mirror of https://github.com/pvnis/srsRAN_4G.git
SRSUE: initial scell sync
SRSUE: SCell Synch feedbacks delay SRSUE: Implemented SCell Radio offset correctionmaster
Xavier Arteaga
5 years ago
committed by
Xavier Arteaga
parent
5c0bb000ca
commit
e0e8405285
@ -0,0 +1,192 @@
|
||||
/*
|
||||
* Copyright 2013-2020 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/.
|
||||
*
|
||||
*/
|
||||
|
||||
#ifndef SRSLTE_SCELL_SYNC_H
|
||||
#define SRSLTE_SCELL_SYNC_H
|
||||
|
||||
namespace srsue {
|
||||
namespace scell {
|
||||
|
||||
/**
|
||||
* Radio feedback interface
|
||||
*/
|
||||
class sync_callback
|
||||
{
|
||||
public:
|
||||
/**
|
||||
* Provides secondary serving cell synchronization feedback
|
||||
* @param ch channel index
|
||||
* @param offset Number of samples to offset
|
||||
*/
|
||||
virtual void set_rx_channel_offset(uint32_t ch, int32_t offset) = 0;
|
||||
};
|
||||
|
||||
class sync
|
||||
{
|
||||
private:
|
||||
/**
|
||||
* FSM
|
||||
*
|
||||
* Init +------+ Set cell +------------+ PSS found +----------+
|
||||
* or -->| IDLE |---------->| Search PSS |---------->| In-Synch |
|
||||
* Stop +------+ +------------+ +----------+
|
||||
* ^ Set Cell |
|
||||
* | |
|
||||
* +----------------------+
|
||||
*/
|
||||
typedef enum { STATE_IDLE = 0, STATE_SEARCH_PSS, STATE_IN_SYNCH } state_t;
|
||||
|
||||
state_t state = STATE_IDLE;
|
||||
sync_callback* callback = nullptr;
|
||||
uint32_t channel = 0;
|
||||
srslte_sync_t find_pss = {};
|
||||
int32_t sf_len = 0;
|
||||
std::array<cf_t, SRSLTE_SF_LEN_MAX> temp;
|
||||
|
||||
/**
|
||||
* Executes the PSS search state
|
||||
* @param tti
|
||||
* @param buffer
|
||||
*/
|
||||
void run_state_search_pss(uint32_t tti, cf_t* buffer)
|
||||
{
|
||||
uint32_t peak_pos = 0;
|
||||
|
||||
// Append new base-band
|
||||
srslte_vec_cf_copy(&temp[sf_len], buffer, sf_len);
|
||||
|
||||
// Run PSS search
|
||||
switch (srslte_sync_find(&find_pss, temp.data(), 0, &peak_pos)) {
|
||||
|
||||
case SRSLTE_SYNC_FOUND:
|
||||
if (callback != nullptr) {
|
||||
// Calculate Sample Offset from TTI difference
|
||||
int tti_mod = (int)tti % (SRSLTE_NOF_SF_X_FRAME / 2);
|
||||
int tti_offset = (tti_mod < 3) ? tti_mod : (tti_mod - SRSLTE_NOF_SF_X_FRAME / 2);
|
||||
|
||||
// Calculate sample offset from PSS correlation peak
|
||||
int offset = (int)(peak_pos - (3 * sf_len) / 2);
|
||||
|
||||
// Provide offset through feedback interface
|
||||
callback->set_rx_channel_offset(channel, offset + tti_offset * sf_len);
|
||||
}
|
||||
state = STATE_IN_SYNCH;
|
||||
break;
|
||||
case SRSLTE_SYNC_FOUND_NOSPACE:
|
||||
ERROR("No space error\n");
|
||||
break;
|
||||
case SRSLTE_SYNC_NOFOUND:
|
||||
// Ignore
|
||||
break;
|
||||
case SRSLTE_SYNC_ERROR:
|
||||
ERROR("Error finding PSS\n");
|
||||
break;
|
||||
}
|
||||
|
||||
// If the state has not changed, copy new data into the temp buffer
|
||||
if (state == STATE_SEARCH_PSS) {
|
||||
srslte_vec_cf_copy(&temp[0], buffer, sf_len);
|
||||
}
|
||||
}
|
||||
|
||||
public:
|
||||
/**
|
||||
* Constructor
|
||||
* @param _callback provides the class for giving feedback
|
||||
* @param _channel provides the channel index where the feedback needs to be applied
|
||||
*/
|
||||
sync(sync_callback* _callback, uint32_t _channel) : callback(_callback), channel(_channel)
|
||||
{
|
||||
// Initialise Find PSS object
|
||||
if (srslte_sync_init(&find_pss, SRSLTE_SF_LEN_MAX, SRSLTE_SF_LEN_MAX, SRSLTE_SYMBOL_SZ_MAX) != SRSLTE_SUCCESS) {
|
||||
ERROR("Initiating Synchroniser\n");
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Sets the cell for the synchronizer
|
||||
*/
|
||||
void set_cell(const srslte_cell_t& cell)
|
||||
{
|
||||
uint32_t symbol_sz = srslte_symbol_sz(cell.nof_prb);
|
||||
sf_len = SRSLTE_SF_LEN_PRB(cell.nof_prb);
|
||||
|
||||
// Resize Sync object
|
||||
if (srslte_sync_resize(&find_pss, 2 * sf_len, 2 * sf_len, symbol_sz) != SRSLTE_SUCCESS) {
|
||||
ERROR("Error setting cell sync find\n");
|
||||
}
|
||||
|
||||
// Configure
|
||||
srslte_sync_set_frame_type(&find_pss, cell.frame_type);
|
||||
srslte_sync_set_N_id_2(&find_pss, cell.id % SRSLTE_NOF_NID_2);
|
||||
srslte_sync_set_N_id_1(&find_pss, cell.id / SRSLTE_NOF_NID_2);
|
||||
srslte_sync_set_cfo_ema_alpha(&find_pss, 0.1);
|
||||
srslte_sync_set_em_alpha(&find_pss, 1);
|
||||
srslte_sync_set_threshold(&find_pss, 3.0);
|
||||
|
||||
// Reset Temporal buffer
|
||||
srslte_vec_cf_zero(temp.data(), 2 * sf_len);
|
||||
|
||||
// Go to search PSS
|
||||
state = STATE_SEARCH_PSS;
|
||||
}
|
||||
|
||||
/**
|
||||
* Resets the class, goes back into IDLE mode
|
||||
*/
|
||||
void stop() { state = STATE_IDLE; }
|
||||
|
||||
/**
|
||||
* Runs internal FSM, performing Synchronization operations on the provided buffer. It expects data per sub-frame
|
||||
* basis (1 ms).
|
||||
* @param tti Current primary serving cell time
|
||||
* @param buffer Base-band buffer of the given secondary serving cell
|
||||
*/
|
||||
void run(uint32_t tti, cf_t* buffer)
|
||||
{
|
||||
switch (state) {
|
||||
case STATE_IDLE:
|
||||
// Do nothing
|
||||
break;
|
||||
case STATE_SEARCH_PSS:
|
||||
run_state_search_pss(tti, buffer);
|
||||
break;
|
||||
case STATE_IN_SYNCH:
|
||||
// Do nothing
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Get channel index
|
||||
* @return The channel number it has been configured
|
||||
*/
|
||||
uint32_t get_channel() const { return channel; }
|
||||
|
||||
/**
|
||||
* Indicates whether the secondary serving cell assigned to the instance is in-sync
|
||||
* @return true if it is in sync state
|
||||
*/
|
||||
bool is_in_sync() const { return state == STATE_IN_SYNCH; }
|
||||
};
|
||||
} // namespace scell
|
||||
} // namespace srsue
|
||||
#endif // SRSLTE_SCELL_SYNC_H
|
||||
Loading…
Reference in New Issue