srsLTE/srsue/src/phy/scell/intra_measure_nr.cc

/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2021 Software Radio Systems Limited
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the distribution.
 *
 */
#include "srsue/hdr/phy/scell/intra_measure_nr.h"

#define Log(level, fmt, ...)                                                                                           \
  do {                                                                                                                 \
    logger.level("INTRA-%s: " fmt, to_string(get_rat()).c_str(), ##__VA_ARGS__);                                       \
  } while (false)

namespace srsue {
namespace scell {

intra_measure_nr::intra_measure_nr(srslog::basic_logger& logger_, meas_itf& new_meas_itf_) :
  logger(logger_), intra_measure_base(logger_, new_meas_itf_)
{}

intra_measure_nr::~intra_measure_nr()
{
  srsran_ssb_free(&ssb);
}

bool intra_measure_nr::init(uint32_t cc_idx_, const args_t& args)
{
  cc_idx     = cc_idx_;
  thr_snr_db = args.thr_snr_db;

  // Initialise generic side
  intra_measure_base::args_t base_args = {};
  base_args.srate_hz                   = args.max_srate_hz;
  base_args.len_ms                     = args.max_len_ms;
  base_args.period_ms                  = 20; // Hard-coded, it does not make a difference at this stage
  base_args.rx_gain_offset_db          = args.rx_gain_offset_dB;
  init_generic(cc_idx, base_args);

  // Initialise SSB
  srsran_ssb_args_t ssb_args = {};
  ssb_args.max_srate_hz      = args.max_srate_hz;
  ssb_args.min_scs           = args.min_scs;
  ssb_args.enable_search     = true;
  if (srsran_ssb_init(&ssb, &ssb_args) < SRSRAN_SUCCESS) {
    Log(error, "Error initiating SSB");
    return false;
  }

  return true;
}

bool intra_measure_nr::set_config(uint32_t arfcn, const config_t& cfg)
{
  // Update ARFCN
  current_arfcn    = arfcn;
  serving_cell_pci = cfg.serving_cell_pci;

  // Configure generic side
  intra_measure_base::args_t base_cfg = {};
  base_cfg.srate_hz                   = cfg.srate_hz;
  base_cfg.len_ms                     = cfg.len_ms;
  base_cfg.period_ms                  = cfg.periodicity_ms;
  base_cfg.rx_gain_offset_db          = cfg.rx_gain_offset_db;
  init_generic(cc_idx, base_cfg);

  // Configure SSB
  srsran_ssb_cfg_t ssb_cfg = {};
  ssb_cfg.srate_hz         = cfg.srate_hz;
  ssb_cfg.center_freq_hz   = cfg.center_freq_hz;
  ssb_cfg.ssb_freq_hz      = cfg.ssb_freq_hz;
  ssb_cfg.scs              = cfg.scs;
  if (srsran_ssb_set_cfg(&ssb, &ssb_cfg) < SRSRAN_SUCCESS) {
    Log(error, "Error configuring SSB");
    return false;
  }

  return true;
}

void intra_measure_nr::measure_rat(const measure_context_t& context, std::vector<cf_t>& buffer)
{
  // Search and measure the best cell
  srsran_csi_trs_measurements_t meas = {};
  uint32_t                      N_id = 0;
  if (srsran_ssb_csi_search(&ssb, buffer.data(), context.sf_len * context.meas_len_ms, &N_id, &meas) < SRSRAN_SUCCESS) {
    Log(error, "Error searching for SSB");
  }

  // Early return if the found PCI matches with the serving cell ID
  if (serving_cell_pci == (int)N_id) {
    return;
  }

  // Check threshold
  if (meas.snr_dB >= thr_snr_db) {
    // Log finding
    if (logger.info.enabled()) {
      std::array<char, 512> str_info = {};
      srsran_csi_rs_measure_info(&meas, str_info.data(), (uint32_t)str_info.size());
      Log(info, "Found neighbour cell: ARFCN=%d PCI=%03d %s", get_earfcn(), N_id, str_info.data());
    }

    // Prepare found measurements
    std::vector<phy_meas_t> meas_list(1);
    meas_list[0].rat    = get_rat();
    meas_list[0].rsrp   = meas.rsrp_dB + context.rx_gain_offset_db;
    meas_list[0].cfo_hz = meas.cfo_hz;
    meas_list[0].earfcn = get_earfcn();
    meas_list[0].pci    = N_id;

    // Push measurements to higher layers
    context.new_cell_itf.new_cell_meas(cc_idx, meas_list);
  }
}

} // namespace scell
} // namespace srsue