srsRAN_4G/srsenb/src/phy/txrx.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 <unistd.h>

#include "srsran/common/threads.h"
#include "srsran/srsran.h"

#include "srsenb/hdr/phy/txrx.h"

#define Error(fmt, ...)                                                                                                \
  if (SRSRAN_DEBUG_ENABLED)                                                                                            \
  logger.error(fmt, ##__VA_ARGS__)
#define Warning(fmt, ...)                                                                                              \
  if (SRSRAN_DEBUG_ENABLED)                                                                                            \
  logger.warning(fmt, ##__VA_ARGS__)
#define Info(fmt, ...)                                                                                                 \
  if (SRSRAN_DEBUG_ENABLED)                                                                                            \
  logger.info(fmt, ##__VA_ARGS__)
#define Debug(fmt, ...)                                                                                                \
  if (SRSRAN_DEBUG_ENABLED)                                                                                            \
  logger.debug(fmt, ##__VA_ARGS__)

using namespace std;

namespace srsenb {

txrx::txrx(srslog::basic_logger& logger) : thread("TXRX"), logger(logger), running(false)
{
  /* Do nothing */
}

bool txrx::init(stack_interface_phy_lte*     stack_,
                srsran::radio_interface_phy* radio_h_,
                lte::worker_pool*            lte_workers_,
                nr::worker_pool*             nr_workers_,
                phy_common*                  worker_com_,
                prach_worker_pool*           prach_,
                uint32_t                     prio_)
{
  stack         = stack_;
  radio_h       = radio_h_;
  lte_workers   = lte_workers_;
  nr_workers    = nr_workers_;
  worker_com    = worker_com_;
  prach         = prach_;
  tx_worker_cnt = 0;
  running       = true;

  nof_workers = lte_workers->get_nof_workers();

  // Instantiate UL channel emulator
  if (worker_com->params.ul_channel_args.enable) {
    ul_channel = srsran::channel_ptr(
        new srsran::channel(worker_com->params.ul_channel_args, worker_com->get_nof_rf_channels(), logger));
  }

  start(prio_);
  return true;
}

void txrx::stop()
{
  if (running) {
    running = false;
    wait_thread_finish();
  }
}

void txrx::run_thread()
{
  srsran::rf_buffer_t    buffer    = {};
  srsran::rf_timestamp_t timestamp = {};
  uint32_t               sf_len    = SRSRAN_SF_LEN_PRB(worker_com->get_nof_prb(0));

  float samp_rate = srsran_sampling_freq_hz(worker_com->get_nof_prb(0));

  // Configure radio
  radio_h->set_rx_srate(samp_rate);
  radio_h->set_tx_srate(samp_rate);

  // Set Tx/Rx frequencies
  for (uint32_t cc_idx = 0; cc_idx < worker_com->get_nof_carriers(); cc_idx++) {
    double   tx_freq_hz = worker_com->get_dl_freq_hz(cc_idx);
    double   rx_freq_hz = worker_com->get_ul_freq_hz(cc_idx);
    uint32_t rf_port    = worker_com->get_rf_port(cc_idx);
    srsran::console("Setting frequency: DL=%.1f Mhz, UL=%.1f MHz for cc_idx=%d nof_prb=%d\n",
                    tx_freq_hz / 1e6f,
                    rx_freq_hz / 1e6f,
                    cc_idx,
                    worker_com->get_nof_prb(cc_idx));
    radio_h->set_tx_freq(rf_port, tx_freq_hz);
    radio_h->set_rx_freq(rf_port, rx_freq_hz);
  }

  // Set channel emulator sampling rate
  if (ul_channel) {
    ul_channel->set_srate(static_cast<uint32_t>(samp_rate));
  }

  logger.info("Starting RX/TX thread nof_prb=%d, sf_len=%d", worker_com->get_nof_prb(0), sf_len);

  // Set TTI so that first TX is at tti=0
  tti = TTI_SUB(0, FDD_HARQ_DELAY_UL_MS + 1);

  // Main loop
  while (running) {
    tti = TTI_ADD(tti, 1);
    logger.set_context(tti);

    lte::sf_worker* lte_worker = nullptr;
    if (worker_com->get_nof_carriers_lte() > 0) {
      lte_worker = lte_workers->wait_worker(tti);
      if (lte_worker == nullptr) {
        // wait_worker() only returns NULL if it's being closed. Quit now to avoid unnecessary loops here
        running = false;
        continue;
      }
    }

    nr::sf_worker* nr_worker = nullptr;
    if (worker_com->get_nof_carriers_nr() > 0) {
      nr_worker = nr_workers->wait_worker(tti);
      if (nr_worker == nullptr) {
        running = false;
        continue;
      }
    }

    // Multiple cell buffer mapping
    {
      uint32_t cc = 0;
      for (uint32_t cc_lte = 0; cc_lte < worker_com->get_nof_carriers_lte(); cc_lte++, cc++) {
        uint32_t rf_port = worker_com->get_rf_port(cc);

        for (uint32_t p = 0; p < worker_com->get_nof_ports(cc); p++) {
          // WARNING: The number of ports for all cells must be the same
          buffer.set(rf_port, p, worker_com->get_nof_ports(0), lte_worker->get_buffer_rx(cc_lte, p));
        }
      }
      for (uint32_t cc_nr = 0; cc_nr < worker_com->get_nof_carriers_lte(); cc_nr++, cc++) {
        uint32_t rf_port = worker_com->get_rf_port(cc);

        for (uint32_t p = 0; p < worker_com->get_nof_ports(cc); p++) {
          // WARNING: The number of ports for all cells must be the same
          buffer.set(rf_port, p, worker_com->get_nof_ports(0), nr_worker->get_buffer_rx(cc_nr, p));
        }
      }
    }

    buffer.set_nof_samples(sf_len);
    radio_h->rx_now(buffer, timestamp);

    if (ul_channel) {
      ul_channel->run(buffer.to_cf_t(), buffer.to_cf_t(), sf_len, timestamp.get(0));
    }

    // Compute TX time: Any transmission happens in TTI+4 thus advance 4 ms the reception time
    timestamp.add(FDD_HARQ_DELAY_UL_MS * 1e-3);

    Debug("Setting TTI=%d, tx_mutex=%d, tx_time=%ld:%f to worker %d",
          tti,
          tx_worker_cnt,
          timestamp.get(0).full_secs,
          timestamp.get(0).frac_secs,
          lte_worker->get_id());

    lte_worker->set_time(tti, tx_worker_cnt, timestamp);
    tx_worker_cnt = (tx_worker_cnt + 1) % nof_workers;

    // Trigger prach worker execution
    for (uint32_t cc = 0; cc < worker_com->get_nof_carriers_lte(); cc++) {
      prach->new_tti(cc, tti, buffer.get(worker_com->get_rf_port(cc), 0, worker_com->get_nof_ports(0)));
    }

    // Launch NR worker only if available
    if (nr_worker != nullptr) {
      nr_worker->set_tti(tti);
      worker_com->semaphore.push(nr_worker);
      nr_workers->start_worker(nr_worker);
    }

    // Trigger phy worker execution
    worker_com->semaphore.push(lte_worker);
    lte_workers->start_worker(lte_worker);

    // Advance stack in time
    stack->tti_clock();
  }
}

} // namespace srsenb