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srsRAN/srsue/src/phy/sync.cc

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/*
* Copyright 2013-2019 Software Radio Systems Limited
*
* This file is part of srsLTE.
*
* srsLTE 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.
*
* srsLTE 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.
*
* A copy of the GNU Affero General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
*
*/
#include "srsue/hdr/phy/sync.h"
#include "srslte/common/log.h"
#include "srslte/phy/channel/channel.h"
#include "srslte/srslte.h"
#include "srsue/hdr/phy/sf_worker.h"
#include <algorithm>
#include <unistd.h>
#define Error(fmt, ...) if (SRSLTE_DEBUG_ENABLED) log_h->error(fmt, ##__VA_ARGS__)
#define Warning(fmt, ...) if (SRSLTE_DEBUG_ENABLED) log_h->warning(fmt, ##__VA_ARGS__)
#define Info(fmt, ...) if (SRSLTE_DEBUG_ENABLED) log_h->info(fmt, ##__VA_ARGS__)
#define Debug(fmt, ...) if (SRSLTE_DEBUG_ENABLED) log_h->debug(fmt, ##__VA_ARGS__)
namespace srsue {
int radio_recv_callback(void *obj, cf_t *data[SRSLTE_MAX_PORTS], uint32_t nsamples, srslte_timestamp_t *rx_time) {
return ((sync*)obj)->radio_recv_fnc(data, nsamples, rx_time);
}
double callback_set_rx_gain(void *h, double gain) {
return ((sync*)h)->set_rx_gain(gain);
}
void sync::init(srslte::radio_interface_phy* _radio,
stack_interface_phy_lte* _stack,
prach* _prach_buffer,
srslte::thread_pool* _workers_pool,
phy_common* _worker_com,
srslte::log* _log_h,
srslte::log* _log_phy_lib_h,
scell::async_recv_vector* scell_sync_,
uint32_t prio,
int sync_cpu_affinity)
{
radio_h = _radio;
log_h = _log_h;
log_phy_lib_h = _log_phy_lib_h;
stack = _stack;
scell_sync = scell_sync_;
workers_pool = _workers_pool;
worker_com = _worker_com;
prach_buffer = _prach_buffer;
uint32_t nof_rf_channels = worker_com->args->nof_rf_channels * worker_com->args->nof_rx_ant;
for (uint32_t r = 0; r < worker_com->args->nof_radios; r++) {
for (uint32_t p = 0; p < nof_rf_channels; p++) {
sf_buffer[r][p] = (cf_t*)srslte_vec_malloc(sizeof(cf_t) * 3 * SRSLTE_SF_LEN_PRB(100));
}
}
if (srslte_ue_sync_init_multi(&ue_sync, SRSLTE_MAX_PRB, false, radio_recv_callback, nof_rf_channels, this)) {
Error("SYNC: Initiating ue_sync\n");
return;
}
if (worker_com->args->dl_channel_args.enable) {
channel_emulator = srslte::channel_ptr(new srslte::channel(worker_com->args->dl_channel_args, nof_rf_channels));
}
nof_workers = workers_pool->get_nof_workers();
worker_com->set_nof_workers(nof_workers);
// Initialize cell searcher
search_p.init(sf_buffer[0], log_h, nof_rf_channels, this);
// Initialize SFN synchronizer, it uses only pcell buffer
sfn_p.init(&ue_sync, sf_buffer[0], log_h);
// Start intra-frequency measurement
intra_freq_meas.init(worker_com, stack, log_h);
reset();
running = true;
// Enable AGC
set_agc_enable(worker_com->args->agc_enable);
// Start main thread
if (sync_cpu_affinity < 0) {
start(prio);
} else {
start_cpu(prio, sync_cpu_affinity);
}
}
sync::~sync()
{
for (uint32_t r = 0; r < SRSLTE_MAX_RADIOS; r++) {
for (uint32_t p = 0; p < SRSLTE_MAX_PORTS; p++) {
if (sf_buffer[r][p]) {
free(sf_buffer[r][p]);
}
}
}
srslte_ue_sync_free(&ue_sync);
}
void sync::stop()
{
intra_freq_meas.stop();
running = false;
wait_thread_finish();
}
void sync::reset()
{
radio_is_overflow = false;
radio_overflow_return = false;
in_sync_cnt = 0;
out_of_sync_cnt = 0;
tx_worker_cnt = 0;
time_adv_sec = 0;
next_offset = 0;
ZERO_OBJECT(next_radio_offset);
srate_mode = SRATE_NONE;
current_earfcn = -1;
sfn_p.reset();
search_p.reset();
}
/**
* Higher layers API.
*
* These functions are called by higher layers (RRC) to control the Cell search and cell selection procedures.
* They manipulate the SYNC state machine to switch states and perform different actions. In order to ensure mutual
* exclusion any change of state variables such as cell configuration, MIB decoder, etc. must be done while the
* SYNC thread is in IDLE.
*
* Functions will manipulate the SYNC state machine (sync_state class) to jump to states and wait for result then
* return the result to the higher layers.
*
* Cell Search:
* It's the process of searching for cells in the bands or set of EARFCNs supported by the UE. Cell search is performed
* at 1.92 MHz sampling rate and involves PSS/SSS synchronization (PCI extraction) and MIB decoding for number of Ports and PRB.
*
*
* Cell Select:
* It's the process of moving the cell state from IDLE->CAMPING or from CAMPING->IDLE->CAMPING when RRC indicates to
* select a different cell.
*
* If it is a new cell, the reconfiguration must take place while sync_state is on IDLE.
*
* cell_search() and cell_select() functions can not be called concurrently. A mutex is used to prevent it from happening.
*
*/
/* A call to cell_search() finds the strongest cell in the set of supported EARFCNs. When the first cell is found,
* returns 1 and stores cell information and RSRP values in the pointers (if provided). If a cell is not found in the current
* frequency it moves to the next one and the next call to cell_search() will look in the next EARFCN in the set.
* If no cells are found in any frequency it returns 0. If error returns -1.
*/
phy_interface_rrc_lte::cell_search_ret_t sync::cell_search(phy_interface_rrc_lte::phy_cell_t* found_cell)
{
phy_interface_rrc_lte::cell_search_ret_t ret;
ret.found = phy_interface_rrc_lte::cell_search_ret_t::ERROR;
ret.last_freq = phy_interface_rrc_lte::cell_search_ret_t::NO_MORE_FREQS;
rrc_mutex.lock();
// Move state to IDLE
Info("Cell Search: Start EARFCN index=%u/%zd\n", cellsearch_earfcn_index, earfcn.size());
phy_state.go_idle();
try {
if (current_earfcn != (int)earfcn.at(cellsearch_earfcn_index)) {
current_earfcn = (int)earfcn[cellsearch_earfcn_index];
Info("Cell Search: changing frequency to EARFCN=%d\n", current_earfcn);
set_frequency();
}
} catch (const std::out_of_range& oor) {
Error("Index %d is not a valid EARFCN element.\n", cellsearch_earfcn_index);
return ret;
}
// Move to CELL SEARCH and wait to finish
Info("Cell Search: Setting Cell search state\n");
phy_state.run_cell_search();
// Check return state
switch(cell_search_ret) {
case search::CELL_FOUND:
// If a cell is found, configure it, synchronize and measure it
if (set_cell()) {
Info("Cell Search: Setting sampling rate and synchronizing SFN...\n");
set_sampling_rate();
phy_state.run_sfn_sync();
if (phy_state.is_camping()) {
log_h->info("Cell Search: Sync OK. Camping on cell PCI=%d\n", cell.id);
if (found_cell) {
found_cell->earfcn = current_earfcn;
found_cell->cell = cell;
}
ret.found = phy_interface_rrc_lte::cell_search_ret_t::CELL_FOUND;
} else {
log_h->info("Cell Search: Could not synchronize with cell\n");
ret.found = phy_interface_rrc_lte::cell_search_ret_t::CELL_NOT_FOUND;
}
} else {
Error("Cell Search: Setting cell PCI=%d, nof_prb=%d\n", cell.id, cell.nof_prb);
}
break;
case search::CELL_NOT_FOUND:
Info("Cell Search: No cell found in this frequency\n");
ret.found = phy_interface_rrc_lte::cell_search_ret_t::CELL_NOT_FOUND;
break;
default:
Error("Cell Search: while receiving samples\n");
radio_error();
break;
}
cellsearch_earfcn_index++;
if (cellsearch_earfcn_index >= earfcn.size()) {
Info("Cell Search: No more frequencies in the current EARFCN set\n");
cellsearch_earfcn_index = 0;
ret.last_freq = phy_interface_rrc_lte::cell_search_ret_t::NO_MORE_FREQS;
} else {
ret.last_freq = phy_interface_rrc_lte::cell_search_ret_t::MORE_FREQS;
}
rrc_mutex.unlock();
return ret;
}
/* Cell select synchronizes to a new cell (e.g. during HO or during cell reselection on IDLE) or
* re-synchronizes with the current cell if cell argument is NULL
*/
bool sync::cell_select(phy_interface_rrc_lte::phy_cell_t* new_cell)
{
std::unique_lock<std::mutex> ul(rrc_mutex);
bool ret = false;
int cnt = 0;
// Move state to IDLE
if (!new_cell) {
Info("Cell Select: Starting cell resynchronization\n");
} else {
if (!srslte_cell_isvalid(&cell)) {
log_h->error("Cell Select: Invalid cell. ID=%d, PRB=%d, ports=%d\n", cell.id, cell.nof_prb, cell.nof_ports);
return ret;
}
Info("Cell Select: Starting cell selection for PCI=%d, EARFCN=%d\n", new_cell->cell.id, new_cell->earfcn);
}
// Wait for any pending PHICH
while (worker_com->is_any_ul_pending_ack() && cnt < 10) {
usleep(1000);
cnt++;
Info("Cell Select: waiting pending PHICH (cnt=%d)\n", cnt);
}
Info("Cell Select: Going to IDLE\n");
phy_state.go_idle();
worker_com->reset();
sfn_p.reset();
search_p.reset();
srslte_ue_sync_reset(&ue_sync);
/* Reconfigure cell if necessary */
if (new_cell) {
if (new_cell->cell.id != cell.id) {
Info("Cell Select: Reconfiguring cell\n");
cell = new_cell->cell;
if (!set_cell()) {
Error("Cell Select: Reconfiguring cell\n");
return ret;
}
}
/* Select new frequency if necessary */
if ((int) new_cell->earfcn != current_earfcn) {
current_earfcn = new_cell->earfcn;
Info("Cell Select: Setting new frequency EARFCN=%d\n", new_cell->earfcn);
if (!set_frequency()) {
Error("Cell Select: Setting new frequency EARFCN=%d\n", new_cell->earfcn);
return ret;
}
}
}
/* Change sampling rate if necessary */
if (srate_mode != SRATE_CAMP) {
set_sampling_rate();
log_h->info("Cell Select: Setting CAMPING sampling rate\n");
}
/* SFN synchronization */
phy_state.run_sfn_sync();
if (phy_state.is_camping()) {
Info("Cell Select: SFN synchronized. CAMPING...\n");
ret = true;
} else {
Info("Cell Select: Could not synchronize SFN\n");
}
return ret;
}
bool sync::cell_is_camping()
{
return phy_state.is_camping();
}
/**
* MAIN THREAD
*
* The main thread process the SYNC state machine. Every state except IDLE must have exclusive access to
* all variables. If any change of cell configuration must be done, the thread must be in IDLE.
*
* On each state except campling, 1 function is called and the thread jumps to the next state based on the output.
*
* It has 3 states: Cell search, SFN synchronization, initial measurement and camping.
* - CELL_SEARCH: Initial Cell id and MIB acquisition. Uses 1.92 MHz sampling rate
* - CELL_SYNC: Full sampling rate, uses MIB to obtain SFN. When SFN is obtained, moves to CELL_CAMP
* - CELL_CAMP: Cell camping state. Calls the PHCH workers to process subframes and maintains cell synchronization.
* - IDLE: Receives and discards received samples. Does not maintain synchronization.
*
*/
void sync::run_thread()
{
sf_worker* worker = NULL;
sf_worker* last_worker = NULL;
cf_t* buffer[SRSLTE_MAX_RADIOS][SRSLTE_MAX_PORTS] = {NULL};
bool is_end_of_burst = false;
bool force_camping_sfn_sync = false;
cf_t *dummy_buffer[SRSLTE_MAX_PORTS];
uint32_t nof_rf_channels = worker_com->args->nof_rf_channels * worker_com->args->nof_rx_ant;
for (uint32_t i = 0; i < nof_rf_channels; i++) {
dummy_buffer[i] = (cf_t*)malloc(sizeof(cf_t) * SRSLTE_SF_LEN_PRB(100));
}
uint32_t prach_nof_sf = 0;
uint32_t prach_sf_cnt = 0;
cf_t *prach_ptr = NULL;
float prach_power = 0;
while (running)
{
Debug("SYNC: state=%s, tti=%d\n", phy_state.to_string(), tti);
// If not camping, clear SFN sync
if (!phy_state.is_camping()) {
force_camping_sfn_sync = false;
}
if (log_phy_lib_h) {
log_phy_lib_h->step(tti);
}
switch (phy_state.run_state()) {
case sync_state::CELL_SEARCH:
/* Search for a cell in the current frequency and go to IDLE.
* The function search_p.run() will not return until the search finishes
*/
cell_search_ret = search_p.run(&cell, mib);
if (cell_search_ret == search::CELL_FOUND) {
stack->bch_decoded_ok(mib.data(), mib.size() / 8);
}
phy_state.state_exit();
break;
case sync_state::SFN_SYNC:
/* SFN synchronization using MIB. run_subframe() receives and processes 1 subframe
* and returns
*/
switch (sfn_p.run_subframe(&cell, &tti, mib)) {
case sfn_sync::SFN_FOUND:
stack->in_sync();
phy_state.state_exit();
break;
case sfn_sync::IDLE:
break;
default:
phy_state.state_exit(false);
break;
}
break;
case sync_state::CAMPING:
worker = (sf_worker*)workers_pool->wait_worker(tti);
if (worker) {
// For each carrier...
for (uint32_t c = 0; c < worker_com->args->nof_carriers; c++) {
// get carrier mapping
carrier_map_t* m = &worker_com->args->carrier_map[c];
for (uint32_t i = 0; i < worker_com->args->nof_rx_ant; i++) {
buffer[m->radio_idx][m->channel_idx + i] = worker->get_buffer(c, i);
}
}
// Primary Cell (PCell) Synchronization
switch (srslte_ue_sync_zerocopy(&ue_sync, buffer[0])) {
case 1:
// Check tti is synched with ue_sync
if (srslte_ue_sync_get_sfidx(&ue_sync) != tti % 10) {
uint32_t sfn = tti / 10;
tti = (sfn * 10 + srslte_ue_sync_get_sfidx(&ue_sync)) % 10240;
// Force SFN decode, just in case it is in the wrong frame
force_camping_sfn_sync = true;
}
// Force decode MIB if required
if (force_camping_sfn_sync) {
uint32_t _tti = 0;
sync::sfn_sync::ret_code ret = sfn_p.decode_mib(&cell, &_tti, buffer[0], mib);
if (ret == sfn_sync::SFN_FOUND) {
// Force tti
tti = _tti;
// Disable
force_camping_sfn_sync = false;
}
}
Debug("SYNC: Worker %d synchronized\n", worker->get_id());
// Read Asynchronous SCell, for each asynch active object
for (uint32_t i = 0; i < worker_com->args->nof_radios - 1; i++) {
srslte_timestamp_t tx_time;
srslte_timestamp_init(&tx_time, 0, 0);
// Request TTI aligment
if (scell_sync->at(i)->tti_align(tti)) {
scell_sync->at(i)->read_sf(buffer[i + 1], &tx_time, &next_radio_offset[i + 1]);
srslte_timestamp_add(&tx_time, 0, TX_DELAY * 1e-3 - time_adv_sec);
} else {
// Failed, keep default Timestamp
// Error("SCell asynchronous failed to synchronise (%d)\n", i);
}
worker->set_tx_time(i + 1, tx_time, next_radio_offset[i + 1] + next_offset);
}
metrics.sfo = srslte_ue_sync_get_sfo(&ue_sync);
metrics.cfo = srslte_ue_sync_get_cfo(&ue_sync);
metrics.ta_us = time_adv_sec * 1e6f;
for (uint32_t i = 0; i < worker_com->args->nof_carriers; i++) {
if (worker_com->args->carrier_map[i].radio_idx == 0) {
worker_com->set_sync_metrics(i, metrics);
}
}
// Check if we need to TX a PRACH
if (prach_buffer->is_ready_to_send(tti)) {
prach_ptr = prach_buffer->generate(get_tx_cfo(), &prach_nof_sf, &prach_power);
if (!prach_ptr) {
Error("Generating PRACH\n");
}
}
/* Compute TX time: Any transmission happens in TTI+4 thus advance 4 ms the reception time */
srslte_timestamp_t rx_time, tx_time;
srslte_ue_sync_get_last_timestamp(&ue_sync, &rx_time);
srslte_timestamp_copy(&tx_time, &rx_time);
srslte_timestamp_add(&tx_time, 0, TX_DELAY * 1e-3 - time_adv_sec);
worker->set_prach(prach_ptr?&prach_ptr[prach_sf_cnt*SRSLTE_SF_LEN_PRB(cell.nof_prb)]:NULL, prach_power);
// Set CFO for all Carriers
for (uint32_t cc = 0; cc < worker_com->args->nof_carriers; cc++) {
float cfo;
// Get radio index for the given carrier
uint32_t radio_idx = worker_com->args->carrier_map[cc].radio_idx;
if (radio_idx == 0) {
// Use local CFO
cfo = get_tx_cfo();
} else {
// Request CFO in the asynchronous receiver
cfo = scell_sync->at(radio_idx - 1)->get_tx_cfo();
}
worker->set_cfo(cc, cfo);
}
worker->set_tti(tti, tx_worker_cnt);
worker->set_tx_time(0, tx_time, next_radio_offset[0] + next_offset);
next_offset = 0;
ZERO_OBJECT(next_radio_offset);
// Process time aligment command
if (next_time_adv_sec != time_adv_sec) {
time_adv_sec = next_time_adv_sec;
}
tx_worker_cnt = (tx_worker_cnt+1) % nof_workers;
// Advance/reset prach subframe pointer
if (prach_ptr) {
prach_sf_cnt++;
if (prach_sf_cnt == prach_nof_sf) {
prach_sf_cnt = 0;
prach_ptr = NULL;
}
}
is_end_of_burst = true;
// Start worker
workers_pool->start_worker(worker);
// Save signal for Intra-frequency measurement
if ((tti%5) == 0 && worker_com->args->sic_pss_enabled) {
srslte_pss_sic(&ue_sync.strack.pss,
&buffer[0][0][SRSLTE_SF_LEN_PRB(cell.nof_prb) / 2 - ue_sync.strack.fft_size]);
}
if (srslte_cell_isvalid(&cell)) {
intra_freq_meas.write(tti, buffer[0][0], SRSLTE_SF_LEN_PRB(cell.nof_prb));
}
break;
case 0:
Warning("SYNC: Out-of-sync detected in PSS/SSS\n");
out_of_sync();
worker->release();
// Force decoding MIB, for making sure that the TTI will be right
if (!force_camping_sfn_sync) {
force_camping_sfn_sync = true;
}
break;
default:
radio_error();
break;
}
} else {
// wait_worker() only returns NULL if it's being closed. Quit now to avoid unnecessary loops here
running = false;
}
break;
case sync_state::IDLE:
if (radio_h->is_init()) {
uint32_t nsamples = 1920;
if (current_srate > 0) {
nsamples = current_srate/1000;
}
Debug("Discarting %d samples\n", nsamples);
srslte_timestamp_t rx_time;
if (!radio_h->rx_now(0, dummy_buffer, nsamples, &rx_time)) {
log_h->console("SYNC: Receiving from radio while in IDLE_RX\n");
}
// If radio is in locked state returns inmidiatetly. In that case, do a 1 ms sleep
if (rx_time.frac_secs == 0 && rx_time.full_secs == 0) {
usleep(1000);
}
if (is_end_of_burst) {
radio_h->tx_end();
is_end_of_burst = true;
}
} else {
Debug("Sleeping\n");
usleep(1000);
}
break;
}
/* Radio overflow detected. If CAMPING, go through SFN sync again and when
* SFN is found again go back to camping
*/
if (!rrc_mutex.try_lock()) {
if (radio_is_overflow) {
// If we are coming back from an overflow
if (radio_overflow_return) {
if (phy_state.is_camping()) {
log_h->info("Successfully resynchronized after overflow. Returning to CAMPING\n");
radio_overflow_return = false;
radio_is_overflow = false;
} else if (phy_state.is_idle()) {
log_h->warning("Could not synchronize SFN after radio overflow. Trying again\n");
stack->out_of_sync();
phy_state.force_sfn_sync();
}
} else {
// Overflow has occurred now while camping
if (phy_state.is_camping()) {
log_h->warning("Detected radio overflow while camping. Resynchronizing cell\n");
sfn_p.reset();
srslte_ue_sync_reset(&ue_sync);
phy_state.force_sfn_sync();
radio_overflow_return = true;
} else {
radio_is_overflow = false;
}
// If overflow occurs in any other state, it does not harm
}
}
rrc_mutex.unlock();
}
// Increase TTI counter
tti = (tti+1) % 10240;
stack->run_tti(tti);
}
for (uint32_t p = 0; p < nof_rf_channels; p++) {
if (dummy_buffer[p]) {
free(dummy_buffer[p]);
}
}
}
/***************
*
* Utility functions called by the main thread or by functions called by other threads
*
*/
void sync::radio_overflow()
{
radio_is_overflow = true;
}
void sync::radio_error()
{
log_h->error("SYNC: Receiving from radio.\n");
// Need to find a method to effectively reset radio, reloading the driver does not work
radio_h->reset();
}
void sync::in_sync()
{
in_sync_cnt++;
// Send RRC in-sync signal after 100 ms consecutive subframes
if (in_sync_cnt == NOF_IN_SYNC_SF) {
stack->in_sync();
in_sync_cnt = 0;
out_of_sync_cnt = 0;
}
}
// Out of sync called by worker or sync every 1 or 5 ms
void sync::out_of_sync()
{
// Send RRC out-of-sync signal after NOF_OUT_OF_SYNC_SF consecutive subframes
Info("Out-of-sync %d/%d\n", out_of_sync_cnt, NOF_OUT_OF_SYNC_SF);
out_of_sync_cnt++;
if (out_of_sync_cnt == NOF_OUT_OF_SYNC_SF) {
Info("Sending to RRC\n");
stack->out_of_sync();
out_of_sync_cnt = 0;
in_sync_cnt = 0;
}
}
void sync::set_cfo(float cfo)
{
srslte_ue_sync_set_cfo_ref(&ue_sync, cfo);
}
void sync::set_agc_enable(bool enable)
{
if (enable) {
if (running && radio_h) {
srslte_rf_info_t* rf_info = radio_h->get_info(0);
srslte_ue_sync_start_agc(
&ue_sync, callback_set_rx_gain, rf_info->min_rx_gain, rf_info->max_rx_gain, radio_h->get_rx_gain(0));
search_p.set_agc_enable(true);
} else {
ERROR("Error setting AGC: PHY not initiatec\n");
}
} else {
ERROR("Error stopping AGC: not implemented\n");
}
}
void sync::set_time_adv_sec(float time_adv_sec)
{
// If transmitting earlier, transmit less samples to align time advance. If transmit later just delay next TX
next_offset = (int)round((this->time_adv_sec - time_adv_sec) * srslte_sampling_freq_hz(cell.nof_prb));
this->next_time_adv_sec = time_adv_sec;
Info("Applying time_adv_sec=%.1f us, next_offset=%d\n", time_adv_sec*1e6, next_offset);
}
float sync::get_tx_cfo()
{
float cfo = srslte_ue_sync_get_cfo(&ue_sync);
float ret = cfo*ul_dl_factor;
if (worker_com->args->cfo_is_doppler) {
ret *= -1;
} else {
/* Compensates the radio frequency offset applied equally to DL and UL. Does not work in doppler mode */
if (radio_h->get_freq_offset() != 0.0f) {
const float offset_hz = (float) radio_h->get_freq_offset() * (1.0f - ul_dl_factor);
ret = cfo - offset_hz;
}
}
return ret/15000;
}
void sync::set_ue_sync_opts(srslte_ue_sync_t* q, float cfo)
{
if (worker_com->args->cfo_integer_enabled) {
srslte_ue_sync_set_cfo_i_enable(q, true);
}
srslte_ue_sync_set_cfo_ema(q, worker_com->args->cfo_pss_ema);
srslte_ue_sync_set_cfo_tol(q, worker_com->args->cfo_correct_tol_hz);
srslte_ue_sync_set_cfo_loop_bw(q, worker_com->args->cfo_loop_bw_pss, worker_com->args->cfo_loop_bw_ref,
worker_com->args->cfo_loop_pss_tol,
worker_com->args->cfo_loop_ref_min,
worker_com->args->cfo_loop_pss_tol,
worker_com->args->cfo_loop_pss_conv);
q->strack.pss.chest_on_filter = worker_com->args->sic_pss_enabled;
// Disable CP based CFO estimation during find
if (cfo != 0) {
q->cfo_current_value = cfo/15000;
q->cfo_is_copied = true;
q->cfo_correct_enable_find = true;
srslte_sync_set_cfo_cp_enable(&q->sfind, false, 0);
}
// Set SFO ema and correct period
srslte_ue_sync_set_sfo_correct_period(q, worker_com->args->sfo_correct_period);
srslte_ue_sync_set_sfo_ema(q, worker_com->args->sfo_ema);
sss_alg_t sss_alg = SSS_FULL;
if (!worker_com->args->sss_algorithm.compare("diff")) {
sss_alg = SSS_DIFF;
} else if (!worker_com->args->sss_algorithm.compare("partial")) {
sss_alg = SSS_PARTIAL_3;
} else if (!worker_com->args->sss_algorithm.compare("full")) {
sss_alg = SSS_FULL;
} else {
Warning("SYNC: Invalid SSS algorithm %s. Using 'full'\n", worker_com->args->sss_algorithm.c_str());
}
srslte_sync_set_sss_algorithm(&q->strack, (sss_alg_t) sss_alg);
srslte_sync_set_sss_algorithm(&q->sfind, (sss_alg_t) sss_alg);
}
bool sync::set_cell()
{
if (!phy_state.is_idle()) {
Warning("Can not change Cell while not in IDLE\n");
return false;
}
// Set cell in all objects
if (srslte_ue_sync_set_cell(&ue_sync, cell)) {
Error("SYNC: Setting cell: initiating ue_sync\n");
return false;
}
sfn_p.set_cell(cell);
worker_com->set_cell(cell);
intra_freq_meas.set_primay_cell(current_earfcn, cell);
for (uint32_t i = 0; i < workers_pool->get_nof_workers(); i++) {
if (!((sf_worker*)workers_pool->get_worker(i))->set_cell(0, cell)) {
Error("SYNC: Setting cell: initiating PHCH worker\n");
return false;
}
}
// Set options defined in expert section
set_ue_sync_opts(&ue_sync, search_p.get_last_cfo());
// Reset ue_sync and set CFO/gain from search procedure
srslte_ue_sync_reset(&ue_sync);
return true;
}
void sync::set_earfcn(std::vector<uint32_t> earfcn)
{
this->earfcn = earfcn;
}
void sync::force_freq(float dl_freq, float ul_freq)
{
this->dl_freq = dl_freq;
this->ul_freq = ul_freq;
}
bool sync::set_frequency()
{
double set_dl_freq = 0;
double set_ul_freq = 0;
if (this->dl_freq > 0 && this->ul_freq > 0) {
set_dl_freq = this->dl_freq;
set_ul_freq = this->ul_freq;
} else {
set_dl_freq = 1e6*srslte_band_fd(current_earfcn);
if (srslte_band_is_tdd(srslte_band_get_band(current_earfcn))) {
set_ul_freq = set_dl_freq;
} else {
set_ul_freq = 1e6 * srslte_band_fu(srslte_band_ul_earfcn(current_earfcn));
}
}
if (set_dl_freq > 0 && set_ul_freq > 0) {
log_h->info("SYNC: Set DL EARFCN=%d, f_dl=%.1f MHz, f_ul=%.1f MHz\n",
current_earfcn, set_dl_freq / 1e6, set_ul_freq / 1e6);
log_h->console("Searching cell in DL EARFCN=%d, f_dl=%.1f MHz, f_ul=%.1f MHz\n",
current_earfcn, set_dl_freq / 1e6, set_ul_freq / 1e6);
carrier_map_t* m = &worker_com->args->carrier_map[0];
for (uint32_t i = 0; i < worker_com->args->nof_rx_ant; i++) {
radio_h->set_rx_freq(m->radio_idx, m->channel_idx + i, set_dl_freq);
radio_h->set_tx_freq(m->radio_idx, m->channel_idx + i, set_ul_freq);
}
ul_dl_factor = (float)(radio_h->get_tx_freq(m->radio_idx) / radio_h->get_rx_freq(m->radio_idx));
srslte_ue_sync_reset(&ue_sync);
return true;
} else {
log_h->error("SYNC: Cell Search: Invalid EARFCN=%d\n", current_earfcn);
return false;
}
}
void sync::set_sampling_rate()
{
float new_srate = (float)srslte_sampling_freq_hz(cell.nof_prb);
current_sflen = (uint32_t)SRSLTE_SF_LEN_PRB(cell.nof_prb);
if (current_srate != new_srate || srate_mode != SRATE_CAMP) {
current_srate = new_srate;
Info("SYNC: Setting sampling rate %.2f MHz\n", current_srate/1000000);
srate_mode = SRATE_CAMP;
radio_h->set_rx_srate(0, current_srate);
radio_h->set_tx_srate(0, current_srate);
} else {
Error("Error setting sampling rate for cell with %d PRBs\n", cell.nof_prb);
}
}
uint32_t sync::get_current_tti()
{
return tti;
}
void sync::get_current_cell(srslte_cell_t* cell, uint32_t* earfcn)
{
if (cell) {
*cell = this->cell;
}
if (earfcn) {
*earfcn = current_earfcn;
}
}
int sync::radio_recv_fnc(cf_t* data[SRSLTE_MAX_PORTS], uint32_t nsamples, srslte_timestamp_t* rx_time)
{
if (radio_h->rx_now(0, data, nsamples, rx_time)) {
if (channel_emulator && rx_time) {
channel_emulator->set_srate(current_srate);
channel_emulator->run(data, data, nsamples, *rx_time);
}
int offset = nsamples - current_sflen;
if (abs(offset) < 10 && offset != 0) {
next_radio_offset[0] = offset;
} else if (nsamples < 10) {
next_radio_offset[0] = nsamples;
}
log_h->debug("SYNC: received %d samples from radio\n", nsamples);
return nsamples;
} else {
return -1;
}
}
double sync::set_rx_gain(double gain)
{
return radio_h->set_rx_gain_th(gain);
}
/*********
* Cell search class
*/
sync::search::~search()
{
srslte_ue_mib_sync_free(&ue_mib_sync);
srslte_ue_cellsearch_free(&cs);
}
void sync::search::init(cf_t* buffer[SRSLTE_MAX_PORTS], srslte::log* log_h, uint32_t nof_rx_antennas, sync* parent)
{
this->log_h = log_h;
this->p = parent;
for (int i=0;i<SRSLTE_MAX_PORTS;i++) {
this->buffer[i] = buffer[i];
}
if (srslte_ue_cellsearch_init_multi(&cs, 8, radio_recv_callback, nof_rx_antennas, parent)) {
Error("SYNC: Initiating UE cell search\n");
}
srslte_ue_cellsearch_set_nof_valid_frames(&cs, 4);
if (srslte_ue_mib_sync_init_multi(&ue_mib_sync, radio_recv_callback, nof_rx_antennas, parent)) {
Error("SYNC: Initiating UE MIB synchronization\n");
}
// Set options defined in expert section
p->set_ue_sync_opts(&cs.ue_sync, 0);
force_N_id_2 = -1;
}
void sync::search::reset()
{
srslte_ue_sync_reset(&ue_mib_sync.ue_sync);
}
float sync::search::get_last_cfo()
{
return srslte_ue_sync_get_cfo(&ue_mib_sync.ue_sync);
}
void sync::search::set_agc_enable(bool enable)
{
if (enable) {
srslte_rf_info_t* rf_info = p->radio_h->get_info(0);
srslte_ue_sync_start_agc(&ue_mib_sync.ue_sync,
callback_set_rx_gain,
rf_info->min_rx_gain,
rf_info->max_rx_gain,
p->radio_h->get_rx_gain(0));
} else {
ERROR("Error stop AGC not implemented\n");
}
}
sync::search::ret_code sync::search::run(srslte_cell_t* cell, std::array<uint8_t, SRSLTE_BCH_PAYLOAD_LEN>& bch_payload)
{
if (!cell) {
return ERROR;
}
srslte_ue_cellsearch_result_t found_cells[3];
bzero(cell, sizeof(srslte_cell_t));
bzero(found_cells, 3 * sizeof(srslte_ue_cellsearch_result_t));
if (p->srate_mode != SRATE_FIND) {
p->srate_mode = SRATE_FIND;
p->radio_h->set_rx_srate(0, 1.92e6);
p->radio_h->set_tx_srate(0, 1.92e6);
Info("SYNC: Setting Cell Search sampling rate\n");
}
/* Find a cell in the given N_id_2 or go through the 3 of them to find the strongest */
uint32_t max_peak_cell = 0;
int ret = SRSLTE_ERROR;
Info("SYNC: Searching for cell...\n");
log_h->console(".");
if (force_N_id_2 >= 0 && force_N_id_2 < 3) {
ret = srslte_ue_cellsearch_scan_N_id_2(&cs, force_N_id_2, &found_cells[force_N_id_2]);
max_peak_cell = force_N_id_2;
} else {
ret = srslte_ue_cellsearch_scan(&cs, found_cells, &max_peak_cell);
}
if (ret < 0) {
Error("SYNC: Error decoding MIB: Error searching PSS\n");
return ERROR;
} else if (ret == 0) {
Info("SYNC: Could not find any cell in this frequency\n");
return CELL_NOT_FOUND;
}
// Save result
cell->id = found_cells[max_peak_cell].cell_id;
cell->cp = found_cells[max_peak_cell].cp;
cell->frame_type = found_cells[max_peak_cell].frame_type;
float cfo = found_cells[max_peak_cell].cfo;
log_h->console("\n");
Info("SYNC: PSS/SSS detected: Mode=%s, PCI=%d, CFO=%.1f KHz, CP=%s\n",
cell->frame_type ? "TDD" : "FDD",
cell->id,
cfo / 1000,
srslte_cp_string(cell->cp));
if (srslte_ue_mib_sync_set_cell(&ue_mib_sync, *cell)) {
Error("SYNC: Setting UE MIB cell\n");
return ERROR;
}
// Set options defined in expert section
p->set_ue_sync_opts(&ue_mib_sync.ue_sync, cfo);
srslte_ue_sync_reset(&ue_mib_sync.ue_sync);
/* Find and decode MIB */
int sfn_offset;
ret = srslte_ue_mib_sync_decode(&ue_mib_sync, 40, bch_payload.data(), &cell->nof_ports, &sfn_offset);
if (ret == 1) {
srslte_pbch_mib_unpack(bch_payload.data(), cell, NULL);
// pack MIB and store inplace for PCAP dump
std::array<uint8_t, SRSLTE_BCH_PAYLOAD_LEN / 8> mib_packed;
srslte_bit_pack_vector(bch_payload.data(), mib_packed.data(), SRSLTE_BCH_PAYLOAD_LEN);
std::copy(std::begin(mib_packed), std::end(mib_packed), std::begin(bch_payload));
fprintf(stdout,
"Found Cell: Mode=%s, PCI=%d, PRB=%d, Ports=%d, CFO=%.1f KHz\n",
cell->frame_type ? "TDD" : "FDD",
cell->id,
cell->nof_prb,
cell->nof_ports,
cfo / 1000);
Info("SYNC: MIB Decoded: Mode=%s, PCI=%d, PRB=%d, Ports=%d, CFO=%.1f KHz\n",
cell->frame_type ? "TDD" : "FDD",
cell->id,
cell->nof_prb,
cell->nof_ports,
cfo / 1000);
if (!srslte_cell_isvalid(cell)) {
Error("SYNC: Detected invalid cell.\n");
return CELL_NOT_FOUND;
}
return CELL_FOUND;
} else if (ret == 0) {
Warning("SYNC: Found PSS but could not decode PBCH\n");
return CELL_NOT_FOUND;
} else {
Error("SYNC: Receiving MIB\n");
return ERROR;
}
}
/*********
* SFN synchronizer class
*/
sync::sfn_sync::~sfn_sync()
{
srslte_ue_mib_free(&ue_mib);
}
void sync::sfn_sync::init(srslte_ue_sync_t* ue_sync,
cf_t* buffer[SRSLTE_MAX_PORTS],
srslte::log* log_h,
uint32_t nof_subframes)
{
this->log_h = log_h;
this->ue_sync = ue_sync;
this->timeout = nof_subframes;
for (int p = 0; p < SRSLTE_MAX_PORTS; p++) {
this->buffer[p] = buffer[p];
}
if (srslte_ue_mib_init(&ue_mib, this->buffer, SRSLTE_MAX_PRB)) {
Error("SYNC: Initiating UE MIB decoder\n");
}
}
bool sync::sfn_sync::set_cell(srslte_cell_t cell)
{
if (srslte_ue_mib_set_cell(&ue_mib, cell)) {
Error("SYNC: Setting cell: initiating ue_mib\n");
return false;
}
reset();
return true;
}
void sync::sfn_sync::reset()
{
cnt = 0;
srslte_ue_mib_reset(&ue_mib);
}
sync::sfn_sync::ret_code sync::sfn_sync::run_subframe(srslte_cell_t* cell,
uint32_t* tti_cnt,
std::array<uint8_t, SRSLTE_BCH_PAYLOAD_LEN>& bch_payload,
bool sfidx_only)
{
int ret = srslte_ue_sync_zerocopy(ue_sync, buffer);
if (ret < 0) {
Error("SYNC: Error calling ue_sync_get_buffer.\n");
return ERROR;
}
if (ret == 1) {
sync::sfn_sync::ret_code ret2 = decode_mib(cell, tti_cnt, NULL, bch_payload, sfidx_only);
if (ret2 != SFN_NOFOUND) {
return ret2;
}
} else {
Info("SYNC: Waiting for PSS while trying to decode MIB (%d/%d)\n", cnt, timeout);
}
cnt++;
if (cnt >= timeout) {
cnt = 0;
return SFN_NOFOUND;
}
return IDLE;
}
sync::sfn_sync::ret_code sync::sfn_sync::decode_mib(srslte_cell_t* cell,
uint32_t* tti_cnt,
cf_t* ext_buffer[SRSLTE_MAX_PORTS],
std::array<uint8_t, SRSLTE_BCH_PAYLOAD_LEN>& bch_payload,
bool sfidx_only)
{
// If external buffer provided not equal to internal buffer, copy data
if ((ext_buffer != NULL) && (ext_buffer != buffer)) {
memcpy(buffer[0], ext_buffer[0], sizeof(cf_t) * ue_sync->sf_len);
}
if (srslte_ue_sync_get_sfidx(ue_sync) == 0) {
// Skip MIB decoding if we are only interested in subframe 0
if (sfidx_only) {
if (tti_cnt) {
*tti_cnt = 0;
}
return SFX0_FOUND;
}
int sfn_offset = 0;
int n = srslte_ue_mib_decode(&ue_mib, bch_payload.data(), NULL, &sfn_offset);
switch (n) {
default:
Error("SYNC: Error decoding MIB while synchronising SFN");
return ERROR;
case SRSLTE_UE_MIB_FOUND:
uint32_t sfn;
srslte_pbch_mib_unpack(bch_payload.data(), cell, &sfn);
sfn = (sfn + sfn_offset) % 1024;
if (tti_cnt) {
*tti_cnt = 10 * sfn;
Info("SYNC: DONE, SNR=%.1f dB, TTI=%d, sfn_offset=%d\n", ue_mib.chest_res.snr_db, *tti_cnt, sfn_offset);
}
reset();
return SFN_FOUND;
case SRSLTE_UE_MIB_NOTFOUND:
Info("SYNC: Found PSS but could not decode MIB. SNR=%.1f dB (%d/%d)\n", ue_mib.chest_res.snr_db, cnt, timeout);
return SFN_NOFOUND;
}
}
return IDLE;
}
/**********
* PHY measurements
*
*/
void sync::meas_reset()
{
// Stop all measurements
intra_freq_meas.clear_cells();
}
int sync::meas_start(uint32_t earfcn, int pci)
{
if ((int) earfcn == current_earfcn) {
if (pci != (int) cell.id) {
intra_freq_meas.add_cell(pci);
}
return 0;
} else {
Warning("INTRA: Inter-frequency measurements not supported (current EARFCN=%d, requested measurement for %d)\n",
current_earfcn, earfcn);
return -1;
}
}
int sync::meas_stop(uint32_t earfcn, int pci)
{
if ((int) earfcn == current_earfcn) {
intra_freq_meas.rem_cell(pci);
return 0;
} else {
Warning("INTRA: Inter-frequency measurements not supported (current EARFCN=%d, requested stop measurement for %d)\n",
current_earfcn, earfcn);
}
return -1;
}
}
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