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296494ea4c010e0fb4cd8ca72fe69743a45c92b4
openairinterface5g/openair1/PHY/LTE_ESTIMATION/lte_sync_time.c
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frtabu 296494ea4c create dft shared lib
2020-03-30 18:23:32 +02:00

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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
*/
/* file: lte_sync_time.c
purpose: coarse timing synchronization for LTE (using PSS)
author: florian.kaltenberger@eurecom.fr, oscar.tonelli@yahoo.it
date: 22.10.2009
*/
//#include <string.h>
#include <math.h>
#include "LAYER2/MAC/mac.h"
#include "PHY/defs_UE.h"
#include "PHY/phy_extern_ue.h"
#include "PHY_INTERFACE/phy_interface.h"
#include "PHY/LTE_REFSIG/lte_refsig.h"
#include "RRC/LTE/rrc_extern.h"
// Note: this is for prototype of generate_drs_pusch (OTA synchronization of RRUs)
#include "PHY/LTE_UE_TRANSPORT/transport_proto_ue.h"
int* sync_corr_ue0 = NULL;
int* sync_corr_ue1 = NULL;
int* sync_corr_ue2 = NULL;
int sync_tmp[2048*4] __attribute__((aligned(32)));
short syncF_tmp[2048*2] __attribute__((aligned(32)));
int lte_sync_time_init(LTE_DL_FRAME_PARMS *frame_parms ) // LTE_UE_COMMON *common_vars
{
int i,k;
sync_corr_ue0 = (int *)malloc16(LTE_NUMBER_OF_SUBFRAMES_PER_FRAME*sizeof(int)*frame_parms->samples_per_tti);
sync_corr_ue1 = (int *)malloc16(LTE_NUMBER_OF_SUBFRAMES_PER_FRAME*sizeof(int)*frame_parms->samples_per_tti);
sync_corr_ue2 = (int *)malloc16(LTE_NUMBER_OF_SUBFRAMES_PER_FRAME*sizeof(int)*frame_parms->samples_per_tti);
if (sync_corr_ue0) {
#ifdef DEBUG_PHY
LOG_D(PHY,"[openair][LTE_PHY][SYNC] sync_corr_ue allocated at %p\n", sync_corr_ue0);
#endif
//common_vars->sync_corr = sync_corr;
} else {
LOG_E(PHY,"[openair][LTE_PHY][SYNC] sync_corr_ue0 not allocated\n");
return(-1);
}
if (sync_corr_ue1) {
#ifdef DEBUG_PHY
LOG_D(PHY,"[openair][LTE_PHY][SYNC] sync_corr_ue allocated at %p\n", sync_corr_ue1);
#endif
//common_vars->sync_corr = sync_corr;
} else {
LOG_E(PHY,"[openair][LTE_PHY][SYNC] sync_corr_ue1 not allocated\n");
return(-1);
}
if (sync_corr_ue2) {
#ifdef DEBUG_PHY
LOG_D(PHY,"[openair][LTE_PHY][SYNC] sync_corr_ue allocated at %p\n", sync_corr_ue2);
#endif
//common_vars->sync_corr = sync_corr;
} else {
LOG_E(PHY,"[openair][LTE_PHY][SYNC] sync_corr_ue2 not allocated\n");
return(-1);
}
// primary_synch0_time = (int *)malloc16((frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples)*sizeof(int));
primary_synch0_time = (int16_t *)malloc16((frame_parms->ofdm_symbol_size)*sizeof(int16_t)*2);
if (primary_synch0_time) {
// bzero(primary_synch0_time,(frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples)*sizeof(int));
bzero(primary_synch0_time,(frame_parms->ofdm_symbol_size)*sizeof(int16_t)*2);
#ifdef DEBUG_PHY
LOG_D(PHY,"[openair][LTE_PHY][SYNC] primary_synch0_time allocated at %p\n", primary_synch0_time);
#endif
} else {
LOG_E(PHY,"[openair][LTE_PHY][SYNC] primary_synch0_time not allocated\n");
return(-1);
}
// primary_synch1_time = (int *)malloc16((frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples)*sizeof(int));
primary_synch1_time = (int16_t *)malloc16((frame_parms->ofdm_symbol_size)*sizeof(int16_t)*2);
if (primary_synch1_time) {
// bzero(primary_synch1_time,(frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples)*sizeof(int));
bzero(primary_synch1_time,(frame_parms->ofdm_symbol_size)*sizeof(int16_t)*2);
#ifdef DEBUG_PHY
LOG_D(PHY,"[openair][LTE_PHY][SYNC] primary_synch1_time allocated at %p\n", primary_synch1_time);
#endif
} else {
LOG_E(PHY,"[openair][LTE_PHY][SYNC] primary_synch1_time not allocated\n");
return(-1);
}
// primary_synch2_time = (int *)malloc16((frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples)*sizeof(int));
primary_synch2_time = (int16_t *)malloc16((frame_parms->ofdm_symbol_size)*sizeof(int16_t)*2);
if (primary_synch2_time) {
// bzero(primary_synch2_time,(frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples)*sizeof(int));
bzero(primary_synch2_time,(frame_parms->ofdm_symbol_size)*sizeof(int16_t)*2);
#ifdef DEBUG_PHY
LOG_D(PHY,"[openair][LTE_PHY][SYNC] primary_synch2_time allocated at %p\n", primary_synch2_time);
#endif
} else {
LOG_E(PHY,"[openair][LTE_PHY][SYNC] primary_synch2_time not allocated\n");
return(-1);
}
// generate oversampled sync_time sequences
k=frame_parms->ofdm_symbol_size-36;
for (i=0; i<72; i++) {
syncF_tmp[2*k] = primary_synch0[2*i]>>2; //we need to shift input to avoid overflow in fft
syncF_tmp[2*k+1] = primary_synch0[2*i+1]>>2;
k++;
if (k >= frame_parms->ofdm_symbol_size) {
k++; // skip DC carrier
k-=frame_parms->ofdm_symbol_size;
}
}
switch (frame_parms->N_RB_DL) {
case 6:
idft(IDFT_128,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 25:
idft(IDFT_512,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 50:
idft(IDFT_1024,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 75:
idft(IDFT_1536,(short*)syncF_tmp, /// complex input
(short*)sync_tmp,
1); /// complex output
break;
case 100:
idft(IDFT_2048,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
default:
LOG_E(PHY,"Unsupported N_RB_DL %d\n",frame_parms->N_RB_DL);
break;
}
for (i=0; i<frame_parms->ofdm_symbol_size; i++)
((int32_t*)primary_synch0_time)[i] = sync_tmp[i];
k=frame_parms->ofdm_symbol_size-36;
for (i=0; i<72; i++) {
syncF_tmp[2*k] = primary_synch1[2*i]>>2; //we need to shift input to avoid overflow in fft
syncF_tmp[2*k+1] = primary_synch1[2*i+1]>>2;
k++;
if (k >= frame_parms->ofdm_symbol_size) {
k++; // skip DC carrier
k-=frame_parms->ofdm_symbol_size;
}
}
switch (frame_parms->N_RB_DL) {
case 6:
idft(IDFT_128,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 25:
idft(IDFT_512,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 50:
idft(IDFT_1024,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 75:
idft(IDFT_1536,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 100:
idft(IDFT_2048,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
default:
LOG_E(PHY,"Unsupported N_RB_DL %d\n",frame_parms->N_RB_DL);
break;
}
for (i=0; i<frame_parms->ofdm_symbol_size; i++)
((int32_t*)primary_synch1_time)[i] = sync_tmp[i];
k=frame_parms->ofdm_symbol_size-36;
for (i=0; i<72; i++) {
syncF_tmp[2*k] = primary_synch2[2*i]>>2; //we need to shift input to avoid overflow in fft
syncF_tmp[2*k+1] = primary_synch2[2*i+1]>>2;
k++;
if (k >= frame_parms->ofdm_symbol_size) {
k++; // skip DC carrier
k-=frame_parms->ofdm_symbol_size;
}
}
switch (frame_parms->N_RB_DL) {
case 6:
idft(IDFT_128,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 25:
idft(IDFT_512,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 50:
idft(IDFT_1024,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 75:
idft(IDFT_1536,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
case 100:
idft(IDFT_2048,(short*)syncF_tmp, /// complex input
(short*)sync_tmp, /// complex output
1);
break;
default:
LOG_E(PHY,"Unsupported N_RB_DL %d\n",frame_parms->N_RB_DL);
break;
}
for (i=0; i<frame_parms->ofdm_symbol_size; i++)
((int32_t*)primary_synch2_time)[i] = sync_tmp[i];
if ( LOG_DUMPFLAG(DEBUG_LTEESTIM)){
LOG_M("primary_sync0.m","psync0",primary_synch0_time,frame_parms->ofdm_symbol_size,1,1);
LOG_M("primary_sync1.m","psync1",primary_synch1_time,frame_parms->ofdm_symbol_size,1,1);
LOG_M("primary_sync2.m","psync2",primary_synch2_time,frame_parms->ofdm_symbol_size,1,1);
}
return (1);
}
void lte_sync_time_free(void)
{
if (sync_corr_ue0) {
LOG_D(PHY,"Freeing sync_corr_ue (%p)...\n",sync_corr_ue0);
free(sync_corr_ue0);
}
if (sync_corr_ue1) {
LOG_D(PHY,"Freeing sync_corr_ue (%p)...\n",sync_corr_ue1);
free(sync_corr_ue1);
}
if (sync_corr_ue2) {
LOG_D(PHY,"Freeing sync_corr_ue (%p)...\n",sync_corr_ue2);
free(sync_corr_ue2);
}
if (primary_synch0_time) {
LOG_D(PHY,"Freeing primary_sync0_time ...\n");
free(primary_synch0_time);
}
if (primary_synch1_time) {
LOG_D(PHY,"Freeing primary_sync1_time ...\n");
free(primary_synch1_time);
}
if (primary_synch2_time) {
LOG_D(PHY,"Freeing primary_sync2_time ...\n");
free(primary_synch2_time);
}
sync_corr_ue0 = NULL;
sync_corr_ue1 = NULL;
sync_corr_ue2 = NULL;
primary_synch0_time = NULL;
primary_synch1_time = NULL;
primary_synch2_time = NULL;
}
static inline int abs32(int x)
{
return (((int)((short*)&x)[0])*((int)((short*)&x)[0]) + ((int)((short*)&x)[1])*((int)((short*)&x)[1]));
}
#define SHIFT 17
int lte_sync_time(int **rxdata, ///rx data in time domain
LTE_DL_FRAME_PARMS *frame_parms,
int *eNB_id)
{
// perform a time domain correlation using the oversampled sync sequence
unsigned int n, ar, s, peak_pos, peak_val, sync_source;
int result,result2;
int sync_out[3] = {0,0,0},sync_out2[3] = {0,0,0};
int tmp[3] = {0,0,0};
int length = LTE_NUMBER_OF_SUBFRAMES_PER_FRAME*frame_parms->samples_per_tti>>1;
//LOG_D(PHY,"[SYNC TIME] Calling sync_time.\n");
AssertFatal(sync_corr_ue0 != NULL,
"sync_corr_ue0 not yet allocated! Exiting.\n");
AssertFatal(sync_corr_ue1 != NULL,
"sync_corr_ue0 not yet allocated! Exiting.\n");
AssertFatal(sync_corr_ue2 != NULL,
"sync_corr_ue0 not yet allocated! Exiting.\n");
peak_val = 0;
peak_pos = 0;
sync_source = 0;
for (n=0; n<length; n+=4) {
sync_corr_ue0[n] = 0;
sync_corr_ue0[n+length] = 0;
sync_corr_ue1[n] = 0;
sync_corr_ue1[n+length] = 0;
sync_corr_ue2[n] = 0;
sync_corr_ue2[n+length] = 0;
for (s=0; s<3; s++) {
sync_out[s]=0;
sync_out2[s]=0;
}
// if (n<(length-frame_parms->ofdm_symbol_size-frame_parms->nb_prefix_samples)) {
if (n<(length-frame_parms->ofdm_symbol_size)) {
//calculate dot product of primary_synch0_time and rxdata[ar][n] (ar=0..nb_ant_rx) and store the sum in temp[n];
for (ar=0; ar<frame_parms->nb_antennas_rx; ar++) {
result = dot_product((short*)primary_synch0_time, (short*) &(rxdata[ar][n]), frame_parms->ofdm_symbol_size, SHIFT);
result2 = dot_product((short*)primary_synch0_time, (short*) &(rxdata[ar][n+length]), frame_parms->ofdm_symbol_size, SHIFT);
((short*)sync_corr_ue0)[2*n] += ((short*) &result)[0];
((short*)sync_corr_ue0)[2*n+1] += ((short*) &result)[1];
((short*)sync_corr_ue0)[2*(length+n)] += ((short*) &result2)[0];
((short*)sync_corr_ue0)[(2*(length+n))+1] += ((short*) &result2)[1];
((short*)sync_out)[0] += ((short*) &result)[0];
((short*)sync_out)[1] += ((short*) &result)[1];
((short*)sync_out2)[0] += ((short*) &result2)[0];
((short*)sync_out2)[1] += ((short*) &result2)[1];
}
for (ar=0; ar<frame_parms->nb_antennas_rx; ar++) {
result = dot_product((short*)primary_synch1_time, (short*) &(rxdata[ar][n]), frame_parms->ofdm_symbol_size, SHIFT);
result2 = dot_product((short*)primary_synch1_time, (short*) &(rxdata[ar][n+length]), frame_parms->ofdm_symbol_size, SHIFT);
((short*)sync_corr_ue1)[2*n] += ((short*) &result)[0];
((short*)sync_corr_ue1)[2*n+1] += ((short*) &result)[1];
((short*)sync_corr_ue1)[2*(length+n)] += ((short*) &result2)[0];
((short*)sync_corr_ue1)[(2*(length+n))+1] += ((short*) &result2)[1];
((short*)sync_out)[2] += ((short*) &result)[0];
((short*)sync_out)[3] += ((short*) &result)[1];
((short*)sync_out2)[2] += ((short*) &result2)[0];
((short*)sync_out2)[3] += ((short*) &result2)[1];
}
for (ar=0; ar<frame_parms->nb_antennas_rx; ar++) {
result = dot_product((short*)primary_synch2_time, (short*) &(rxdata[ar][n]), frame_parms->ofdm_symbol_size, SHIFT);
result2 = dot_product((short*)primary_synch2_time, (short*) &(rxdata[ar][n+length]), frame_parms->ofdm_symbol_size, SHIFT);
((short*)sync_corr_ue2)[2*n] += ((short*) &result)[0];
((short*)sync_corr_ue2)[2*n+1] += ((short*) &result)[1];
((short*)sync_corr_ue2)[2*(length+n)] += ((short*) &result2)[0];
((short*)sync_corr_ue2)[(2*(length+n))+1] += ((short*) &result2)[1];
((short*)sync_out)[4] += ((short*) &result)[0];
((short*)sync_out)[5] += ((short*) &result)[1];
((short*)sync_out2)[4] += ((short*) &result2)[0];
((short*)sync_out2)[5] += ((short*) &result2)[1];
}
}
// calculate the absolute value of sync_corr[n]
sync_corr_ue0[n] = abs32(sync_corr_ue0[n]);
sync_corr_ue0[n+length] = abs32(sync_corr_ue0[n+length]);
sync_corr_ue1[n] = abs32(sync_corr_ue1[n]);
sync_corr_ue1[n+length] = abs32(sync_corr_ue1[n+length]);
sync_corr_ue2[n] = abs32(sync_corr_ue2[n]);
sync_corr_ue2[n+length] = abs32(sync_corr_ue2[n+length]);
for (s=0; s<3; s++) {
tmp[s] = (abs32(sync_out[s])>>1) + (abs32(sync_out2[s])>>1);
if (tmp[s]>peak_val) {
peak_val = tmp[s];
peak_pos = n;
sync_source = s;
/*
printf("s %d: n %d sync_out %d, sync_out2 %d (sync_corr %d,%d), (%d,%d) (%d,%d)\n",s,n,abs32(sync_out[s]),abs32(sync_out2[s]),sync_corr_ue0[n],
sync_corr_ue0[n+length],((int16_t*)&sync_out[s])[0],((int16_t*)&sync_out[s])[1],((int16_t*)&sync_out2[s])[0],((int16_t*)&sync_out2[s])[1]);
*/
}
}
}
*eNB_id = sync_source;
LOG_I(PHY,"[UE] lte_sync_time: Sync source = %d, Peak found at pos %d, val = %d (%d dB)\n",sync_source,peak_pos,peak_val,dB_fixed(peak_val)/2);
if ( LOG_DUMPFLAG(DEBUG_LTEESTIM)){
static int debug_cnt;
if (debug_cnt == 0) {
LOG_M("sync_corr0_ue.m","synccorr0",sync_corr_ue0,2*length,1,2);
LOG_M("sync_corr1_ue.m","synccorr1",sync_corr_ue1,2*length,1,2);
LOG_M("sync_corr2_ue.m","synccorr2",sync_corr_ue2,2*length,1,2);
LOG_M("rxdata0.m","rxd0",rxdata[0],length<<1,1,1);
// exit(-1);
} else {
debug_cnt++;
}
}
return(peak_pos);
}
int ru_sync_time_init(RU_t *ru) // LTE_UE_COMMON *common_vars
{
/*
int16_t dmrs[2048];
int16_t *dmrsp[2] = {dmrs,NULL};
*/
int32_t dmrs[ru->frame_parms->ofdm_symbol_size*14] __attribute__((aligned(32)));
//int32_t *dmrsp[2] = {&dmrs[(3-ru->frame_parms->Ncp)*ru->frame_parms->ofdm_symbol_size],NULL};
int32_t *dmrsp[2] = {&dmrs[0],NULL};
generate_ul_ref_sigs();
ru->dmrssync = (int16_t*)malloc16_clear(ru->frame_parms->ofdm_symbol_size*2*sizeof(int16_t));
ru->dmrs_corr = (uint64_t*)malloc16_clear(ru->frame_parms->samples_per_tti*10*sizeof(uint64_t));
generate_drs_pusch(NULL,
NULL,
ru->frame_parms,
dmrsp,
0,
AMP,
0,
0,
ru->frame_parms->N_RB_DL,
0);
switch (ru->frame_parms->N_RB_DL) {
case 6:
idft(IDFT_128,(int16_t*)(&dmrsp[0][3*ru->frame_parms->ofdm_symbol_size]),
ru->dmrssync, /// complex output
1);
break;
case 25:
idft(IDFT_512,(int16_t*)(&dmrsp[0][3*ru->frame_parms->ofdm_symbol_size]),
ru->dmrssync, /// complex output
1);
break;
case 50:
idft(IDFT_1024,(int16_t*)(&dmrsp[0][3*ru->frame_parms->ofdm_symbol_size]),
ru->dmrssync, /// complex output
1);
break;
case 75:
idft(IDFT_1536,(int16_t*)(&dmrsp[0][3*ru->frame_parms->ofdm_symbol_size]),
ru->dmrssync,
1); /// complex output
break;
case 100:
idft(IDFT_2048,(int16_t*)(&dmrsp[0][3*ru->frame_parms->ofdm_symbol_size]),
ru->dmrssync, /// complex output
1);
break;
default:
AssertFatal(1==0,"Unsupported N_RB_DL %d\n",ru->frame_parms->N_RB_DL);
break;
}
return(0);
}
void ru_sync_time_free(RU_t *ru) {
AssertFatal(ru->dmrssync!=NULL,"ru->dmrssync is NULL\n");
free(ru->dmrssync);
if (ru->dmrs_corr) free(ru->dmrs_corr);
}
//#define DEBUG_PHY
int lte_sync_time_eNB(int32_t **rxdata, ///rx data in time domain
LTE_DL_FRAME_PARMS *frame_parms,
uint32_t length,
uint32_t *peak_val_out,
uint32_t *sync_corr_eNB)
{
// perform a time domain correlation using the oversampled sync sequence
unsigned int n, ar, peak_val, peak_pos;
uint64_t mean_val;
int result;
short *primary_synch_time;
int eNB_id = frame_parms->Nid_cell%3;
// LOG_E(PHY,"[SYNC TIME] Calling sync_time_eNB(%p,%p,%d,%d)\n",rxdata,frame_parms,eNB_id,length);
if (sync_corr_eNB == NULL) {
LOG_E(PHY,"[SYNC TIME] sync_corr_eNB not yet allocated! Exiting.\n");
return(-1);
}
switch (eNB_id) {
case 0:
primary_synch_time = (short*)primary_synch0_time;
break;
case 1:
primary_synch_time = (short*)primary_synch1_time;
break;
case 2:
primary_synch_time = (short*)primary_synch2_time;
break;
default:
LOG_E(PHY,"[SYNC TIME] Illegal eNB_id!\n");
return (-1);
}
peak_val = 0;
peak_pos = 0;
mean_val = 0;
for (n=0; n<length; n+=4) {
sync_corr_eNB[n] = 0;
if (n<(length-frame_parms->ofdm_symbol_size-frame_parms->nb_prefix_samples)) {
//calculate dot product of primary_synch0_time and rxdata[ar][n] (ar=0..nb_ant_rx) and store the sum in temp[n];
for (ar=0; ar<frame_parms->nb_antennas_rx; ar++) {
result = dot_product((short*)primary_synch_time, (short*) &(rxdata[ar][n]), frame_parms->ofdm_symbol_size, SHIFT);
//((short*)sync_corr)[2*n] += ((short*) &result)[0];
//((short*)sync_corr)[2*n+1] += ((short*) &result)[1];
sync_corr_eNB[n] += abs32(result);
}
}
/*
if (eNB_id == 2) {
printf("sync_time_eNB %d : %d,%d (%d)\n",n,sync_corr_eNB[n],mean_val,
peak_val);
}
*/
mean_val += sync_corr_eNB[n];
if (sync_corr_eNB[n]>peak_val) {
peak_val = sync_corr_eNB[n];
peak_pos = n;
}
}
mean_val/=length;
*peak_val_out = peak_val;
if (peak_val <= (40*(uint32_t)mean_val)) {
LOG_I(PHY,"[SYNC TIME] No peak found (%u,%u,%"PRIu64",%"PRIu64")\n",peak_pos,peak_val,mean_val,40*mean_val);
return(-1);
} else {
LOG_I(PHY,"[SYNC TIME] Peak found at pos %u, val = %u, mean_val = %"PRIu64"\n",peak_pos,peak_val,mean_val);
return(peak_pos);
}
}
static inline int64_t abs64(int64_t x)
{
return (((int64_t)((int32_t*)&x)[0])*((int64_t)((int32_t*)&x)[0]) + ((int64_t)
((int32_t*)&x)[1])*((int64_t)((int32_t*)&x)[1]));
}
int ru_sync_time(RU_t *ru,
int64_t *lev,
int64_t *avg)
{
LTE_DL_FRAME_PARMS *frame_parms = ru->frame_parms;
RU_CALIBRATION *calibration = &ru->calibration;
// perform a time domain correlation using the oversampled sync sequence
int length = LTE_NUMBER_OF_SUBFRAMES_PER_FRAME*frame_parms->samples_per_tti;
// circular copy of beginning to end of rxdata buffer. Note: buffer should be big enough upon calling this function
for (int ar=0;ar<ru->nb_rx;ar++) memcpy((void*)&ru->common.rxdata[ar][2*length],
(void*)&ru->common.rxdata[ar][0],
frame_parms->ofdm_symbol_size);
int32_t maxlev0=0;
int maxpos0=0;
int64_t avg0=0;
int64_t result;
int64_t dmrs_corr;
int maxval=0;
for (int i=0;i<2*(frame_parms->ofdm_symbol_size);i++) {
maxval = max(maxval,ru->dmrssync[i]);
maxval = max(maxval,-ru->dmrssync[i]);
}
if (ru->state == RU_CHECK_SYNC) {
for (int i=0;i<2*(frame_parms->ofdm_symbol_size);i++) {
maxval = max(maxval,calibration->drs_ch_estimates_time[0][i]);
maxval = max(maxval,-calibration->drs_ch_estimates_time[0][i]);
}
}
int shift = log2_approx(maxval);
for (int n=0; n<length; n+=4) {
dmrs_corr = 0;
//calculate dot product of primary_synch0_time and rxdata[ar][n] (ar=0..nb_ant_rx) and store the sum in temp[n];
for (int ar=0; ar<ru->nb_rx; ar++) {
result = dot_product64(ru->dmrssync,
(int16_t*) &ru->common.rxdata[ar][n],
frame_parms->ofdm_symbol_size,
shift);
if (ru->state == RU_CHECK_SYNC) {
result = dot_product64((int16_t*) &calibration->drs_ch_estimates_time[ar],
(int16_t*) &ru->common.rxdata[ar][n],
frame_parms->ofdm_symbol_size,
shift);
}
dmrs_corr += abs64(result);
}
if (ru->dmrs_corr != NULL) ru->dmrs_corr[n] = dmrs_corr;
// tmpi holds <synchi,rx0>+<synci,rx1>+...+<synchi,rx_{nbrx-1}>
if (dmrs_corr>maxlev0) { maxlev0 = dmrs_corr; maxpos0 = n; }
avg0 += dmrs_corr;
}
avg0/=(length/4);
int dmrsoffset = frame_parms->samples_per_tti + (3*frame_parms->ofdm_symbol_size)+(3*frame_parms->nb_prefix_samples) + frame_parms->nb_prefix_samples0;
if ((int64_t)maxlev0 > (10*avg0)) {*lev = maxlev0; *avg=avg0; return((length+maxpos0-dmrsoffset)%length);}
return(-1);
}
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