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/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.1 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
#include "PHY/types.h"
#include "PHY/defs_UE.h"
#include "PHY/LTE_ESTIMATION/lte_estimation.h"
#include "PHY/impl_defs_top.h"
#include "openair2/LAYER2/MAC/mac_proto.h"
#include "common/utils/LOG/vcd_signal_dumper.h"
#define DEBUG_PHY
// Adjust location synchronization point to account for drift
// The adjustment is performed once per frame based on the
// last channel estimate of the receiver
void lte_adjust_synch(LTE_DL_FRAME_PARMS *frame_parms,
PHY_VARS_UE *ue,
module_id_t eNB_id,
uint8_t subframe,
unsigned char clear,
short coef)
{
static int max_pos_fil = 0;
static int count_max_pos_ok = 0;
static int first_time = 1;
int temp = 0, i, aa, max_val = 0, max_pos = 0;
int diff;
short Re,Im,ncoef;
VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_ADJUST_SYNCH, VCD_FUNCTION_IN);
ncoef = 32767 - coef;
#ifdef DEBUG_PHY
LOG_D(PHY,"AbsSubframe %d.%d: rx_offset (before) = %d\n",ue->proc.proc_rxtx[0].frame_rx%1024,subframe,ue->rx_offset);
#endif //DEBUG_PHY
// we only use channel estimates from tx antenna 0 here
for (i = 0; i < frame_parms->nb_prefix_samples; i++) {
temp = 0;
for (aa=0; aa<frame_parms->nb_antennas_rx; aa++) {
Re = ((int16_t*)ue->common_vars.common_vars_rx_data_per_thread[ue->current_thread_id[subframe]].dl_ch_estimates_time[eNB_id][aa])[(i<<2)];
Im = ((int16_t*)ue->common_vars.common_vars_rx_data_per_thread[ue->current_thread_id[subframe]].dl_ch_estimates_time[eNB_id][aa])[1+(i<<2)];
temp += (Re*Re/2) + (Im*Im/2);
}
if (temp > max_val) {
max_pos = i;
max_val = temp;
}
}
// filter position to reduce jitter
if (clear == 1)
max_pos_fil = max_pos;
else
max_pos_fil = ((max_pos_fil * coef) + (max_pos * ncoef)) >> 15;
// do not filter to have proactive timing adjustment
max_pos_fil = max_pos;
if(subframe == 5)
{
diff = max_pos_fil - (frame_parms->nb_prefix_samples>>3);
if ( abs(diff) < SYNCH_HYST )
ue->rx_offset = 0;
else
ue->rx_offset = diff;
if(abs(diff)<5)
count_max_pos_ok ++;
else
count_max_pos_ok = 0;
if(count_max_pos_ok > 10 && first_time == 1)
{
first_time = 0;
ue->time_sync_cell = 1;
if (ue->mac_enabled==1) {
LOG_I(PHY,"[UE%d] Sending synch status to higher layers\n",ue->Mod_id);
//mac_resynch();
dl_phy_sync_success(ue->Mod_id,ue->proc.proc_rxtx[0].frame_rx,0,1);//ue->common_vars.eNb_id);
ue->UE_mode[0] = PRACH;
}
else {
ue->UE_mode[0] = PUSCH;
}
}
if ( ue->rx_offset < 0 )
ue->rx_offset += FRAME_LENGTH_COMPLEX_SAMPLES;
if ( ue->rx_offset >= FRAME_LENGTH_COMPLEX_SAMPLES )
ue->rx_offset -= FRAME_LENGTH_COMPLEX_SAMPLES;
#ifdef DEBUG_PHY
LOG_D(PHY,"AbsSubframe %d.%d: ThreadId %d diff =%i rx_offset (final) = %i : clear %d,max_pos = %d,max_pos_fil = %d (peak %d) max_val %d target_pos %d \n",
ue->proc.proc_rxtx[ue->current_thread_id[subframe]].frame_rx,
subframe,
ue->current_thread_id[subframe],
diff,
ue->rx_offset,
clear,
max_pos,
max_pos_fil,
temp,max_val,
(frame_parms->nb_prefix_samples>>3));
#endif //DEBUG_PHY
VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_ADJUST_SYNCH, VCD_FUNCTION_OUT);
}
}