/* * 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<<1)]; 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<<1)]; 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); } }