int lte_est_freq_offset(int **dl_ch_estimates,
LTE_DL_FRAME_PARMS *frame_parms,
int l,
int* freq_offset) {
int ch_offset, omega, dl_ch_shift;
struct complex16 *omega_cpx;
double phase_offset;
int freq_offset_est;
unsigned char aa;
s16 *dl_ch,*dl_ch_prev;
static int first_run = 1;
int coef = 1<<10;
int ncoef = 32767 - coef;
ch_offset = (l*(frame_parms->ofdm_symbol_size));
if ((l!=0) && (l!=(4-frame_parms->Ncp))) {
msg("lte_est_freq_offset: l (%d) must be 0 or %d\n",l,4-frame_parms->Ncp);
return(-1);
}
phase_offset = 0.0;
// for (aa=0;aa<frame_parms->nb_antennas_rx*frame_parms->nb_antennas_tx;aa++) {
for (aa=0;aa<1;aa++) {
dl_ch = (s16 *)&dl_ch_estimates[aa][12+ch_offset];
dl_ch_shift = 4+(log2_approx(dl_channel_level(dl_ch,frame_parms))/2);
// printf("dl_ch_shift: %d\n",dl_ch_shift);
if (ch_offset == 0)
dl_ch_prev = (s16 *)&dl_ch_estimates[aa][12+(4-frame_parms->Ncp)*(frame_parms->ofdm_symbol_size)];
else
dl_ch_prev = (s16 *)&dl_ch_estimates[aa][12+0];
// calculate omega = angle(conj(dl_ch)*dl_ch_prev))
// printf("Computing freq_offset\n");
omega = dot_product(dl_ch,dl_ch_prev,(frame_parms->N_RB_DL/2 - 1)*12,dl_ch_shift);
//omega = dot_product(dl_ch,dl_ch_prev,frame_parms->ofdm_symbol_size,15);
omega_cpx = (struct complex16*) ω
// printf("omega (%d,%d)\n",omega_cpx->r,omega_cpx->i);
dl_ch = (s16 *)&dl_ch_estimates[aa][(((frame_parms->N_RB_DL/2) + 1)*12) + ch_offset];
if (ch_offset == 0)
dl_ch_prev = (s16 *)&dl_ch_estimates[aa][(((frame_parms->N_RB_DL/2) + 1)*12)+(4-frame_parms->Ncp)*(frame_parms->ofdm_symbol_size)];
else
dl_ch_prev = (s16 *)&dl_ch_estimates[aa][((frame_parms->N_RB_DL/2) + 1)*12];
// calculate omega = angle(conj(dl_ch)*dl_ch_prev))
omega = dot_product(dl_ch,dl_ch_prev,((frame_parms->N_RB_DL/2) - 1)*12,dl_ch_shift);
omega_cpx->r += ((struct complex16*) &omega)->r;
omega_cpx->i += ((struct complex16*) &omega)->i;
// phase_offset += atan2((double)omega_cpx->i,(double)omega_cpx->r);
phase_offset += atan2((double)omega_cpx->i,(double)omega_cpx->r);
// printf("omega (%d,%d) -> %f\n",omega_cpx->r,omega_cpx->i,phase_offset);
}
// phase_offset /= (frame_parms->nb_antennas_rx*frame_parms->nb_antennas_tx);
freq_offset_est = (int) (phase_offset/(2*M_PI)/2.5e-4); //2.5e-4 is the time between pilot symbols
// printf("symbol %d : freq_offset_est %d\n",l,freq_offset_est);
// update freq_offset with phase_offset using a moving average filter
if (first_run == 1) {
*freq_offset = freq_offset_est;
first_run = 0;
}
else
*freq_offset = ((freq_offset_est * coef) + (*freq_offset * ncoef)) >> 15;
//#ifdef DEBUG_PHY
// msg("l=%d, phase_offset = %f (%d,%d), freq_offset_est = %d Hz, freq_offset_filt = %d \n",l,phase_offset,omega_cpx->r,omega_cpx->i,freq_offset_est,*freq_offset);
/*
for (i=0;i<150;i++)
msg("i %d : %d,%d <=> %d,%d\n",i,dl_ch[2*i],dl_ch[(2*i)+1],dl_ch_prev[2*i],dl_ch_prev[(2*i)+1]);
*/
//#endif
return(0);
}
void rx_ulsch(LTE_eNB_COMMON *eNB_common_vars,
LTE_eNB_ULSCH *eNB_ulsch_vars,
LTE_DL_FRAME_PARMS *frame_parms,
unsigned int subframe,
unsigned char eNB_id, // this is the effective sector id
LTE_eNB_ULSCH_t *ulsch,
u8 cooperation_flag) {
unsigned int l,i;
int avgs;
unsigned char log2_maxh,aarx;
int avgs_0,avgs_1;
unsigned log2_maxh_0,log2_maxh_1;
// unsigned char harq_pid = ( ulsch->RRCConnRequest_flag== 0) ? subframe2harq_pid_tdd(frame_parms->tdd_config,subframe) : 0;
unsigned char harq_pid = subframe2harq_pid(frame_parms,subframe);
unsigned char Qm = get_Qm(ulsch->harq_processes[harq_pid]->mcs);
unsigned short rx_power_correction;
#ifdef DEBUG_ULSCH
debug_msg("rx_ulsch: eNB_id %d, harq_pid %d, nb_rb %d first_rb %d, cooperation %d\n",eNB_id,harq_pid,ulsch->harq_processes[harq_pid]->nb_rb,ulsch->harq_processes[harq_pid]->first_rb, cooperation_flag);
#endif //DEBUG_ULSCH
if ( (frame_parms->ofdm_symbol_size == 128) ||
(frame_parms->ofdm_symbol_size == 512) )
rx_power_correction = 2;
else
rx_power_correction = 1;
for (l=0;l<frame_parms->symbols_per_tti-1;l++) {
#ifdef DEBUG_ULSCH
msg("rx_ulsch : symbol %d (first_rb %d,nb_rb %d), rxdataF %p, rxdataF_ext %p\n",l,
ulsch->harq_processes[harq_pid]->first_rb,
ulsch->harq_processes[harq_pid]->nb_rb,
eNB_common_vars->rxdataF[eNB_id],
eNB_ulsch_vars->rxdataF_ext[eNB_id]);
#endif //DEBUG_ULSCH
ulsch_extract_rbs_single(eNB_common_vars->rxdataF[eNB_id],
eNB_ulsch_vars->rxdataF_ext[eNB_id],
ulsch->harq_processes[harq_pid]->first_rb,
ulsch->harq_processes[harq_pid]->nb_rb,
l%(frame_parms->symbols_per_tti/2),
l/(frame_parms->symbols_per_tti/2),
frame_parms);
lte_ul_channel_estimation(eNB_ulsch_vars->drs_ch_estimates[eNB_id],
eNB_ulsch_vars->drs_ch_estimates_time[eNB_id],
eNB_ulsch_vars->drs_ch_estimates_0[eNB_id],
eNB_ulsch_vars->drs_ch_estimates_1[eNB_id],
eNB_ulsch_vars->rxdataF_ext[eNB_id],
frame_parms,
l%(frame_parms->symbols_per_tti/2),
l/(frame_parms->symbols_per_tti/2),
ulsch->harq_processes[harq_pid]->nb_rb,
ulsch->cyclicShift,
cooperation_flag);
ulsch_correct_ext(eNB_ulsch_vars->rxdataF_ext[eNB_id],
eNB_ulsch_vars->rxdataF_ext2[eNB_id],
l,
frame_parms,
ulsch->harq_processes[harq_pid]->nb_rb);
if(cooperation_flag == 2)
{
for (i=0;i<frame_parms->nb_antennas_rx;i++){
eNB_ulsch_vars->ulsch_power_0[i] = signal_energy_nodc(eNB_ulsch_vars->drs_ch_estimates_0[eNB_id][i],
ulsch->harq_processes[harq_pid]->nb_rb*12)*rx_power_correction;
eNB_ulsch_vars->ulsch_power_1[i] = signal_energy_nodc(eNB_ulsch_vars->drs_ch_estimates_1[eNB_id][i],
ulsch->harq_processes[harq_pid]->nb_rb*12)*rx_power_correction;
}
}
else
{
for (i=0;i<frame_parms->nb_antennas_rx;i++)
eNB_ulsch_vars->ulsch_power[i] = signal_energy_nodc(eNB_ulsch_vars->drs_ch_estimates[eNB_id][i],
ulsch->harq_processes[harq_pid]->nb_rb*12)*rx_power_correction;
}
}
if(cooperation_flag == 2)
{
ulsch_channel_level(eNB_ulsch_vars->drs_ch_estimates_0[eNB_id],
frame_parms,
avgU_0,
ulsch->harq_processes[harq_pid]->nb_rb);
// msg("[ULSCH] avg_0[0] %d\n",avgU_0[0]);
avgs_0 = 0;
for (aarx=0;aarx<frame_parms->nb_antennas_rx;aarx++)
avgs_0 = cmax(avgs_0,avgU_0[(aarx<<1)]);
log2_maxh_0 = 4+(log2_approx(avgs_0)/2);
#ifdef DEBUG_ULSCH
msg("[ULSCH] log2_maxh_0 = %d (%d,%d)\n",log2_maxh_0,avgU_0[0],avgs_0);
#endif
ulsch_channel_level(eNB_ulsch_vars->drs_ch_estimates_1[eNB_id],
frame_parms,
avgU_1,
ulsch->harq_processes[harq_pid]->nb_rb);
// msg("[ULSCH] avg_1[0] %d\n",avgU_1[0]);
avgs_1 = 0;
for (aarx=0;aarx<frame_parms->nb_antennas_rx;aarx++)
avgs_1 = cmax(avgs_1,avgU_1[(aarx<<1)]);
log2_maxh_1 = 4+(log2_approx(avgs_1)/2);
#ifdef DEBUG_ULSCH
msg("[ULSCH] log2_maxh_1 = %d (%d,%d)\n",log2_maxh_1,avgU_1[0],avgs_1);
#endif
}
else
{
ulsch_channel_level(eNB_ulsch_vars->drs_ch_estimates[eNB_id],
frame_parms,
avgU,
ulsch->harq_processes[harq_pid]->nb_rb);
// msg("[ULSCH] avg[0] %d\n",avgU[0]);
avgs = 0;
for (aarx=0;aarx<frame_parms->nb_antennas_rx;aarx++)
avgs = cmax(avgs,avgU[(aarx<<1)]);
log2_maxh = 2+(log2_approx(avgs)/2);
#ifdef DEBUG_ULSCH
msg("[ULSCH] log2_maxh = %d (%d,%d)\n",log2_maxh,avgU[0],avgs);
#endif
}
for (l=0;l<frame_parms->symbols_per_tti-1;l++) {
if (((frame_parms->Ncp == 0) && ((l==3) || (l==10)))|| // skip pilots
((frame_parms->Ncp == 1) && ((l==2) || (l==8)))) {
l++;
}
if(cooperation_flag == 2)
{
ulsch_channel_compensation_alamouti(eNB_ulsch_vars->rxdataF_ext2[eNB_id],
eNB_ulsch_vars->drs_ch_estimates_0[eNB_id],
eNB_ulsch_vars->drs_ch_estimates_1[eNB_id],
eNB_ulsch_vars->ul_ch_mag_0[eNB_id],
eNB_ulsch_vars->ul_ch_magb_0[eNB_id],
eNB_ulsch_vars->ul_ch_mag_1[eNB_id],
eNB_ulsch_vars->ul_ch_magb_1[eNB_id],
eNB_ulsch_vars->rxdataF_comp_0[eNB_id],
eNB_ulsch_vars->rxdataF_comp_1[eNB_id],
frame_parms,
l,
Qm,
ulsch->harq_processes[harq_pid]->nb_rb,
log2_maxh_0,
log2_maxh_1); // log2_maxh+I0_shift
ulsch_alamouti(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id],
eNB_ulsch_vars->rxdataF_comp_0[eNB_id],
eNB_ulsch_vars->rxdataF_comp_1[eNB_id],
eNB_ulsch_vars->ul_ch_mag[eNB_id],
eNB_ulsch_vars->ul_ch_magb[eNB_id],
eNB_ulsch_vars->ul_ch_mag_0[eNB_id],
eNB_ulsch_vars->ul_ch_magb_0[eNB_id],
eNB_ulsch_vars->ul_ch_mag_1[eNB_id],
eNB_ulsch_vars->ul_ch_magb_1[eNB_id],
l,
ulsch->harq_processes[harq_pid]->nb_rb);
}
else
{
ulsch_channel_compensation(eNB_ulsch_vars->rxdataF_ext2[eNB_id],
eNB_ulsch_vars->drs_ch_estimates[eNB_id],
eNB_ulsch_vars->ul_ch_mag[eNB_id],
eNB_ulsch_vars->ul_ch_magb[eNB_id],
eNB_ulsch_vars->rxdataF_comp[eNB_id],
frame_parms,
l,
Qm,
ulsch->harq_processes[harq_pid]->nb_rb,
log2_maxh); // log2_maxh+I0_shift
}
if (frame_parms->nb_antennas_rx > 1)
ulsch_detection_mrc(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id],
eNB_ulsch_vars->ul_ch_mag[eNB_id],
eNB_ulsch_vars->ul_ch_magb[eNB_id],
l,
ulsch->harq_processes[harq_pid]->nb_rb);
#ifndef OFDMA_ULSCH
freq_equalization(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id],
eNB_ulsch_vars->ul_ch_mag[eNB_id],
eNB_ulsch_vars->ul_ch_magb[eNB_id],
l,
ulsch->harq_processes[harq_pid]->nb_rb*12,
Qm);
#endif
}
#ifndef OFDMA_ULSCH
//#ifdef DEBUG_ULSCH
// Inverse-Transform equalized outputs
// msg("Doing IDFTs\n");
lte_idft(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id][0],
ulsch->harq_processes[harq_pid]->nb_rb*12);
// msg("Done\n");
//#endif //DEBUG_ULSCH
#endif
for (l=0;l<frame_parms->symbols_per_tti-1;l++) {
if (((frame_parms->Ncp == 0) && ((l==3) || (l==10)))|| // skip pilots
((frame_parms->Ncp == 1) && ((l==2) || (l==8)))) {
l++;
}
switch (Qm) {
case 2 :
ulsch_qpsk_llr(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id],
eNB_ulsch_vars->llr,
l,
ulsch->harq_processes[harq_pid]->nb_rb);
break;
case 4 :
ulsch_16qam_llr(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id],
eNB_ulsch_vars->llr,
eNB_ulsch_vars->ul_ch_mag[eNB_id],
l,ulsch->harq_processes[harq_pid]->nb_rb);
break;
case 6 :
ulsch_64qam_llr(frame_parms,
eNB_ulsch_vars->rxdataF_comp[eNB_id],
eNB_ulsch_vars->llr,
eNB_ulsch_vars->ul_ch_mag[eNB_id],
eNB_ulsch_vars->ul_ch_magb[eNB_id],
l,ulsch->harq_processes[harq_pid]->nb_rb);
break;
default:
#ifdef DEBUG_ULSCH
msg("ulsch_demodulation.c (rx_ulsch): Unknown Qm!!!!\n");
#endif //DEBUG_ULSCH
break;
}
}
}
