/******************************************************************************* OpenAirInterface Copyright(c) 1999 - 2014 Eurecom OpenAirInterface is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. OpenAirInterface 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenAirInterface.The full GNU General Public License is included in this distribution in the file called "COPYING". If not, see . Contact Information OpenAirInterface Admin: openair_admin@eurecom.fr OpenAirInterface Tech : openair_tech@eurecom.fr OpenAirInterface Dev : openair4g-devel@eurecom.fr Address : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE *******************************************************************************/ #include "PHY/types.h" #include "PHY/defs.h" #include "PHY/extern.h" #include "MAC_INTERFACE/defs.h" #include "MAC_INTERFACE/extern.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 *phy_vars_ue, unsigned char eNB_id, unsigned char clear, short coef) { static int max_pos_fil = 0; int temp = 0, i, aa, max_val = 0, max_pos = 0; int diff; short Re,Im,ncoef; ncoef = 32767 - coef; #ifdef DEBUG_PHY LOG_D(PHY,"frame %d: rx_offset (before) = %d\n",phy_vars_ue->frame_rx,phy_vars_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;aanb_antennas_rx;aa++) { Re = ((int16_t*)phy_vars_ue->lte_ue_common_vars.dl_ch_estimates_time[eNB_id][aa])[(i<<2)]; Im = ((int16_t*)phy_vars_ue->lte_ue_common_vars.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; diff = max_pos_fil - 2; //frame_parms->nb_prefix_samples/8; if ( diff > SYNCH_HYST ) phy_vars_ue->rx_offset++; else if (diff < -SYNCH_HYST) phy_vars_ue->rx_offset--; if ( phy_vars_ue->rx_offset < 0 ) phy_vars_ue->rx_offset += FRAME_LENGTH_COMPLEX_SAMPLES; if ( phy_vars_ue->rx_offset >= FRAME_LENGTH_COMPLEX_SAMPLES ) phy_vars_ue->rx_offset -= FRAME_LENGTH_COMPLEX_SAMPLES; #ifdef DEBUG_PHY LOG_D(PHY,"frame %d: rx_offset (after) = %d : max_pos = %d,max_pos_fil = %d (peak %d)\n", phy_vars_ue->frame_rx,phy_vars_ue->rx_offset,max_pos,max_pos_fil,temp); #endif //DEBUG_PHY } int lte_est_timing_advance(LTE_DL_FRAME_PARMS *frame_parms, LTE_eNB_SRS *lte_eNb_srs, unsigned int *eNB_id, unsigned char clear, unsigned char number_of_cards, short coef) { static int max_pos_fil2 = 0; int temp, i, aa, max_pos = 0,ind; int max_val=0; short Re,Im,ncoef; #ifdef USER_MODE #ifdef DEBUG_PHY char fname[100],vname[100]; #endif #endif ncoef = 32768 - coef; for (ind=0;indnb_antennas_rx;aa++) { // do ifft of channel estimate fft((short*) <e_eNb_srs->srs_ch_estimates[ind][aa][0], (short*) lte_eNb_srs->srs_ch_estimates_time[ind][aa], frame_parms->twiddle_ifft, frame_parms->rev, frame_parms->log2_symbol_size, frame_parms->log2_symbol_size/2, 0); #ifdef USER_MODE #ifdef DEBUG_PHY sprintf(fname,"srs_ch_estimates_time_%d%d.m",ind,aa); sprintf(vname,"srs_time_%d%d",ind,aa); write_output(fname,vname,lte_eNb_srs->srs_ch_estimates_time[ind][aa],frame_parms->ofdm_symbol_size*2,2,1); #endif #endif } // we only use channel estimates from tx antenna 0 here // remember we fixed the SRS to use only every second subcarriers for (i = 0; i < frame_parms->ofdm_symbol_size/2; i++) { temp = 0; for (aa=0;aanb_antennas_rx;aa++) { Re = ((int16_t*)lte_eNb_srs->srs_ch_estimates_time[ind][aa])[(i<<2)]; Im = ((int16_t*)lte_eNb_srs->srs_ch_estimates_time[ind][aa])[1+(i<<2)]; temp += (Re*Re/2) + (Im*Im/2); } if (temp > max_val) { max_pos = i; max_val = temp; *eNB_id = ind; } } } // filter position to reduce jitter if (clear == 1) max_pos_fil2 = max_pos; else max_pos_fil2 = ((max_pos_fil2 * coef) + (max_pos * ncoef)) >> 15; #ifdef DEBUG_PHY //LOG_D(PHY,"frame %d: max_pos = %d, max_pos_fil = %d\n",mac_xface->frame,max_pos,max_pos_fil2); #endif //DEBUG_PHY return(max_pos_fil2); } int lte_est_timing_advance_pusch(PHY_VARS_eNB* phy_vars_eNB,uint8_t UE_id,uint8_t sched_subframe) { static int first_run=1; static int max_pos_fil2=0; int temp, i, aa, max_pos=0, max_val=0; short Re,Im,coef=24576; short ncoef = 32768 - coef; LTE_DL_FRAME_PARMS *frame_parms = &phy_vars_eNB->lte_frame_parms; LTE_eNB_PUSCH *eNB_pusch_vars = phy_vars_eNB->lte_eNB_pusch_vars[UE_id]; int32_t **ul_ch_estimates_time= eNB_pusch_vars->drs_ch_estimates_time[0]; int subframe = phy_vars_eNB->proc[sched_subframe].subframe_rx; uint8_t harq_pid; uint8_t Ns = 1; //we take the estimate from the second slot uint8_t cyclic_shift = 0;//(frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.cyclicShift + //phy_vars_eNB->ulsch_eNB[UE_id]->harq_processes[harq_pid]->n_DMRS2 + //frame_parms->pusch_config_common.ul_ReferenceSignalsPUSCH.nPRS[(subframe<<1)+Ns]) % 12; harq_pid = subframe2harq_pid(frame_parms,phy_vars_eNB->proc[sched_subframe].frame_rx,subframe); int sync_pos = (frame_parms->ofdm_symbol_size-cyclic_shift*frame_parms->ofdm_symbol_size/12)%(frame_parms->ofdm_symbol_size); for (i = 0; i < frame_parms->ofdm_symbol_size; i++) { temp = 0; for (aa=0;aanb_antennas_rx;aa++) { Re = ((int16_t*)ul_ch_estimates_time[aa])[(i<<2)]; Im = ((int16_t*)ul_ch_estimates_time[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 (first_run == 1){ first_run=0; max_pos_fil2 = max_pos; } else max_pos_fil2 = ((max_pos_fil2 * coef) + (max_pos * ncoef)) >> 15; #ifdef DEBUG_PHY LOG_I(PHY,"frame %d: max_pos = %d, max_pos_fil = %d, sync_pos=%d\n",phy_vars_eNB->proc[sched_subframe].frame_rx,max_pos,max_pos_fil2,sync_pos); #endif //DEBUG_PHY return(max_pos_fil2-sync_pos); }