/* * 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 1.0 (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 PHY/LTE_TRANSPORT/initial_sync.c * \brief Routines for initial UE synchronization procedure (PSS,SSS,PBCH and frame format detection) * \author R. Knopp, F. Kaltenberger * \date 2011 * \version 0.1 * \company Eurecom * \email: knopp@eurecom.fr,kaltenberger@eurecom.fr * \note * \warning */ #include "PHY/types.h" #include "PHY/defs.h" #include "PHY/extern.h" #include "SCHED/defs.h" #include "SCHED/extern.h" #include "defs.h" #include "extern.h" #include "common_lib.h" extern openair0_config_t openair0_cfg[]; //#define DEBUG_INITIAL_SYNCH int pbch_detection(PHY_VARS_UE *ue, runmode_t mode) { uint8_t l,pbch_decoded,frame_mod4,pbch_tx_ant,dummy; LTE_DL_FRAME_PARMS *frame_parms=&ue->frame_parms; char phich_resource[6]; #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"[UE%d] Initial sync: starting PBCH detection (rx_offset %d)\n",ue->Mod_id, ue->rx_offset); #endif for (l=0; l<frame_parms->symbols_per_tti/2; l++) { slot_fep(ue, l, 0, ue->rx_offset, 0, 1); } for (l=0; l<frame_parms->symbols_per_tti/2; l++) { slot_fep(ue, l, 1, ue->rx_offset, 0, 1); } slot_fep(ue, 0, 2, ue->rx_offset, 0, 1); lte_ue_measurements(ue, ue->rx_offset, 0, 0); if (ue->frame_parms.frame_type == TDD) { ue_rrc_measurements(ue, 1, 0); } else { ue_rrc_measurements(ue, 0, 0); } #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"[UE %d] RX RSSI %d dBm, digital (%d, %d) dB, linear (%d, %d), avg rx power %d dB (%d lin), RX gain %d dB\n", ue->Mod_id, ue->measurements.rx_rssi_dBm[0] - ((ue->frame_parms.nb_antennas_rx==2) ? 3 : 0), ue->measurements.rx_power_dB[0][0], ue->measurements.rx_power_dB[0][1], ue->measurements.rx_power[0][0], ue->measurements.rx_power[0][1], ue->measurements.rx_power_avg_dB[0], ue->measurements.rx_power_avg[0], ue->rx_total_gain_dB); LOG_I(PHY,"[UE %d] N0 %d dBm digital (%d, %d) dB, linear (%d, %d), avg noise power %d dB (%d lin)\n", ue->Mod_id, ue->measurements.n0_power_tot_dBm, ue->measurements.n0_power_dB[0], ue->measurements.n0_power_dB[1], ue->measurements.n0_power[0], ue->measurements.n0_power[1], ue->measurements.n0_power_avg_dB, ue->measurements.n0_power_avg); #endif pbch_decoded = 0; for (frame_mod4=0; frame_mod4<4; frame_mod4++) { pbch_tx_ant = rx_pbch(&ue->common_vars, ue->pbch_vars[0], frame_parms, 0, SISO, ue->high_speed_flag, frame_mod4); if ((pbch_tx_ant>0) && (pbch_tx_ant<=2)) { pbch_decoded = 1; break; } pbch_tx_ant = rx_pbch(&ue->common_vars, ue->pbch_vars[0], frame_parms, 0, ALAMOUTI, ue->high_speed_flag, frame_mod4); if ((pbch_tx_ant>0) && (pbch_tx_ant<=2)) { pbch_decoded = 1; break; } } if (pbch_decoded) { frame_parms->nb_antennas_tx_eNB = pbch_tx_ant; // set initial transmission mode to 1 or 2 depending on number of detected TX antennas frame_parms->mode1_flag = (pbch_tx_ant==1); // openair_daq_vars.dlsch_transmission_mode = (pbch_tx_ant>1) ? 2 : 1; // flip byte endian on 24-bits for MIB // dummy = ue->pbch_vars[0]->decoded_output[0]; // ue->pbch_vars[0]->decoded_output[0] = ue->pbch_vars[0]->decoded_output[2]; // ue->pbch_vars[0]->decoded_output[2] = dummy; // now check for Bandwidth of Cell dummy = (ue->pbch_vars[0]->decoded_output[2]>>5)&7; switch (dummy) { case 0 : frame_parms->N_RB_DL = 6; break; case 1 : frame_parms->N_RB_DL = 15; break; case 2 : frame_parms->N_RB_DL = 25; break; case 3 : frame_parms->N_RB_DL = 50; break; case 4 : frame_parms->N_RB_DL = 75; break; case 5: frame_parms->N_RB_DL = 100; break; default: LOG_E(PHY,"[UE%d] Initial sync: PBCH decoding: Unknown N_RB_DL\n",ue->Mod_id); return -1; break; } // now check for PHICH parameters frame_parms->phich_config_common.phich_duration = (PHICH_DURATION_t)((ue->pbch_vars[0]->decoded_output[2]>>4)&1); dummy = (ue->pbch_vars[0]->decoded_output[2]>>2)&3; switch (dummy) { case 0: frame_parms->phich_config_common.phich_resource = oneSixth; sprintf(phich_resource,"1/6"); break; case 1: frame_parms->phich_config_common.phich_resource = half; sprintf(phich_resource,"1/2"); break; case 2: frame_parms->phich_config_common.phich_resource = one; sprintf(phich_resource,"1"); break; case 3: frame_parms->phich_config_common.phich_resource = two; sprintf(phich_resource,"2"); break; default: LOG_E(PHY,"[UE%d] Initial sync: Unknown PHICH_DURATION\n",ue->Mod_id); return -1; break; } ue->proc.proc_rxtx[0].frame_rx = (((ue->pbch_vars[0]->decoded_output[2]&3)<<6) + (ue->pbch_vars[0]->decoded_output[1]>>2))<<2; ue->proc.proc_rxtx[0].frame_rx += frame_mod4; ue->proc.proc_rxtx[1].frame_rx = (((ue->pbch_vars[0]->decoded_output[2]&3)<<6) + (ue->pbch_vars[0]->decoded_output[1]>>2))<<2; ue->proc.proc_rxtx[1].frame_rx += frame_mod4; #ifndef USER_MODE // one frame delay ue->proc.proc_rxtx[0].frame_rx ++; ue->proc.proc_rxtx[1].frame_rx ++; #endif ue->proc.proc_rxtx[0].frame_tx = ue->proc.proc_rxtx[0].frame_rx; ue->proc.proc_rxtx[1].frame_tx = ue->proc.proc_rxtx[1].frame_rx; #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"[UE%d] Initial sync: pbch decoded sucessfully mode1_flag %d, tx_ant %d, frame %d, N_RB_DL %d, phich_duration %d, phich_resource %s!\n", ue->Mod_id, frame_parms->mode1_flag, pbch_tx_ant, ue->proc.proc_rxtx[0].frame_rx, frame_parms->N_RB_DL, frame_parms->phich_config_common.phich_duration, phich_resource); //frame_parms->phich_config_common.phich_resource); #endif return(0); } else { return(-1); } } char phich_string[13][4] = {"","1/6","","1/2","","","one","","","","","","two"}; char duplex_string[2][4] = {"FDD","TDD"}; char prefix_string[2][9] = {"NORMAL","EXTENDED"}; int initial_sync(PHY_VARS_UE *ue, runmode_t mode) { int32_t sync_pos,sync_pos2,sync_pos_slot; int32_t metric_fdd_ncp=0,metric_fdd_ecp=0,metric_tdd_ncp=0,metric_tdd_ecp=0; uint8_t phase_fdd_ncp,phase_fdd_ecp,phase_tdd_ncp,phase_tdd_ecp; uint8_t flip_fdd_ncp,flip_fdd_ecp,flip_tdd_ncp,flip_tdd_ecp; // uint16_t Nid_cell_fdd_ncp=0,Nid_cell_fdd_ecp=0,Nid_cell_tdd_ncp=0,Nid_cell_tdd_ecp=0; LTE_DL_FRAME_PARMS *frame_parms = &ue->frame_parms; int ret=-1; int aarx,rx_power=0; /*#ifdef OAI_USRP __m128i *rxdata128; #endif*/ // LOG_I(PHY,"**************************************************************\n"); // First try FDD normal prefix frame_parms->Ncp=NORMAL; frame_parms->frame_type=FDD; init_frame_parms(frame_parms,1); /* write_output("rxdata0.m","rxd0",ue->common_vars.rxdata[0],10*frame_parms->samples_per_tti,1,1); exit(-1); */ sync_pos = lte_sync_time(ue->common_vars.rxdata, frame_parms, (int *)&ue->common_vars.eNb_id); // write_output("rxdata1.m","rxd1",ue->common_vars.rxdata[0],10*frame_parms->samples_per_tti,1,1); if (sync_pos >= frame_parms->nb_prefix_samples) sync_pos2 = sync_pos - frame_parms->nb_prefix_samples; else sync_pos2 = sync_pos + FRAME_LENGTH_COMPLEX_SAMPLES - frame_parms->nb_prefix_samples; #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"[UE%d] Initial sync : Estimated PSS position %d, Nid2 %d\n",ue->Mod_id,sync_pos,ue->common_vars.eNb_id); #endif // SSS detection // PSS is hypothesized in last symbol of first slot in Frame sync_pos_slot = (frame_parms->samples_per_tti>>1) - frame_parms->ofdm_symbol_size - frame_parms->nb_prefix_samples; if (sync_pos2 >= sync_pos_slot) ue->rx_offset = sync_pos2 - sync_pos_slot; else ue->rx_offset = FRAME_LENGTH_COMPLEX_SAMPLES + sync_pos2 - sync_pos_slot; if (((sync_pos2 - sync_pos_slot) >=0 ) && ((sync_pos2 - sync_pos_slot) < ((FRAME_LENGTH_COMPLEX_SAMPLES-frame_parms->samples_per_tti/2)))) { #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"Calling sss detection (FDD normal CP)\n"); #endif rx_sss(ue,&metric_fdd_ncp,&flip_fdd_ncp,&phase_fdd_ncp); frame_parms->nushift = frame_parms->Nid_cell%6; if (flip_fdd_ncp==1) ue->rx_offset += (FRAME_LENGTH_COMPLEX_SAMPLES>>1); init_frame_parms(&ue->frame_parms,1); lte_gold(frame_parms,ue->lte_gold_table[0],frame_parms->Nid_cell); ret = pbch_detection(ue,mode); // write_output("rxdata2.m","rxd2",ue->common_vars.rxdata[0],10*frame_parms->samples_per_tti,1,1); #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"FDD Normal prefix: CellId %d metric %d, phase %d, flip %d, pbch %d\n", frame_parms->Nid_cell,metric_fdd_ncp,phase_fdd_ncp,flip_fdd_ncp,ret); #endif } else { #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"FDD Normal prefix: SSS error condition: sync_pos %d, sync_pos_slot %d\n", sync_pos, sync_pos_slot); #endif } if (ret==-1) { // Now FDD extended prefix frame_parms->Ncp=EXTENDED; frame_parms->frame_type=FDD; init_frame_parms(frame_parms,1); if (sync_pos < frame_parms->nb_prefix_samples) sync_pos2 = sync_pos + FRAME_LENGTH_COMPLEX_SAMPLES - frame_parms->nb_prefix_samples; else sync_pos2 = sync_pos - frame_parms->nb_prefix_samples; // PSS is hypothesized in last symbol of first slot in Frame sync_pos_slot = (frame_parms->samples_per_tti>>1) - frame_parms->ofdm_symbol_size - (frame_parms->nb_prefix_samples); if (sync_pos2 >= sync_pos_slot) ue->rx_offset = sync_pos2 - sync_pos_slot; else ue->rx_offset = FRAME_LENGTH_COMPLEX_SAMPLES + sync_pos2 - sync_pos_slot; //msg("nb_prefix_samples %d, rx_offset %d\n",frame_parms->nb_prefix_samples,ue->rx_offset); if (((sync_pos2 - sync_pos_slot) >=0 ) && ((sync_pos2 - sync_pos_slot) < ((FRAME_LENGTH_COMPLEX_SAMPLES-frame_parms->samples_per_tti/2)))) { rx_sss(ue,&metric_fdd_ecp,&flip_fdd_ecp,&phase_fdd_ecp); frame_parms->nushift = frame_parms->Nid_cell%6; if (flip_fdd_ecp==1) ue->rx_offset += (FRAME_LENGTH_COMPLEX_SAMPLES>>1); init_frame_parms(&ue->frame_parms,1); lte_gold(frame_parms,ue->lte_gold_table[0],frame_parms->Nid_cell); ret = pbch_detection(ue,mode); // write_output("rxdata3.m","rxd3",ue->common_vars.rxdata[0],10*frame_parms->samples_per_tti,1,1); #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"FDD Extended prefix: CellId %d metric %d, phase %d, flip %d, pbch %d\n", frame_parms->Nid_cell,metric_fdd_ecp,phase_fdd_ecp,flip_fdd_ecp,ret); #endif } else { #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"FDD Extended prefix: SSS error condition: sync_pos %d, sync_pos_slot %d\n", sync_pos, sync_pos_slot); #endif } if (ret==-1) { // Now TDD normal prefix frame_parms->Ncp=NORMAL; frame_parms->frame_type=TDD; init_frame_parms(frame_parms,1); if (sync_pos >= frame_parms->nb_prefix_samples) sync_pos2 = sync_pos - frame_parms->nb_prefix_samples; else sync_pos2 = sync_pos + FRAME_LENGTH_COMPLEX_SAMPLES - frame_parms->nb_prefix_samples; // PSS is hypothesized in 2nd symbol of third slot in Frame (S-subframe) sync_pos_slot = frame_parms->samples_per_tti + (frame_parms->ofdm_symbol_size<<1) + frame_parms->nb_prefix_samples0 + (frame_parms->nb_prefix_samples); if (sync_pos2 >= sync_pos_slot) ue->rx_offset = sync_pos2 - sync_pos_slot; else ue->rx_offset = (FRAME_LENGTH_COMPLEX_SAMPLES>>1) + sync_pos2 - sync_pos_slot; rx_sss(ue,&metric_tdd_ncp,&flip_tdd_ncp,&phase_tdd_ncp); if (flip_tdd_ncp==1) ue->rx_offset += (FRAME_LENGTH_COMPLEX_SAMPLES>>1); frame_parms->nushift = frame_parms->Nid_cell%6; init_frame_parms(&ue->frame_parms,1); lte_gold(frame_parms,ue->lte_gold_table[0],frame_parms->Nid_cell); ret = pbch_detection(ue,mode); // write_output("rxdata4.m","rxd4",ue->common_vars.rxdata[0],10*frame_parms->samples_per_tti,1,1); #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"TDD Normal prefix: CellId %d metric %d, phase %d, flip %d, pbch %d\n", frame_parms->Nid_cell,metric_tdd_ncp,phase_tdd_ncp,flip_tdd_ncp,ret); #endif if (ret==-1) { // Now TDD extended prefix frame_parms->Ncp=EXTENDED; frame_parms->frame_type=TDD; init_frame_parms(frame_parms,1); sync_pos2 = sync_pos - frame_parms->nb_prefix_samples; if (sync_pos >= frame_parms->nb_prefix_samples) sync_pos2 = sync_pos - frame_parms->nb_prefix_samples; else sync_pos2 = sync_pos + FRAME_LENGTH_COMPLEX_SAMPLES - frame_parms->nb_prefix_samples; // PSS is hypothesized in 2nd symbol of third slot in Frame (S-subframe) sync_pos_slot = frame_parms->samples_per_tti + (frame_parms->ofdm_symbol_size<<1) + (frame_parms->nb_prefix_samples<<1); if (sync_pos2 >= sync_pos_slot) ue->rx_offset = sync_pos2 - sync_pos_slot; else ue->rx_offset = (FRAME_LENGTH_COMPLEX_SAMPLES>>1) + sync_pos2 - sync_pos_slot; rx_sss(ue,&metric_tdd_ecp,&flip_tdd_ecp,&phase_tdd_ecp); frame_parms->nushift = frame_parms->Nid_cell%6; if (flip_tdd_ecp==1) ue->rx_offset += (FRAME_LENGTH_COMPLEX_SAMPLES>>1); init_frame_parms(&ue->frame_parms,1); lte_gold(frame_parms,ue->lte_gold_table[0],frame_parms->Nid_cell); ret = pbch_detection(ue,mode); // write_output("rxdata5.m","rxd5",ue->common_vars.rxdata[0],10*frame_parms->samples_per_tti,1,1); #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"TDD Extended prefix: CellId %d metric %d, phase %d, flip %d, pbch %d\n", frame_parms->Nid_cell,metric_tdd_ecp,phase_tdd_ecp,flip_tdd_ecp,ret); #endif } } } /* Consider this is a false detection if the offset is > 1000 Hz */ if( (abs(ue->common_vars.freq_offset) > 1000) && (ret == 0) ) { ret=-1; LOG_E(HW,"Ignore MIB with high freq offset [%d Hz] estimation \n",ue->common_vars.freq_offset); } if (ret==0) { // PBCH found so indicate sync to higher layers and configure frame parameters //#ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"[UE%d] In synch, rx_offset %d samples\n",ue->Mod_id, ue->rx_offset); //#endif if (ue->UE_scan_carrier == 0) { if (ue->mac_enabled==1) { LOG_I(PHY,"[UE%d] Sending synch status to higher layers\n",ue->Mod_id); //mac_resynch(); mac_xface->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; } generate_pcfich_reg_mapping(frame_parms); generate_phich_reg_mapping(frame_parms); ue->pbch_vars[0]->pdu_errors_conseq=0; } LOG_I(PHY,"[UE %d] Frame %d RRC Measurements => rssi %3.1f dBm (dig %3.1f dB, gain %d), N0 %d dBm, rsrp %3.1f dBm/RE, rsrq %3.1f dB\n",ue->Mod_id, ue->proc.proc_rxtx[0].frame_rx, 10*log10(ue->measurements.rssi)-ue->rx_total_gain_dB, 10*log10(ue->measurements.rssi), ue->rx_total_gain_dB, ue->measurements.n0_power_tot_dBm, 10*log10(ue->measurements.rsrp[0])-ue->rx_total_gain_dB, (10*log10(ue->measurements.rsrq[0]))); LOG_I(PHY,"[UE %d] Frame %d MIB Information => %s, %s, NidCell %d, N_RB_DL %d, PHICH DURATION %d, PHICH RESOURCE %s, TX_ANT %d\n", ue->Mod_id, ue->proc.proc_rxtx[0].frame_rx, duplex_string[ue->frame_parms.frame_type], prefix_string[ue->frame_parms.Ncp], ue->frame_parms.Nid_cell, ue->frame_parms.N_RB_DL, ue->frame_parms.phich_config_common.phich_duration, phich_string[ue->frame_parms.phich_config_common.phich_resource], ue->frame_parms.nb_antennas_tx_eNB); #if defined(OAI_USRP) || defined(EXMIMO) || defined(OAI_BLADERF) || defined(OAI_LMSSDR) LOG_I(PHY,"[UE %d] Frame %d Measured Carrier Frequency %.0f Hz (offset %d Hz)\n", ue->Mod_id, ue->proc.proc_rxtx[0].frame_rx, openair0_cfg[0].rx_freq[0]-ue->common_vars.freq_offset, ue->common_vars.freq_offset); #endif } else { #ifdef DEBUG_INITIAL_SYNC LOG_I(PHY,"[UE%d] Initial sync : PBCH not ok\n",ue->Mod_id); LOG_I(PHY,"[UE%d] Initial sync : Estimated PSS position %d, Nid2 %d\n",ue->Mod_id,sync_pos,ue->common_vars.eNb_id); /* LOG_I(PHY,"[UE%d] Initial sync: (metric fdd_ncp %d (%d), metric fdd_ecp %d (%d), metric_tdd_ncp %d (%d), metric_tdd_ecp %d (%d))\n", ue->Mod_id, metric_fdd_ncp,Nid_cell_fdd_ncp, metric_fdd_ecp,Nid_cell_fdd_ecp, metric_tdd_ncp,Nid_cell_tdd_ncp, metric_tdd_ecp,Nid_cell_tdd_ecp);*/ LOG_I(PHY,"[UE%d] Initial sync : Estimated Nid_cell %d, Frame_type %d\n",ue->Mod_id, frame_parms->Nid_cell,frame_parms->frame_type); #endif ue->UE_mode[0] = NOT_SYNCHED; ue->pbch_vars[0]->pdu_errors_last=ue->pbch_vars[0]->pdu_errors; ue->pbch_vars[0]->pdu_errors++; ue->pbch_vars[0]->pdu_errors_conseq++; } // gain control if (ret!=0) { //we are not synched, so we cannot use rssi measurement (which is based on channel estimates) rx_power = 0; // do a measurement on the best guess of the PSS for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) rx_power += signal_energy(&ue->common_vars.rxdata[aarx][sync_pos2], frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples); /* // do a measurement on the full frame for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) rx_power += signal_energy(&ue->common_vars.rxdata[aarx][0], frame_parms->samples_per_tti*10); */ // we might add a low-pass filter here later ue->measurements.rx_power_avg[0] = rx_power/frame_parms->nb_antennas_rx; ue->measurements.rx_power_avg_dB[0] = dB_fixed(ue->measurements.rx_power_avg[0]); #ifdef DEBUG_INITIAL_SYNCH LOG_I(PHY,"[UE%d] Initial sync : Estimated power: %d dB\n",ue->Mod_id,ue->measurements.rx_power_avg_dB[0] ); #endif #ifndef OAI_USRP #ifndef OAI_BLADERF #ifndef OAI_LMSSDR phy_adjust_gain(ue,ue->measurements.rx_power_avg_dB[0],0); #endif #endif #endif } else { #ifndef OAI_USRP #ifndef OAI_BLADERF #ifndef OAI_LMSSDR phy_adjust_gain(ue,dB_fixed(ue->measurements.rssi),0); #endif #endif #endif } // exit_fun("debug exit"); return ret; }