nr_dl_channel_estimation.c

/*
 * 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 "SCHED/defs.h"
#include "PHY/defs_nr_UE.h"
#include "filt16a_32.h"
#include "T.h"
//#define DEBUG_CH

int nr_pbch_channel_estimation(PHY_VARS_NR_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 aarx;
  unsigned short k;
  unsigned int pilot_cnt;
  int16_t ch[2],*pil,*rxF,*dl_ch,*fl,*fm,*fr;
  int ch_offset,symbol_offset;

  //uint16_t Nid_cell = (eNB_offset == 0) ? ue->frame_parms.Nid_cell : ue->measurements.adj_cell_id[eNB_offset-1];

  uint8_t nushift, ssb_index=0, n_hf=0;
  int **dl_ch_estimates  =ue->common_vars.common_vars_rx_data_per_thread[ue->current_thread_id[Ns>>1]].dl_ch_estimates[eNB_offset];
  int **rxdataF=ue->common_vars.common_vars_rx_data_per_thread[ue->current_thread_id[Ns>>1]].rxdataF;

  nushift =  ue->frame_parms.Nid_cell%4;
  ue->frame_parms.nushift = nushift;
 
  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 = nushift;

#ifdef DEBUG_CH
  printf("PBCH Channel Estimation : ThreadId %d, eNB_offset %d cell_id %d ch_offset %d, OFDM size %d, Ncp=%d, l=%d, Ns=%d, k=%d symbol %d\n",ue->current_thread_id[Ns>>1], eNB_offset,Nid_cell,ch_offset,ue->frame_parms.ofdm_symbol_size,
         ue->frame_parms.Ncp,l,Ns,k, symbol);
#endif

  switch (k) {
  case 0:
        fl = filt16a_l0;
        fm = filt16a_m0;
        fr = filt16a_r0;
        break;

  case 1:
        fl = filt16a_l1;
        fm = filt16a_m1;
        fr = filt16a_r1;
        break;

  case 2:
        fl = filt16a_l2;
        fm = filt16a_m2;
        fr = filt16a_r2;
        break;

  case 3:
        fl = filt16a_l3;
        fm = filt16a_m3;
        fr = filt16a_r3;
        break;

  default:
    msg("pbch_channel_estimation: k=%d -> ERROR\n",k);
    return(-1);
    break;
  }

  // generate pilot
  nr_pbch_dmrs_rx(ue->nr_gold_pbch[n_hf][ssb_index], &pilot[p][0]);

  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.ofdm_symbol_size-10*12))];
    dl_ch = (int16_t *)&dl_ch_estimates[(p<<1)+aarx][ch_offset];

    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("ch est pilot addr %p RB_DL %d\n",&pilot[p][0], ue->frame_parms.N_RB_DL);
    printf("k %d, first_carrier %d\n",k,ue->frame_parms.first_carrier_offset);
    printf("rxF addr %p\n", rxF);
    printf("dl_ch addr %p\n",dl_ch);
#endif
    if ((ue->frame_parms.N_RB_DL&1)==0) {

      // 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("ch 0 %d\n",((int32_t)pil[0]*rxF[0] - (int32_t)pil[1]*rxF[1]));
      printf("pilot 0 : rxF - > (%d,%d) addr %p  ch -> (%d,%d), pil -> (%d,%d) \n",rxF[0],rxF[1],&rxF[0],ch[0],ch[1],pil[0],pil[1]);
#endif
      multadd_real_vector_complex_scalar(fl,
                                         ch,
                                         dl_ch,
                                         16);
      pil+=2;
      rxF+=8;
      //for (int i= 0; i<8; i++)
      //printf("dl_ch addr %p %d\n", dl_ch+i, *(dl_ch+i));

      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(fm,
                                         ch,
                                         dl_ch,
                                         16);
      pil+=2;
      rxF+=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 2 : 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(fr,
                                         ch,
                                         dl_ch,
                                         16);
      pil+=2;
      rxF+=8;
      dl_ch+=24;

      for (pilot_cnt=3; pilot_cnt<(3*20); pilot_cnt+=3) {

	if (pilot_cnt == 30)
	  rxF   = (int16_t *)&rxdataF[aarx][(symbol_offset+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 %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(fl,
                                           ch,
                                           dl_ch,
                                           16);

        //for (int i= 0; i<8; i++)
        //            printf("pilot_cnt %d dl_ch %d %d\n", pilot_cnt, dl_ch+i, *(dl_ch+i));

        pil+=2;
        rxF+=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(fm,
                                           ch,
                                           dl_ch,
                                           16);
        pil+=2;
        rxF+=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(fr,
                                           ch,
                                           dl_ch,
                                           16);
        pil+=2;
        rxF+=8;
        dl_ch+=24;

      }


    }

  }

  return(0);
}