.3) { |
| if (ebp.toa < ts_offset_symb) |
| ebp.toa = d; |
| else |
| ebp.toa = -d; |
| temp_ts_corr_offset += ebp.toa * 4; |
| |
| DBGLG() << "offs: " << ebp.toa << " " << temp_ts_corr_offset << std::endl; |
| } |
| } |
| |
| auto a = gsm_sch_check_fn(current_gsm_time_updated.FN() - 1); |
| auto b = gsm_sch_check_fn(current_gsm_time_updated.FN()); |
| auto c = gsm_sch_check_fn(current_gsm_time_updated.FN() + 1); |
| DBGLG() << "L SCH : Timing offset " << rv << " " << ebp.toa << " " << a << b << c << "fn " |
| << current_gsm_time_updated.FN() << ":" << current_gsm_time_updated.TN() << std::endl; |
| |
| delete bits; |
| return true; |
| } else { |
| DBGLG2() << "L SCH : \x1B[31m decode fail \033[0m @ toa:" << ebp.toa << " " |
| << current_gsm_time.FN() << ":" << current_gsm_time.TN() << std::endl; |
| } |
| |
| delete bits; |
| } |
| return false; |
| } |
| |
| /* |
| accumulates a full big buffer consisting of 8*12 timeslots, then: |
| either |
| 1) adjusts gain if necessary and starts over |
| 2) searches and finds SCH and is done |
| */ |
| SCH_STATE ms_trx::search_for_sch(dev_buf_t *rcd) |
| { |
| static unsigned int sch_pos = 0; |
| auto to_copy = SCH_LEN_SPS - sch_pos; |
| |
| if (sch_thread_done) |
| return SCH_STATE::FOUND; |
| |
| if (rcv_done) |
| return SCH_STATE::SEARCHING; |
| |
| if (sch_pos == 0) // keep first ts for time delta calc |
| first_sch_buf_rcv_ts = rcd->get_first_ts(); |
| |
| if (to_copy) { |
| auto spsmax = rcd->actual_samples_per_buffer(); |
| if (to_copy > (unsigned int)spsmax) |
| sch_pos += rcd->readall(first_sch_buf + sch_pos); |
| else |
| sch_pos += rcd->read_n(first_sch_buf + sch_pos, 0, to_copy); |
| } else { // (!to_copy) |
| sch_pos = 0; |
| rcv_done = true; |
| auto sch_search_fun = [this] { |
| const auto target_val = rxFullScale / 8; |
| float sum = normed_abs_sum(first_sch_buf, SCH_LEN_SPS); |
| |
| //FIXME: arbitrary value, gain cutoff |
| if (sum > target_val || cfg.rxgain >= 60) // enough ? |
| sch_thread_done = this->handle_sch(true); |
| else { |
| std::cerr << "\x1B[32m #RXG \033[0m gain " << cfg.rxgain << " -> " << cfg.rxgain + 4 |
| << " sample avg:" << sum << " target: >=" << target_val << std::endl; |
| setRxGain(cfg.rxgain + 4); |
| } |
| |
| if (!sch_thread_done) |
| rcv_done = false; // retry! |
| }; |
| worker_thread.add_task(sch_search_fun); |
| } |
| return SCH_STATE::SEARCHING; |
| } |
| |
| void ms_trx::grab_bursts(dev_buf_t *rcd) |
| { |
| // partial burst samples read from the last buffer |
| static int partial_rdofs = 0; |
| static bool first_call = true; |
| int to_skip = 0; |
| |
| // round up to next burst by calculating the time between sch detection and now |
| if (first_call) { |
| const auto next_burst_start = rcd->get_first_ts() - first_sch_ts_start; |
| const auto fullts = next_burst_start / ONE_TS_BURST_LEN; |
| const auto fracts = next_burst_start % ONE_TS_BURST_LEN; |
| to_skip = ONE_TS_BURST_LEN - fracts; |
| |
| for (unsigned int i = 0; i < fullts; i++) |
| timekeeper.inc_and_update(first_sch_ts_start + i * ONE_TS_BURST_LEN); |
| |
| if (fracts) |
| timekeeper.inc_both(); |
| |
| timekeeper.dec_by_one(); // oops, off by one? |
| |
| timekeeper.set(timekeeper.gsmtime(), rcd->get_first_ts() - ONE_TS_BURST_LEN + to_skip); |
| |
| DBGLG() << "this ts: " << rcd->get_first_ts() << " diff full TN: " << fullts << " frac TN: " << fracts |
| << " GSM now: " << timekeeper.gsmtime().FN() << ":" << timekeeper.gsmtime().TN() << " is sch? " |
| << gsm_sch_check_fn(timekeeper.gsmtime().FN()) << std::endl; |
| first_call = false; |
| } |
| |
| if (partial_rdofs) { |
| auto first_remaining = ONE_TS_BURST_LEN - partial_rdofs; |
| auto rd = rcd->read_n(burst_copy_buffer + partial_rdofs, 0, first_remaining); |
| if (rd != (int)first_remaining) { |
| partial_rdofs += rd; |
| return; |
| } |
| |
| timekeeper.inc_and_update_safe(rcd->get_first_ts() - partial_rdofs); |
| handle_sch_or_nb(); |
| to_skip = first_remaining; |
| } |
| |
| // apply sample rate slippage compensation |
| to_skip -= temp_ts_corr_offset; |
| |
| // FIXME: happens rarely, read_n start -1 blows up |
| // this is fine: will just be corrected one buffer later |
| if (to_skip < 0) |
| to_skip = 0; |
| else |
| temp_ts_corr_offset = 0; |
| |
| const auto left_after_burst = rcd->actual_samples_per_buffer() - to_skip; |
| |
| const int full = left_after_burst / ONE_TS_BURST_LEN; |
| const int frac = left_after_burst % ONE_TS_BURST_LEN; |
| |
| for (int i = 0; i < full; i++) { |
| rcd->read_n(burst_copy_buffer, to_skip + i * ONE_TS_BURST_LEN, ONE_TS_BURST_LEN); |
| timekeeper.inc_and_update_safe(rcd->get_first_ts() + to_skip + i * ONE_TS_BURST_LEN); |
| handle_sch_or_nb(); |
| } |
| |
| if (frac) |
| rcd->read_n(burst_copy_buffer, to_skip + full * ONE_TS_BURST_LEN, frac); |
| partial_rdofs = frac; |
| } |