/* * 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 */ #ifdef USER_MODE #include <string.h> #endif #include "defs.h" #include "PHY/defs.h" #include "filt96_32.h" #include "T.h" //#define DEBUG_CH int lte_dl_channel_estimation(PHY_VARS_UE *ue, uint8_t eNB_id, uint8_t eNB_offset, unsigned char Ns, unsigned char p, unsigned char l, unsigned char symbol) { int pilot[2][200] __attribute__((aligned(16))); unsigned char nu,aarx; unsigned short k; unsigned int rb,pilot_cnt; int16_t ch[2],*pil,*rxF,*dl_ch,*dl_ch_prev,*f,*f2,*fl,*f2l2,*fr,*f2r2,*f2_dc,*f_dc; int ch_offset,symbol_offset; // unsigned int n; // int i; static int interpolateS11S12 = 1; uint16_t Nid_cell = (eNB_offset == 0) ? ue->frame_parms.Nid_cell : ue->measurements.adj_cell_id[eNB_offset-1]; uint8_t nushift,pilot1,pilot2,pilot3; int **dl_ch_estimates =ue->common_vars.common_vars_rx_data_per_thread[(Ns>>1)&0x1].dl_ch_estimates[eNB_offset]; int **dl_ch_estimates_previous=ue->common_vars.common_vars_rx_data_per_thread[((Ns>>1)+1)&0x1].dl_ch_estimates[eNB_offset]; int **rxdataF=ue->common_vars.common_vars_rx_data_per_thread[(Ns>>1)&0x1].rxdataF; if (ue->frame_parms.Ncp == 0) { // normal prefix pilot1 = 4; pilot2 = 7; pilot3 = 11; } else { // extended prefix pilot1 = 3; pilot2 = 6; pilot3 = 9; } // recompute nushift with eNB_offset corresponding to adjacent eNB on which to perform channel estimation nushift = Nid_cell%6; if ((p==0) && (l==0) ) nu = 0; else if ((p==0) && (l>0)) nu = 3; else if ((p==1) && (l==0)) nu = 3; else if ((p==1) && (l>0)) nu = 0; else { msg("lte_dl_channel_estimation: p %d, l %d -> ERROR\n",p,l); return(-1); } //ch_offset = (l*(ue->frame_parms.ofdm_symbol_size)); if (ue->high_speed_flag == 0) // use second channel estimate position for temporary storage ch_offset = ue->frame_parms.ofdm_symbol_size ; else ch_offset = ue->frame_parms.ofdm_symbol_size*symbol; symbol_offset = ue->frame_parms.ofdm_symbol_size*symbol; k = (nu + nushift)%6; #ifdef DEBUG_CH printf("Channel Estimation : eNB_offset %d cell_id %d ch_offset %d, OFDM size %d, Ncp=%d, l=%d, Ns=%d, k=%d\n",eNB_offset,Nid_cell,ch_offset,ue->frame_parms.ofdm_symbol_size, ue->frame_parms.Ncp,l,Ns,k); #endif switch (k) { case 0 : f=filt24_0; //for first pilot of RB, first half f2=filt24_2; //for second pilot of RB, first half fl=filt24_0; //for first pilot of leftmost RB f2l2=filt24_2; // fr=filt24_2r; //for first pilot of rightmost RB fr=filt24_0r2; //for first pilot of rightmost RB // f2r2=filt24_0r2; f2r2=filt24_2r; f_dc=filt24_0_dcr; f2_dc=filt24_2_dcl; break; case 1 : f=filt24_1; f2=filt24_3; fl=filt24_1l; f2l2=filt24_3l2; fr=filt24_1r2; f2r2=filt24_3r; f_dc=filt24_1_dcr; //for first pilot of RB, first half f2_dc=filt24_3_dcl; //for first pilot of RB, first half break; case 2 : f=filt24_2; f2=filt24_4; fl=filt24_2l; f2l2=filt24_4l2; fr=filt24_2r2; f2r2=filt24_4r; f_dc=filt24_2_dcr; //for first pilot of RB, first half f2_dc=filt24_4_dcl; //for first pilot of RB, first half break; case 3 : f=filt24_3; f2=filt24_5; fl=filt24_3l; f2l2=filt24_5l2; fr=filt24_3r2; f2r2=filt24_5r; f_dc=filt24_3_dcr; //for first pilot of RB, first half f2_dc=filt24_5_dcl; //for first pilot of RB, first half break; case 4 : f=filt24_4; f2=filt24_6; fl=filt24_4l; f2l2=filt24_6l2; fr=filt24_4r2; f2r2=filt24_6r; f_dc=filt24_4_dcr; //for first pilot of RB, first half f2_dc=filt24_6_dcl; //for first pilot of RB, first half break; case 5 : f=filt24_5; f2=filt24_7; fl=filt24_5l; f2l2=filt24_7l2; fr=filt24_5r2; f2r2=filt24_7r; f_dc=filt24_5_dcr; //for first pilot of RB, first half f2_dc=filt24_7_dcl; //for first pilot of RB, first half break; default: msg("lte_dl_channel_estimation: k=%d -> ERROR\n",k); return(-1); break; } // generate pilot lte_dl_cell_spec_rx(ue, eNB_offset, &pilot[p][0], Ns, (l==0)?0:1, p); for (aarx=0; aarx<ue->frame_parms.nb_antennas_rx; aarx++) { pil = (int16_t *)&pilot[p][0]; rxF = (int16_t *)&rxdataF[aarx][((symbol_offset+k+ue->frame_parms.first_carrier_offset))]; dl_ch = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][ch_offset]; // if (eNb_id==0) memset(dl_ch,0,4*(ue->frame_parms.ofdm_symbol_size)); if (ue->high_speed_flag==0) // multiply previous channel estimate by ch_est_alpha multadd_complex_vector_real_scalar(dl_ch-(ue->frame_parms.ofdm_symbol_size<<1), ue->ch_est_alpha,dl_ch-(ue->frame_parms.ofdm_symbol_size<<1), 1,ue->frame_parms.ofdm_symbol_size); #ifdef DEBUG_CH printf("k %d, first_carrier %d\n",k,ue->frame_parms.first_carrier_offset); #endif if ((ue->frame_parms.N_RB_DL==6) || (ue->frame_parms.N_RB_DL==50) || (ue->frame_parms.N_RB_DL==100)) { //First half of pilots // Treat first 2 pilots specially (left edge) ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 0 : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(fl, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 1 : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(f2l2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; for (pilot_cnt=2; pilot_cnt<((ue->frame_parms.N_RB_DL)-1); pilot_cnt+=2) { ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); //Re ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); //Im #ifdef DEBUG_CH printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt+1,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; } // printf("Second half\n"); // Second half of RBs k = (nu + nushift)%6; if (k > 6) k -=6; rxF = (int16_t *)&rxdataF[aarx][((symbol_offset+1+k))]; #ifdef DEBUG_CH printf("second half k %d\n",k); #endif for (pilot_cnt=0; pilot_cnt<((ue->frame_parms.N_RB_DL)-3); pilot_cnt+=2) { ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt+1,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; } ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d: rxF -> (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(fr, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d: rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt+1,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); #endif multadd_real_vector_complex_scalar(f2r2, ch, dl_ch, 24); } else if (ue->frame_parms.N_RB_DL==25) { //printf("Channel estimation\n"); // Treat first 2 pilots specially (left edge) ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 0 : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(fl, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 1 : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f2l2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; for (pilot_cnt=2; pilot_cnt<24; pilot_cnt+=2) { // printf("pilot[%d][%d] (%d,%d)\n",p,rb,pil[0],pil[1]); // printf("rx[%d][%d] -> (%d,%d)\n",p,ue->frame_parms.first_carrier_offset + ue->frame_parms.nushift + 6*rb+(3*p),rxF[0],rxF[1]); ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d : rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",pilot_cnt+1,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; } ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 24: rxF -> (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f_dc, ch, dl_ch, 24); pil+=2; // Re Im dl_ch+=8; // printf("Second half\n"); // Second half of RBs rxF = (int16_t *)&rxdataF[aarx][((symbol_offset+1+k))]; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 25: rxF -> (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f2_dc, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; for (pilot_cnt=0; pilot_cnt<22; pilot_cnt+=2) { // printf("* pilot[%d][%d] (%d,%d)\n",p,rb,pil[0],pil[1]); // printf("rx[%d][%d] -> (%d,%d)\n",p,ue->frame_parms.first_carrier_offset + ue->frame_parms.nushift + 6*rb+(3*p),rxF[0],rxF[1]); ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d rxF -> (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",26+pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot %d : rxF -> (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",27+pilot_cnt,rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; } ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 49: rxF -> (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(fr, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); #ifdef DEBUG_CH printf("pilot 50: rxF - > (%d,%d) ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],ch[0],ch[1],pil[0],pil[1]); // ch[0] = 1024; // ch[1] = -128; #endif multadd_real_vector_complex_scalar(f2r2, ch, dl_ch, 24); } else if (ue->frame_parms.N_RB_DL==15) { //printf("First Half\n"); for (rb=0; rb<28; rb+=4) { //printf("aarx=%d\n",aarx); //printf("pilot[%d][%d] (%d,%d)\n",p,rb,pil[0],pil[1]); //printf("rx[%d][%d] -> (%d,%d)\n",p, // ue->frame_parms.first_carrier_offset + ue->frame_parms.nushift + 6*rb+(3*p), // rxF[0], // rxF[1]); ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); //printf("ch -> (%d,%d)\n",ch[0],ch[1]); multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; // Re Im rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); //printf("ch -> (%d,%d)\n",ch[0],ch[1]); multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; } ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); // printf("ch -> (%d,%d)\n",ch[0],ch[1]); multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; // Re Im dl_ch+=8; //printf("Second half\n"); //Second half of RBs rxF = (int16_t *)&rxdataF[aarx][((symbol_offset+1+nushift + (3*p)))]; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; for (rb=0; rb<28; rb+=4) { //printf("aarx=%d\n",aarx); //printf("pilot[%d][%d] (%d,%d)\n",p,rb,pil[0],pil[1]); //printf("rx[%d][%d] -> (%d,%d)\n",p, // ue->frame_parms.first_carrier_offset + ue->frame_parms.nushift + 6*rb+(3*p), // rxF[0], // rxF[1]); ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); multadd_real_vector_complex_scalar(f, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=8; ch[0] = (int16_t)(((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1])>>15); ch[1] = (int16_t)(((int32_t)pil[0]*rxF[1] + (int32_t)pil[1]*rxF[0])>>15); multadd_real_vector_complex_scalar(f2, ch, dl_ch, 24); pil+=2; rxF+=12; dl_ch+=16; } } else { msg("channel estimation not implemented for ue->frame_parms.N_RB_DL = %d\n",ue->frame_parms.N_RB_DL); } if (ue->perfect_ce == 0) { // Temporal Interpolation // printf("ch_offset %d\n",ch_offset); dl_ch = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][ch_offset]; if (ue->high_speed_flag == 0) { multadd_complex_vector_real_scalar(dl_ch, 32767-ue->ch_est_alpha, dl_ch-(ue->frame_parms.ofdm_symbol_size<<1),0,ue->frame_parms.ofdm_symbol_size); } else { // high_speed_flag == 1 if (symbol == 0) { // printf("Interpolating %d->0\n",4-ue->frame_parms.Ncp); // dl_ch_prev = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][(4-ue->frame_parms.Ncp)*(ue->frame_parms.ofdm_symbol_size)]; if(((Ns>>1)!=0) || ( ((Ns>>1)==0) && interpolateS11S12)) { //LOG_D(PHY,"Interpolate s11-->s0 to get s12 and s13 Ns %d \n", Ns); dl_ch_prev = (int16_t *)&dl_ch_estimates_previous[(p<<1)+aarx][pilot3*(ue->frame_parms.ofdm_symbol_size)]; multadd_complex_vector_real_scalar(dl_ch_prev,21845,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,10923,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,10923,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,21845,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),0,ue->frame_parms.ofdm_symbol_size); } interpolateS11S12 = 1; } // this is 1/3,2/3 combination for pilots spaced by 3 symbols else if (symbol == pilot1) { dl_ch_prev = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][0]; if (ue->frame_parms.Ncp==0) {// pilot spacing 4 symbols (1/4,1/2,3/4 combination) multadd_complex_vector_real_scalar(dl_ch_prev,24576,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,8192,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,16384,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,16384,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,8192,dl_ch_prev+(3*2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,24576,dl_ch_prev+(3*2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); } else { multadd_complex_vector_real_scalar(dl_ch_prev,10923,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,21845,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,21845,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)<<1),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,10923,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),0,ue->frame_parms.ofdm_symbol_size); } // pilot spacing 3 symbols (1/3,2/3 combination) } else if (symbol == pilot2) { dl_ch_prev = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][pilot1*(ue->frame_parms.ofdm_symbol_size)]; multadd_complex_vector_real_scalar(dl_ch_prev,21845,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,10923,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,10923,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,21845,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),0,ue->frame_parms.ofdm_symbol_size); } else { // symbol == pilot3 // printf("Interpolating 0->%d\n",4-ue->frame_parms.Ncp); dl_ch_prev = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][pilot2*(ue->frame_parms.ofdm_symbol_size)]; if (ue->frame_parms.Ncp==0) {// pilot spacing 4 symbols (1/4,1/2,3/4 combination) multadd_complex_vector_real_scalar(dl_ch_prev,24576,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,8192,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,16384,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,16384,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,8192,dl_ch_prev+(3*2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,24576,dl_ch_prev+(3*2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); } else { multadd_complex_vector_real_scalar(dl_ch_prev,10923,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,21845,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)),0,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch_prev,21845,dl_ch_prev+(2*(ue->frame_parms.ofdm_symbol_size)<<1),1,ue->frame_parms.ofdm_symbol_size); multadd_complex_vector_real_scalar(dl_ch,10923,dl_ch_prev+(2*((ue->frame_parms.ofdm_symbol_size)<<1)),0,ue->frame_parms.ofdm_symbol_size); } // pilot spacing 3 symbols (1/3,2/3 combination) if((ue->rx_offset_diff !=0) && ((Ns>>1) == 9)) { //LOG_D(PHY,"Extrapolate s7-->s11 to get s12 and s13 Ns %d\n", Ns); interpolateS11S12 = 0; //LOG_E(PHY,"Interpolate s7--s11 s12 s13 pilot 3 Ns %d l %d symbol %d \n", Ns, l, symbol); int16_t *dlChEst_ofdm11 = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][pilot3*(ue->frame_parms.ofdm_symbol_size)]; int16_t *dlChEst_ofdm7 = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][pilot2*(ue->frame_parms.ofdm_symbol_size)]; // interpolate ofdm s12: 5/4*ofdms11 + -1/4*ofdms7 5/4 q1.15 40960 -1/4 q1.15 8192 int16_t *dlChEst_ofdm12 = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][12*ue->frame_parms.ofdm_symbol_size]; for(int i=0; i<(2*ue->frame_parms.ofdm_symbol_size); i++) { int64_t tmp_mult = 0; tmp_mult = ((int64_t)dlChEst_ofdm11[i] * 40960 - (int64_t)dlChEst_ofdm7[i] * 8192); tmp_mult = tmp_mult >> 15; dlChEst_ofdm12[i] = tmp_mult; } // interpolate ofdm s13: 3/2*ofdms11 + -1/2*ofdms7 3/2 q1.15 49152 1/2 q1.15 16384 int16_t *dlChEst_ofdm13 = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][13*ue->frame_parms.ofdm_symbol_size]; for(int i=0; i<(2*ue->frame_parms.ofdm_symbol_size); i++) { int64_t tmp_mult = 0; tmp_mult = ((int64_t)dlChEst_ofdm11[i] * 49152 - (int64_t)dlChEst_ofdm7[i] * 16384); tmp_mult = tmp_mult >> 15; dlChEst_ofdm13[i] = tmp_mult; } } } } } } void (*idft)(int16_t *,int16_t *, int); switch (ue->frame_parms.ofdm_symbol_size) { case 128: idft = idft128; break; case 256: idft = idft256; break; case 512: idft = idft512; break; case 1024: idft = idft1024; break; case 1536: idft = idft1536; break; case 2048: idft = idft2048; break; default: idft = idft512; break; } // do ifft of channel estimate for (aarx=0; aarx<ue->frame_parms.nb_antennas_rx; aarx++) for (p=0; p<ue->frame_parms.nb_antenna_ports_eNB; p++) { if (ue->common_vars.common_vars_rx_data_per_thread[(Ns>>1)&0x1].dl_ch_estimates[eNB_offset][(p<<1)+aarx]) idft((int16_t*) &ue->common_vars.common_vars_rx_data_per_thread[(Ns>>1)&0x1].dl_ch_estimates[eNB_offset][(p<<1)+aarx][8], (int16_t*) ue->common_vars.common_vars_rx_data_per_thread[(Ns>>1)&0x1].dl_ch_estimates_time[eNB_offset][(p<<1)+aarx],1); } #if T_TRACER T(T_UE_PHY_DL_CHANNEL_ESTIMATE, T_INT(eNB_id), T_INT(ue->Mod_id), T_INT(ue->proc.proc_rxtx[(Ns>>1)&1].frame_rx%1024), T_INT(ue->proc.proc_rxtx[(Ns>>1)&1].subframe_rx), T_INT(0), T_BUFFER(&ue->common_vars.common_vars_rx_data_per_thread[(Ns>>1)&0x1].dl_ch_estimates_time[eNB_offset][0][0], 512 * 4)); #endif return(0); }